JP2021093711A - Antenna module and radar device - Google Patents

Abstract

To provide an antenna module equipped with a planar antenna with a wide band of over 7 GHz and excellent radiation characteristics in the millimeter wave band, and a radar device using the module.SOLUTION: In an antenna module 5b, a patch antenna element includes a main patch element 11a formed in a substantially rectangular shape with a metal pattern on the surface of a dielectric substrate 100, and a pair of sub-patch elements 11c formed in a substantially rectangular shape with a metal pattern on both sides of the main patch element 11a, and the main patch element 11a and the sub patch element 11c are arranged in parallel by being separated from each other by a slit-shaped gap 12. The slit-shaped gap 12 is λg/100 to λg/10 when the operating wavelength on the dielectric substrate 100 is λg, and when the direction in which the main patch element 11a and the sub patch element 11c are arranged on the dielectric substrate 100 is the element width direction, and the orthogonal direction thereof is the element length direction, and a power supply line 20 is provided on the element length direction side of the main patch element 11a.SELECTED DRAWING: Figure 4

Description

The present invention relates to an antenna module and a radar device used in a communication device and a radar device.

As a background technique, an antenna module using a planar antenna described in Patent Document 1 will be exemplified.

The present invention will be outlined with reference to the plan view shown in FIG. 42 (a) and the cross-sectional view shown in FIG. 42 (b).

This antenna module includes a patch antenna resonator 1120 composed of a metal plane pattern formed on the surface of a dielectric substrate 1110 and a surface wave radiation resonator having a metal plane pattern arranged apart from the patch antenna resonator 1120. The surface wave radiating resonator 1130 is configured to surround the patch antenna resonator 1120. A gap of a constant ring-shaped gap 1125 is formed between the patch antenna antenna resonator 1120 and the surface wave radiation resonator 1130.

The surface wave resonator 1130 can radiate a signal flowing along the surface of the dielectric substrate 1110 from the patch antenna resonator 1120.

With this configuration, the operating frequency bandwidth and antenna gain can be increased by providing two resonators, a patch antenna resonator 1120 and a surface wave emission resonator 1130.

Japanese Unexamined Patent Publication No. 2012-19503

However, in the antenna module of the background technology, since the diameter of the surface wave radiation resonator 1130 is larger than the diameter of the patch antenna antenna resonator 1120, the resonance frequency becomes low, and the resonance frequency of each resonator is controlled. That is difficult.

That is, the patch antenna antenna resonator 1120 and the surface wave emission resonator 1130 each have a unique size as a resonator and each have a circular shape, and the resonance frequency is determined by the diameter. When the dielectric constant is 9.2 as in the embodiment, the wavelength (λg) on the substrate is about 2 mm in the 60 GHz band (57 GHz to 64 GHz), and the half-wave resonance wavelength is about 1 mm.

The ring-shaped gap 1125 is usually a finite gap of 50 μm or more in the process of manufacturing the substrate, and at least 50 μm or more is required on both sides. For the size of the half-wavelength resonance wavelength of the antenna resonator 1120 to be about 1 mm, the total size of the gaps on both sides must be at least 100 μm or more, and the resonance frequency of the surface wave radiation resonator 1130 is the patch antenna resonator 1120. It will be greatly reduced compared to. It is difficult to finely adjust the resonance frequency of the surface wave radiating resonator 1130 independently of the resonance frequency of the patch antenna resonator 1120 to secure a desired operating bandwidth.

Further, in the surface wave resonator 1130 that resonates on the low frequency side, ring resonance of the ring-shaped gap 1125 also occurs, and even if the resonance bandwidth of the input impedance (return loss) is widened in total, the radiation pattern of the antenna is changed. In the wide band operating band, the radiation pattern changes depending on the frequency, the radiation beam splits into multiple pieces, and the side lobe component becomes abnormally large. Therefore, it is not possible to obtain the same radiation pattern that is uniform over a wide band, which is originally required.

Further, since the feeder line 1121 and the surface wave radiating resonator 1130 are formed by the gap of the slot 1135, the input impedance and the bandwidth of the antenna are affected, which makes the optimum design difficult. .. Moreover, since the surface wave radiating resonator 1130 is arranged so as to surround the patch antenna resonator 1120, the patch antenna resonator 1130 is vertically stabbed (in the arrangement shown in the drawing). In the feeding line, it is not possible to form an antenna in which a plurality of patch resonators 1120 are connected, and it is difficult to narrow the beam width.

In order to solve the above problems, the antenna module of the first invention
A patch antenna is composed of a main patch element formed in a substantially rectangular shape with a metal pattern on the surface of a dielectric substrate, and at least one sub-patch element formed in a substantially rectangular shape with a metal pattern on both sides of the main patch element. The element is configured,
The main patch element and the at least one sub patch element are arranged in a row along one direction and are arranged in parallel by being separated from each other by a slit-shaped gap.
The slit-shaped gap is λg / 100 to λg / 10, assuming that the operating wavelength on the dielectric substrate is λg.
When the one direction on the dielectric substrate is the element width direction and the orthogonal direction thereof is the element length direction, a feeding line is provided on the element length direction side of the main patch element.

The operating wavelength λg is represented by the following equation 1.
λg ＝ λair / √er (Equation 1)
Here, er is the relative permittivity and λair is the wavelength in the air. Although not particularly limited, in general, the er of the antenna substrate is often 2 to 4.

In the following, when a plurality of the sub-patch elements are formed on both sides of the main patch element, the plurality of the sub-patch elements are simply referred to in the description of their operation and functions. It may be described as a sub patch element.

According to this configuration, since the resonance frequency also depends on the patch area of a slightly rectangular shape, at least the main patch element and at least both sides (of the main patch element) are formed in this slit-shaped gap. By dividing into one sub-patch element, the areas of the main patch element and the sub-patch element can be changed, the resonance frequency can be finely adjusted, and the bandwidth can be widened.
Further, in the case of a single patch antenna element, the length of the side in the feeding (electric field) direction is the element length, and the resonance frequency is roughly determined by the half-wavelength resonance of the element length, and the patch in the rowing direction. The width (magnetic field) direction mainly contributes to radiation. However, when the width of one patch is increased, a current component is also generated in the width direction, and the gain is increased, but gradually saturated, the resonance frequency changes, and the radiation pattern collapses. In the present invention, by dividing the patch element by the slit-shaped gap, it is possible to prevent the radiation pattern from collapsing, maintain a high gain, and obtain a wider band and a more uniform radiation pattern.
Hereinafter, in the description, the slit-shaped gap is referred to as a “slit”, and the size of the gap is also referred to as a “slit width”.
Further, assuming that the operating wavelength on the dielectric substrate is λg, this slit is set to λg / 100 to λg / 10 to stabilize the coupling between the divided main patch element and the sub patch element. It can be maintained and the coupling loss in this gap can be prevented.
As described above, not only can a patch antenna having a wide band and high radiation efficiency be configured, but also it is possible to prevent the planar antenna from becoming large. By arranging a plurality of antennas described later in parallel, the antennas described later can be arranged side by side. Antenna control with a MIMO (Multiple Input Multiple Output) configuration is possible. This MIMO-configured microwave radar device can detect targets in two-dimensional and three-dimensional spaces with high accuracy.
Here, when the gap is smaller than λg / 100, it becomes 50 μm or less (when er = 4) in the microwave band of 30 GHz or more, and the space width becomes difficult to manufacture by a normal substrate process. On the other hand, if the gap exceeds λg / 10, the space becomes 500 μm or more, and the coupling loss between the sub patch and the main patch exceeds 3 dB at the end of the frequency, which not only reduces the gain of the antenna but also conversely. The bandwidth is narrowed. In addition, the width of one patch antenna becomes closer to λg (for example, in the case of er = 4, λg = λair / 2 from the above equation 1) and becomes larger, and they are arranged in parallel at λair / 2 intervals, which will be described later. Becomes difficult.

The antenna module of the second invention is described in the first invention.
The main patch element and the at least one sub-patch element exemplify an embodiment in which element lengths, which are lengths in the element length direction, are different from each other.

According to this configuration, since the resonance wavelength of the at least one sub-patch element is generally determined by the element length in each feeding (electric field) direction, the main patch element and the at least one sub-patch element By setting the lengths of the respective elements to be different from each other, the resonance wavelengths of the main patch element and the sub patch element can be changed independently, and a stable radiation pattern can be obtained over a wide band.
It is better to resonate the patch antenna element with the main patch element in the low frequency range to the middle frequency range of the operating band, and to resonate the middle frequency range to the high frequency side of the operating band with the sub patch element in the center. Since the main patch element needs to be operated as a resonator and a transmission line, each of the main patch elements is divided by a slit by gradually reducing the element length and increasing the resonance frequency from the main patch element to the outside. The coupling loss between the patch elements is reduced, and an antenna element having high radiation efficiency can be configured over a wide band.

As the antenna module of the third invention, in the first or second invention,
An embodiment in which a plurality of the patch antenna elements are arranged in a row and the main patch elements in the patch antenna elements are connected to each other by a feeding line is illustrated.

According to this configuration, by arranging the plurality of the patch antenna elements in a row and connecting them with a feeding line, the radiation pattern is narrowed down in the direction in which the plurality of antenna elements are arranged, and the periphery of the intermediate portion of the plurality of patch antenna elements. The beam can be concentrated on the antenna, and an antenna emission pattern with a narrow beam and high gain can be obtained in a wide frequency band. As a result, in the application to the radar system, a high-precision range-finding radar system becomes possible.

As the antenna module of the fourth invention, in any one of the first to third inventions,
An embodiment in which one sub-patch element is provided on each side of the main patch element will be illustrated.

With this configuration as well, the same effects as those of the first to third inventions can be obtained.

As the antenna module of the fifth invention, in any one of the first to third inventions.
An embodiment in which a plurality of the sub-patch elements are provided on both sides of the main patch element will be illustrated.

Hereinafter, a patch antenna element having a structure composed of a plurality of slits is referred to as a "patch antenna element having a multiple slit structure", and an element having a structure composed of two slits is referred to as a "patch antenna element having a double slit structure". ".

According to this configuration, since the resonance frequency also depends on the rectangular patch area, the main patch element and the plurality of the main patch elements are divided by the main patch element and the plurality of the sub patch elements. The area of the sub-patch element can be changed, the resonance frequency can be adjusted more widely, and the bandwidth can be further widened. As a result, the reflection loss represented by the input reflection coefficient (S11 described later) of this antenna can be changed. (Return loss, negative value) can be made smaller over a wide band, and the signal can be efficiently supplied to the antenna. In addition, it is possible to prevent the radiation pattern from collapsing, maintain a high gain, and obtain a wider band and more uniform radiation pattern.
Further, the slit widths of the slit between the main patch element and the sub patch element and the slit width between the sub patch elements are λg / 100 to λg / when the operating wavelength on the dielectric substrate is λg. By setting it to 10, the coupling between the divided main patch element and the plurality of sub-patch elements can be stably maintained, and the coupling loss in this gap can be prevented.

The antenna module of the sixth invention is the antenna module of the sixth invention in the fifth invention.
An embodiment in which the slit-shaped gaps between the main patch element and the sub-patch element and the slit-shaped gaps between the sub-patch elements are different from each other is illustrated.

According to this configuration, by changing the widths of the two slits, the input impedance seen from the feeding line shifts in the direction of becoming lower, so that the impedance can be easily adjusted to 50Ω, and the two sub-patch elements can be used. The patch antenna element composed of the main patch element can be easily matched by the present antenna itself. Therefore, the electric field concentration can be relaxed in the matching line portion of the feeding line input portion of the antenna element, unnecessary radiation from the electric field concentration portion can be reduced, and a more constant radiation pattern can be obtained in the operating frequency band.
In addition, these slit widths can be used to control the degree of coupling between the main patch element and the sub-patch element, or between the sub-patch elements, and these are used against strong radiation in the central portion of the main patch element. The more the sub-patch element is moved away from the main patch element by adjusting the slit width of the sub-patch element, the weaker the radiation state can be gradually weakened by the sub-patch element, and the side lobe can be reduced in a wide band.

The antenna module of the seventh invention is described in the third invention.
The first-stage patch antenna element connected to the feeding line in the arrangement exemplifies an embodiment in which two sub-patch elements are provided on both sides of the main patch element.

According to this configuration, the first stage portion in which the plurality of the patch antenna elements are arranged has the double slit structure, so that the input impedance seen from the feeding line of the present antenna element is lowered and the input impedance of 50Ω is obtained. Can be approached to. As a result, it is possible to connect the transmission / reception MMIC connected to the antenna with less reflection, and to obtain a microwave antenna module having stable operating characteristics in a wide band.

The antenna module of the eighth invention is the antenna module of the third invention.
It is an array of three or more of the patch antenna elements.
An embodiment in which the element width of the patch antenna element at the intermediate portion in the array is wider than the element width of the patch antenna element at the end portion in the array is illustrated.

Here, in this document, the intermediate part in the sequence may be any part located in the middle of the sequence, for example, all parts other than the end part in the sequence, or the center in the sequence. It may be only a part.

According to this configuration, with respect to a patch antenna in which N patch antenna elements are arranged, in the formation of a narrow beam radiation pattern, the radiation of a plurality of patch antenna elements strengthens each other, and the beam width is narrow in the arrangement direction of the patch antenna elements. A pattern is formed, but the width of the patch antenna element in the middle part (consisting of the main and sub patch elements) is increased, strong radiation is emitted from the middle part, and the width of the patch element is gradually reduced in the direction of the end of the patch. By gradually weakening the radiation, the radiation pattern from the N-arranged patch antenna elements can obtain a radiation pattern with a small side lobe in which the main beam is more emphasized. As a result, in application to a radar system, the side lobe of the antenna becomes a ghost and causes erroneous detection. Therefore, by reducing the side lobe characteristic, it is possible to configure a radar device with less erroneous detection.

The antenna module of the ninth invention is the antenna module of the third or eighth invention.
It is an array of three or more of the patch antenna elements.
The element width of the main patch element of the patch antenna element in the intermediate portion in the array is wider than the element width of the main patch element of the patch antenna element on the end side in the array.
An embodiment in which the element width of the sub-patch element outermost from the main patch element of all the patch antenna elements in the arrangement is constant is illustrated.

According to this configuration, similarly to the patch antenna in which three or more patch antenna elements are arranged, the width of the patch antenna element in the intermediate portion is increased as described above, strong radiation is emitted from the intermediate portion, and the patch is gradually patched. By reducing the width of the patch antenna element toward the end of the antenna and gradually weakening the radiation, the radiation pattern from the patch antenna elements arranged in three or more emphasizes the main beam more and has a smaller side lobe. A radiation pattern can be obtained.
However, if the width of the sub-patch element and the width of the main patch element are reduced from the intermediate patch antenna element in which a plurality of patch antenna elements are arranged toward the end side, the sub-patch element is reduced. In both the main patch element and the main patch element, the radiation suddenly becomes small, it becomes difficult to secure a stable radiation pattern at the end of the operating frequency band, and it may not be possible to obtain an antenna radiation pattern in a wide band. come.
According to the present invention, the width of the main patch element is from the middle part of the array toward the end side, and even if the width of the main patch element is reduced, the sub-patch element at the boundary between the metal pattern forming the patch element and the substrate. The element width of, that is, the element width of the sub-patch element outermost from the main patch element is set to a constant width, so that the radiation is more constant from a plurality of sub-patch elements, so that even on the high frequency side of the frequency. The radiation pattern does not easily collapse, and a stable radiation pattern can be obtained over a wide band.

As the antenna module of the tenth invention, in any one of the third, eight or nine inventions.
It is an array of three or more of the patch antenna elements.
An embodiment in which the element width of the main patch element of all the patch antenna elements in the arrangement is constant is illustrated.

According to this configuration, the element width of the main patch element of the plurality of arranged patch antenna elements is divided into three together with the sub-patch antenna element, so that the width of the plurality of main patch elements is narrowed to 30Ω to 30Ω. The width of the transmission line is about 60Ω. By making the plurality of main patch elements have the same width, the input impedance of the antenna element can be lowered and the input impedance can be approached to 50Ω. As a result, it is possible to connect the transmission / reception MMIC connected to the antenna with less reflection, and to obtain a microwave antenna module having stable operating characteristics in a wide band.

As the antenna module of the eleventh invention, in any one of the third and seventh to tenth inventions.
The plurality of patch antenna elements are arranged in a row in the element length direction.
The main patch elements of the adjacent patch antenna elements in the array are connected to each other by a feeding line extending in the element length direction at the center of each element in the width direction.

According to this configuration, since the central portion of the main patch element in the element width direction is connected by a feeding line in the element length direction, the main patch element is also a transmission line, and the input impedance of the feeding line is the main slit. The influence of the current from the sub-patch element separated by is also small, and the power supply line is shortened because the current path, that is, the main patch element as the transmission line is fed by the shortest path, and stable power supply and high gain are achieved. It will be possible. As a result, high gain radiation characteristics can be obtained over a wide band.

As the antenna module of the twelfth invention, in any one of the third and seventh to tenth inventions.
The plurality of patch antenna elements are arranged in a row in the element width direction.
In the main patch element of each patch antenna element in the arrangement, a lead-out line portion extending in the element length direction is connected to the central portion in the element width direction, and each lead-out line portion is connected to a feeding line extending in the element width direction. An embodiment in which they are connected is illustrated.

According to this configuration, the direction of the feeding line for bundling a plurality of patch elements is the element width direction, the feeding portion of each patch antenna element is the element length direction, and this direction mainly determines the frequency, while The element spacing of each of the plurality of patch elements is in the element width direction, and the plurality of patch antenna elements having the lead-out line portion are bundled at regular intervals in that direction. That is, the element spacing for determining the antenna gain by phase synthesis is orthogonal to the element length direction for determining the antenna resonance frequency, which is 90 ° different from each other and is an independent direction. Therefore, the resonance frequency of the antenna element and the antenna gain can be determined independently, and the bandwidth can be widened.
In addition, in this configuration, even in the manufacturing process of the antenna module substrate, the element length that determines the resonance frequency and the element spacing that determines the radiation beam by phase synthesis are different by 90 degrees and are independent, so that the resonance frequency and the beam are independent. The composition does not change at the same time and the balance of radiation characteristics is not disturbed. Therefore, the influence of variation due to pattern thinning due to etching or the like in the substrate manufacturing process can be reduced, and a stable radiation pattern and gain characteristics with a small frequency deviation can be obtained even in a mass production process of repeated manufacturing.

Further, the radar device of the thirteenth invention is
A transmitting side antenna array including the antenna module of any one of the first to twelfth inventions and a receiving side antenna array including the antenna module of any one of the first to twelfth inventions are provided on a dielectric substrate.
The transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel.
The receiving side antenna array is configured by arranging a plurality of the antenna modules in parallel.

The number of the antenna modules constituting the transmitting side antenna array and the number of the antenna modules constituting the receiving side antenna array may be the same or different. Further, the number of the patch antenna elements included in the antenna module constituting the transmitting side antenna array and the number of the patch antenna elements included in the antenna module constituting the receiving side antenna array may be the same. , May be different.

In the radar device having this configuration, a plurality of a row of a plurality of transmitting side series antennas and a plurality of rows of a plurality of receiving side series antennas are arranged on the same substrate at appropriate intervals in the row direction (horizontal direction). When a MIMO (Multiple Input Multiple Output) radar device is configured, the transmitting side series antenna and the receiving side series antenna, respectively, can have wide directivity in the transmission / reception row direction over a wide band, and transmit. It is possible to electrically swing the antenna beam (change the directivity angle) on the side and the receiving side by using techniques such as beam forming. For example, it is possible to detect a target at high speed with excellent distance resolution in the two-dimensional direction. Become.

Further, the radar device of the fourteenth invention is
A transmitting side antenna array including the antenna module of the first or second invention and a receiving side antenna array including the antenna module of any one of the first to twelfth inventions are provided on a dielectric substrate.
The transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel in two different directions.
The receiving side antenna array is configured by arranging a plurality of the antenna modules in parallel in any one of the two directions.

In the radar device having this configuration, in the antenna module of the first or second invention, the transmitting side antenna array is configured as a single element antenna, and the two directions (for example, the vertical direction and the horizontal direction orthogonal to each other) are formed on a small substrate. ) Can be arranged at the same time. Then, in combination with the antenna array on the receiving side, for example, by performing the beamforming process in the horizontal direction or the beamforming process in the vertical direction, it is possible to detect the target in the three-dimensional directions of vertical, horizontal, and height. Become.

The radar device of the fifteenth invention is
The transmitting side antenna array including the antenna module of any one of the first, second, and twelve inventions and the receiving side antenna array including the antenna module of any one of the first, second, and twelve inventions are mounted on a dielectric substrate. In preparation for
The transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel in the horizontal direction on a dielectric substrate.
The receiving side antenna array is configured by arranging a plurality of the antenna modules in parallel in the horizontal direction on a dielectric substrate.

According to this configuration, when the present device is installed in the azimuth (horizontal) direction of the transmitting / receiving array (row) direction, the transmitting side series antenna array in one row and the receiving side antenna array in each row are oriented. It has a radiation pattern with wide angular direction and can be operated with horizontal polarization, and for a target in the azimuth direction, the input reflectance coefficient of the feeding part to the receiving antenna array is small and the azimuth It also has a Brewster angle at which the input reflectance coefficient becomes zero with respect to incident in the angular direction, and has good reception characteristics.

As the radar device of the sixteenth invention, in any one of the thirteenth to fifteenth inventions.
An embodiment in which the number of the patch antenna elements included in the antenna module constituting the transmitting side antenna array is equal to or less than the number of the patch antenna elements included in the antenna module constituting the receiving side antenna array is exemplified. To do.

According to this configuration, when the present device is installed in the transmission / reception array (row) direction in the azimuth angle direction, the transmission side has a wide directivity in the vertical component direction because the number of elements is small, and the reception side has a wide directivity. Since the antenna has a narrow directional beam due to the large number of elements, for example, in a room, radio waves are irradiated over a wide range on the transmitting side, and when a person is irradiated as a target, the radio waves are reflected and scattered over a wide range. However, by configuring the reception and detection with a narrow beam receiving antenna, the radio waves reflected and scattered from the target are received only in the direction of the target, so that ground reflection, floor reflection, and ceiling reflection are unnecessary. The wave component (clutter component) can be suppressed, and good detection characteristics can be obtained.

According to the present invention, in the microwave milliwave band, not only can a planar antenna having a uniform and constant radiation pattern in a wide band and having high radiation efficiency be constructed, but also the antenna element becomes large. By preventing this from happening and arranging a plurality of the antennas in parallel, it is possible to construct a high-precision radar device suitable for the MIMO (Multiple Input Multiple Output) method, which has an excellent effect.

It is a figure which shows the structure of the 1st Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 1st Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 1st Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 1st Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 1st Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the 2nd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 2nd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 2nd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 2nd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 2nd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the input return loss characteristic at the time of Ls = 1.36 mm, Lu = 1.32 mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz in the case of Ls = 1.36mm, Lu = 1.32mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz in the case of Ls = 1.36mm, Lu = 1.32mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz in the case of Ls = 1.36mm, Lu = 1.32mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the input return loss characteristic at the time of Ls = Lu = 1.36 mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz in the case of Ls = 1.36mm, Lu = 1.32mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz in the case of Ls = 1.36mm, Lu = 1.32mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz in the case of Ls = 1.36mm, Lu = 1.32mm in the 3rd Example of the antenna module which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the 1st Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the 2nd Example of the antenna module which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the 3rd Example of the antenna module which concerns on the 2nd Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 1st Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 1st Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 1st Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 1st Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 2nd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 2nd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 2nd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 2nd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 3rd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 3rd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 3rd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 62GHz of the 3rd Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the 4th Example of the antenna module which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the other structure of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the other configuration of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention, in which antennas are arranged and made into an array. It is a figure which shows the input return loss characteristic of the 4th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 58GHz of the 4th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 4th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 4th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 58GHz of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the input return loss characteristic of another Example of 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 58GHz of another Example of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of another Example of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of another Example of the 5th Example of the antenna module which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the 1st Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the structure of the 2nd Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 1st Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 1st Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 1st Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 1st Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the input return loss characteristic of the 2nd Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 57GHz of the 2nd Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 60GHz of the 2nd Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the radiation pattern characteristic of the frequency 64GHz of the 2nd Example of the antenna module which concerns on 3rd Embodiment of this invention. It is a figure which shows the structure of the 1st Example of the radar apparatus which concerns on 4th Embodiment of this invention. It is (a) side view and (b) top view which shows the detection example in the room of the radar apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the structure of the 2nd Example of the radar apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the structure of the 3rd Example of the radar apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the arrangement of the virtual antenna of the MIMO antenna, (a) shows 2.5D detection, (b) shows 2D detection, (c) shows the virtual antenna arrangement of 3D detection. It is (a) plan view and (b) sectional view which show the structure of the background technique.

[First Embodiment]
Hereinafter, the first embodiment and the second embodiment of the first embodiment of the present invention will be described with reference to the drawings.
In the following description, the same parts are designated by the same reference numerals. Their names and functions are the same. Therefore, the detailed description of them will not be repeated.

(First Example)
FIG. 1 is a plan view showing the configuration of the antenna module 5a according to the first embodiment of the present embodiment, and is a cross-sectional view taken along the line AA'of the plan view.
The dielectric substrate 100 has a specific dielectric constant of 3.0, a substrate thickness d of 0.13 mm, a ground metal 111 on the back surface of the substrate, and a feeding line and an input matching circuit unit 20 on the antenna surface (board surface) 101. A microstrip patch antenna composed of the patch antenna element 11 is configured.
In addition, in the present embodiment, the dielectric substrate 100 is described as a two-layer substrate having a metal pattern on the antenna surface 101 and a metal pattern on the ground metal 111 on the back surface of the substrate. It doesn't matter if there is one.

Specifically, on the antenna surface 101, the feeding line, the input matching circuit unit 20, and the patch antenna element 11 are made of copper metal, and the patch antenna element 11 is a rectangular main patch element 11a. , Slits 12 are provided on both sides of the main patch element, and a rectangular sub-patch element 11b is formed with a gap 12 in between. The main patch element 11a and the sub patch element 11b are arranged in parallel with each other. The width Lm of the main patch element and the width Ls of the sub patch element are the same (Lm = Ls), and are about λg / 2 when the operating wavelength on the dielectric substrate is λg. When the rowing direction of the main patch element 11a and the sub patch element 11b on the dielectric substrate is the element width direction and the orthogonal direction thereof is the element length direction, the power supply line and the input matching are on the element length direction side of the main patch element 11a. The circuit unit 20 is provided.

Specifically, at 60 GHz, when the relative permittivity is 3.0, the magnitude of the operating wavelength (λg) on the substrate is around 2.9 mm in the 60 GHz band (57 GHz to 64 GHz) (the above formula). 1). In this embodiment, Lm = 1.36 mm was set. The substrate thickness d used is 0.13 mm, and the back surface of the substrate is ground metal 111.

On the other hand, the width S of the slit 12 is λg / 100 to λg / 10, specifically, a size of 30 μm to 300 μm in the 60 GHz band, and this size is the resonance of the wavelength of λg / 2 on the substrate. Compared with the length of 1.45 mm, it is sufficiently short, and the coupling between the main patch element 11a and the sub patch element 11b divided by the main slit 12 can be stably maintained. In this example, S = 0.14 mm.
Here, if the width S is smaller than 30 μm, it becomes difficult to manufacture on the substrate, while if the width S is larger than 300 μm, the coupling loss between the main patch element antenna 11a and the sub patch element antenna 11b is large. As a result, not only the antenna gain is lowered, but also the width of the patch antenna element 11 composed of the main patch element and the sub patch element becomes large, which hinders the miniaturization.
Furthermore, for example, when the patch antennas are arranged side by side at λair / 2 (2.5 mm in the 60 GHz band) to form a patch antenna array, the width of one patch element becomes close to 2.5 mm and becomes too large. As a result, it comes into contact with or couples with adjacent antennas, making it impossible to array them.

In both the main patch element 11a and the sub patch antenna 11b element, the half-wave resonance frequency is roughly determined by the length Lm of the side in the feeding (electric field) direction, and the patch width (magnetic field) direction mainly contributes to radiation.
Since the resonance frequency is slightly dependent on the rectangular patch area, the main patch element is divided into three parts by the main patch element and the sub-patch elements on both sides (of the main patch element) by the slit 12. The width and the area of the width of the sub patch element can be changed, and the resonance frequency can be finely adjusted by the main patch element 11a and the sub patch element 11b, and the bandwidth can be widened.

The specifically evaluated performance characteristics shown in FIGS. 2 and 3a to 3c will be described.
FIG. 2 shows an input return loss characteristic (S11 dB).
It shows a characteristic of -5 dB or less over 57.0 GHz to 64.0 GHz, indicating that a signal is efficiently input to the antenna itself over this band.
3a to 3c show the radiation characteristics of the antenna. Specifically, FIG. 3b shows the characteristics of a frequency of 60.0 GHz near the center of the operating band, FIG. 3a shows the low frequency side of the operating band of 57 GHz, and FIG. 3c shows the operation. The 64 GHz radiation pattern characteristic on the high frequency side of the band is shown for the case of Pi (θ) = 0 ° and 90 ° with respect to the Theta (θ) azimuth direction. Both show antenna gain characteristics of 6 dBi to 5 dBi in the front direction, and have uniform and equivalent radiation pattern characteristics over a wide band with a bandwidth of 57 GHz to 64 GHz and 7 GHz. As a result, in application to a radar system, a high-precision range-finding radar system becomes possible. For example, if an FMCW radar device having a band of 7 GHz in the 60 GHz band is configured, a range-finding radar device having a basic resolution of 2.5 cm is possible. It becomes.

(Second Example)
FIG. 4 is a plan view showing the configuration of the antenna module 5b according to the second embodiment of the present embodiment, and a cross-sectional view taken along the line BB'in the plan view.
The difference from the first embodiment is that the element length Ls of the sub patch element 11c is different from the element length Lm of the main patch element 11b. That is, in this embodiment, the main patch element 11a and the sub patch element 11c have different element widths, which are the lengths in the element width direction, and different element lengths, which are the lengths in the element length direction. There is. The difference in the resonance frequency of the patch element is clearly different, the resonance length Ls of the sub patch element is smaller (Lm> Ls) than the resonance length Lm of the main patch antenna, and the resonance frequency of the sub patch element is higher. ..
The method of taking the sub-patch element length Ls is arbitrary, but the length Ls may be determined based on the central portion (BB'line) of the element length of the main patch element, or the upper side CC'of the main patch element width. The length Ls may be determined based on the line, or the length Ls may be determined based on the lower side DD'line of the main patch element width. Equivalent characteristics can be obtained. Hereinafter, the method of determining the length Ls of the sub-patch (the first sub-patch element Ls and the second sub-patch element Lu described in the third embodiment of the present embodiment) is the same in the other embodiments.

The main patch element and the sub patch element are divided into three parts. In the patch antenna element, the feeding line is arranged in the center of the main patch element, and the main patch element resonates in the low frequency side to the middle range of the operating band to obtain the operating band. It is better to resonate the mid-to-high frequency side with the sub-patch element, because the main patch element in the center needs to operate as a resonator and transmission line, so the element length is increased outward from the main patch element. By gradually reducing the value and increasing the resonance frequency, the coupling loss between the patch elements divided by the slits on both sides becomes small, and an antenna element having high radiation efficiency over a wide band can be constructed.
On the other hand, conversely, the sub-patch element length may be slightly larger than the main patch element length [Ls> Lm] to extend the low-frequency side characteristics.

The evaluated performance characteristics shown in FIGS. 5 and 6a to 6c will be described. The evaluation was performed on the patch antenna element 11 in the case where the sub-patch element antenna element Ls is smaller than the main patch element Lm [Lm> Ls].
In this embodiment, Lm = 1.36 mm and Ls = 1.32 mm, and the others are the same as those in the first embodiment.

FIG. 5 shows the input return loss characteristic (S11dB) of the S parameter.
It shows a characteristic of -5 dB or less over 57.0 GHz to 65.6 GHz, indicating that a signal is efficiently input to the antenna itself over this band.
6a to 6c show the radiation characteristics of the antenna. Specifically, FIG. 6b shows the characteristics of the frequency 60.0 GHz near the center of the operating band, FIG. 6a shows the low frequency side 57 GHz of the operating band, and FIG. 6c shows the operation. The 66 GHz radiation pattern characteristic on the high frequency side of the band is shown for the case of Pi (θ) = 0 ° and 90 ° with respect to the Theta (θ) azimuth direction. Both show antenna gain characteristics of 6 dBi to 5 dBi in the front direction, and have uniform and equivalent radiation pattern characteristics over a wide band with a bandwidth of 57 GHz to 66 GHz and a bandwidth of 9 GHz. This is because the transmission loss becomes large on the high frequency side and the performance tends to deteriorate on the high frequency side in the radar module or device having a wide band of 7 GHz in the 60 GHz band, and the influence thereof can be reduced. Further, it is possible to configure an ultra-wideband radar device in the 9 GHz band.

(Third Example)
FIG. 7 is a plan view showing the configuration of the antenna module 5c according to the third embodiment of the present embodiment, and a cross-sectional view taken along the line BB'in the plan view.
The difference from the second embodiment is that the main patch element 11a is provided, the first sub-patch element 11d is provided on both sides thereof, and the second sub-patch element 11e is provided on both sides thereof. A first slit S1 is provided between the main patch element 11a and the first sub-patch element 11d, and a slit S2 is provided between the first sub-patch element 11d and the second sub-patch element 11e. It has a heavy slit configuration.
The main patch element 11a, the first sub-patch element 11d, and the second sub-patch element 11e are arranged in parallel with each other.

Here, the first slit S1 and the second slit S2 are λg / 100 to λg / 10, which is the size of the width S of the main slit 12 in Examples 1 and 2, and specifically, the 60 GHz band. The size is set to 30 μm to 300 μm.
In this embodiment, S1 ≧ S2 is desirable, and a wider band design becomes possible. Specifically, S1 = 180 μm and S2 = 140 μm are used.
On the other hand, the element length of the main patch element is Lm, the element length Ls of the first sub-patch element, and the element length Lu of the second sub-patch element are preferably Lm ≧ Ls ≧ Lu. Wideband design is achieved by using low-frequency resonance and the first and second sub-patch elements as high-frequency resonance. In this embodiment, Lm = 1.4 mm.

The method of taking the first sub-patch element length Ls and the second sub-patch element length Lu is arbitrary, but the length Ls is determined with reference to the central portion (BB'line) of the element length of the main patch element. Alternatively, the length Ls may be determined based on the upper CC'line of the main patch element width, or the length Ls may be determined based on the lower DD' line of the main patch element width. By the method of determining the length in the case of the three, almost the same characteristics can be obtained. Hereinafter, the method of determining the first sub-patch element Ls and the second sub-patch element Lu is the same in other embodiments.

On the other hand, regarding the relationship of the element width, since the patch width (magnetic field) direction mainly contributes to radiation, the element width Lwa of the main patch element and the element widths Lwb and Lwc of the first and second sub patch elements are used. H has the following relationship.
H = Lwa + 2, Lwb + 2, Lwc + 2, S1 + 2, S2

In this configuration, even if the element width is widened to about H = λair / 2, it is possible to obtain a good gain characteristic with an antenna gain of about 8 dBi.
However, when the patch antennas are arranged side by side to form a patch antenna array, if the width of one patch element becomes too close to λair / 2 and becomes too large, it will come into contact with or couple with adjacent antennas, resulting in an array. You will not be able to do it.

In the present invention, conversely, when the element width H is made as small as possible and the antennas are arranged side by side, the degree of interference / coupling between the antennas can be made smaller.
As an example, Lwb and Lwc are made smaller than the element length Lm to form a strip-shaped rectangular shape, and the relationship between the first slit S1 and the second slit S2 described above is used to provide good radiation over a wide band. Not only the characteristics but also the element width H can be made close to the shape of a square patch having an element length Lm, and when arrayed as described above, the degree of interference / coupling between the patch antennas can be reduced. That is, it is possible to construct a small patch antenna element suitable for arraying. In order to reduce the interference between the patch antennas, not only the element width H is reduced, but also the first slit S1 and the second slit S2 are provided. The effect of reducing the degree of interference / coupling is included (see Example 4 of the second embodiment).

The characteristics of the antenna 5c will be described.
FIG. 8 shows an input return loss characteristic (S11 dB) when the element lengths are Lm = 1.4 mm, Ls = 1.36 mm, and Lu = 1.32 mm. It exhibits a characteristic of -5 dB or less over 58.0 GHz to 65.3 GHz, indicating that a signal is efficiently input to the antenna itself over this band.
Compared with the cases of Examples 1 and 2, in this double slit configuration, the present input return loss characteristic (negative value) becomes smaller and deep resonance is obtained.

9 (a), (b) and (c) show the radiation characteristics of the antenna 5c.
Specifically, FIG. 9 (b) shows the characteristics of a frequency of 60.0 GHz near the center of the operating band, FIG. 9 (a) shows 57 GHz on the low frequency side of the operating band, and FIG. 9 (c) shows the high frequency of the operating band. The side 65 GHz emission pattern characteristic is shown for the case of Ph (θ) = 0 ° and 90 ° with respect to the Theta (θ) azimuth direction. Both show antenna gain characteristics of 5 dBi ± 1 dBi in the front direction, and have uniform and equivalent radiation pattern characteristics over a wide band with a bandwidth of 57 GHz to 64 GHz and 7 GHz.

Further, with respect to the present antenna 5c, FIG. 10 shows an input return loss characteristic (S11 dB) when the element length is Lm = 1.4 mm and Ls = Lu = 1.32 mm. It shows a characteristic of -5 dB or less from 57.9 GHz to 64.6 GHz, and shows that deep resonance is obtained over this band and a signal is efficiently input to the antenna itself.
11 (a), (b) and (c) show the radiation characteristics of the antenna 5c. Specifically, FIG. 11 (b) shows the characteristics of a frequency of 60.0 GHz near the center of the operating band, and FIG. 11 (a) shows the characteristics. Shows the low frequency side 57 GHz of the operating band, and FIG. 11 (c) shows the high frequency side 64 GHz radiation pattern characteristics of the operating band in the case of Phi (θ) = 0 ° and 90 ° with respect to the Theta (θ) azimuth direction. ing. Both show antenna gain characteristics of 5 dBi ± 1 dBi in the front direction, and have uniform and equivalent radiation pattern characteristics over a wide band with a bandwidth of 57 GHz to 64 GHz and 7 GHz.

[Second Embodiment]
Hereinafter, the second embodiment of the present invention will be described where it differs from the first embodiment.
In the first embodiment, the patch antenna element composed of the main patch element and the sub patch element separated by the slit 12 is one element, but in the present embodiment, the first embodiment (first embodiment). A patch in which N (N: natural number) elements, that is, a plurality of the present patch antenna elements of Example 1 or 2) are arranged in a row, and the main patch elements in the patch antenna element are connected to each other by a feeding line. Regarding the configuration of the antenna. Further, in the present embodiment, the plurality of patch antenna elements are arranged in a row in the element length direction, and the main patch elements in the adjacent patch antenna elements in the arrangement have the central portion in the element width direction of each. The present invention relates to a configuration of a patch antenna connected by a feeding line extending in the element length direction.

In this embodiment, the configuration diagrams for the first to third embodiments are shown in FIGS. 12, 13, and 14, respectively. The material, thickness, and cross-sectional shape of the substrate are the same as those in the first embodiment. A case where the four-element patch antenna element of N = 4 is skewered in the element length direction (vertical direction in this drawing) on the feeding line will be described.
In FIGS. 12 to 14, the horizontal direction is defined as the horizontal direction (H) and the vertical direction is defined as the vertical direction (V) with respect to the substrate direction.

(First Example)
The antenna module 6a includes the main patch elements 31a, 32a, 33a, and 34a (using the patch antenna elements of the first embodiment and the second embodiment), and the main patch elements via slits 12 on both sides of each main patch element. , Sub-patch elements 31b, 32b, 33b, 34b, and the power supply circuit unit 21 and the power supply lines 22, 23, 24 skewer the central portions of the main patch elements 31a, 32a, 33a, 34a in the element length direction. It is composed of.
The element spacing of the power supply lines 22, 23, and 24 is also determined, and is appropriately adjusted by λg / 2 to λair / 2. As a result, the direction of the element length that determines the resonance frequency and the direction of the element spacing for phase-synthesizing the beam of each patch antenna element are the same direction.

The element lengths of the main patch elements 31a, 32a, 33a, and 34a are Lm, and the element lengths of the sub patch elements 31b, 32b, 33b, and 34b are Ls. Specifically, Lm is 1.36 mm and Ls. Is set to 1.32 mm, and the slit 12 is set to a width S = 0.14 mm.

Here, in the first embodiment, N = 4, and the widths of the main patch elements 31a, 32a, 33a, 34a are Wm1, Wm2, Wm3, and Wm4, respectively, and the sub patch elements 31b, 32b, The widths of 33b and 34b are Ws1, Ws2, Ws3, and Ws4, respectively, and the width Lk of one patch element is Lk = Wmk + Wsk + 2S, (k = 1, 2, 3, 4), N = 4, but Wmk. , Wsk, the main patch element width and the sub patch element width at the middle part (k = N / 2, rounded to the minority point if k is a minority point) rather than the end part (k = 1, k = N). Is large (N includes even and odd numbers). That is, in this embodiment, three or more patch antenna elements are arranged, and the element width of the patch antenna element in the middle portion in the arrangement is larger than the element width of the patch antenna element at the end portion in the arrangement. Is also widening.

In this embodiment, as an example, the intermediate portion Wm2 = Wm3 = 0.86 mm and Ws2 = Ws3 = 0.4 mm, while the end portion Wm1 = Wm4 = Ws1 = Ws4 = 0.3 mm, but even the above relationship can be satisfied. For example, it can be changed as appropriate according to the desired desired characteristics.

Further, the power feeding circuit unit 21 to the main patch element 31a with k = 1 includes an input matching unit including a line unit having a characteristic impedance of 50Ω.
Here, the input return loss (input impedance) characteristic is roughly determined by the element length Lm of the main patch elements 31a, 32a, 33a, 34a and the element widths Wm1, Wm2, Wm3, and Wm4, respectively, and the sub patch element 31b. , 32b, 33b, 34b have a small dependence on the element length Ls and the element widths Ws1, Ws2, Ws3, Ws4.

Further, the lengths of the feeding lines 22, 23, and 24 to the main patch elements 32a, 33a, and 34a for each k = 2 to k = 4 are the wavelengths of the center frequencies λg / 2 to λair / 2 on the substrate. The length is appropriately adjusted within this range according to the desired gain and side lobe characteristics. Similar to the first embodiment, the wavelength at the center frequency of the operating band on the dielectric substrate, λg = 1.45 mm in this embodiment (see the above formula 1).

(Second Example)
The basic configuration of the antenna module 6b is the same as that of the antenna module 6a of the first embodiment. The difference is that the element widths of the sub-patch elements 41b, 42b, 43b, 44b are Ws1 = Ws2 = Ws3 =. It has a Ws4 relationship.

Specifically, in the case where the number of arrangements of the patch antenna elements N = 4, the main patch elements 41a, 42a, 43a, 44a and the sub-patch elements 41b, 42b via slits 12 on both sides of each main patch element. , 43b, 44b are configured.

It is the same that the feeding lines 21, 22, 23, 24 are formed in a skewered shape in the element length direction (vertical direction in this drawing) at the central portion of the main patch elements 41a, 42a, 43a, 44a. The element lengths of 41a, 42a, 43a, and 44a of each main patch element are Lm, and the element lengths of the sub patch elements 41b, 42b, 43b, and 44b are Ls. Specifically, Lm is 1.36 mm. Similarly, Ls is set to 1.32 m, and the slit 12 is set to a width S = 0.14 mm. In addition, the same applies to the input matching circuit unit 21 and the feeding lines 22, 23, 24.

Here, in the second embodiment, N = 4, and the widths of the main patch elements 41a, 42a, 43a, and 44a are Wm1, Wm2, Wm3, and Wm4, respectively, and the sub patch elements 41b, 42b, and 43b. , 44b have widths of Ws1, Ws2, Ws3, and Ws4, respectively, and the width Lk of one patch element is Lk = Wmk + Wsk + 2S (k = 1, 2, 3, 4), N = 4, and the second embodiment. The basic configuration is the same as that of the first embodiment, except that the element widths of the sub-patch elements 41b, 42b, 43b, and 44b have a relationship of Ws1 = Ws2 = Ws3 = Ws4. That is, in this embodiment, three or more patch antenna elements are arranged, and the element width of the main patch element of the intermediate patch antenna element in the arrangement is the end side patch antenna in the arrangement. It is wider than the element width of the main patch element of the element, and the element width of the sub-patch element of all the patch antenna elements in the arrangement is constant.

Similar to the first embodiment, Wmk is preferably an intermediate portion (k = N / 2) rather than an end portion (k = 1, k = N) in order to reduce the sidelobe characteristic of the antenna radiation pattern characteristic. ), The main patch element width is increased (N includes even and odd numbers).

In this embodiment, as an example, Ws1 = Ws2 = Ws3 = Ws4 = 0.4 mm (= constant), the central portion Wm2 = Wm3 = 0.86 mm, and the end portion is Wm1 = Wm4 = 0.3 mm. As long as the above relationship is satisfied, it can be appropriately changed according to the desired desired characteristics.

(Third Example)
The basic configuration of the antenna module 6c is the same as that of the antenna module 6b of the second embodiment. The difference is that the element widths of the main patch elements 51a, 52a, 53a, 54a are Wm1 = Wm2 = Wm3 =. It has a Wm4 relationship.

Specifically, in the case where the number of arrangements of the patch antenna elements N = 4, the main patch elements 51a, 52a, 53a, 54a and the sub-patch elements 51b, 52b via slits 12 on both sides of each main patch element. , 53b, 54b are configured.

It is the same that the feeding lines 21, 22, 23, 24 are formed in a skewered shape in the element length direction (vertical direction in this drawing) at the central portion of the main patch elements 51a, 52a, 53a, 54a.
The element lengths of 51a, 52a, 53a, and 54a of each main patch element are Lm, and the element lengths of the sub patch elements 51b, 52b, 53b, and 54b are Ls. Specifically, Lm is 1.36 mm. Similarly, Ls is set to 1.32 m, and the slit 12 is set to a width S = 0.14 mm. The same applies to the input matching circuit unit 21 and the power supply lines 22, 23, and 24.

Here, in the third embodiment, N = 4, and the widths of the main patch elements 51a, 52a, 53a, 54a are Wm1, Wm2, Wm3, and Wm4, respectively, and the sub patch elements 51b, 52b, respectively. The widths of 53b and 54b are Ws1, Ws2, Ws3, and Ws4, respectively, and the width Lk of one patch element is Lk = Wmk + Wsk + 2S (k = 1, 2, 3, 4), N = 4, and the second implementation. The basic configuration is the same as that of the first embodiment, except that the element widths of the main patch elements 51a, 52a, 53a, and 54a have a relationship of Wm1 = Wm2 = Wm3 = Wm4. That is, in this embodiment, three or more patch antenna elements are arranged, and the element width of the sub-patch element of the patch antenna element in the middle portion in the arrangement is the patch antenna on the end side in the arrangement. It is wider than the element width of the sub-patch element of the element, and the element width of the main patch element of all the patch antenna elements in the arrangement is constant.

Similar to the first embodiment, in order to reduce the sidelobe characteristic of the antenna radiation pattern characteristic, the Wsk is set at the intermediate portion (k = N / 2) rather than at the end portion (K = 1, K = N). , The sub-patch element width is increased (N includes even and odd numbers).
In this embodiment, as an example, Wm1 = Wm2 = Wm3 = Wm4 = 0.58 mm, the middle portion Ws2 = Ws3 = 0.5 mm, and the end portion is Ws1 = Ws4 = 0.2 mm, but even the above relationship can be satisfied. For example, it can be changed as appropriate according to the desired desired characteristics.

(Return loss and radiation pattern characteristics of Examples 1 to 3)
The evaluation characteristics of the return loss and the radiation pattern in the cases of Examples 1 to 3 will be described.
The case of the first embodiment is shown in FIGS. 15 and 16a to 16c, the case of the second embodiment is shown in FIGS. 17 and 18a to 18c, and the case of the third embodiment is shown in FIGS. 19 and 20a to 20c. ..
Regarding the return loss characteristics of FIGS. 15, 17, and 19, in the first embodiment and the second embodiment, a wide band characteristic of approximately return loss of -5 dB or less is shown in the band of 57.0 GHz to 65.0 GHz. In the third embodiment, it has a wide band characteristic of a return loss of -5 dB or less at 57.3 GHz to 66.8 GHz.

On the other hand, the radiation pattern characteristics of FIGS. 16a to 16c, FIGS. 18a to 18c, and FIGS. 20a to 20c show the radiation pattern at the low frequency, the center frequency, and the high frequency. Specifically, as shown in the insets of FIGS. 16a, 18a, and 20a, a radiation pattern in which the beam is focused is shown in the direction of Phi = 90 °, and a radiation pattern having a wide beam width in Phi = 0 °. It has a uniform and equivalent radiation pattern from the low frequency range (FIG. 16a, FIG. 18a, FIG. 20a) to the high frequency range (FIG. 16c, FIG. 18c, FIG. 20c).

In the first embodiment and the second embodiment, the antenna Gain is 7 dBi to 10 dBi, the 3 dB bandwidth of 57 GHz to 64 GHz is 7 GHz, and the radiation pattern is uniform and equivalent over a wide band.
On the other hand, in the third embodiment, the bandwidth is slightly narrower than that of the first embodiment and the second embodiment, but the antenna Gain shows a value of 7 dBi to 10 dBi, and 3 dB of 57 GHz to 62 GHz. It has a bandwidth of 5 GHz and has a uniform and equivalent radiation pattern over a wide band.

A set of patch antenna elements (31 to 34, 41 to 44, 51 to 54) divided into three by the slit 12 is connected by N (N = 4 in this embodiment) and power supply lines 21 to 24, and a plurality of them are connected. By arranging the radiation beam, the patch antenna elements are narrowed down in the direction in which the patch antenna elements are arranged (Phi = 90 ° direction, vertical direction V), and the radiation beam can be concentrated around the central portion of the plurality of antenna elements. An antenna emission pattern with a high gain of a narrow beam can be obtained in a wide frequency band.

That is, in the invention of the present embodiment, when the plurality of arranged first to N = 4 patch antenna elements are arranged in a row in a series antenna configuration and the arrangement direction is the vertical direction V. , Since the feeding line is vertically skewered in the center of each of the four main patch elements, the main patch elements (31a, 32a, 33a, 34a, 41a, 42a, 43a, 44a, 51a, 52a, 53a). , 54a) is configured to be vertically connected by power supply lines (22, 23, 24), and the influence of the current from the sub-patch element separated by the main slit 12 is small. The feeding lines (21, 22, 23, 24) are fed to the main patch element by the shortest current path, and are excited by electromagnetic coupling between the main patch element and the sub patch element by the slit 12. As a result, a wide band and high gain antenna radiation characteristic can be obtained. This is because the direction of the element length that determines the resonance frequency (vertical direction: vertical direction V) and the direction of the element spacing for phase-synthesizing the beams of each patch antenna element (vertical direction: vertical direction V) are the same. Therefore, the basic configuration of the present embodiment is that the power supply lines 22, 23, and 24 are essentially short, but in addition, the width of the main patch element is small and the sub patch element is the main patch by electromagnetic coupling. It is excited from the element and does not require a current path.
As a result, in the present embodiment, in addition to the effect of the first embodiment, the feeding to each patch antenna element becomes the shortest current path, which is an added effect of gain improvement and bandwidth expansion. ..

Summarizing the above embodiments in the present embodiment, in the first embodiment, the main patch element widths (Wm1, Wm2, Wm3, Wm4), the slit 12, and the sub patch element widths (Ws1, Ws2, Ws3) are summarized. , Ws4), the first to fourth patch antenna elements arranged in k (k: natural numbers) have a main patch element width Wm2 (k = N / 2) in the middle portion. , Wider than the main patch element widths Wm1 and Wm4 at the end (Wm2> Wm1, Wm4), and the sub-patch element width Ws2 at the middle part is wider than the sub-patch element widths Ws1 and Ws4 at the end. By (Ws2> Ws1, Ws4), in the radiation pattern formation, the patch antenna element composed of the main patch elements (31a, 32a, 33a, 34a) and the sub patch elements (31b, 32b, 33b, 34b) arranged in plurality is used. The radiation of the four patch antenna elements strengthens each other to form a radiation pattern with a narrow beam width in the element arrangement direction (Phi = 90 ° direction shown in the inset of FIG. 16a), but the main and sub parts of the intermediate portion are formed. By increasing the width of the patch element, radiating strongly from the middle part, gradually reducing the width of the main and sub patch elements toward the end of the patch, and gradually reducing the radiation, from multiple patch antennas arranged. As for the radiation pattern, the main beam is more emphasized, and a radiation pattern with a small side lobe can be obtained.
As a result, in application to a radar system, the side lobe of the antenna becomes a ghost and causes false detection. Therefore, in the present invention, a radar device with less false detection is configured by reducing the side lobe characteristic. be able to.

In the second embodiment, as in the first embodiment, the main patch elements (41a, 42a, 43a, 44a), the slit 12, and the sub patch elements (41b, 42b, 43b, 44b) are configured. In the patch antenna element, the width Wm2 of the main patch element in the middle part is increased and strong radiation is emitted from the middle part, and the width of the main patch element is gradually reduced in the direction of the end of the patch to gradually weaken the radiation. Therefore, in the radiation pattern from the plurality of arranged patch antennas, the main beam is more emphasized, and a radiation pattern with a small side lobe can be obtained. However, for example, if the element widths of both the sub-patch element width and the main patch element width are reduced from the intermediate portion in which a plurality of N = 4 elements are arranged toward the end side, the sub-patch element and the sub-patch element are formed. In both main patch elements, the radiation suddenly becomes small, and it becomes difficult to secure a stable radiation pattern, especially at the end of the operating frequency band. In the second embodiment, the width of the main patch element is gradually reduced from the middle part to the end side of the array because it may not be possible to obtain the antenna radiation pattern of (1). By setting the sub patch element width to a constant width (Ws1 = Ws2 = Ws3 = Ws4) together with Wm2> Wm1 and Wm4), the radiation pattern is less likely to collapse even on the high frequency side, and the antenna gain is more stable over a wide band. However, a uniform and equivalent radiation pattern can be obtained.

In the third embodiment, the main patch element needs to operate as a transmission line as well, and the operation as a transmission line is focused on and devised. That is, the widths of the main patch elements (51a, 52a, 53a, 54a) of the first to fourth (N = 4) patch elements arranged in a plurality of arrangements are set to the same width (Wm1 = Wm2 = wm3 = Wm4). At the same time, the widths of the first to fourth sub-patch elements are made wider than the width of the sub-patch elements at the ends by making the width of the sub-patch elements in the middle portion wider (Ws2> Ws1, Ws4). The total width of the arranged first to fourth patch antenna elements (51, 52, 53, 54) is divided into three by the main patch element and the sub patch element. Therefore, the width of the main patch element (Wm1, Wm2, Wm3, Wm4) is narrowed, and when the substrate 100 thickness d = 100 μm to 200 μm, the width is about the same as the width of the microstrip transmission line of about 30 Ω to 60 Ω.
In the third embodiment, the input impedance of the antenna element can be approached to 50Ω by setting N = 4 main patch elements to have the same width (Wm1 = Wm2 = Wm3 = Wm4).
As a result, it is possible to obtain an antenna module having a good connection with a transmission / reception MMIC (Microwave Monolithic IC) connected to the antenna, a wide band, less unnecessary reflection, and stable operating characteristics.

(Fourth Example)
The configuration of the antenna module 6d will be described by showing the difference from the antenna module 6a of the second embodiment.
As shown in FIG. 21, the patch antenna element 91 of the first stage connected to the power feeding line 21 includes the main patch element 91a, the first slit S1, the first sub-patch element 91b, and the second slit S2. The configuration is provided with a double slit structure of the second sub patch element 91c. The second-stage patch antenna elements 32a and 32b, the third-stage patch antenna elements 33a and 33b, and the fourth-stage patch antenna elements 34a and 34b are the same as those in the first embodiment.
With this configuration, the first stage portion of the configuration in which a plurality of patch antenna elements are connected in the vertical (V) direction, that is, in the element length direction is a patch antenna element having a double slit structure. In this way, by forming the first stage portion as the patch antenna element 91 having a double slit structure, the input impedance seen from the feeding line 21 of the present antenna element can be lowered and approached to the input impedance of 50Ω. As a result, a transmission / reception MMIC connected to the antenna can be connected with less reflection, and an antenna module having a wide band and stable operating characteristics can be obtained.

(Fifth Example) Vertically Polarized Connection All Stages of WSL The difference between this antenna module 6e and the antenna module 6d of the fourth embodiment is that, as shown in FIG. 22, the element length direction (V) In the direction), a plurality of patch antenna elements connected are the first to fourth stages (all stages), and the patch antenna elements 91, 92, 93, 94 are all patch antenna elements having a double slit structure. It is a prepared configuration.

With this configuration, since each of the patch antenna elements 91, 92, 93, 94 exhibits stable radiation pattern characteristics over a wide band, even with the configuration in which the patch antenna elements are connected, radiation pattern characteristics that do not easily collapse over a wide band can be obtained. At the same time, it is easy to match the input, and the input impedance of 50Ω can be approached. As a result, it is possible to connect the transmission / reception MMIC connected to the antenna with less reflection, and to obtain a microwave antenna module having stable operating characteristics in a wide band.

In addition, in FIG. 22 of this embodiment, the second subpatch element widths 91c, 92c, 93c, 94c are equalized, and Wu1 = Wu2 = Wu3 = Wu4, so that the radiation pattern characteristic is set in the band. The pattern can be made more uniform.

Further, as shown in FIG. 23, in the antenna module 6f of another embodiment of this embodiment, the main patch element widths 91a, 92a, 93a, 94a of all stages are equal, that is, the relationship of Wm1 = Wm2 = Wm3 = Wm4. Further, the widths of the second subpatch elements 91c, 92c, 93c, and 94c can be equalized, and Wu1 = Wu2 = Wu3 = Wu4 can be satisfied. That is, by adopting this double slit structure, the width of the sub-patch element shown in the second embodiment can be made constant, and the width of the main patch element shown in the third embodiment can be made constant. In addition to being able to make the radiation pattern characteristics more uniform in the band while ensuring the input return loss characteristics, which is the effect of, the side lobe characteristics are the width Ws1 of the first subpatch element. , Ws2, Ws3, Ws4 can be adjusted to narrow the end and widen the center in the element length (V) direction, so that the wideband characteristics of the patch antenna element having the slits S1 and S2 can be ensured. , Side lobe characteristics can also be reduced and good radiation characteristics can be obtained.

Here, in Example 4, only the first stage is used, and in Example 5, all stages are set as patch antenna elements from the main patch element and the first and second sub-patches, but the first stage and the second to fourth stages are appropriately used. It is also possible to combine.

Further, another feature of the antenna modules 6e and 6f of the present embodiment will be described. As shown in FIG. 24, in this configuration, the element width is, for example, the element width Wm in the width H of the second stage (i = 2) main patch element having the largest element width H among the four patch antenna elements. Assuming that the first and second sub-patch element widths Ws and Wu, the element width H has the following relationship.
H = Wmi + 2, Wsi + 2, Wii + 2, S1 + 2, S2 (i = 2)

In this configuration, if the width H of the patch element becomes too close to λair / 2 and becomes too large, it will come into contact with or couple with adjacent antennas, and it is possible to support arraying that needs to be arranged at λair / 2 intervals. I can't do it.
In the present invention, when the element width H is made as small as possible and the antennas are arranged side by side (horizontally H direction) at intervals of λair / 2, the degree of interference / coupling between the antennas can be further reduced.
Each patch element width Wmi, Wsi, and Wii is formed into a strip-shaped rectangle that is smaller than the element length Lm, and is set to the following relationship (H: patch element width, D: spacing between patch elements).
H ≤ (λair / 2-D)
D ≧ λg / 4

In the case of this embodiment, λair / 2 = 2.5 mm and λg / 4 = 0.78 mm, and as an example, by setting the element width H to H ≦ 1.72 mm, as shown in FIG. 24, λair / 2 When arrayed at intervals, it is possible to reduce the degree of coupling between the antennas. Here, the distance D between the patch elements is λg / 4 or more at the wavelength on the substrate, so that the degree of interference / coupling between the arranged antennas can be reduced.
At this time, it is necessary to reduce the element width H of the patch antenna element, but in the case of a patch antenna (with a single metal surface) that simply does not have a conventional slit, if the element width H is reduced, input matching is achieved. It was difficult to take and the band characteristics had become narrow band characteristics.

In this configuration, by using a patch antenna element having a double slit configuration, the first and second slits S1 and S2 are appropriately provided, and the main patch element and the first and second sub-patch elements are in the shape of a strip. Even if it is made small, input matching is easy, wideband characteristics can be secured, and even if it is arranged horizontally (horizontal VV direction) and arrayed, interference between antennas is reduced and individual antennas are made. It is possible to demonstrate the original characteristics of the antenna.
Here, in order to reduce the interference between the patch antennas, not only the element width H is reduced, but also the first slit S1 and the second slit S2 are provided. Therefore, for example, a patch antenna having a single metal surface. This includes the effect of reducing the degree of interference / coupling between patch antennas of adjacent array antennas.

(Return loss and radiation pattern characteristics of Examples 4 and 5)
The evaluation characteristics of the return loss and the radiation pattern in the cases of Examples 4 and 5 will be described.
In the case of the fourth embodiment, FIGS. 25 and 26a to 26c are shown, and in the fifth embodiment, the cases where the second patch element widths of the respective stages are the same, Wu1 = Wu2 = Wu3 = Wu4, are shown in FIGS. 27 and 28a. As shown in FIG. 28c, as another embodiment of Example 5, Wm1 = Wm2 = Wm3 = Wm4 having the same main patch element width in each stage, and Wu1 = Wu2 having the same second sub patch element width in each stage. The case of = Wu3 = Wu4 is shown in FIGS. 29 and 30a to 30c.

In the fourth embodiment, the patch unantenna element 91 of the first stage has a double slit structure, and in any case, the return loss characteristic shows a characteristic of -5 dB or less over a wide band of 58.2 GHz to 64.9 GHz. It shows a stable input return loss in the band. Regarding the radiation pattern characteristics, the antenna gain is 9 dB9 ± 1.5 dB over 58 GHz to 64 GHz, showing a uniform radiation pattern characteristics in which the radiation pattern does not easily collapse.

In the fifth embodiment, all four patch antenna elements have a double slit structure, and the width of the second patch element in each stage is the same as Wu1 = Wu2 = Wu3 = Wu4, and the patch element width 92. In 93, Hmax = 1.94 mm. It shows a characteristic of -5 dB or less over a wide band of 58.0 GHz to 64.7 GHz, and also shows a good characteristic of -7 dB or less even in the central part of the band. Regarding the radiation pattern characteristics, the antenna gain is 10 dB ± 1.5 dB over 57.8 GHz to 64.4 GHz, showing uniform radiation pattern characteristics in which the radiation pattern does not easily collapse, and particularly good characteristics on the low frequency side. Shown.

In another embodiment of the fifth embodiment, when all four patch antenna elements have a double slit structure, the widths of the second patch elements in each stage are the same, Wu1 = Wu2 = Wu3 = Wu4, and the main patch element. In the case of Wm1 = Wm2 = Wm3 = Wm4 having the same width, the return loss characteristic shows a characteristic of -5 dB or less over a wide band of 58.0 GHz to 64.8 GHz, and shows a deep input return loss on the low frequency side. .. Regarding the radiation pattern characteristics, the antenna gain is 10 dB ± 1.5 dB over 58 GHz to 64 GHz, despite the small patch antenna element width (1.7 mm), and the radiation pattern itself collapses within the band. It has a difficult and uniform radiation pattern characteristic.

[Third Embodiment] Horizontally polarized wave Hereinafter, the third embodiment of the present invention will be described where it differs from the first embodiment and the second embodiment. The configurations of the first and second embodiments of this embodiment will be described with reference to FIGS. 31 and 32, respectively.
In this figure, the horizontal direction is defined as the horizontal direction (H) and the vertical direction is defined as the vertical direction (V) with respect to the substrate direction.
In this embodiment, a plurality of patch antenna elements are arranged in a row in the element width direction, and the main patch element of each patch antenna element in the arrangement is located at the center of each element width direction in the element length direction. The present invention relates to a configuration of a patch antenna in which extending lead-out line portions are connected and each lead-out line portion is connected to a feeding line extending in the element width direction.

(First Example)
In the antenna modules 6a, 6b, 6c of the second embodiment, the patch antenna element is fed from the main patch element and the sub-patch element separated by the slit 12, and the central portion of the main patch element is set to the element length (vertical V). ) Direction is skewered, and the element length direction and the direction of the element spacing of the feeding line are also the same direction in the vertical direction: vertical direction V, but in this configuration, the element length direction is horizontal direction H. The difference is that the element spacing direction is the vertical direction V.

In the antenna modules 7a and 7b of the present embodiment, when the direction of the feeding line for bundling N = 4 patch elements is the vertical direction (V), the main patch elements (61a, 62a, 63a) pass through the slit 12. The feeding portion of each patch antenna element composed of the 64a) and the sub-patch elements (61b, 62b, 63b, 64b) includes a horizontal (H) lead-out line portion 122, 123, 124, 125.
The element lengths Lm · Ls that mainly determine the frequency are H in the horizontal direction, and the distance between each N = 4 patch antenna elements is the distance between the lead-out line portions (122 and 123, 123 and 124, 124 and 125). Yes, it is adjusted appropriately in the vertical direction V in the range of λair / 2 to λg at regular intervals.

According to the present invention, when the direction of the feeding line for bundling N patch elements is the vertical direction, the feeding portion of each patch antenna element is in the horizontal direction (horizontal direction H), and the element length mainly determines the frequency. Is in the horizontal (horizontal H) direction, while the intervals between the N elements are fixed in the vertical (vertical V) direction, and N patch antenna elements having a lead-out line portion are bundled together.
That is, the element length that determines the antenna resonance frequency is in the horizontal (horizontal H) direction, and the element spacing that determines the antenna gain is in the vertical (vertical V) direction, which differ by 90 ° and are independent directions. Therefore, the resonance frequency of the antenna element and the antenna gain can be determined independently, and the bandwidth can be widened.
That is, the resonance frequency of the antenna element is generally determined in the horizontal direction (horizontal direction H), and the antenna gain depending on the element spacing is determined in the vertical direction (vertical direction V), and each can be determined independently. It is different from the second embodiment. Therefore, in the antenna characteristics described later, the frequency bandwidth determined by the input return loss characteristics to the antenna and the 3 dB bandwidth of the antenna gain of the peak of each frequency can be further widened.

The antenna module 7a of this embodiment has a plurality of arrangements in the patch antenna element composed of the main patch element (61a, 62a, 63a, 64a), the slit 12, and the sub patch element (61b, 62b, 63b, 64b). In the first to fourth patch antenna elements, the patch element width Wm2 + 2 · Ws2 in the middle portion is wider than the patch element widths Wm1 + 2 · Ws1 and Wm4 + 2 · Ws4 at the end portion, and in addition, the sub patch element width is It is constant (Ws1 = Ws2 = Ws3 = Ws4).

At N = 4, the widths of the main patch elements 61a, 62a, 63a, 64a are Wm1, Wm2, Wm3, and Wm4, respectively, and the widths of the sub patch elements 61b, 62b, 63b, and 64b are Ws1, Ws2, respectively. Ws3 and Ws4, and the width Lk of one patch element has a relationship of Lk = Wmk + 2, Wsk + 2S (k = 1, 2, 3, 4), and N = 4.
In order to reduce the sidelobe characteristics of the antenna radiation pattern characteristics, Wsk is set to a minority point when the intermediate portion (k = N / 2, k is a minority point) rather than the end portion (k = 1, k = N). (Rounding off) may be such that the patch antenna element width Lk becomes large (N includes even and odd numbers).

As an example, Lm = 1.36 mm, Ls = 1.32 m, S = 0.14 mm, Ws1 = Ws2 = Ws3 = Ws4 = 0.22 mm, Wm2 = 0.7 mm, Wm3 = 0.74 mm, Wm1 = 0.46 mm. , Wm4 = 0.58 mm, Ws1 = Ws2 = Ws3 = Ws4 = constant, and can be appropriately changed according to desired and necessary characteristics as long as the relationship of Wm1 + Ws1 <Wm2 + Ws2 is satisfied.

Here, the reason why the sub-patch element width Ws1 = Ws2 = Ws3 = Ws4 = constant is the same reason as in the second embodiment of the second embodiment, and a plurality of N = 4 elements are arranged. If the element widths of both the sub-patch element width and the main patch element width are reduced from the middle portion toward the end side, the radiation of both the sub-patch element and the main patch element suddenly decreases, and in particular, At the end of the operating frequency band, it becomes difficult to secure a stable radiation pattern, and depending on how the Wmk and Wsk (k: 1, 2, 3, 4) values are taken, the same antenna radiation pattern over a wide band In this embodiment, the width of the main patch element is gradually reduced from the middle portion to the end side of the arrangement (Wm2> Wm1, Wm4). At the same time, by setting the width of the sub patch element to a constant width (Ws1 = Ws2 = Ws3 = Ws4), the radiation pattern does not easily collapse even on the high frequency side, and the antenna gain is more constant over a wide band, and a stable radiation pattern. Can be obtained.

In this configuration, the element length that determines the antenna resonance frequency is in the horizontal (horizontal H) direction, and the element spacing that determines the antenna gain is in the vertical (vertical V) direction, which differ by 90 ° and are independent directions. Therefore, the resonance frequency of the antenna element and the antenna gain can be determined independently (the element length and the element spacing do not affect each other), and the band can be further widened. Further, in this configuration, even in the manufacturing process of the antenna module substrate, the element length that determines the resonance frequency and the element interval that determines the radiation beam by phase synthesis are in independent directions different by 90 degrees, so that the resonance frequency and the beam are different. It does not disrupt the radiation pattern due to simultaneous changes in composition. In addition, this independent direction can reduce the effect of simultaneous changes in element length and element spacing due to variations due to etching in the substrate manufacturing process, and is stable with small frequency deviation even in mass production processes that are repeatedly manufactured. The radiation pattern and gain characteristics can be obtained.

(Second Example)
The configuration of the second embodiment will be described with reference to FIG.
In the antenna module 7b of this embodiment, a plurality of patches are arranged in the patch antenna element composed of the main patch element (71a, 72a, 73a, 74a), the slit 12, and the sub patch element (71b, 72b, 73b, 74b). In the first to fourth patch antenna elements, the patch element width Wm2 + 2 · Ws2 in the middle portion is wider than the patch element widths Wm1 + 2 · Ws1 and Wm4 + 2 · Ws4 at the end portion, and in addition, the main patch element width is It is constant (Wm1 = Wm2 = Wm3 = Wm4).

At N = 4, the widths of the main patch elements 71a, 72a, 73a, 74a are Wm1, Wm2, Wm3, and Wm4, respectively, and the widths of the sub patch elements 71b, 72b, 73b, and 74b are Ws1, Ws2, respectively. Ws3 and Ws4, and the width Lk of one patch element is
It has a relationship of Lk = Wmk + 2, Wsk + 2S (k = 1, 2, 3, 4), and N = 4.
In order to reduce the sidelobe characteristic of the antenna radiation pattern characteristic, the patch antenna element width Lk of Wsk is larger at the intermediate portion (k = N / 2) than at the end portion (k = 1, k = N). The relationship may be as follows (N includes even and odd numbers).

As an example, Lm = 1.40 mm, Ls = 1.36 m, S = 0.14 mm, Wm1 = Wm2 = Wm3 = Wm4 = 0.58 mm, Ws1 = 0.18 mm, Ws2 = 0.3 mm, Ws3 = 0.32 mm. , Ws4 = 0.24 mm, Wm1 = Wm2 = Wm3 = Wm4 = constant, and can be appropriately changed according to desired and necessary characteristics as long as the relationship of Wm1 + Ws1 <Wm2 + Ws2 is satisfied.

Here, the reason why the sub-patch element width Wm1 = Wm2 = Wm3 = Wm4 = constant is the same reason as in the third embodiment of the second embodiment, and the plurality of arranged first to fourth elements are used. The widths of the main patch elements (71a, 72a, 73a, 74a) of the patch element (N = 4) are the same width (Wm1 = Wm2 = wm3 = Wm4), and the first to fourth sub-patch elements are used. By making the width of the sub-patch element in the middle portion wider than the width of the sub-patch element at the end (Ws2> Ws1, Ws4), a plurality of arranged first to fourth patch antenna elements Since the total width Lk of (71, 72, 73, 74) is divided into three by the main patch element and the sub patch element, the width of the main patch element (Wm1, Wm2, Wm3, Wm4) becomes narrow and the substrate. When the thickness d = 100 μm to 200 μm, the size is about the same as the width of the transmission line of about 30 Ω to 60 Ω.
In this embodiment, the input impedance of the antenna element can be approached to 50Ω by setting N = 4 main patch elements to have the same width (Wm1 = Wm2 = Wm3 = Wm4).
As a result, it is possible to obtain an antenna module having a good connection with a transmission / reception MMIC (Microwave Monolithic IC) connected to the antenna, a wide band, less unnecessary reflection, and stable operating characteristics.

(Return loss and radiation pattern characteristics of the first embodiment and the second embodiment)
The evaluation characteristics of the return loss and the radiation pattern in the case of the first embodiment and the second embodiment will be described.
The case of the first embodiment is shown in FIGS. 33 and 34a to 34c, and the case of the second embodiment is shown in FIGS. 35 and 36a to 36c.

Regarding the return loss characteristics of FIGS. 33 and 35, in the first embodiment, a wide band characteristic of approximately return loss of -5 dB or less is exhibited in the band of 57.0 GHz to 66.0 GHz, and in the second embodiment, the return loss characteristics are shown. It has a wide band characteristic with a return loss of -5 dB or less at 57.0 GHz to 66.8 GHz.

On the other hand, the radiation pattern characteristics of FIGS. 34a to 34c and 36a to 36c show the radiation pattern at the low frequency, the center frequency, and the high frequency. Specifically, as shown in the inset of this figure (FIGS. 34a and 36a), a radiation pattern in which the beam is focused is shown in the direction of Phi = 90 °, and radiation with a wide beam width at Phi = 0 °. The pattern is shown, and a uniform and equivalent radiation pattern is shown in the low frequency range (FIG. 34a, FIG. 36a) to the high frequency range (FIG. 34c, FIG. 36c).
Specifically, the antenna Gains of FIGS. 34a to 34c of the first embodiment are 57 GHz to 64 GHz, a 3 dB bandwidth of 7 GHz, and an antenna gain of 7 dBi to 10 dBi in each case over a wide band of the 7 GHz band. Has the same uniform radiation pattern characteristics. On the other hand, in the second embodiment, in FIGS. 36a to 36c, the antenna gain is 6 to 9 dBi, and the antenna gain is 57 GHz to 64 GHz and has the same uniform radiation pattern characteristics in the 3 dB bandwidth 7 GHz band. Regarding the above antenna characteristics of the third embodiment, when a radar device using the antenna modules of the first embodiment and the second embodiment is configured, it has a special effect in addition to the wideband characteristics. There is. This effect will be described in the fourth embodiment.

[Fourth Embodiment]
Hereinafter, regarding the fourth embodiment of the present invention, the first embodiment to the third embodiment of the radar devices 8a, 8b, and 8c using the antenna modules from the first embodiment to the third embodiment, respectively. An example will be described.
In this embodiment, the transmitting side antenna array including the antenna module and the receiving side antenna array are provided on the dielectric substrate, and the transmitting side antenna array is configured by arranging a plurality of antenna modules in parallel. The receiving side antenna array relates to the configuration of a radar device configured by arranging a plurality of antenna modules in parallel.
Further, in the present embodiment, the transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel in the horizontal direction on the dielectric substrate, and the receiving side antenna array is the antenna module. It also relates to a radar device configured by arranging a plurality of antennas in parallel on a dielectric substrate in the horizontal direction.
Further, in this embodiment, the number of the patch antenna elements included in the antenna module constituting the transmitting side antenna array is equal to or less than the number of the patch antenna elements included in the antenna module constituting the receiving side antenna array. It is also related to the radar device that has become.

(First Example)
The configuration of the radar device 8b according to the first embodiment of the present embodiment will be described with reference to FIG. 37.
The radar device 8a of the present embodiment is configured on the antenna surface 301 of the substrate of the radar device, and the material of the substrate of the antenna module portion, the substrate thickness d, the cross-sectional shape, and the ground conductor layer are composed of the first. The same applies to the third and third embodiments.
In the present embodiment, the substrate 300 of the radar device is a substrate having a multi-layer structure including a ground conductor layer in the middle and different types of substrates, and the patch antenna is connected to the opposite side of the antenna surface 301 of the antenna substrate. MMIC (Microwave Monolithic IC) and other circuit components are mounted (not shown).

Further, regarding the substrate direction, the horizontal direction is defined as the horizontal direction (H) and the vertical direction is defined as the vertical direction (V) with respect to the substrate 300 of the present device shown in FIG. 37.

A transmitting antenna 151 to 153 and a receiving antenna 160 to 164 are configured on the antenna surface 301 of the substrate 300 of the radar device of the apparatus 8a, and the circuit side opposite to the antenna surface 301 of the substrate 300, the VIA hole, and the VIA. It is composed of conductors that receive. The metal of the VIA receiving conductor and the VIA hole is Cu (copper) metal, and the surface of the Cu metal may be Au-plated. Here, the VIA hole is composed of a signal VIA hole 211 for transmitting a signal, a VIA receiving metal 210 around the VIA, a ground VIA221, and a ground receiving metal 220 around the ground VIA. The signal VIA hall 211 for transmitting signals is the transmitting antenna 151 to 153 on the antenna surface 301 of the main board, and the receiving antennas 161 to 164 are the signal connection terminals on the transmitting side and the receiving side of the back surface of the board 300. Is connected with. Further, the ground VIA hole 221 includes a transmission antenna 151 to 153 on the antenna surface 301 of the main board, a ground portion of the reception antennas 161 to 164, a ground layer in the middle of the main board 300, and a transmission side / reception side on the back surface of the main board 300. It is connected to the ground terminal on the individual circuit side of (not shown).

In this embodiment, it is composed of three transmitting antennas 151 to 153 and four receiving antennas 161 to 164, but the number of transmitting antennas and receiving antennas is not limited to three and four in this embodiment. Generally, the receiving side M1 (M1: natural number) and the transmitting side M2 (M2: natural number) may be used.

The two receiving antennas 160 are dummy antennas configured on both sides of the receiving antennas 161 to 164 and connected to the ground, and the individual antenna radiation patterns of the receiving antennas 161 to 164 sandwiched between the receiving antennas 160. Can be made uniform, and better reception characteristics can be obtained.

In this embodiment, the transmitting antennas 151 to 153 are the patch antennas of the first embodiment, the receiving antennas 160 to 164 are the patch antennas of the second embodiment, and the number of elements is N = 4. Is.
Each receiving antenna 160 to 164 is arranged at an interval of λair / 2. Specifically, when the 60 GHz band (57 GHz to 64 GHz) is used, λair = 5 mm.
The shape center points 201 (x) of the individual receiving antennas 160 to 164 are arranged on the DD'line on the same line. Here, the shape center point 201 (x) of this antenna is the shape center of the antenna to which the 4-element patch antenna is connected (excluding the input feeding circuit and the matching circuit), and when N is an even number, each element is used. It is located at the center of the power supply line to be connected, and when N is an odd number, it is located at the center of the central patch antenna element.

On the other hand, the three transmitting antennas 151 to 153 are arranged at horizontal λair intervals, and the center points (x) of the transmitting antennas 151 and 153 are the center points (x) of the receiving antennas 160 to 164. Similarly, it is on the DD'line. On the other hand, the center point (x) of the transmitting antenna 152 is arranged so as to be shifted in the vertical direction by λair / 2 as compared with the transmitting antennas 151 and 153 located outside the present antenna.
FIG. 41 (a) shows an arrangement configuration of a total of 12 virtual antennas composed of 3 transmitting antennas and 4 receiving antennas having this configuration. The antenna spacing is 2 rows in the vertical (V) direction and 8 columns in the horizontal (H) direction. By performing antenna beamforming processing in the horizontal (H) direction, the directivity of the antenna can be electronically directed in the direction of arrival of radio waves. In addition, in the vertical direction, a rough target in the vertical (V) direction can be detected from the antenna phase difference in the vertical direction.

In the present microwave FMCW radar device 8a, the horizontal direction and the vertical direction are left as they are, and when installed at a certain height, the configuration of the above virtual antenna FIG. 41 (a) makes it horizontal (for example, ± 90 degrees). It is possible to detect not only targets of stationary objects and moving objects (including people) in the H) direction, but also targets in the vertical (V) direction. For example, a person sitting in a chair indoors or a standing posture. Can be detected separately.

Further, in the present configuration, when the number of elements of the transmitting antennas 151 to 153 is N1 and the number of receiving antenna elements is N2, it is desirable that N1 ≦ N2. The element antenna (N1 = 1), and the receiving antennas 160 to 164 are 4-element antennas (N2 = 4).

A detection example of the radar device 8a shown in FIG. 41 having the above configuration is shown in FIGS. 38 (a) and 38 (b). FIG. 38 (a) is a side view of the room 270, and when the radar device 8a is mounted at a high place in the room with a slight oblique downward offset in the direction of the HV in the drawing, from the transmitting antennas 151 to 153. In addition to showing the spread of radio waves indoors (see the radiation pattern 250 of the transmitting antenna), when the radio waves are applied to the person 260, the directions of the reflected scattered waves 251a to 251d from the person are shown. Since the number of patch antenna elements of the transmitting antennas 151 to 153 of the apparatus 8a is one, the vertical direction V includes a blind region of radio waves that is irradiated in a wide direction of the room 270 (see the radiation pattern 250 of the transmitting antenna). Can be reduced.

In addition, by using an antenna in which four elements are arranged in the vertical direction (V) of the receiving antennas 160 to 164 of the present device 8a, the radio wave beam width (half-value angle) in the vertical direction is narrowed down to about ± 15 degrees. When a person is the target, the receiving antennas 160 to 164 can receive and detect only the radio wave component (reflected scattered wave 251b) in the direction connecting the person and the radar device 8a. On the other hand, the radio wave components (reflected scattered waves 251a, 251c, 251d) reflected and scattered from humans become unnecessary reflected waves (clutter components) reflected by the ceiling, floor, wall, etc., and suppress the reception of these unnecessary reflected components. And good detection characteristics can be obtained.

It should be noted that it is suitable for detecting occupants in the second and third rows not only indoors but also in the passenger compartment of an automobile, and is located near the room lamp near the center of the ceiling in the vehicle, as shown in FIG. 38. By arranging the board 300 in the horizontal direction (H) so as to be parallel to the seats in the second and third rows by slightly offsetting it downward as in the room, the second and third rows Not only can it accurately detect the position of the occupants and minute movements such as body movements and breathing, but it can also determine the vertical component, so it is possible to determine with high accuracy whether or not the child is crouching in the seat. Can be done.
Further, in this embodiment, three transmitting antennas and four receiving antennas are used, but as basic performance, two transmitting antennas 151 and 152 shifted by λair / 2 in the height (V) direction and a receiving antenna are used. There may be a total of four antennas, 161 and 162 in the horizontal (H) direction, but the detection characteristics and the detection resolution can be improved by appropriately increasing the number from four or more.

In this embodiment, by aligning the shape center points of the transmitting antenna (151 to 153) and the receiving antenna (160 to 164), the baseline of the beam of the antenna is aligned, so that not only the transmitting antenna but also the receiving side N Even with an element antenna, as a MIMO radar, the position of the transmitting / receiving antenna can be treated as a coordinate point, and good antenna beam control becomes possible.

(Second Example)
The configuration of the radar device 8b of the second embodiment of the present embodiment will be described with reference to FIG. 39.
The difference from the radar device 8a of the first embodiment of this embodiment will be described. The difference is that the configurations of the transmitting antennas 171, 172, 173 on the antenna surface 302 of the present board and the antenna portions of the receiving antennas 180 to 184 are different. Specifically, in this embodiment, both the transmitting side and the receiving side use the configuration of the antenna module of the third embodiment, and the element length direction (feeding direction) of each antenna is the horizontal direction H.
In the receiving antennas 180 to 184, six antennas of eight elements (N = 8) are arranged at λair / 2 intervals so that the shape center points 201 of the antennas are on the DD'line. On the other hand, in the transmitting antennas 171 and 172, 173, the four element (N = 4) antennas are arranged at intervals of 2.λair (specifically, when 57 GHz to 64 GHz in the 60 GHz band is used, the center frequency is 60 GHz. Λair = 5 mm.)
Here, the shape center point 201 (x) of the present antenna has the same definition as the first embodiment in the definition of the shape center of the antenna to which the 8-element patch antenna is connected.

The three transmitting antennas 171 to 173 are arranged at intervals of 2λair in the horizontal direction, and the shape center points (x) of the three transmitting antennas 171, 172, and 173 are located at the same positions with respect to the V direction. Yes, the center points (x) of the receiving antennas 180 to 184 are also at the same positions with respect to the V direction. In this embodiment, the transmitting antennas 171 to 173 and the receiving antennas 180 to 184 are also arranged on the DD'line. As a result, the positions of the antenna radiation beams on the transmitting side and the receiving side are aligned. That is, as in the first embodiment, in this embodiment, by aligning the shape center points of the transmitting antenna (171 to 173) and the receiving antenna (180 to 184), the baseline of the beam of the antenna is aligned. , The transmitting N1 element antenna and the receiving side N2 element antenna can also handle the transmitting / receiving antenna position as a coordinate point as a MIMO radar, enabling good antenna beam control, and consists of 3 transmitting and 4 receiving. It is possible to perform good operation as 12 virtual antennas (transmission 3 × reception 4).

FIG. 41B shows an arrangement configuration of a total of 12 virtual antennas, which are composed of the three transmitting antennas and four receiving antennas. The virtual antennas are arranged in 12 rows in the horizontal (H) direction. By performing antenna beamforming processing in the horizontal (H) direction, the directivity of the antenna can be electronically directed in the direction of arrival of radio waves, and the larger the number of antennas, the sharper the direction of arrival can be. Will improve.

As shown in FIG. 38 (a), the directions (H, V) of the substrate of the radar device 8b are installed at a certain height as in the first embodiment, and for example, when the microwave FMCW radar device 8b is configured. In the detection of a stationary object or a moving object (including a person) with a horizontal (H) component 259, it can be operated as an H-direction array antenna as 12 virtual antennas, that is, 12 antennas are beamed. The directivity of the virtual antenna can be sharpened by antenna signal processing such as forming, and higher resolution can be obtained in the horizontal H direction.

Further, in this configuration, the number of elements of the transmitting antennas 171 to 173 is a 4-element antenna (N1 = 4), and the number of receiving antennas 180 to 184 is an 8-element antenna (N2 = 8), which is the number of indoors and the like. In the area of m, the detection area can be widened by widening the directivity in the V direction on the transmitting side.
When a 4-element antenna is used on the transmitting side as in this embodiment, the half-value angle is ± 15 ° in the V direction, and it looks narrow at first glance, but at a point 10 m away, the spread of radio waves is about 5.4 m ( (10m x 2 x tan 15 °), which means that the radio wave has a sufficient spread even in the vertical direction when viewed from the height of a person.

In this embodiment, in a wide area exceeding 10 m indoors, outdoors, etc., the transmitting side uses an 8-element antenna (N1 = 8) like the receiving side to narrow down the directivity in the V direction. The antenna gain becomes large, it becomes possible to cope with a longer distance, and it becomes possible to reduce the influence of unnecessary reflection and the like.

On the other hand, in a relatively small room of about 5 m, one element on the transmitting side (N1 = 1) and four elements on the receiving side (N2 = 4) may be used as in the first embodiment, depending on the size. It is desirable to decide.
Here, in a relatively narrow room such as a vehicle interior within a few meters, the number of elements N1 and N2 may be one element on the transmitting side, three elements on the receiving side, or one element as in the first embodiment. It is desirable to appropriately determine the size according to the size while satisfying the relationship of N1 ≦ N2.

Furthermore, when this radar device is installed as shown in FIG. 38 (a), the feeding direction of the transmitting / receiving antenna element is substantially horizontal, and the reflected scattered wave of the horizontal component from a person is shown in FIG. As shown in 38 (b), the radio waves radiated from the transmitting antennas 171 to 173 hit the target (person), and the radio waves 251b reflected and scattered are the MIMO technology using the receiving antennas 180 to 184 of the radar device 8b. By the beamforming of, it is possible to receive the arrival direction component 251rx of the radio wave as the receiving beam. When the movement of a person in the room moves horizontally in the room, the radio wave of the horizontally polarized component transmitted from the transmitting side is received as the radio wave of the horizontally polarized component by the receiving antenna, but the radio wave of the person in the horizontal direction For radio waves from motion, the horizontally polarized radio waves incident on the receiving antennas 181 to 184 are wider in the horizontal direction than the vertically polarized radio waves (as in the first embodiment). The output reflection coefficient from the receiving antenna becomes smaller at the azimuth angle, and it has good sensitivity characteristics. In addition, depending on the azimuth angle of the position where the person is, there is also a Brewster angle at which the output reflectance coefficient from the receiving antenna becomes zero, and it has a wide radiation pattern in the horizontal direction and good sensitivity characteristics. Better detection characteristics can be obtained.

(Third Example)
The configuration of the radar device 8c according to the third embodiment of the present embodiment will be described with reference to FIG. 40.
The difference from the radar device 8a of the first embodiment of this embodiment will be described.
In the radar device 8a of the first embodiment, the transmitting antennas 151 to 153 and the receiving antennas 160 to 164 are arranged on the antenna surface 301 of the board, and the circuit side is MMIC and other circuit components on the opposite surface 299 of the antenna surface 301 of the board. However, in the radar device 8c of the present embodiment, the transmitting antennas 240 to 243 and the receiving antennas 190 to 194 are configured on the circuit surface 299 including the MMIC, and the transmitting side feeding lines 230 to 232 are installed. , The microwave signal is directly connected to the MMIC (not shown) mounted on the same surface via the receiving side feeding lines 271-274.
In this embodiment, FIG. 40 shows the configuration of the antenna portion shown after the EE'line portion of the substrate 299. Here, the receiving antenna 190 on both sides and the transmitting antenna 240 on both sides are non-feeding dummy antennas connected to the ground. The dummy antennas 190 and 240 are non-feeding antennas for keeping the radiation patterns of the transmitting antennas 241 and 242, 243 and the receiving antennas 191 to 194 more constant. Although the present non-feeding antenna is connected to the ground in this embodiment, it may be an open terminal without a connection or a non-reflective terminal connection to which a pure resistor of 50Ω is connected.

In FIG. 40, the transmission output from the MMIC is connected to the transmission side feeding unit 230, 231 and 232, and is connected by the ground coplanar line (GCPW line) 279. The GCPW line is composed of a signal line 211, grounds 220 on both sides, and VIA hole 221. The gap Gs between the signal line width Wg and the ground determines the characteristic impedance together with the substrate 299.

Similarly, on the receiving antenna side, the four receiving input terminals of the MMIC are connected to the receiving side feeding units 271, 272, 273, 274, and a part of the feeding line is connected by the ground coplanar line (GCPW line) 279.
Each transmitting side feeding line 230, 231 and 232 and receiving side feeding line section 271, 272, 273, 274 leading to the input / output terminal of the MMIC below the EE'plane are also connected by the above-mentioned ground coplanar line (GCPW line). It is desirable to be done. In this GCPW line, the ground 220 is located on the circuit surface 299 and is located on the same surface as the MMIC at 299, thereby enhancing the signal confinement effect. Unnecessary radiation from the antenna can be reduced, and the influence of the transmitting antennas 241 and 242, 243 and the receiving antennas 191, 192, 193, and 194 on the radiation pattern can be reduced, and the characteristics of the antenna can be brought closer to the original radiation pattern. it can.

Here, the transmitting side antennas 240 to 243 and the receiving side antennas 190 to 194 are arranged at λair / 2 intervals, respectively, and the individual 1-element patch antennas are of the double slit type according to the third embodiment of the first embodiment. It consists of a patch antenna. In particular, on the transmitting side, since the patch antennas are arranged in the vertical (V) direction, the width H of the patch elements preferably satisfies the following relationship.
H ≤ λair / 2-λg / 4

By using a double-slit type patch antenna for this antenna, this relationship can be satisfied and wideband characteristics can be realized. The degree of mutual interference / coupling between the transmitting side patch antennas 242, 242, and 243 can be reduced, and the ideal characteristics of the one-element antenna can be brought closer.

Here, since the transmitting antennas 241 to 243 and the receiving antennas 191 to 194 are single-element antennas, the shape center point (x) of the antenna is the center point of one patch antenna, and transmission is performed as shown in FIG. 40. It is desirable that the shape center point (x) of one of the patch antennas on the side coincides with the shape center point (x) of the patch antenna array on the receiving side, and the shape center points (x) of transmission and reception are aligned. As a result, by aligning the base lines of the antenna beams, the transmitting / receiving antenna position can be treated as a coordinate point as a MIMO radar, and good antenna beam control becomes possible, and it is composed of 3 transmissions and 4 receptions. It is possible to operate as a virtual antenna of 12 antennas (transmission 3 × reception 4).

FIG. 41 (c) shows an arrangement configuration of a total of 12 virtual antennas, which are composed of the three transmitting antennas and four receiving antennas. The antenna spacing is 3 rows in the vertical (V) direction and 4 columns in the horizontal (H) direction. By performing antenna beamforming processing or the like in the horizontal (H) direction and the vertical (V) direction, respectively, the directivity of the antenna can be electronically directed to the direction of arrival of radio waves in three dimensions. That is, in addition to the target detection in the traveling direction (depth) direction of the radio wave of the FMCW radar device, the distance measurement and the angle measurement in the three-dimensional direction become possible, and the target can be detected.
As shown in FIG. 38A, the direction (H, V) of the substrate of the radar device 8c is set to a certain height as in the first embodiment, and for example, the microwave FMCW radar device 8c is installed. When configured, the virtual antenna operates as a total of 12 array antennas, 4 in the H direction and 3 in the V direction, when detecting targets of stationary objects and moving objects (including humans) with the horizontal (H) component 259. By antenna signal processing such as beam forming in the HV direction, it is possible to measure the angle not only in the horizontal direction but also in the vertical direction, and it is possible to detect a target with high accuracy. For example, the movement of a person standing or sitting indoors can be detected more accurately than in the case of the first embodiment.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

The present invention can be used for modules and radar devices provided with antennas such as microwaves and millimeter waves. In particular, it is useful for a moving object detection sensor, a biological sensor, and a distance measuring sensor.

5a, 5b, 5c, 6b, 6c, 6d, 6e, 6f, 7a, 7b Antenna modules 8a, 8b, 8c Radar devices 11, 31, 32, 33, 34, 41, 42, 43, 44, 51, 52, 53, 54, 61, 62, 63, 64, 71, 72, 73, 74, 91, 92, 93, 94 Patch antenna elements 11a, 31a, 32a, 33a, 34a, 41a, 42a, 43a, 44a, 51a, 52a, 53a, 54a, 61a, 62a, 63a, 64a, 71a, 72a, 73a, 74a, 91a, 92a, 93a, 94a Main patch elements 11b, 31b, 32b, 33b, 34b, 41b, 42b, 43b, 44b, 51b, 52b, 53b, 54b, 61b, 62b, 63b, 64b, 71b, 72b, 73b, 74b Sub-patch elements 11d, 91b, 92b, 93b, 94b First sub-patch elements 11e, 91c, 92c, 93c, 94c Second sub-patch element 12 Slit-shaped gaps 20, 21, 121 Feed line and input matching circuit unit 22, 23, 24, 231, 232, 233, 272, 272, 273, 274 Feed line 100 Dielectric substrate 101 Dielectric Antenna surface of body board 111 Ground metal 122, 123, 124, 125 Lead-out line part 151, 152, 153, 171, 172, 173, 240, 241, 242, 243, 244 Transmitting antenna 160, 161, 162, 163, 164 , 180, 181, 182, 183, 184, 190, 191, 192, 193, 194 Receiving antenna 200a, 200b, 200c Transmission antenna shape Center point 201 Receiving antenna shape Center point 250 Transmission antenna Radiation pattern 253 Receiving antenna horizontal Directional incident pattern 251a, 251b, 251c, 251d Reflected scattered wave 251rx Incident radio wave to receiving antenna 252 Vertical radiation pattern of receiving antenna 260 people 270 Indoor 279 Grand coplanar line (GCPWG)
299 Radar device board circuit surface 300 Radar device board 301, 302 Radar device board antenna surface 330 Virtual antenna

Claims (16)

A patch antenna is composed of a main patch element formed in a substantially rectangular shape with a metal pattern on the surface of a dielectric substrate, and at least one sub-patch element formed in a substantially rectangular shape with a metal pattern on both sides of the main patch element. The element is configured,
The main patch element and the at least one sub patch element are arranged in a row along one direction and are arranged in parallel by being separated from each other by a slit-shaped gap.
The slit-shaped gap is λg / 100 to λg / 10, assuming that the operating wavelength on the dielectric substrate is λg.
When the one direction on the dielectric substrate is the element width direction and the orthogonal direction thereof is the element length direction, an antenna module in which a feeding line is provided on the element length direction side of the main patch element. The antenna module according to claim 1, wherein the main patch element and at least one sub-patch element have different element lengths in the element length direction. The antenna module according to claim 1 or 2, wherein a plurality of the patch antenna elements are arranged in a row, and the main patch elements in the patch antenna element are connected to each other by a feeding line. The antenna module according to any one of claims 1 to 3, further comprising one sub-patch element on each side of the main patch element. The antenna module according to any one of claims 1 to 3, further comprising a plurality of the sub-patch elements on both sides of the main patch element. The antenna module according to claim 5, wherein the slit-shaped gap between the main patch element and the sub-patch element and the slit-shaped gap between the sub-patch elements are different from each other. The antenna module according to claim 3, wherein the first-stage patch antenna element connected to the feeding line in the arrangement includes two sub-patch elements on both sides of the main patch element. It is an array of three or more of the patch antenna elements.
The antenna module according to claim 3, wherein the element width of the patch antenna element at the intermediate portion in the arrangement is wider than the element width of the patch antenna element at the end portion in the arrangement. It is an array of three or more of the patch antenna elements.
The element width of the main patch element of the patch antenna element in the intermediate portion in the arrangement is wider than the element width of the main patch element of the patch antenna element on the end side in the arrangement.
The antenna module according to claim 3 or 8, wherein the element width of the sub-patch element outermost from the main patch element in the arrangement is constant. It is an array of three or more of the patch antenna elements.
The antenna module according to any one of claims 3, 8 or 9, wherein the element width of the main patch element of all the patch antenna elements in the array is constant. The plurality of patch antenna elements are arranged in a row in the element length direction.
The invention according to any one of claims 3 and 7 to 10, wherein the main patch elements of the adjacent patch antenna elements in the arrangement are connected to each other by a feeding line whose central portion in the element width direction extends in the element length direction. Antenna module. The plurality of patch antenna elements are arranged in a row in the element width direction.
In the main patch element of each patch antenna element in the arrangement, a lead-out line portion extending in the element length direction is connected to the central portion in the element width direction, and each lead-out line portion is connected to a feeding line extending in the element width direction. The antenna module according to any one of claims 3 and 7 to 10, which is connected. A transmitting side antenna array including the antenna module according to any one of claims 1 to 12 and a receiving side antenna array including the antenna module according to any one of claims 1 to 12 are mounted on a dielectric substrate. In preparation for
The transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel.
The receiving side antenna array is a radar device configured by arranging a plurality of the antenna modules in parallel. A transmitting side antenna array including the antenna module according to claim 1 or 2 and a receiving side antenna array including the antenna module according to any one of claims 1 to 12 are provided on a dielectric substrate.
The transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel in two different directions.
The receiving side antenna array is a radar device in which a plurality of the antenna modules are arranged in parallel in any one of the two directions. A transmitting side antenna array including the antenna module according to any one of claims 1, 2 and 12 and a receiving side antenna array including the antenna module according to any one of claims 1, 2 and 12. Prepared on a dielectric substrate
The transmitting side antenna array is configured by arranging a plurality of the antenna modules in parallel in the horizontal direction on a dielectric substrate.
The receiving side antenna array is a radar device in which a plurality of the antenna modules are arranged in parallel in the horizontal direction on a dielectric substrate. 13. Claim 13 that the number of the patch antenna elements included in the antenna module constituting the transmitting side antenna array is equal to or less than the number of the patch antenna elements included in the antenna module constituting the receiving side antenna array. The radar device according to any one of 1 to 15.

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