JPH07120546A - Doppler module - Google Patents

Abstract

PURPOSE:To improve manufacturing property with a simple configuration and to reduce transmission loss of a feeder part in a Doppler module. CONSTITUTION:Oscillation power from an oscillator 1 is supplied to a feeder part 6 by a strip line 4 for feeder. A part of the power is fed to an antenna 2 provided at the upper part of the feeder part 6 by electromagnetic coupling. The remaining power is fed to a strip line 5 for receiving signal as a local oscillation power, led to a detection circuit 3, received by the antenna 2, and detected by a reception signal which is subjected to Doppler frequency shift which is led via the strip line 5 for receiving signal, thus obtaining a detection signal 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Doppler module for detecting a moving body by detecting a detected wave by receiving a received wave whose frequency is shifted by the Doppler effect when the transmitted radio wave is reflected by the moving body.

[0002]

2. Description of the Related Art This type of Doppler module generally comprises an oscillator, an antenna and a detection circuit. In the example shown in FIG. 9A, the radio wave oscillated by the Gunn diode 30 and the cavity resonator 31 such as a waveguide is radiated into space from the horn antenna 32. The received wave reflected by the moving body and subjected to the Doppler frequency shift is the same cavity resonator 3
It is detected by the mixer diode 33 provided in the unit 1.
The local oscillation power is supplied to the mixer diode 33 by electrical coupling in the cavity resonator 31, and a detection signal is output. In the example shown in FIG. 9B, electric power from an oscillator 34 provided outside the cavity resonator 31 is fed to the cavity resonator 31 by a feeding probe 36 composed of a pin, etc. Is emitted. Part of the radiated power is supplied to the detection circuit 35 by the receiving probe 37. The reception wave subjected to the Doppler frequency shift is guided to the detection circuit 35 by the reception probe 37 via the horn antenna 32, and the detection signal is output.

On the other hand, due to recent advances in device and circuit board technologies, especially in the X band, FE for super high frequencies is used.
An oscillator is often formed on a substrate by using T or the like. Also in the Doppler module, the one in which the oscillator and other circuits are formed on the flat substrate in this manner is put to practical use. FIG. 10 shows a schematic configuration diagram thereof. The power of the oscillator 38 formed on the substrate 46 is supplied via the strip line 45 to the power supply circuit 3 formed by a strip line or the like.
9, the antenna 41 is used as a part of the transmission power 40
, The rest is input to the detection circuit 43 as the local oscillation power 42. The received wave 44 received from the antenna 41 and subjected to the Doppler frequency shift is guided to the detection circuit 43 via the power feeding circuit 39 and a detection signal is output.

[0004]

However, among the above Doppler modules using the Gunn diode 30, the current consumption becomes relatively large, and a sleeping phenomenon in which oscillation suddenly stops occurs. Furthermore, the structure is complicated for mass production, and parts such as pins are required, resulting in high cost.

On the other hand, in the Doppler module in which the oscillator 38 is formed on the substrate by using the FET for super high frequency, and the feeding circuit 39, the detection circuit 43, etc. are also formed on the substrate, the feeding circuit 39 includes a Wilkinson distributor and a rat race. Circuit, 90
° Hybrid, directional coupler using ¼ wavelength line, etc. are used alone or in combination, so that the line length of the strip line becomes long and the transmission loss increases. Therefore, an expensive dielectric substrate such as Teflon is required.
Therefore, the configuration becomes complicated and the layout of the circuit is limited. Further, there is a problem of signal interference between circuits such as the power feeding circuit 39 and the detection circuit 43 and leakage of radio waves from the module. Further, when a horn antenna is used as the antenna 41, power is supplied by the pin or the like shown in FIG. 9B, and the manufacturability is poor. On the other hand, although there is an example in which the antenna 41 is formed as a printed antenna, in this case, although the manufacturability is good, the directivity of the antenna that determines the detection range is determined by the printed antenna, and the directivity of the aperture shape like a horn antenna is determined. It does not have the degree of freedom to determine sex.

The present invention has been made in view of the above points, and an object of the present invention is to provide a Doppler module having a simple structure, good manufacturability, and low transmission loss in a power feeding section. is there.

[0007]

According to a first aspect of the present invention, there is provided a Doppler module having an oscillating section, an antenna, and a detecting section for detecting a moving object by a received wave that has been frequency-shifted by the Doppler effect. A feeding stripline connected to the oscillating section and a receiving stripline having one end connected to the detecting section, and the open ends of the feeding stripline and the receiving stripline are arranged close to and opposite to each other on the substrate. In this configuration, the opposing portions of the open ends of the strip lines with respect to the antenna are used as a power feeding unit, and the power feeding unit feeds power to the antenna.

According to a second aspect of the present invention, in the first aspect, the antenna is a horn antenna,
It is characterized in that a cavity is provided at a position facing the horn antenna with a power feeding part formed of facing parts at the open ends of the strip lines sandwiched therebetween.

According to a third aspect of the present invention, in the second aspect, the oscillating portion, the detecting portion and both strip lines are formed on the same substrate, and the horn antenna is integrally formed from a conductive material. An upper case and a lower case made of a conductive material in which the cavity is provided. One of the cases includes the substrate, and the other case includes the parts formed on the substrate. A partition for spatially partitioning is provided, and the upper housing and the lower housing are fitted so that the tip of the partition and the substrate are in contact with each other.

According to a fourth aspect of the present invention, in the third aspect, a ground pattern is formed on a portion of the substrate where each partition is in contact with the substrate, and the ground pattern comprises: It is characterized in that the through-holes arranged at intervals shorter than the wavelength of the oscillation signal of the oscillating section are electrically connected to the ground surface on the back surface of the substrate.

According to a fifth aspect of the present invention, in the third or fourth aspect, the partition wall is provided with a groove having a cross section sufficiently smaller than the wavelength of the oscillation signal of the oscillation section along the wall surface thereof. A power supply line and a signal line connected to an external circuit are passed through the groove.

According to a sixth aspect of the present invention, in the third to fifth aspects, a power supply circuit for supplying power to the oscillating section is provided in a section in which the oscillating section partitioned by the partition wall is installed. The feature is that they are installed in adjacent sections.

According to a seventh aspect of the present invention, in the third to sixth aspects, damping is provided in a section between the section in which the oscillator is installed and the section in which the power supply stripline is formed. At least one of a container, a filter, and an isolator is provided.

According to an eighth aspect of the present invention, in any one of the third to seventh aspects, an amplification section for amplifying a detection signal from the detection section is provided in a section adjacent to the section where the detection section is provided. It is characterized by being provided.

According to a ninth aspect of the present invention, in the third aspect, the length of the side edge of the fitting portion between the upper casing and the lower casing is set to the wavelength of the oscillation signal of the oscillation unit. It is characterized in that it is set to 1/4 or more.

According to a tenth aspect of the present invention, in the third aspect of the present invention, a cavity and a bend connected to the cavity are attached to an upper portion of the power feeding portion of the upper housing, and a horn is provided at a tip of the bend. It is characterized in that an antenna is formed.

[0017]

In the Doppler module of the present invention, the oscillated power from the oscillating unit is guided to the power feeding unit by the power feeding strip line, and a part of the power is fed to the antenna attached above the power feeding unit by electromagnetic coupling. The remaining power is supplied to the receiving stripline as local oscillation power, guided to the detection circuit, received by the antenna, and received by the Doppler frequency shift guided through the receiving stripline. It is detected and a detection signal is obtained.
In addition, a case in which a housing provided with a partition for spatially partitioning each circuit formed on the substrate and a housing containing the substrate are fitted together reduces the signal interference between the circuits due to the partition. Since the board is completely surrounded by the upper and lower housings,
Leakage power from the Doppler module is suppressed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a basic configuration of a Doppler module according to an embodiment of the present invention. Reference numeral 1 denotes an oscillator, which is formed on a substrate by using an FET for super high frequency, and supplies oscillating power as transmitting power to an antenna 2 which will be described later and at the same time as local oscillating power to a detecting circuit 3. Reference numeral 2 denotes an antenna, which radiates oscillation power from the oscillator 1 as a transmission wave 7 into space and also receives a reception wave 8
Is to take in. Reference numeral 3 is a detection circuit, which is formed on the substrate and performs detection using a local oscillation signal from the oscillator 1 and a reception signal received by the antenna 2 and outputs a detection signal 9. Reference numerals 4 and 5 denote strip lines for power supply and reception formed on the substrate, one end of which is connected to the oscillator 1 or the detector 3, and the other ends of which are arranged close to and opposite to each other. . Opposing portions of the strip lines 4 and 5 form a power feeding portion 6.
Further, the antenna 2 is provided in the vicinity of the upper portion of the power feeding section 6 so as to be electromagnetically fed. As the power feeding unit 6, various shapes are conceivable as shown in FIGS. 2 (f) and 2 (g).
With respect to, the opposing portions of the strip lines 4 and 5 form an overlapping portion in which only the portion corresponding to the length of approximately 1/4 wavelength of the oscillation signal is parallel. Further, FIG. 3 shows an example of the antenna 2, FIG. 3A shows a patch antenna 10, and FIG. 3B shows a slot antenna 11.

According to the present embodiment, the feeding portion 6 is composed of two strip lines 4 and 5, and the antenna is arranged at a position close to the open ends of the strip lines 4 and 5 arranged close to each other and facing each other. Since it is a structure that does, it is very simple and has good manufacturability. Also strip line 4,
Since the routing of 5 is shorter than the conventional one, the transmission loss can be reduced, and as a result, a relatively inexpensive dielectric substrate such as glass epoxy can be used as the substrate.

FIG. 4 is an exploded perspective view of a Doppler module showing another embodiment according to the present invention. In the present embodiment, the horn antenna 12 is used as the antenna 2 in the embodiment shown in FIG. 1, and the cavity portion 13 is installed at a position facing the horn antenna 12 with the feeding portion 6 interposed therebetween. Has become. Reference numeral 14 is a substrate that forms each part. The surface of the substrate 14 opposite to the surface on which the strip lines 4 and 5 are formed is a ground plane, and the conductor is removed along the opening shape of the cavity 13. is doing. That is, the oscillator 1, the feeding unit 6 including the strip lines 4 and 5, and the detection circuit 3 are formed on the same substrate 14, and the substrate 14 is sandwiched between the horn antenna 12 and the cavity 13 in the Doppler module. Oscillation power from the oscillator 1 is guided to the power supply section 6 through the power supply stripline 4, and a part of the oscillation power resonating at the oscillation frequency in the power supply section 6 and the cavity 13 is radiated into space from the horn antenna 12. The remaining power is coupled to the receiving strip line 5 and becomes the local oscillation power of the detection circuit 3. The received wave is taken in by the horn antenna 12, coupled to the receiving strip line 5 and detected by the detection circuit 3 to output a detection signal. In addition, in the example of FIG. 4, each part is formed on the upper surface of the substrate 14, but it goes without saying that it may be formed on the lower surface.

According to the present embodiment, the feeding portion 6 has a simpler structure than the conventional one and is superior in cost and manufacturability, and since the horn antenna 12 is used, the antenna The degree of freedom in determining the directivity is increased.

FIG. 5 is an exploded perspective view of a Doppler module showing another embodiment according to the present invention. Reference numeral 15 denotes an upper casing made of a conductive material, which is integrally formed with the horn antenna 12. Reference numeral 16 denotes a lower housing made of a conductive material, which encloses the substrate 14 and has the cavity 13 provided therein. A Doppler module is configured by fitting the upper casing 15 and the lower casing 16 together. Upper housing 15
A partition wall 17 for spatially partitioning each portion formed on the substrate 14 is provided on the substrate 14, and the substrate 14 is formed with through holes arranged at intervals shorter than the wavelength of the oscillation signal of the oscillator 1 on the substrate 14. A ground pattern 18 is formed so as to be electrically connected to the ground plane on the back surface of the. Then, when the upper casing 15 and the lower casing 16 are fitted to each other, the tip of the partition wall 17 contacts the ground pattern 18.

Here, the structure of each part formed on the substrate 14 will be described. Reference numeral 20 denotes a power supply circuit that supplies power to the oscillator 1, and the power supply circuit 20 is installed in a partition adjacent to the partition in which the oscillator 1 is installed, which is partitioned by the partition wall 17. 21
Is at least one of an attenuator, a filter and an isolator
It is a circuit formed by a stripline with two
The oscillator 1 is installed in a section adjacent to the section of the oscillator 1, and the oscillated power from the oscillator 1 is guided to the power supply section 6 via the circuit 21 and the power supply stripline 4. Reference numeral 22 is a low-frequency amplifier circuit that amplifies the detection signal output from the detection circuit 3, and is installed in a section adjacent to the section in which the detection circuit 3 is installed. The ground plane on the back surface of the substrate 14 is removed along the opening shape of the cavity 13 as in the above-described embodiment.

In the present embodiment, a part of the oscillating power resonating at the frequency of the oscillating signal by the power feeding portion 6 and the cavity portion 13 is radiated into the space from the horn antenna 12 formed integrally with the upper housing 15, and the rest thereof. The power is the receiving strip line 5
And is supplied as local oscillation power to the detection circuit 3 installed in the adjacent section. The received wave is taken in by the horn antenna 12, coupled to the receiving strip line 5 and detected by the detection circuit 3 to output a detection signal. The detection signal is input to the low frequency amplification circuit 22 installed in the adjacent section. Signal transmission between the circuits is performed by the partition wall 17
The strip line is formed through a passage formed by the concave portion 19 and the substrate 14 provided on the substrate.

According to this embodiment, since the upper housing 15, the lower housing 16 and the substrate 14 are provided in three parts, the structure is very simple and the manufacturability is good. Further, since each circuit formed on the substrate 14 is spatially partitioned by the partition wall 17, extra coupling between striplines and interference between circuits are reduced, and unnecessary from the input / output terminals of the Doppler module. And the oscillator 1
Since the circuit 21 formed of a strip line including at least one of an attenuator, a filter, and an isolator is additionally provided between the power supply unit 6 and the power supply unit 6, the oscillator 1 becomes strong against load fluctuation and the second harmonic. The wave radiation can be suppressed. Further, the length of the side edge portion 23 of the partition wall 17 provided in the upper housing 15, that is, the fitting length is ¼ of the wavelength of the oscillation signal.
As described above, it is possible to reduce the leakage power from the fitting portions of the housings 15 and 16. Although the partition wall 17 is formed in the upper housing 15 and the substrate 14 is enclosed in the lower housing 16 in this embodiment, the partition wall 17 is formed in the lower housing 16 and the substrate 14 is turned upside down. It may be included in.

FIG. 6 is a sectional view of a Doppler module showing another embodiment according to the present invention. In this embodiment, the substrate 1
A groove 25 having a cross section sufficiently smaller than the wavelength of the oscillation signal is formed along the wall surface of the housing in the lower housing 16 containing 4 and the input / output line 2 to / from the Doppler module 2 is formed in this groove 25.
I try to pass 6. The groove 25 is covered by the ground surface on the back surface of the substrate 14 included in the lower housing 16.

According to the present embodiment, the elongated groove 25 attenuates the high frequency component, so that the leakage power from the input / output terminal can be suppressed, and the conventional leakage power countermeasure using a through capacitor or the like is unnecessary. Becomes

Further, in the embodiment shown in FIG. 7, in the embodiment shown in FIG. 5, for example, as in the signal line 24 between the detection circuit 3 and the low frequency amplification circuit 22, a direct current or a low frequency is applied. A signal line for transmitting a signal is made to pass through a portion sandwiched between the ground patterns 27 of the substrate 14, and a recess 19 provided in the partition wall 17 is formed corresponding to the ground pattern 27 to form a passage. , By making the cross section of the passage sufficiently smaller than the wavelength of the oscillation signal,
Leakage power of high frequency components from the detection circuit 3 to the low frequency amplification circuit 22 can be suppressed, and a circuit configuration resistant to noise can be obtained. Also in this embodiment, the partition wall 17 may be formed in the lower housing 16 and the substrate 14 may be contained in the upper housing 15.

FIG. 8 is a sectional view of a Doppler module showing another embodiment according to the present invention. In this embodiment, the cavity 28 and the cavity 2 are provided above the power supply section 6 in the upper housing 15.
Bends 29 connected to each other are provided, and a horn antenna 30 is attached to the tip of the bend 29.

According to this embodiment, due to the transmission loss of the bend 29, the second harmonic of the oscillation power, which is unnecessary radiation, can be attenuated. Also in this embodiment, the partition wall 17 may be formed in the lower housing 16 and the substrate 14 may be contained in the upper housing 15.

[0031]

As described above, according to the first aspect of the present invention, the power feeding portion is formed by disposing the power feeding strip line and the receiving strip line so that the open ends thereof closely face each other. We were able to provide a Doppler module with good manufacturability and low power transmission loss. Also,
According to the second aspect of the invention, the use of the horn antenna further increases the degree of freedom in directivity. In the invention according to claim 3, the upper housing, the lower housing, and the substrate 2 are provided.
Since only one part is used, the structure is simpler and the manufacturability is improved. Further, in the inventions according to claims 4 to 9, it is possible to further reduce interference between signals and suppress leakage power. According to the tenth aspect of the invention, unnecessary second harmonics of the oscillation power can be attenuated due to the transmission loss of the bend.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of a Doppler module according to an embodiment of the present invention.

FIG. 2 is a pattern diagram showing a power feeding unit according to the above.

FIG. 3 is a schematic view showing an antenna according to the above.

FIG. 4 is an exploded perspective view of a Doppler module according to another embodiment of the present invention.

FIG. 5 is an exploded perspective view of a Doppler module according to another embodiment of the present invention.

FIG. 6 is a sectional view of a Doppler module according to another embodiment of the present invention.

FIG. 7 is a schematic view of a Doppler module according to another embodiment of the present invention.

FIG. 8 is a sectional view of a Doppler module according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view of a Doppler module according to a conventional example.

FIG. 10 is a basic configuration diagram of a Doppler module according to another conventional example.

[Explanation of symbols]

 1 Oscillator 2 Antenna 3 Detection Circuit 4 Feeding Stripline 5 Reception Stripline 6 Feeding Part 7 Transmitting Wave 8 Received Wave 9 Detection Signal

Claims (10)

[Claims] 1. An oscillator, an antenna, and a detector are provided,
In a Doppler module that detects a moving object by a received wave that has undergone frequency shift due to the Doppler effect, a power supply stripline whose one end is connected to the oscillation section and a receiving stripline whose one end is connected to the detection section are provided on a substrate. The feeding stripline and the receiving stripline are formed so that the open ends of the stripline are close to each other and face each other, and the facing part of the open ends of the striplines with respect to the antenna is a power feeding part, and the power feeding part The Doppler module is characterized in that the antenna is used to feed power. 2. The horn antenna is used as the antenna, and a cavity is provided at a position facing the horn antenna with a power feeding portion consisting of facing portions at the open ends of the strip lines being sandwiched. The Doppler module described. 3. An oscillating portion, a detecting portion and both strip lines are formed on the same substrate, and an upper casing made of a conductive material integrally formed with the horn antenna and a conductive material in which the cavity is provided. And a lower housing, one of the housings contains the substrate, and the other housing has a partition for spatially partitioning each part formed on the substrate. 3. The front end of the partition wall and the substrate are fitted so as to be in contact with each other.
The Doppler module described. 4. A ground pattern is formed on a surface of each part of the substrate where the partition wall is in contact with the substrate, and the ground pattern is a through hole arranged at an interval shorter than a wavelength of an oscillation signal of the oscillation part. 5. The Doppler module according to claim 3, wherein the ground plane on the back surface of the substrate is electrically connected. 5. A groove having a cross section sufficiently smaller than the wavelength of the oscillation signal of the oscillating portion is provided along the wall surface of the partition wall, and a power supply line or a signal line connected to an external circuit is passed through the groove. The Doppler module according to claim 3 or 4, wherein 6. The power supply circuit for supplying power to the oscillating section is installed in a section adjacent to the section in which the oscillating section partitioned by the partition wall is installed. Doppler module. 7. At least one of an attenuator, a filter, and an isolator is provided in a section between the section in which the oscillator is installed and the section in which the power supply stripline is formed. The Doppler module according to any one of claims 3 to 6. 8. The Doppler module according to claim 3, wherein an amplification section for amplifying a detection signal from the detection section is provided in a section adjacent to the section in which the detection section is provided. 9. A length of a side edge of a fitting portion between the upper casing and the lower casing is set to be ¼ or more of a wavelength of an oscillation signal of the oscillation unit. The Doppler module described in 3. 10. The Doppler module according to claim 3, wherein a cavity and a bend connected to the cavity are attached to an upper portion of the power feeding portion of the upper housing, and a horn antenna is formed at a tip of the bend. .