JP2001267812A - Circulator for non-radiative dielectric line and milliwave transmitter and receiver using the circulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of off-center between two ferrite plates, to obtain the characteristics of a circulator at high reproducibility and to improve mass production based on easy production by improving the insertion loss and isolation characteristic of a high frequency signal in a higher frequency band and a wide band, improving positional accuracy between a mode suppressor and a ferrite plate and improving the assembling reproducibility of the circulator. SOLUTION: An impedance matching member 5 having a width different from the line width of each mode suppressor 1 is attached to the tip of the suppressor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circulator which is incorporated in a nonradiative dielectric line type millimeter wave integrated circuit, a millimeter wave radar module or the like, and converts a propagation path of a high frequency signal among a plurality of dielectric lines. And a millimeter-wave transceiver having a nonradiative dielectric line structure using the same.

[0002]

2. Description of the Related Art Conventionally, a nonradiative dielectric line (NonRadiative Diel) for transmitting a microwave or millimeter wave high-frequency signal has been conventionally used.
FIG. 2 shows a basic configuration of an ectric waveguide (hereinafter, referred to as an NRD guide). As shown in FIG. 1, a rectangular dielectric line 13 having a rectangular cross section or the like is arranged between parallel plate conductors 11 and 12 arranged in parallel at a predetermined interval a. If a ≦ λ / 2 with respect to the wavelength λ of the high-frequency signal, the intrusion of noise from the outside into the dielectric line 13 and the emission of the high-frequency signal to the outside are eliminated, and the high-frequency Signals can be propagated. The wavelength λ of the high-frequency signal is the wavelength in the air (free space) at the operating frequency.

FIG. 3 shows a circulator incorporated in such an NRD guide (conventional example 1; Transactions of the Institute of Electronics, Information and Communication Engineers, CI Vol. J73-CI No. 3 pp. 87-94 199).
March 2000, "Millimeter-wave integrated circuit using non-radiative dielectric line" (Yoneyama). In the figure, 20a, 20b,
20c is a dielectric line made of Teflon, polystyrene or the like, 21 is provided at the tip of each of the dielectric lines 20a, 20b, 20c, and is a LSE (Longitudinal Section Elect).
ric) mode suppressor that blocks mode electromagnetic waves, 2
Reference numeral 2 denotes two ferrite disks for a circulator to which the tip of a mode suppressor 21 is connected, and dielectric lines 20a, 20b, and 20c are arranged radially at intervals of 120 ° around the ferrite disk. Reference numeral 23 denotes an inside of the mode suppressor 21. Placed,
It is a strip line conductor made of Cu foil or the like, and blocks an LSE mode electromagnetic wave in which the electric field is perpendicular to the main surface of the parallel plate conductor (vertical direction in FIG. 3). The strip line conductor 23 is made of a TEM (Transverse ElectroMagneti).
c) A λ / 4 choke pattern is applied to eliminate the mode.

The electromagnetic wave propagating in the dielectric line 20a is rotated counterclockwise by the ferrite disk 22, and propagates to the dielectric line 20b, but does not propagate to the dielectric line 20c. Similarly, the electromagnetic wave propagating in the dielectric line 20b is propagated to the dielectric line 20c. Thus, the propagation path of the electromagnetic wave is converted.

In the NRD guide provided with the circulator and the dielectric line, as shown in FIG.
A stepped portion 34 having a step equal to the thickness of the ferrite disk 32 is formed on each of the upper and lower surfaces of the tip of the mode suppressor 31, and the ferrite disk 32 is engaged with the upper and lower stepped portions 34, respectively. (Japanese Patent Application Laid-Open No. Hei 9-186507) has been proposed in which the concentricity of the ferrite disk 32 can be guaranteed with high reproducibility and high accuracy by supporting the ferrite disk 32 with the mode suppressor 31. reference). In FIG. 4, reference numerals 30a, 30b, and 30c denote dielectric lines, and 33 denotes a strip line conductor disposed inside the mode suppressor 31 and made of Cu foil or the like.

[0006]

However, the NRD
The circulator for guiding is mainly composed of two ferrite disks concentrically arranged in parallel at predetermined intervals in the vertical direction. In the conventional example 1 (FIG. 3), two ferrite disks are used. A cylindrical dielectric spacer 24 for arranging the 22 at predetermined intervals is required. Further, in the conventional circulator using the dielectric spacer 24, the pass frequency band is narrowed and the frequency fluctuates due to the change in the relative dielectric constant due to the thickness of the cylindrical dielectric spacer 24. However, there has been a problem that the center frequency of the data is shifted.

Therefore, in order to solve such a problem, there has been proposed a mode suppressor 31 having a stepped portion 34 formed at the front end thereof as in Conventional Example 2 (FIG. 4).
As a result, the reproducibility of the assembly of the circulator is improved, and there is no misalignment between the upper and lower ferrite disks 32, and the band characteristics of the positive pass frequency between the ports of each dielectric line are equal to each other with respect to the center frequency of the pass band. A trapezoidal shape having a symmetrical shape is obtained, and a flat passband characteristic is obtained, and an isolation characteristic having a symmetrical shape with respect to the center frequency is obtained.

However, in addition to the flat passband characteristics, it is important to reduce the reflection of the high-frequency signal at the circulator to reduce the transmission loss (insertion loss). This point is not mentioned in Conventional Example 2.

As a configuration for improving the transmission loss, a step is formed by cutting off the tip of the mode suppressor of the dielectric line, and a stepped impedance converter is provided to reduce insertion loss and isolation. An improved version has been proposed {Conventional Example 3; IEICE Technical Report MW83-135 pp.63-66 (1984; Yoneyama, Sugaya, Nishida)}. However, in the configuration of Conventional Example 3, 50 G
The bandwidth of 1 dB insertion loss in the Hz band is about 1.5 GH
z, isolation within this band is 24d at minimum
B, the maximum value was 30 dB or more, the bandwidth in which the insertion loss and isolation were improved was narrow, and the improvement effect was insufficient. In addition, it is difficult to finely process the line width of the dielectric line in a step shape, and there is a problem that mass productivity is poor.

[0010] Accordingly, the present invention has been completed in view of the above circumstances, and an object of the present invention is to improve the reproducibility of assembly of a circulator and prevent the misalignment of two ferrite plates from occurring. To be obtained with good reproducibility and stable, and to improve the insertion loss and isolation characteristics of high frequency signals in a higher frequency band. The bandwidth is remarkably wide, and manufacturing is simplified and mass production is excellent. It is in.

[0011]

A circulator for a nonradiative dielectric line according to the present invention comprises two ferrite plates interposed between parallel flat conductors arranged at intervals of not more than half the wavelength of a high-frequency signal. A plurality of dielectric lines for transmitting high-frequency signals, which are disposed on the inner surface of the parallel plate conductor so as to face each other and are arranged substantially radially with respect to the two ferrite plates, are provided at the tip of the dielectric line. A mode suppressor for blocking electromagnetic waves of the mode and an impedance matching member provided at the tip of the mode suppressor and having a width different from that of the mode suppressor are connected.

According to the present invention, reflection of a high-frequency signal is reduced by providing an impedance matching member having a width different from that of the dielectric line, and the insertion loss and isolation characteristics of the high-frequency signal are reduced in a higher frequency band. The bandwidth to be improved is much wider.

In the present invention, preferably, an intermediate dielectric line member having substantially the same width as the mode suppressor is interposed between the mode suppressor and the impedance matching member.

With the above configuration, the operating frequency of the circulator can be controlled by controlling the length of the intermediate dielectric line member.

More preferably, a step portion is provided at a tip of the impedance matching member in a vertical direction at an interval substantially equal to the interval between the two ferrite plates, and the step portion is sandwiched between the two ferrite plates. The impedance matching member is connected to the two ferrite plates.

With such a configuration, the positional accuracy between the mode suppressor and the ferrite plate is improved, the reproducibility of the assembly of the circulator is improved, the misalignment of the two ferrite plates hardly occurs, and the reproducibility of the circulator characteristics is improved. A good and stable product is obtained, and the production is facilitated, resulting in excellent mass productivity.

In the millimeter wave transceiver according to the present invention, the frequency modulated or pulsed output from the high frequency generating element is output between the parallel plate conductors arranged at an interval of one half or less of the wavelength of the millimeter wave signal for transmission. A first dielectric line for transmitting a millimeter-wave signal, and a high-frequency signal output from the high-frequency generating element, which is attached to the first dielectric line and periodically frequency-modulated or pulsed, for transmission. A millimeter-wave signal oscillating unit that outputs the signal as a millimeter-wave signal and propagates through the first dielectric line, and is disposed close to the first dielectric line so that one end is electromagnetically coupled to the first dielectric line, or A second dielectric line, one end of which is joined to the body line, for transmitting a part of the millimeter wave signal to the mixer side; and a first connection unit connected to the output end of the millimeter wave signal of the first dielectric line. Is connected to the circulator A third dielectric line connected to a second connection portion of the circulator for transmitting the millimeter wave signal and having a transmitting and receiving antenna at a tip end; and a third dielectric line received by the transmitting and receiving antenna and propagating through the third dielectric line. A fourth dielectric line that propagates a reception wave output from a third connection portion of the circulator to the mixer side, and a middle of the second dielectric line and a middle of the fourth dielectric line are brought close to each other. By electromagnetically coupling or joining,
In a millimeter wave transmitter / receiver provided with a mixer section for mixing a part of a millimeter wave signal and a reception wave to generate an intermediate frequency signal, the circulator is the circulator of the present invention.

According to the millimeter wave transmitter / receiver of the present invention, the transmission loss and isolation characteristics of a millimeter wave signal are improved in a higher frequency band and a wider bandwidth by the above configuration, and a part of a transmission wave is transmitted to a mixer via a circulator. As a result, when applied to a millimeter wave radar or the like, the detection distance can be increased.

Further, in the millimeter wave transceiver according to the present invention, whether the frequency is output from the high frequency generation element and frequency-modulated between the parallel plate conductors arranged at an interval of one half or less of the wavelength of the millimeter wave signal for transmission. A first dielectric line for propagating a pulsed millimeter wave signal, and a frequency modulation or pulse periodically provided for the first dielectric line and periodically modulating a high-frequency signal output from the high-frequency generation element. A millimeter-wave signal oscillating unit that converts the signal into a millimeter-wave signal for transmission and propagates through the first dielectric line, or is arranged close to the first dielectric line so that one end is electromagnetically coupled to the first dielectric line, or A second dielectric line, one end of which is joined to the first dielectric line, for transmitting a part of the millimeter wave signal to a mixer side; and an output terminal of the first dielectric line for the millimeter wave signal. To which the first connection part is connected A circulator, a third dielectric line connected to a second connection portion of the circulator for transmitting the millimeter-wave signal and having a transmission antenna at the tip, a reception antenna at the tip, and a mixer at the other end. By providing the fourth dielectric line provided, and the middle of the second dielectric line and the middle of the fourth dielectric line in close proximity to each other and electromagnetically coupling or joining them, one millimeter wave signal And a mixer unit that generates an intermediate frequency signal by mixing the unit and the received wave, in a millimeter wave transceiver provided with
The circulator is the circulator of the present invention.

According to the millimeter wave transceiver of the present invention, the transmission loss and isolation characteristics of a millimeter wave signal are improved in a higher frequency band and a wider bandwidth by such a configuration.
Also, the millimeter-wave signal received by the transmitting antenna does not mix into the millimeter-wave signal oscillating unit. Therefore, when applied to a millimeter-wave radar module, the noise of the received signal is reduced, the millimeter-wave signal transmission characteristics are excellent, and the millimeter-wave signal is excellent. Radar detection distance can be further increased.

In the millimeter wave transceiver according to the present invention, the second dielectric line is disposed close to the third dielectric line so that one end side is electromagnetically coupled to the third dielectric line, or
, And one end of the dielectric line may be joined so as to propagate a part of the millimeter wave signal to the mixer side. In this case, the same operation and effect as described above can be obtained.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A circulator for an NRD guide and a millimeter-wave radar module as a millimeter-wave transceiver using the circulator according to the present invention will be described below. FIG. 1A is a perspective view of a circulator according to the present invention, and FIG. 1B is a diagram illustrating an impedance matching member 5 and an intermediate dielectric line member 4.
FIG. 4 is a partially enlarged plan view of d (4e, 4f), in which 4a, 4b, 4c and 4d, 4e, 4f denote Teflon, polystyrene, cordierite (2MgO.2).
A dielectric line and an intermediate dielectric line member made of Al ₂ O ₃ .5SiO ₂ ) ceramics or the like.
a mode suppressor that is provided at the tip of a, 4b, and 4c and blocks LSE-mode electromagnetic waves; 2 is connected to the tip of a mode suppressor 1 and has dielectric lines 4a, 4b,
Two ferrite disks 4c for circulators 4c are radially arranged at intervals of 120 °, 3 is a strip line conductor made of Cu foil or the like, which is arranged inside the mode suppressor 1, and an electric field is a parallel plate conductor. Electromagnetic waves in the LSE mode that is perpendicular to the main surface (vertical direction in FIG. 1) are blocked. The stripline conductor 3 is provided with a λ / 4 choke pattern to remove a TEM mode.
Reference numeral 5 denotes an impedance matching member provided at the tip of the mode suppressor 1.

In this circulator, the dielectric line 4a
The electromagnetic wave propagating through the inside is rotated counterclockwise by the ferrite disk 2 and propagates to the dielectric line 4b, but does not propagate to the dielectric line 4c. Similarly, the electromagnetic wave propagating in the dielectric line 4b is propagated to the dielectric line 4c. Thus, the propagation path of the electromagnetic wave is converted. If the positions of the S and N poles of the DC magnetic field applied substantially perpendicularly to the main surface of the ferrite disk 2 are reversed, the rotation direction of the wavefront of the high-frequency signal is also reversed.

In the present invention, two ferrite disks 2 of the same shape are installed concentrically facing the inner surface of the parallel plate conductor. That is, their main surfaces are provided in contact with the inner surface of the parallel plate conductor and opposed to each other. In some cases, the conductor may be provided at a predetermined interval from the inner surface of the parallel plate conductor. In FIG. 1, the main surface of the two ferrite disks 2 and the main surface of the mode suppressor 1 are flush with each other, and they are in contact with the inner surface of the parallel plate conductor. Such a configuration is preferable for reducing the loss.

Regarding the thickness of the ferrite disk 2,
In the 77 GHz band used in millimeter-wave radar for automobiles, when ferrite having a relative dielectric constant of 13 is used,
The thickness of the ferrite disk 2 is preferably from 0.15 to 0.30 mm. If the thickness is less than 0.15 mm, the strength of the ferrite disk 2 is reduced and handling becomes difficult. If it exceeds 0.30 mm, the diameter must be reduced in order to prevent the shift of the pass band, and if the diameter is reduced, the isolation of the circulator deteriorates.

The diameter of the ferrite disk 2 is 1 to 3 m.
When the thickness is less than 1 mm, the isolation of the circulator deteriorates. When the thickness exceeds 3 mm, the thickness of the circulator needs to be reduced so as not to shift the pass band.
It becomes less than 5 mm and handling becomes difficult.

A regular polygonal ferrite plate may be used in place of the ferrite disk 2. In this case, if the number of connected dielectric lines is n (n is an integer of 2 or more),
Its planar shape is a regular m-sided polygon (m ≧ 3 and m = n or m
= 2n). The main surface of the ferrite disk 2 was 355500 A / m from outside the parallel plate conductor.
The ferrite disk 2 functions as a circulator by providing a magnet, an electromagnet, and the like for applying a DC magnetic field of a degree.

In the present invention, the dielectric lines 4a to 4a
A plurality c is connected to the ferrite disk 2 substantially radially. For example, three dielectric lines 4a to 4c are arranged at equal intervals of 120 ° in the transmission line direction. In FIG. 1, the dielectric lines 4a to 4
b, dielectric line 4b to dielectric line 4c, dielectric line 4
Conversion from c to the dielectric line 4a in three directions is possible.
In addition, it is also possible to provide four at 90 ° intervals, six at 60 ° intervals, and the like.

The impedance matching member 5 of the present invention has a width different from that of the mode suppressor 1 having substantially the same line width as the dielectric lines 4a to 4c, and as shown in FIG. Dielectric line member 4d
Is L1 and the line width of the impedance matching member 5 is L2, 0.5 ≦ L2 / L1 ≦ 2 (L1 ≠ L2)
It is preferred that When L2 / L1 <0.5, the transmission line width of the impedance matching member 5 becomes small, and it becomes difficult to handle the impedance matching member 5, so that the positional accuracy of the installation is reduced.
Transmission loss tends to vary from product to product. If 2 <L2 / L1, it is necessary to shorten the length of the impedance matching member 5 in the transmission direction for impedance matching, which makes handling difficult and reduces the shape accuracy, resulting in transmission loss for each product. Variation is easy. When L1 = L2,
As shown in FIG. 6, the reflection of the high-frequency signal is large, and it is difficult to achieve impedance matching.

Such an impedance matching member 5
The cross-sectional shape is a rectangular shape such as a square or a rectangle. However, as shown in the front view of FIG. 11, the cross-sectional shape may be such that the width changes in the vertical direction. (A) and (b) of the same figure have a rectangular (square) cross section.
(C), the width narrowed linearly toward the center in the up-down direction, (d), the width narrowed in a curve toward the center in the up-down direction, and (e), the width decreased. (F) a width that increases linearly toward the center in the vertical direction, (f) a width that increases in a curve toward the center in the vertical direction,
(G) is a circular shape.

The relative permittivity of the dielectric lines 4a-4c, the mode suppressor 1 and the intermediate dielectric line members 4d-4f is εr1, and the relative permittivity of the impedance matching member 5 is ε.
Assuming that r2 is εr1 = εr2 in the above embodiment, the transmission loss of a high-frequency signal can be controlled by setting εr1 ≠ εr2 as follows. In this case, -10 ≦ ε
It is preferable that r2-er1? As a result, the transmission loss of each product tends to vary. In the case of 20 <εr2−εr1, it is necessary to shorten the length of the impedance matching member 5 in the transmission direction for impedance matching, and it becomes difficult to handle the impedance matching member 5 and the accuracy of the shape is reduced. Variation is easy.

The thickness of the impedance matching member 5 in the transmission path direction is preferably 0.05 to 0.5 mm,
If it is less than 5 mm, the handling becomes difficult and the shape accuracy is reduced, so that the transmission loss of each product tends to vary. If it exceeds 0.5 mm, the isolation characteristics deteriorate.

The material of the impedance matching member 5 is
Alumina ceramics having a relatively high relative dielectric constant of about 9.7, forsterite having a relative dielectric constant of 7 (2MgO.SiO
₂ ) Ceramics, spinel (MgO
・ Al ₂ O ₃ ) ceramics and other mullite (3Al ₂₎
O ₃ · 2SiO ₂ ) ceramics, silicon nitride (Si ₃ N ₄ )
Ceramics and the like are good, and they have small dielectric loss and excellent strength.

In the present invention, preferably, the impedance matching member 5 is provided at least at its tip with a step 6 at a distance substantially equal to the distance between the two ferrite disks 2 in the vertical direction. Two ferrite disks 2
To be connected to the two ferrite disks 2. That is, the interval between the stepped portions 6 in the vertical direction is made substantially equal to the interval between the two ferrite disks 2, and the interval between the upper surface and the lower surface of the impedance matching member 5 is changed between the two ferrite disks 2. The interval is substantially equal to the interval.
Preferably, step portions 6 corresponding to the thickness of the ferrite disk 2 are respectively provided on both sides of the tip of the mode suppressor 1 in the vertical direction, and the two ferrite disks 2 are inserted and engaged with the step portions 6. Good to be. In this case, the two ferrite disks 2 are supported by the impedance matching member 5, and there is no need to arrange a dielectric spacer or the like between the two ferrite disks 2. Further, the concentricity of the two ferrite disks 2 is accurately determined and maintained.

In the example shown in FIG. 1, the impedance matching member 5 has a flat plate shape. In this case, the impedance matching member 5 has a shape in which the side surface shape is such that a convex shape is turned over. It is good also as what has a step part 6 above and below. That is, the step portion 6 may be provided in the up-down direction (upper surface and lower surface) only at the tip of the impedance matching member 5.

In the present invention, the dielectric lines 4a to 4c and the intermediate dielectric line members 4d to 4f are made of a resin-based dielectric material such as Teflon or polystyrene, or cordierite (2MgO.2Al) having a low dielectric constant. ₂ O ₃ · 5S
Ceramics such as iO ₂ ) ceramics, alumina (Al ₂ O ₃ ) ceramics, and glass ceramics are preferable, and these have low loss in a high frequency band.

The intermediate dielectric line members 4d to 4f of the present invention
Can control the operating frequency of the circulator by controlling its length, that is, the distance between the ferrite disk 2 and the strip line conductor 3 of the mode suppressor 1. The length of each of the intermediate dielectric line members 4d to 4f is equal to 0.
1 mm to λ / 2 (approximately 3.0 mm, where λ is the wavelength of the high-frequency signal) is good. If it is less than 0.1 mm, it is difficult to control the operating frequency of the circulator and the strength is weak. In short, the workability at the time of assembly is significantly deteriorated. If it exceeds λ / 2 (about 3.0 mm), the control characteristic of the operating frequency of the circulator is repeated every λ / 2, and the loss of the high-frequency signal increases.

The intermediate dielectric line members 4d to 4f are
The mode suppressor 1 can be installed by means such as bonding to the tip of the mode suppressor 1 with an adhesive, or bonding to one inner surface of the parallel plate conductor with an adhesive.

The high-frequency band referred to in the present invention is expressed by the following equation.
A high frequency band corresponding to the microwave band and the millimeter wave band of the 00 GHz band, for example, 30 GHz or more, particularly 50 GHz or more, and more preferably 70 GHz or more is suitable.

The parallel plate conductor for an NRD guide according to the present invention is characterized in that Cu, A
A conductor plate such as 1, 1, Fe, Ag, Au, Pt, SUS (stainless steel), brass (Cu-Zn alloy), or an insulating plate made of ceramics, resin, etc., may be formed by forming these conductor layers on the surface. .

The NRD guide of the present invention is used for a wireless LAN, a millimeter wave radar of an automobile, etc. by incorporating a high frequency diode such as a Gunn diode as a high frequency generating element. An object and other vehicles are irradiated with millimeter waves, the reflected wave is combined with the original millimeter waves to obtain an intermediate frequency signal, and the intermediate frequency signal is analyzed to determine the distance to obstacles and other vehicles, Can be measured.

Thus, in the circulator for NRD guide of the present invention, by installing the impedance matching member having a width different from that of the mode suppressor, the reflection of the high-frequency signal is reduced, so that the insertion loss and the isolation of the high-frequency signal in a higher frequency band are reduced. The bandwidth in which the characteristics are improved is significantly wider.

Next, a millimeter wave radar module as a millimeter wave transceiver according to the present invention will be described below. FIG.
10 show the millimeter wave radar module of the present invention, FIG. 7 is a plan view of an integrated transmitting antenna and receiving antenna, and FIG. 8 is a plan view of an independent transmitting antenna and receiving antenna. 9 is a perspective view of a millimeter-wave signal oscillating unit, and FIG. 10 is a perspective view of a wiring board provided with a variable capacitance diode (varactor diode) for the millimeter-wave signal oscillating unit.

In FIG. 7, reference numeral 51 denotes one parallel plate conductor of the present invention (the other is omitted); and 52, a voltage-controlled millimeter-wave signal oscillating section provided at one end of a first dielectric line 53. The bias voltage of the variable capacitance diode arranged near the high-frequency diode (high-frequency generation element) of the first dielectric line 53 is periodically controlled so that the bias voltage application direction matches the electric field direction of the high-frequency signal. , Triangular wave,
By using a sine wave or the like, the signal is output as a frequency-modulated millimeter wave signal for transmission.

Reference numeral 53 denotes a first dielectric line for transmitting a millimeter-wave signal obtained by modulating a high-frequency signal output from a high-frequency diode such as a Gunn diode serving as a high-frequency generation element. Reference numeral 54 denotes a first dielectric line. 4 dielectric lines 53 and 5
The circulator 55 of the present invention, comprising a ferrite disk, having first, second, and third connection portions (not shown) connected to the circulator 5 and 57, respectively, is connected to the second connection portion of the circulator 54. A third dielectric line 56 for transmitting a millimeter wave signal and having a transmission / reception antenna 56 at the distal end thereof is a transmission / reception antenna provided by tapering the distal end of the third dielectric line 55.

Reference numeral 57 denotes a circulator 54 which is received by the transmitting / receiving antenna 56 and propagates through the third dielectric line 55.
The fourth dielectric line 58 for propagating the reception wave output from the third connection portion to the mixer 59 side is disposed close to the first dielectric line 53 such that one end side is electromagnetically coupled to the first dielectric line 53, or A second dielectric line 58a having one end joined to the dielectric line 53 and transmitting a part of the millimeter wave signal to the mixer 59 side is the mixer 59 of the second dielectric line 58.
And a non-reflection terminal (terminator) provided at one end on the opposite side. In the figure, M1 is the second dielectric line 5
8 and the middle of the fourth dielectric line 57 are brought close to each other and electromagnetically coupled or joined to each other to mix a part of the millimeter wave signal and the received wave to generate an intermediate frequency signal. is there.

These various components are provided between parallel plate conductors arranged at an interval of one half or less of the wavelength of the millimeter wave signal.

In FIG. 7, the first dielectric line 5
By providing a switch having the same configuration as that shown in FIG. 10 in the middle of 3, the millimeter wave signal can be pulsed. For example, as shown in FIG. 10, a second choke type bias supply line 90 is formed on one main surface of a wiring board 88,
Beam lead type PIN soldered halfway
This is a switch provided with a diode and a Schottky barrier diode.

As another embodiment of the millimeter wave radar module of the present invention, there is a type shown in FIG. 8 in which a transmitting antenna and a receiving antenna are made independent. In the figure, reference numeral 61 denotes one parallel plate conductor of the present invention (the other is omitted);
Is a millimeter wave signal oscillating unit of a voltage control type provided at one end of the first dielectric line 63, and the high frequency of the first dielectric line 63 is adjusted so that the bias voltage application direction matches the electric field direction of the high frequency signal. By periodically controlling the bias voltage of the variable capacitance diode arranged near the diode to make it a triangular wave, a sine wave, or the like, it outputs a frequency-modulated millimeter wave signal for transmission.

Reference numeral 63 denotes a first dielectric line for transmitting a millimeter-wave signal obtained by frequency-modulating a high-frequency signal output from a high-frequency diode, and 64 denotes first, third, and fifth dielectric lines 63 and 65. , 67 of the present invention, comprising a ferrite disk, having first, second, and third connections (not shown) connected to the circulator 64, respectively. A third dielectric line 66 for transmitting a millimeter wave signal and having a transmission antenna 66 at the tip is a transmission antenna provided by making the tip of the third dielectric line 65 a tapered shape or the like. , A non-reflection termination 67 connected to the third connection of the circulator 64 and attenuating the millimeter-wave signal for transmission
a is the fifth dielectric line provided at the tip.

Reference numeral 68 denotes one end of the first dielectric line 63 which is disposed close to the first dielectric line 63 so as to be electromagnetically coupled to the first dielectric line 63 or one end of which is joined to the first dielectric line 63 to mix a part of the millimeter wave signal into a mixer. The second dielectric line propagating to the 71 side, 68
a is a non-reflection terminal provided at one end of the second dielectric line 68 on the side opposite to the mixer 71; 69 is a fourth for transmitting a reception wave received by the reception antenna 70 to the mixer 71 side. This is a dielectric line. In the figure, M2 indicates a part of the millimeter wave signal and the reception wave by making the middle of the second dielectric line 68 and the middle of the fourth dielectric line 69 close to each other and electromagnetically coupled or joined. And a mixer unit for generating an intermediate frequency signal by mixing

These various components are provided between the parallel plate conductors arranged at an interval of one half or less of the wavelength of the millimeter wave signal.

In FIG. 8, a switch having the same configuration as that shown in FIG. 10 is provided in the middle of the first dielectric line 63, so that the millimeter wave signal can be pulsed. For example, as shown in FIG. 10, a second choke type bias supply line 90 is formed on one main surface of a wiring board 88, and a beam lead type P mounted by soldering in the middle thereof.
This is a switch provided with an IN diode and a Schottky barrier diode.

In these millimeter wave radar modules, the distance between the parallel plate conductors is the wavelength of the millimeter wave signal in the air, which is less than half the wavelength at the operating frequency.

FIGS. 9 and 10 show the millimeter wave signal oscillators 52 and 62 for the millimeter wave radar module shown in FIGS.
In these figures, reference numeral 82 denotes a metal member such as a metal block for mounting (mounting) the gun diode 83;
83 is a Gunn diode which is a kind of high-frequency diode that oscillates a millimeter wave, and 84 is a low-pass filter that is installed on one side of the metal member 82 to supply a bias voltage to the Gunn diode 83 and prevent leakage of high-frequency signals. The wiring board 85 on which the functioning choke-type bias supply line 84 a is formed is a choke-type bias supply line 84.
a is a band-shaped conductor such as a metal foil ribbon for connecting the a to the upper conductor of the Gunn diode 83; 86 is a metal strip resonator provided with a metal strip line 86a for resonance on a dielectric base; 87 is a metal strip resonator This is a dielectric line for guiding the high-frequency signal resonated by 86 to the outside of the millimeter-wave signal oscillating unit.

Further, in the middle of the dielectric line 87, a wiring board 88 loaded with a varactor diode 80 which is a frequency modulation diode and a kind of variable capacitance diode.
Is installed. The bias voltage application direction of the varactor diode 80 is perpendicular to the propagation direction of the high-frequency signal on the dielectric line 87 and parallel to the main surface of the parallel plate conductor (electric field direction). The varactor diode 80
The bias voltage application direction coincides with the direction of the electric field of the high frequency signal of the LSM ₀₁ mode propagating in the dielectric line 87, thereby electromagnetically coupling the high frequency signal with the varactor diode 80 to control the bias voltage. By changing the capacitance of the varactor diode 80 by
The frequency of the high frequency signal can be controlled. Reference numeral 89 denotes a dielectric plate having a high relative dielectric constant for achieving impedance matching between the varactor diode 80 and the dielectric line 87.

As shown in FIG. 10, a second choke type bias supply line 90 is formed on one main surface of the wiring board 88, and a beam lead type varactor is provided in the middle of the second choke type bias supply line 90. A diode 80 is provided. A connection electrode 81 is provided at the connection between the second choke type bias supply line 90 and the varactor diode 80.
Are formed.

The high-frequency signal oscillated from the Gunn diode 83 is guided to the dielectric line 87 through the metal strip resonator 86. Next, part of the high-frequency signal is reflected by the varactor diode 80 and returns to the Gunn diode 83 side. This reflected signal is the varactor diode 8
The oscillation frequency changes with the change of the capacitance of 0, and the oscillation frequency changes.

The millimeter wave radar module shown in FIGS. 7 and 8 is an FMCW (Frequency Modulation Cotinuous).
Waves) method, and its operating principle is as follows. MODI for input of modulation signal of millimeter wave signal oscillator
An input signal whose voltage amplitude changes with time in the form of a triangular wave or a sine wave is input to the N terminal, and the output signal is frequency-modulated so that the output frequency shift of the millimeter wave signal oscillating unit becomes a triangular wave or a sine wave. To shift. And the transmitting and receiving antenna 56,
When an output signal (transmission wave) is radiated from the transmission antenna 66 and a target is present in front of the transmission / reception antenna 56 and the transmission antenna 66, a reflected wave (reception wave) is generated with a time difference corresponding to a reciprocation of the propagation speed of the radio wave. Will come back. At this time, the frequency difference between the transmission wave and the reception wave is output to the IFOUT terminal on the output side of the mixers 59 and 71.

By analyzing frequency components such as the output frequency of the IFOUT terminal, Fif = 4R · fm · Δf / c
(Fif: IF (Intermediate Frequency) output frequency,
R: distance, fm: modulation frequency, Δf: frequency shift width,
c: the speed of light).

In the millimeter wave signal oscillating section of the present invention, the materials of the choke-type bias supply line 84a and the strip conductor 85 are Cu, Al, Au, Ag, W, Ti, Ni, C
Consisting of r, Pd, Pt, etc., Cu and Ag are particularly preferable in that they have good electrical conductivity, low loss, and high oscillation output.

The strip conductor 85 is electromagnetically coupled to the metal member 82 at a predetermined distance from the surface of the metal member 82, and extends between the choke-type bias supply line 84 a and the Gunn diode element 83. That is, the strip conductor 85
Is connected to one end of a choke-type bias supply line 84a by soldering or the like, and the other end of the band-shaped conductor 85 is connected to the upper conductor of the gun diode element 83 by soldering or the like. Except for the middle part, it is floating.

Since the metal member 82 also serves as an electrical ground (earth) for the Gunn diode element 83, it may be a metal conductor, and the material is not particularly limited as long as it is a metal (including alloy) conductor. Not brass (brass: C
u-Zn alloy), Al, Cu, SUS (stainless steel), Ag, Au, Pt, and the like. Metal member 8
Reference numeral 2 denotes a metal block made entirely of metal, an insulating substrate made of ceramics, plastic, or the like, which is entirely or partially metal-plated, or an insulating substrate which is entirely or partially coated with a conductive resin material or the like. May be.

Thus, the millimeter wave radar module as the millimeter wave transceiver according to the present invention has improved transmission loss and isolation characteristics of the millimeter wave signal in a higher frequency band and a wider bandwidth, and as a result, has been applied to the millimeter wave radar. In that case, the detection distance can be increased (FIG. 7). In addition, the transmission loss and isolation characteristics of the millimeter wave signal are improved in a higher frequency band and a wider bandwidth, and the millimeter wave signal for transmission does not enter the mixer via the circulator, and as a result, the noise of the received signal is reduced. Is reduced and the detection distance is increased, and the detection distance of the millimeter wave radar can be further increased (FIG. 8).

It should be noted that the present invention is not limited to the above embodiment, and that various changes can be made without departing from the scope of the present invention.

[0066]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A circulator for an NRD guide according to the present invention will be described below. The circulator of FIG. 1 was configured as follows. Two Al plates having a thickness of 6 mm are arranged at intervals of 1.8 mm as parallel plate conductors, and the cross-sectional shape between them is a rectangular shape of 1.8 mm (height) x 0.8 mm (width). A mode suppressor 1 is connected to each end of three dielectric lines 4a to 4c made of cordierite ceramics having a relative dielectric constant of 4.8, and a cordy having a relative dielectric constant of 4.8 is connected to the end of each mode suppressor 1. An intermediate dielectric line member 4d to 4f having a length of 1.2 mm made of elite ceramics is installed.
４4f are connected to the two ferrite disks 2 and are arranged so as to be radial at equal intervals of 120 °.
The mode suppressor 1 was formed by disposing a strip line conductor 3 made of Cu foil having a λ / 4 choke pattern therein.

At this time, the upper and lower surfaces of the mode suppressor 1 and the intermediate dielectric line members 4d to 4f are made flush with the main surfaces of the two ferrite disks 2. That is, the two ferrite disks 2 are installed facing each other on the inner surface of the parallel plate conductor, and the stepped portions 6 are provided above and below the impedance matching member 5 at intervals substantially equal to the interval between the two ferrite disks 2. The step portion 6 is sandwiched between two ferrite disks 2 and the intermediate dielectric line members 4d to 4d
Steps 6 corresponding to the thickness of the ferrite disk 2 are provided on both sides in the vertical direction of the impedance matching member 5 at the tip of the f.
Are inserted and engaged. The main surfaces at both upper and lower ends of the ferrite disk 2 and the main surfaces at both upper and lower ends of the dielectric lines 4a to 4c are in contact with the inner surface of the parallel plate conductor.

The size of the ferrite disk 2 is 2.0 mm in diameter.
mm and a thickness of 0.21 mm, and magnets for applying a DC magnetic field of 355500 A / m were arranged above and below the ferrite disk 2. That is, a circular concave portion having a diameter of 12.5 mm and a depth of 5 mm is formed concentrically with the ferrite disk 2 in a portion corresponding to the ferrite disk 2 on the outer surface of the parallel plate conductor,
A circular magnet having a thickness of 4.5 mm and a diameter of 12.5 mm was placed in the recess. The impedance matching member 5 is made of cordierite ceramic having a relative dielectric constant of 4.8,
The cross-sectional shape in a plane perpendicular to the transmission direction is 1.38 m in height.
m × width 0.6 mm (L2 / L1 = 0.6 / 0.8 = 0.
75), the length (thickness) in the transmission direction was 0.1 mm. Therefore, the step of the step portion 6 is set to 0.21 mm.

FIG. 5 shows the results of measuring the transmission characteristics | S21 | and the isolation | S31 | of the high-frequency signal in the high-frequency band of 75 to 80 GHz using the spectrum analyzer with the circulator having the above configuration. As a comparative example, the stepped portion 34 shown in FIG.
Except for the formation of the substrate, a device having the same configuration as that of the above embodiment was manufactured, and the transmission characteristics | S21 |
S31 | is shown in FIG.

5 and 6, the transmission characteristic | S21 | of the embodiment of FIG. 5 has a value of -1 to -1.5 over the entire band.
The loss is as low as about dB, and the isolation | S31 |
Is about -35 dB at the highest part, and -2 at the lowest part.
Good characteristics were exhibited over a wide band of about 5 db. In contrast, in the comparative example of FIG. 6, the transmission characteristics | S21
Is approximately −2 to −2.5 dB over the entire band,
-20d at the highest isolation | S31 |
About B, the lowest part was about -19 db, and both characteristics deteriorated.

[0071]

According to the circulator of the present invention, in the NRD guide, two ferrite plates are installed on the inner surface of a parallel plate conductor so as to be opposed to each other, and a high-frequency signal arranged approximately radially with respect to the two ferrite plates. A plurality of transmission dielectric lines are provided via a mode suppressor provided at the tip of the dielectric line to block electromagnetic waves in the LSE mode, and an impedance matching member provided at the tip of the mode suppressor and having a width different from that of the mode suppressor. By the connection, the reflection of the high-frequency signal is reduced by the impedance matching member having a width different from that of the mode suppressor, so that the insertion loss and the isolation characteristics of the high-frequency signal are improved in a higher frequency band and a wider band. Further, it is not necessary to control the width of the dielectric line in order to reduce the transmission loss, and the transmission characteristics can be improved by the impedance matching member. Therefore, the manufacturing is easy, the workability is excellent, and the device is suitable for mass production. .

Preferably, an intermediate dielectric line member having substantially the same width as the mode suppressor is interposed between the mode suppressor and the impedance matching member to control the length of the intermediate dielectric line member. The operating frequency of the circulator can be controlled.

In the present invention, preferably, a step portion is provided at the tip of the impedance matching member at a distance substantially equal to the distance between the two ferrite plates in the vertical direction, and the step portion is sandwiched between the two ferrite plates. By connecting the matching member to two ferrite plates,
Dielectric spacers are not required, and the positional accuracy between the mode suppressor and the ferrite plate is improved, assembling reproducibility of the circulator is improved. It can be obtained stably, and can be easily manufactured, and has excellent mass productivity.

Further, the millimeter-wave transceiver of the present invention uses the circulator of the present invention to improve the transmission loss and isolation characteristics of a millimeter-wave signal in a higher frequency band and a wider bandwidth, and to reduce the transmission wave. The amount of the part mixed into the mixer via the circulator decreases, and as a result, when applied to a millimeter wave radar or the like, the detection distance can be increased. In addition, the millimeter-wave transceiver in which the transmitting antenna and the receiving antenna of the present invention are independent, by using the circulator of the present invention, the transmission loss and isolation characteristics of the millimeter-wave signal in a higher frequency band and a wider bandwidth are improved, Also, the millimeter-wave signal received by the transmitting antenna does not mix into the millimeter-wave signal oscillating unit, so when applied to a millimeter-wave radar module, the noise of the received signal is reduced, the transmission characteristics of the millimeter-wave signal are excellent, and the millimeter-wave signal is excellent. Radar detection distance can be further increased.

[Brief description of the drawings]

FIG. 1A is a perspective view of an embodiment of a circulator for an NRD guide of the present invention, and FIG. 1B is a plan view of an impedance matching member of FIG.

FIG. 2 is a perspective view showing the basic configuration of an NRD guide, with the inside thereof partially seen through;

FIG. 3 is a perspective view of a conventional circulator for an NRD guide.

FIG. 4 is a perspective view of a conventional circulator for an NRD guide.

FIG. 5 is a graph showing the results of measuring transmission characteristics | S21 | and isolation | S31 | of a high-frequency signal for the circulator of the present invention.

6 is a diagram illustrating the transmission characteristics | S21 | and isolation | S31 of a high-frequency signal of the conventional circulator of FIG.
It is a graph of the result of having measured |.

FIG. 7 is a plan view of an embodiment of the millimeter wave radar module of the present invention.

FIG. 8 is a plan view of another embodiment of the millimeter wave radar module of the present invention.

FIG. 9 is a perspective view of a millimeter wave signal oscillator of a voltage control type for a millimeter wave radar module according to the present invention.

FIG. 10 is a perspective view of a wiring board provided with a varactor diode for the millimeter-wave signal oscillating unit of FIG. 9;

11 (a) to 11 (g) show various embodiments of the impedance matching member of the present invention, and are front views thereof.

[Explanation of symbols]

 1: Mode suppressor 2: Ferrite disk 3: Strip line conductor 4a, 4b, 4c: Dielectric line 4d, 4e, 4f: Intermediate dielectric line member 5: Impedance matching member 6: Step portion

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01P 3/16 H01P 3/16 F term (Reference) 5J012 CA01 5J014 HA06 5J070 AB01 AB17 AB24 AC02 AC06 AD01 AD20 AE01 AF03 AK22 AK40

Claims (6)

[Claims] A ferrite plate is disposed between parallel plate conductors arranged at an interval of one half or less of a wavelength of a high-frequency signal so as to face each other on an inner surface of the parallel plate conductor. A plurality of dielectric lines for transmitting high-frequency signals arranged substantially radially with respect to the ferrite plate, a mode suppressor provided at an end of the dielectric line for blocking electromagnetic waves in the LSE mode, and an end provided at the end of the mode suppressor. A circulator for a non-radiative dielectric line, wherein the circulator is connected via a mode suppressor and an impedance matching member having a different width. 2. The non-radiative dielectric line according to claim 1, wherein an intermediate dielectric line member having substantially the same width as the mode suppressor is interposed between the mode suppressor and the impedance matching member. Circulator for 3. A stepped portion is provided at a tip of the impedance matching member at a distance substantially equal to a distance between the two ferrite plates in a vertical direction, and the stepped portion is sandwiched between the two ferrite plates. The circulator for a nonradiative dielectric line according to claim 1, wherein a matching member is connected to the two ferrite plates. 4. A frequency-modulated or pulse-converted millimeter-wave signal output from a high-frequency generating element is propagated between parallel plate conductors arranged at an interval equal to or less than half the wavelength of a millimeter-wave signal for transmission. A first dielectric line, and a high-frequency signal output from the high-frequency generating element, which is attached to the first dielectric line, is periodically frequency-modulated or pulsed and output as a millimeter-wave signal for transmission. A millimeter-wave signal oscillating unit for propagating in the first dielectric line; and one end side is disposed close to the first dielectric line so as to be electromagnetically coupled or one end is joined to the first dielectric line. A second dielectric line for transmitting a part of the millimeter wave signal to the mixer side; and a first dielectric line at an output end of the millimeter wave signal of the first dielectric line.
A circulator to which the connection portion is connected; a third dielectric line connected to the second connection portion of the circulator, which propagates the millimeter wave signal and has a transmission / reception antenna at a distal end; A fourth dielectric line that propagates the reception wave output from the third connection portion of the circulator to the mixer side through the third dielectric line, and a middle portion of the second dielectric line and the fourth dielectric line. A millimeter-wave transmitter / receiver provided with a mixer unit for generating an intermediate-frequency signal by mixing a part of the millimeter-wave signal and a received wave by electromagnetically coupling or joining the middle of the body line so as to be close to each other; The millimeter wave transceiver according to any one of claims 1 to 3, wherein the circulator is the circulator according to any one of claims 1 to 3. 5. A frequency-modulated or pulse-converted millimeter-wave signal output from a high-frequency generating element is placed between parallel plate conductors arranged at an interval equal to or less than half the wavelength of a millimeter-wave signal for transmission. A first dielectric line to be propagated, and a high frequency signal attached to the first dielectric line and periodically frequency-modulated or pulsed as a millimeter-wave signal for transmission, which is output from the high-frequency generator. A millimeter-wave signal oscillating unit for outputting and propagating through the first dielectric line; and one end side of the millimeter-wave signal oscillating unit is disposed close to the first dielectric line so as to be electromagnetically coupled or one end of the first dielectric line. And a second dielectric line for transmitting a part of the millimeter wave signal to the mixer side, and a first dielectric line at an output end of the millimeter wave signal of the first dielectric line.
A circulator to which a connecting portion is connected; a third dielectric line connected to a second connecting portion of the circulator for transmitting the millimeter wave signal and having a transmitting antenna at a distal end; a receiving antenna at a distal end; A fourth dielectric line provided with a mixer at an end thereof, and a midway of the second dielectric line and a midway of the fourth dielectric line being brought into close proximity to each other and electromagnetically coupled or joined. A millimeter-wave transceiver provided with a mixer unit that mixes a part of the millimeter wave signal and the received wave to generate an intermediate frequency signal, wherein the circulator is the circulator according to any one of claims 1 to 3. A millimeter-wave transceiver. 6. The second dielectric line is disposed close to one end of the third dielectric line so as to be electromagnetically coupled to the third dielectric line, or one end of the second dielectric line is joined to the third dielectric line. 6. The millimeter wave transceiver according to claim 5, wherein a part of the millimeter wave signal is arranged to propagate to the mixer side.