JP2003249801A - Circulator of non-radioactive dielectric line, and millimeter-wave transmitter-receiver using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circulator and a millimeter-wave transmitter-receiver improved in reliability and circulator characteristics, such as frequency pass-band width, input/output reflection characteristics, isolation characteristics. <P>SOLUTION: A pair of ferrite disks 2a, 2b, facing in parallel to each other and respectively installed in inner surfaces of parallel plate conductors, are disposed between the parallel plate conductors arranged to have the distance equal to or smaller than one-half of the wavelength of millimeter-wave signal. A plurality of dielectric lines 4a, 4b, 4c one of whose end portions is set close to each other are aligned nearly radially from respective peripheral end portions of the pair of ferrite disks 2a, 2b. Each of the ferrite disks 2a, 2b has a difference in external diameter is equal to or smaller than 200 μm, the circularity is equal to or smaller than 200 μm, and a gap equal to or smaller than 300 μm away from one of respective end portions of the plurality of dielectric lines 4a, 4b, 4c. <P>COPYRIGHT: (C)2003,JPO

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 non-radiative dielectric line type millimeter wave integrated circuit, a millimeter wave radar module or the like to convert a propagation path of a high frequency signal between a plurality of dielectric lines. The present invention relates to a non-radiative dielectric line type millimeter-wave transceiver using the same.

[0002]

2. Description of the Related Art Conventional non-radiative dielectric lines for transmitting high frequency signals such as microwaves and millimeter waves
FIG. 8 shows a basic configuration of an electric wave guide (hereinafter also referred to as an NRD guide). As shown in the figure, parallel plate conductors 11 and 12 arranged in parallel at a predetermined interval a.
A dielectric line 13 having a rectangular cross section is disposed between the dielectric lines 13. If the distance a is a ≦ λ / 2 with respect to the wavelength λ of the high frequency signal, the dielectric line 13 is externally applied. It is possible to efficiently propagate the high frequency signal in the dielectric line 13 by eliminating the intrusion of noise to the outside and the emission of the high frequency signal to the outside. The wavelength λ of the high frequency signal is the wavelength in air (free space) at the used frequency.

A circulator incorporated in such an NRD guide is shown in FIG. 9 (conventional example 1; IEICE Transactions CI Vol.J73-CI No.3 pp.87-94 199).
March 0, "Millimeter-wave integrated circuit using non-radiative dielectric waveguide" (Yoneyama)). In the figure, 20a, 20b,
Reference numeral 20c is a dielectric line made of Teflon (trade name of DuPont; polytetrafluoroethylene), polystyrene, or the like, and 21 is provided at the tip of each of the dielectric lines 20a, 20b, 20c, and LSE (Longitudinal Section Ele).
ctric) mode suppressor that blocks electromagnetic waves in mode. 22 is connected to the tip of the mode suppressor 21, and the dielectric lines 20a, 20b, 20c are surrounded by 120.
Two ferrite discs for circulators, which are radially arranged at intervals of °, 23 are strip line conductors, which are arranged inside the mode suppressor 21 and are made of Cu foil or the like, and are made of a choke type line conductor or the like. The electric field cuts off the electromagnetic wave in the LSE mode, which is the direction perpendicular to the main surface of the parallel plate conductor. In addition, the strip line conductor 23 is a TEM (Tr
A λ / 4 choke pattern is applied to eliminate the ansverse Electro-Magnetic) mode.

The electromagnetic wave propagating in the dielectric line 20a is propagated to the dielectric line 20b with its wavefront rotated counterclockwise by the ferrite disk 22, and 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. In this way, the propagation path of electromagnetic waves is converted.

According to Japanese Patent Laid-Open No. 9-186507 (Prior Art 2), in the NRD guide provided with the circulator and the dielectric line, as shown in FIG. In addition, the stepped portion 34 having steps equal to the thickness of the ferrite disk 32 is
The ferrite discs 32 are formed by engaging the ferrite discs 32 with the upper and lower stepped portions 34 and supporting the two ferrite discs 32 by the mode suppressor 31.
It has been proposed that the concentricity of can be guaranteed with good reproducibility and high accuracy. In FIG. 10, 30a, 30b,
Reference numeral 30c is a dielectric line, and 33 is a strip line conductor arranged inside the mode suppressor 31 and made of Cu foil or the like.

[0006]

[Problems to be Solved by the Invention] However, the NRD
The guide circulator is mainly composed of two opposing upper and lower ferrite discs that are concentrically arranged parallel to each other at a predetermined interval in the vertical direction. Since the concentricity of the upper and lower ferrite disks 22 and 32 is determined by abutting on the mode suppressors 21 and 31, the concentricity is shifted when the outer dimensions of the upper and lower ferrite disks 22 and 32 are different. There was a problem.

For example, when the positions of the mode suppressors 21 and 31 are determined by the lower ferrite disk, the upper ferrite disk does not enter between the mode suppressors 21 and 31, or even if it enters, the upper ferrite disk does not. A gap (air gap) is formed between the disc and the mode suppressors 21 and 31. When the gap is opened, the circulator characteristic is deteriorated due to impedance mismatch due to the presence of air having a relative permittivity of 1 (air gap). If an attempt is made to eliminate the gap to improve the circulator characteristics, there is a problem that the concentricity of the upper and lower ferrite disks deteriorates.

Further, there is a problem that the pass frequency bandwidth, the input / output reflection characteristic, and the isolation characteristic are deteriorated when the different gaps are left for the mode suppressors 21 and 31.

Further, the ferrite disk having a large gap between the mode suppressors 21 and 31 moves due to vibration or shock, and collides with the mode suppressors 21 and 31 to cause cracks or chips, which causes a serious problem in reliability. was there.

Therefore, the present invention has been completed in view of the above circumstances, and an object thereof is to provide a circulator having improved circulator characteristics such as a pass frequency bandwidth, input / output reflection characteristics, and isolation characteristics, and reliability. It is to provide a millimeter wave transceiver.

[0011]

A circulator according to the present invention is arranged between parallel plate conductors arranged at intervals of ½ or less of a wavelength of a millimeter wave signal and parallel to inner surfaces of the parallel plate conductors. Non-radiative dielectric line, in which two opposed ferrite discs are installed, and a plurality of dielectric lines whose one ends are close to the peripheral edge of the two ferrite discs are arranged substantially radially. In the circulator for use in the above, the two ferrite discs have an outer diameter difference of 2
The roundness is 200 μm or less and the circularity of each is 200
It is characterized in that it is less than or equal to μm, and the distance between one end of the plurality of dielectric lines is less than or equal to 300 μm.

According to the present invention, the pass frequency bandwidth is reduced because the concentricity deviation between the two ferrite disks is small and the gap between the two ferrite disks and each dielectric line is small. The input / output reflection characteristics and isolation characteristics are improved, and good circulator characteristics are obtained. In addition, since the gap is small, the impact of the collision between the ferrite disc and the dielectric line due to vibration or shock is reduced, and the ferrite disc is less prone to cracking or chipping, resulting in a highly reliable product. .

The millimeter wave transmitter / receiver of the present invention is a millimeter wave signal output from a high frequency generator and frequency-modulated or pulsed between parallel plate conductors arranged at intervals of ½ or less of the wavelength of a millimeter wave signal. A first dielectric line for propagating a signal, and a high frequency signal output from the high frequency generating element, which is attached to one end of the first dielectric line, is periodically frequency-modulated or pulsed for transmission. And a millimeter wave signal oscillating section that outputs as a millimeter wave signal and propagates in the first dielectric line, and is arranged in proximity to the first dielectric line so that one end side is electromagnetically coupled or the first dielectric line. A second dielectric line having one end joined to the dielectric line and propagating a part of the millimeter wave signal to the mixer side, and a peripheral portion of a ferrite disk arranged in parallel with the parallel plate conductor are provided with a predetermined distance. Spaced and Each of the ferrites has a first connection portion, a second connection portion, and a third connection portion that are input / output terminals of the millimeter wave signal, and the millimeter wave signal input from one of the connection portions is the ferrite. A circulator that outputs from another connecting portion that is adjacent clockwise or counterclockwise in the plane of the disc, wherein the first connecting portion is provided at the output end of the millimeter wave signal of the first dielectric line. A circulator to be connected, and connected to the second connection part of the circulator,
From the third connecting portion of the circulator, which propagates the millimeter wave signal and has a transmitting / receiving antenna at the tip, and which propagates through the third dielectric line received by the transmitting / receiving antenna. A fourth dielectric line for propagating the output received wave to the mixer side and a midway point of the second dielectric line and a midway point of the fourth dielectric line are close to each other to be electromagnetically coupled or joined. In a millimeter wave transceiver provided with a mixer section that mixes a part of a millimeter wave signal and a received wave to generate an intermediate frequency signal, the circulator is the circulator of the present invention. .

The millimeter wave transmitter / receiver of the present invention has the above-mentioned configuration to improve the transmission loss and isolation characteristics of a millimeter wave signal in a high frequency band and a wide bandwidth, and as a result, when applied to a millimeter wave radar or the like. The detection range can be increased.

In the millimeter wave transceiver of the present invention, between the parallel plate conductors arranged at intervals equal to or smaller than ½ of the wavelength of the millimeter wave signal, the frequency is modulated by the high frequency generating element or pulsed. A first dielectric line for propagating the generated millimeter wave signal, and a high frequency signal output from the high frequency generating element, which is attached to one end of the first dielectric line, is periodically frequency-modulated or pulsed. Or a millimeter wave signal oscillating unit that converts the signal into a millimeter wave signal for transmission and propagates in the first dielectric line, and is disposed in close proximity to the first dielectric line so that one end side is electromagnetically coupled. A second dielectric line whose one end is joined to the first dielectric line and which propagates a part of the millimeter wave signal to the mixer side; and a ferrite disk arranged in parallel with the parallel plate conductor. Distribute at specified intervals on the periphery The millimeter-wave signal input from one of the connection parts, the first connection part, the second connection part, and the third connection part serving as input and output ends of the millimeter-wave signal. A circulator for outputting from another connecting portion that is adjacent clockwise or counterclockwise in the plane of the ferrite disk, wherein the first connecting portion is provided at an output end of the millimeter wave signal of the first dielectric line. Connected to the circulator, a third dielectric line which is connected to the second connection part of the circulator and which propagates the millimeter wave signal and has a transmitting antenna at the tip, a receiving antenna at the tip, and the like. A fourth dielectric line each having a mixer provided at its end and a third connection part of the circulator are connected to propagate the millimeter wave signal received and mixed by the transmitting antenna and to the tip part. A fifth dielectric line for attenuating the millimeter wave signal at the non-reflecting end portion, and a midway point of the second dielectric line and a midway point of the fourth dielectric line are close to each other and electromagnetically coupled. In a millimeter wave transceiver provided with a mixer unit that is formed by bonding or joining, and that generates an intermediate frequency signal by mixing a part of the millimeter wave signal and a received wave, the circulator is the circulator of the present invention. It is characterized by being.

The millimeter wave transmitter / receiver of the present invention has the above-mentioned configuration to improve the transmission loss and isolation characteristics of the millimeter wave signal in a higher frequency band and a wider bandwidth, and to reduce the millimeter wave signal received by the transmitting antenna to millimeter wave. Therefore, 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 detection distance can be further increased.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A millimeter wave radar module as a circulator and a millimeter wave transceiver for an NRD guide of the present invention will be described below. In the present invention, the mode suppressor and the dielectric line are described separately, but the mode suppressor is also one type of the dielectric line.

FIG. 1 is a perspective view of the circulator of the present invention, in which the upper and lower parallel plate conductors are omitted. In the figure, 4a, 4b and 4c are dielectric lines, 1a, 1b and 1c.
Is provided at the tip of each dielectric line 4a, 4b, 4c,
It is a mode suppressor that blocks electromagnetic waves in the LSE mode. 2a and 2b are mode suppressors 1a, 1b and 1c
Of the dielectric line 4a,
Two ferrite discs for circulators 4b and 4c arranged radially at an angular interval of 120 °, 3 are arranged inside the mode suppressors 1a, 1b and 1c, and are choke type line conductors made of Cu foil or the like. Of the strip line conductor, and blocks the LSE mode electromagnetic wave in which the electric field is in the direction (vertical direction in FIG. 1) perpendicular to the main surface of the parallel plate conductor. Further, the strip line conductor 3 is provided with a λ / 4 choke pattern for eliminating the TEM mode.

In this circulator, the dielectric line 4a
The electromagnetic waves propagating in the ferrite disk 2a, 2b
The wavefront is rotated counterclockwise by the connecting portions 5a, 5b.
Is propagated to the dielectric line 4b via, and does not propagate to the dielectric line 4c. Similarly, the electromagnetic wave propagating through the dielectric line 4b passes through the connecting portions 5b and 5c and the dielectric line 4c.
Is propagated to. In this way, the propagation path of electromagnetic waves is converted. Needless to say, if the positions of the S pole and the N pole of the DC magnetic field applied substantially perpendicular to the main surfaces of the ferrite discs 2a and 2b are reversed, the rotation direction of the wavefront of the high frequency signal is also reversed.

The mode suppressors 1a, 1b, 1c
Is not necessarily connected to the dielectric lines 4a, 4b, 4c, and in any of the mode suppressors 1a, 1b, 1c, another ferrite disk is connected to the tip opposite to the ferrite disks 2a, 2b. May be done. That is, 2
Mode suppressors 1a, 1 by two circulators
It is possible to adopt a configuration in which either b or 1c is sandwiched. If it is not necessary to block the LSE mode electromagnetic waves or remove the TEM mode, the mode suppressors 1a, 1
A dielectric line may be arranged instead of b and 1c.

In the present invention, two identically shaped ferrite discs 2a and 2b are installed on the inner surface of a parallel plate conductor so as to concentrically face each other in parallel to the inner surface. Regarding the thickness of the ferrite disks 2a and 2b, in the 77 GHz band used in the millimeter wave radar for automobiles, when ferrite having a relative dielectric constant of 13 is used, the thickness of the ferrite disks 2a and 2b is 0. 1 to 0.5 mm is preferable. If the thickness is less than 0.1 mm, the strength of the ferrite discs 2a and 2b is reduced and the handling becomes difficult. If it exceeds 0.5 mm, its diameter must be made small in order to prevent the shift of the pass band, and if the diameter becomes small, the isolation of the circulator deteriorates. Further, the diameter of the ferrite discs 2a, 2b is preferably 1 to 4 mm, and if it is less than 1 mm, the isolation of the circulator deteriorates, and if it exceeds 4 mm, it is necessary to reduce the thickness so that the pass band does not shift. The thickness is less than 0.1 mm, which makes handling difficult.

The ferrite disks 2a, 2b are provided with magnets, electromagnets, etc. for applying a DC magnetic field of about 355500 A / m from the outside of the parallel plate conductors to the main surfaces of the ferrite disks 2a, 2b. Functions as a circulator.

Further, in the present invention, the dielectric lines 4a to 4a
A plurality of c (three in FIG. 1) are ferrite discs 2a and 2b.
Are connected in a substantially radial manner. For example, the dielectric line 4
Three of a to 4c are arranged at equal angular intervals of 120 ° in the direction of their transmission paths. In the case of FIG. 1, 3 from the dielectric line 4a to the dielectric line 4b, from the dielectric line 4b to the dielectric line 4c, and from the dielectric line 4c to the dielectric line 4a.
It is possible to change the direction. In addition, four at 90 ° intervals,
It is also possible to provide six or the like at 60 ° intervals.

In the present invention, two ferrite discs 2a,
2b has an outer diameter difference of 200 μm or less and a circularity of 200 μm or less, and two ferrite disks 2a and 2b and one end of a plurality of dielectric lines (mode suppressors 1a to 1c in FIG. 1). Is 300μ each
m or less.

When the difference in outer diameter between the two ferrite discs 2a and 2b exceeds 200 μm, the ferrite discs 2a and 2b are
Since the centers of the two do not match and their side surfaces move so as to exceed 100 μm, stable circulator characteristics (pass frequency bandwidth, input / output reflection characteristics, isolation characteristics, etc.) cannot be obtained. For example, the outer diameter difference is 200μm
In the case of the above ferrite discs 2a and 2b, the mode suppressor 1a ...
Although the position of 1c is easily determined, the ferrite disk having the smaller outer diameter moves due to collision with the mode suppressors 1a to 1c, and the center position of the ferrite disks 2a and 2b is easily 100 μm or more. Because of the deviation, stable circulator characteristics cannot be obtained. The outer diameter difference is preferably 50
μm or less, more preferably 10 μm or less, further 1 μm
m or less is good, in this case two ferrite discs 2a, 2
The deviation of the center position of b becomes small, and the circulator characteristic becomes stable.

When the circularity of each of the two ferrite discs 2a and 2b exceeds 200 μm, if the maximum outer diameter portion of the ferrite disc 2a and the maximum outer diameter portion of the ferrite disc 2b deviate, the ferrite The position of the disk 2a or the ferrite disk 2b is not fixed by the mode suppressors 1a to 1c, and the ferrite disk 2a or the ferrite disk 2b is not fixed.
Move easily and their center positions deviate by more than 100 μm, so that stable circulator characteristics cannot be obtained. For example, when the positions of the mode suppressors 1a to 1c are determined by the maximum outer diameter portion of the ferrite disc 2a,
The other ferrite disk 2b and the mode suppressors 1a to 1
The maximum outer diameter portion of the ferrite disc 2b is not always located at the connecting portion with c. In that case, the position of the ferrite disk 2b is not fixed by the mode suppressors 1a to 1c, and the center of the ferrite disk 2b is displaced by more than 100 μm. The roundness is preferably 50 μm or less,
It is more preferably 10 μm or less, and further preferably 1 μm or less. In this case, the deviation of the center positions of the two ferrite discs 2a and 2b becomes small, and the circulator characteristic becomes stable.

The roundness means the difference in diameter between the coaxial inscribed circle and circumscribed circle that are in contact with a circle that is not a perfect circle.

Further, two ferrite discs 2a and 2b are provided.
And the space between one end of each of the mode suppressors 1a to 1c is 300 μm or less. As shown in FIG. 2, the space between the ferrite disks 2a and 2b and the mode suppressor 1a is set to this interval.
It is the minimum distance D from 1c.

The outer diameter difference between the ferrite disks 2a and 2b is 20.
Even if the roundness is 0 μm or less and each roundness is 200 μm or less, if the distance from any one end of the mode suppressors 1a to 1c exceeds 300 μm, the electromagnetic wave is not sufficiently propagated, which causes a transmission loss. Not only that, the propagation direction of the electromagnetic wave is not converted to the predetermined direction, and the isolation characteristic is degraded. Also, since the space is large, the ferrite disks 2a and 2b and the mode suppressor 1a due to vibration or shock are
Collisions with ~ 1c become severe, chips and cracks occur, and reliability is lowered. The interval is preferably 50 μm or less, more preferably 10 μm or less, further preferably 1 μm or less. In this case, the propagation direction of the electromagnetic wave is converted to a predetermined direction, and the circulator has excellent isolation characteristics and high reliability.

In the present invention, two ferrite disks 2 are used.
The dielectric spacer 24 or the like in FIG. 9 may be arranged between a and 2b. In this case, the dielectric spacer 24 is
It is preferable that the dielectric constant is as small as possible and the dielectric loss is small. The dielectric spacer 24 has a cylindrical shape as shown in FIG. 9, and a thin plate-shaped dielectric spacer is used as the mode suppressor 1.
a to 1c attached to the end face of the tip, or FIG.
The stepped portion 34 may be used as a dielectric spacer.
Further, the dielectric spacer 24 or the like may not be arranged between the two ferrite discs 2a and 2b and may be a space. In this case, it is possible to solve the problem that the resonance frequency of the ferrite resonator composed of the two ferrite disks 2a and 2b is deviated due to the change in the thickness of the dielectric spacer 24 and the operating frequency of the circulator is deviated.

In the present invention, the dielectric lines 4a-4c,
The materials mode suppressor 1 a to 1 c, Teflon, resin such as polystyrene or a low dielectric constant of the _{cordierite, (2MgO · 2Al 2 O 3} · 5SiO 2) ceramics, alumina (Al ₂ O ₃₎ ceramic, glass ceramic etc. Ceramics are preferable, and they have low loss in the high frequency band.

The high frequency band referred to in the present invention is several tens to one.
A microwave band and a millimeter wave band in the 00 GHz band are suitable, and a high frequency band of, for example, 30 GHz or more, particularly 50 GHz or more, and further 70 GHz or more is suitable.

The parallel plate conductor for the NRD guide of the present invention is Cu, A in terms of high electric conductivity and workability.
1, Fe, Ag, Au, Pt, SUS (stainless steel), brass (Cu-Zn alloy), or other conductor plate, or an insulating plate made of ceramics, resin, or the like on the surface of the metal,
It may be formed of a conductor layer such as an alloy.

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. For example, for an obstacle around the automobile and other automobiles. By irradiating a millimeter wave, the reflected wave is mixed with the original millimeter wave to obtain an intermediate frequency signal, and by analyzing this intermediate frequency signal, the distance to obstacles and other vehicles, their moving speed, etc. are measured. it can.

Thus, the circulator for the NRD guide of the present invention has stable circulator characteristics, and is highly reliable in vibration resistance and impact resistance.

Next, a millimeter wave radar module as a millimeter wave transceiver of the present invention will be described below. Figure 4
7 shows a millimeter wave radar module of the present invention, FIG. 4 is a plan view of a transmission antenna and a reception antenna integrated, FIG. 5 is a plan view of a transmission antenna and a reception antenna independent, and FIG. 6 is a millimeter view. 7 is a perspective view of the wave signal oscillator.
FIG. 3 is a perspective view of a wiring board provided with a variable capacitance diode (varactor diode) for a millimeter wave signal oscillator.

In FIG. 4, 51 is one parallel plate conductor (the other is omitted), 52 is a voltage control type millimeter wave signal oscillator provided at one end of the first dielectric line 53, and a bias is provided. 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 voltage application direction matches the electric field direction of the high frequency signal, and the triangular wave is generated. , A sine wave or the like is output as a millimeter wave signal for frequency modulation.

Reference numeral 53 is a first dielectric line for propagating a millimeter wave signal obtained by modulating a high frequency signal output from a high frequency diode such as a Gunn diode as a high frequency generating element. Reference numeral 54 is a first, a third and a third line. 4 dielectric lines 53, 5
The circulator of the present invention comprising a ferrite disk having first, second and third connecting portions 54a, 54b and 54c respectively connected to 5 and 57, and 55 to the second connecting portion 54b of the circulator 54. A third dielectric line that is connected and has a transmission / reception antenna 56 at its tip while propagating a millimeter wave signal, and 56 is a transmission / reception antenna provided by making the tip of the third dielectric line 55 tapered. Is.

A mode suppressor is connected to the circulator 54 side of the dielectric lines 53, 55 and 57, and the connecting portions 54a, 54b and 54c are connecting portions between the ferrite disk and the mode suppressor.

The transmitting / receiving antenna 56 inputs / outputs a high-frequency signal through the through hole formed in the parallel plate conductor 51, and is installed on the outer surface of the parallel plate conductor 51 via a metal waveguide connected to the through hole. It may be a horn antenna or the like.

Numeral 57 is received by the transmitting / receiving antenna 56, propagates through the third dielectric line 55, and circulates.
The received wave output from the third connection portion 54c of the mixer 5
It is a fourth dielectric line propagated to the 9 side. 58 is disposed close to the first dielectric line 53 so that one end side is electromagnetically coupled, or one end is joined to the first dielectric line 53, and a part of the millimeter wave signal is propagated to the mixer 59 side. The second dielectric line 58a is a second dielectric line 58a.
It is a non-reflection end portion (terminator) provided at one end portion on the side opposite to the mixer 59. Also, in the figure, M1 is the second
The intermediate part of the dielectric line 58 and the intermediate part of the fourth dielectric line 57 are close to each other to be electromagnetically coupled or joined, and a part of the millimeter wave signal and the received wave are mixed to generate an intermediate frequency signal. This is the mixer section.

These various parts are provided between parallel plate conductors arranged at intervals of the wavelength of the millimeter wave signal in air and not more than half the wavelength at the used frequency.

In FIG. 4, the first dielectric line 5
By providing a switch having the same structure as that shown in FIG. 7 in the middle of 3, it is possible to pulse the millimeter wave signal. For example, as shown in FIG. 7, it is a switch in which a choke type bias supply line 90 is formed on one main surface of a wiring substrate 88, and a beam lead type PIN diode or a Schottky barrier diode soldered and mounted in the middle thereof. .

As another example of the millimeter wave radar module of the present invention, there is a type shown in FIG. 5 in which the transmitting antenna and the receiving antenna are independent. In the figure, 61 is one parallel plate conductor (the other is omitted),
Reference numeral 62 denotes a voltage control type millimeter-wave signal oscillator provided at one end of the first dielectric line 63, and the first dielectric line 63 is arranged so that the bias voltage application direction matches the electric field direction of the high frequency signal. The bias voltage of the variable-capacitance diode arranged near the high-frequency diode is periodically controlled to generate a triangular wave, a sine wave, or the like, and the frequency-modulated millimeter-wave signal for transmission is output.

Reference numeral 63 is a first dielectric line that propagates a millimeter wave signal in which the high frequency signal output from the high frequency diode is frequency modulated, and 64 is a first, third and fifth dielectric line 63, 65. , 67, respectively, having the first, second, and third connecting portions 64a, 64b, 64c, which is a circulator of the present invention made of a ferrite disk.
Reference numeral 65 is a third dielectric line which is connected to the second connection portion 64b of the circulator 64 and which propagates a millimeter wave signal and has a transmission antenna 66 at its tip portion.
Is a transmission antenna provided by making the tip of the dielectric line 65 of FIG. Reference numeral 67 is a fifth dielectric line which is connected to the third connecting portion 64c of the circulator 64 and has a reflection-free termination portion 67a for attenuating the millimeter wave signal for transmission provided at the tip.

Further, 68 is disposed close to the first dielectric line 63 so that one end side is electromagnetically coupled, or one end is joined to the first dielectric line 63, and a part of the millimeter wave signal is mixed. A second dielectric line propagating to the 71 side, 68
Reference character a is a non-reflection end portion provided at one end portion of the second dielectric line 68 on the side opposite to the mixer 71. Reference numeral 69 is a fourth dielectric line that propagates the received wave received by the receiving antenna 70 to the mixer 71 side. In addition, M2 in the figure is
The middle part of the second dielectric line 68 and the middle part of the fourth dielectric line 69 are close to each other to be electromagnetically coupled or joined, and a part of the millimeter wave signal and the received wave are mixed to form an intermediate frequency. It is a mixer unit that generates a signal.

The transmitting antenna 66 and the receiving antenna 70 allow a high frequency signal to be input or output through a through hole formed in the parallel plate conductor 61, and the parallel plate conductor 61.
It may be a horn antenna or the like installed on the outer surface of the metal via a metal waveguide connected to the through hole.

These various components are provided between parallel plate conductors arranged at intervals of the wavelength of the millimeter wave signal in the air and not more than ½ of the wavelength at the working frequency.

In FIG. 5, a millimeter wave signal can be pulsed by providing a switch having the same structure as that shown in FIG. 7 in the middle of the first dielectric line 63.
For example, as shown in FIG. 7, it is a switch in which a choke type bias supply line 90 is formed on one main surface of a wiring substrate 88, and a beam lead type PIN diode or a Schottky barrier diode soldered and mounted in the middle thereof. .

Millimeter wave signal oscillators 52 and 62 for the millimeter wave radar module of FIGS. 4 and 5 are shown in FIGS. In these figures, 82 is a metal member such as a substantially rectangular parallelepiped metal block for installing the Gunn diode 83, and 83.
Is a Gunn diode which is a type of high frequency diode that oscillates a high frequency signal (millimeter wave signal). Reference numeral 84 is a wiring board which is installed on one side surface of the metal member 82 and which forms a choke type bias supply line 84a which functions as a low-pass filter that supplies a bias voltage to the Gunn diode 83 and prevents leakage of high frequency signals. It is a strip conductor such as a metal foil ribbon that connects the mold bias supply line 84a and the upper conductor of the Gunn diode 83. 86
Is a metallic strip line 86a for resonance on a dielectric substrate.
The metal strip resonator 87 is provided with a dielectric line (first dielectric line 53, 63) that guides the high frequency signal resonated by the metal strip resonator 86 to the outside of the millimeter wave signal oscillator.
Is equivalent to).

Further, in the middle of the dielectric line 87, a wiring board 88 loaded with a varactor diode 80, which is a type of variable capacitance diode and is a frequency modulation diode.
Has been installed. The bias voltage application direction of the varactor diode 80 is perpendicular to the propagation direction of the high frequency signal in the dielectric line 87 and parallel to the main surface of the parallel plate conductor (electric field direction). The bias voltage application direction of the varactor diode 80 is L which propagates in the dielectric line 87.
It matches the electric field direction of the high frequency signal of SM ₀₁ mode,
As a result, the frequency of the high frequency signal can be controlled by electromagnetically coupling the high frequency signal and the varactor diode 80 and changing the electrostatic capacitance of the varactor diode 80 by controlling the bias voltage. Reference numeral 89 is a dielectric plate having a high relative permittivity for impedance matching between the varactor diode 80 and the dielectric line 87.

Further, as shown in FIG. 7, a choke type bias supply line 90 is formed on one main surface of the wiring substrate 88,
A beam lead type varactor diode 80 is arranged in the middle of the choke type bias supply line 90. An electrode 81 for connection is formed at the connection portion of the choke type bias supply line 90 with the varactor diode 80. The high frequency signal oscillated from the Gunn diode 83 passes through the metal strip resonator 86 and the dielectric line 87.
Be derived to. Next, a part of the high frequency signal is reflected by the varactor diode 80 and returns to the Gunn diode 83 side. This reflected signal changes with the change in the capacitance of the varactor diode 80, and the oscillation frequency changes.

The millimeter wave radar modules shown in FIGS. 4 and 5 are FMCW (Frequency Modulation Continuous).
Waves) method, and its operating principle is as follows. MOD for inputting modulation signal of millimeter wave signal oscillator
An input signal whose voltage amplitude changes with time into a triangular wave, sine wave, etc. is input to the IN terminal, and the output signal is frequency-modulated,
The output frequency deviation of the millimeter wave signal oscillating section is shifted so that it becomes a triangular wave, a sine wave, or the like. And the transmitting / receiving antenna 5
6. When an output signal (transmission wave) is radiated from the transmission antenna 66, if a target is present in front of the transmission / reception antenna 56 and the transmission antenna 66, the reflected wave (reception wave) Waves) are coming back. At this time, IFOUT on the output side of the mixer 59, 71
The frequency difference between the transmitted wave and the received wave is output to the terminal. By analyzing frequency components such as the output frequency of the IFOUT terminal, Fif = 4R · fm · Δf / c (Fif: IF (I
ntermediate Frequency) output frequency, R: distance, f
The distance can be obtained from a relational expression of m: modulation frequency, Δf: frequency shift width, c: speed of light.

In the millimeter wave signal oscillator 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 and C.
It is made of r, Pd, Pt, or the like, and Cu and Ag are particularly preferable because they have good electric conductivity, small loss, and large 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 is bridged between the choke type bias supply line 84a and the Gunn diode 83. That is, one end of the strip conductor 85 is connected to one end of the choke type bias supply line 84a by soldering or the like, and the other end of the strip conductor 85 is connected to the upper conductor of the Gunn diode 83 by soldering or the like. The middle part except the connection part of is in a state of floating in the air.

Since the metal member 82 also serves as an electrical ground (earth) for the Gunn diode element 83, it may be made of metal (including alloy), brass (brass: Cu-Z).
n alloy), Al, Cu, SUS, Ag, Au, Pt and the like. The metal member 82 is a metal block entirely made of metal, a surface of an insulating substrate such as ceramics or plastic that is partially or partially metal-plated, or a surface of the insulating substrate is partially or entirely coated with a conductive resin material or the like. It may be one.

Thus, in the millimeter wave radar module as the millimeter wave transceiver of the present invention, the millimeter wave radar module shown in FIG. 4 has improved transmission loss and isolation characteristics of the millimeter wave signal in a higher frequency band and a wider bandwidth. When it is applied to a millimeter wave radar, its detection range can be increased.
Further, in the one shown in FIG. 5, the transmission loss and the isolation characteristic of the millimeter wave signal are improved in a higher frequency band and a wider bandwidth, and the millimeter wave signal for transmission is not mixed into the mixer through the circulator, As a result, the noise of the received signal is reduced, and the detection range of the millimeter wave radar can be further increased.

[0058]

Embodiments of the circulator of the present invention will be described below.

The circulator of FIG. 1 according to the present invention was constructed as follows. 2 as a parallel plate conductor with a thickness of 6 mm
An adhesive composed of a one-component thermosetting epoxy resin is used on the inner surfaces of the lower parallel plate conductors on a portion corresponding to the dielectric lines 4a to 4c, the mode suppressors 1a to 1c, and the ferrite disk 2a using a single Al plate. Screen printing is performed with a thickness of 50 μm, and the dielectric lines 4a to 4c, the mode suppressors 1a to 1c, and the ferrite disk 2a are each 0.0.
Press down with a pressure of 1 MPa (megapascal) for 12
The adhesive was cured at 0 ° C.

At this time, the lower ferrite disk 2a had a diameter of 2.01 mm, a circularity of 30 μm and a thickness of 0.25 mm. The dielectric lines 4a to 4c have a sectional shape of 1.8 m.
It was a rectangle of m (height) × 0.8 mm (width), and was made of cordierite ceramics having a relative dielectric constant of 4.8. Mode suppressors 1a to 1c made of glass ceramic having a relative permittivity of 4.8 are connected to the respective tips of the three dielectric lines 4a to 4c, and the tips are electromagnetically coupled to one ferrite disk 2a. Connected with 12
It was arranged radially at equal angular intervals of 0 °.

The mode suppressors 1a to 1c were produced by arranging the strip line conductor 3 made of Cu foil having a λ / 4 choke pattern inside them. Further, in the central portion of the tip surfaces of the mode suppressors 1a to 1c, a thickness of 0.23 mm, a width of 0.8 mm, and a length of 1.0 to 1.3 mm made of cordierite ceramics having a relative dielectric constant of 4.8 are used. Plate-shaped dielectric spacers are adhered in advance, and a space of about 0.25 to 0.40 mm, which is approximately equivalent to the thickness of the ferrite disks 2a and 2b, is provided at the upper and lower ends of the tip surfaces of the mode suppressors 1a to 1c. It was

After the adhesive was hardened, the distance between the connecting portions of the ferrite disk 2a and the mode suppressors 1a to 1c was measured by an image measuring device {"QS-L200Z" manufactured by Mitutoyo Corporation). The interval is measured by the mode suppressors 1a to 1
Ferrite disk 2 on the side of the tip surface on the connection side of c and on the lower side
It was done by measuring the distance from a from the side. As a result, the distance between the three connections is 1 μm,
It was 7 μm and 10 μm.

Next, a ferrite disk 2b having a thickness of 0.25 mm and a diameter and a circularity as shown in Table 1 was formed on the upper surfaces of the mode suppressors 1a to 1c and the ferrite disk 2b.
Of the dielectric spacers adhered to the tip surfaces of the mode suppressors 1a to 1c and the tip surfaces of the mode suppressors 1a to 1c, respectively.
I dropped it from above. When the upper ferrite disc 2b was measured with an image measuring device in the same manner as the ferrite disc 2a, the intervals (air gaps) between the three connecting portions were as shown in Table 1.

[0064]

[Table 1]

Then, an upper parallel plate conductor having a circular recess having a diameter of 12.5 mm and a depth of 5 mm formed on the upper surface (outer surface) is arranged so that the recess and the ferrite disks 2a and 2b are concentrically located. Fix it from above and put it in the recess at 355500
A circular magnet having a thickness of 4.5 mm and a diameter of 12.5 mm for applying a DC magnetic field of A / m was installed to prepare a circulator for an NRD guide.

With respect to the circulator having the above structure, the transmission characteristics | S ₂₁ | and | S ₃₁ | of the high frequency signal are measured in a high frequency band of 75 to 79 GHz using a spectrum analyzer, and the difference (isolation) is calculated. The results are shown in FIG. In addition, in FIG. 3, Samples 1 to 5 correspond to Samples 1 to 5 in Table 1.

From FIG. 3, Samples 1 to 4 of the present invention are 76.2.
It showed excellent characteristics that the isolation was -15 dB or less at ˜77 GHz, but the sample 5 of the comparative example had −1.
It was larger than 5 dB and the isolation characteristics were poor.

The present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the gist of the present invention.

[0069]

According to the circulator of the present invention, two parallel plate conductors, which are arranged parallel to the inner surface of the parallel plate conductors, are provided between the parallel plate conductors arranged at intervals of ½ or less of the wavelength of the millimeter wave signal. A circulator for a non-radiative dielectric line, in which a plurality of ferrite discs are installed, and a plurality of dielectric lines whose one ends are close to each other are arranged substantially radially around the peripheral edges of the two ferrite discs. The two ferrite discs have an outer diameter difference of 200 μm or less, a circularity of 200 μm or less, and a distance from one end of the plurality of dielectric lines of 300 μm or less. Deviation of the concentricity of the ferrite disk is reduced, and the gap between the two ferrite disks and each dielectric line is small, the pass frequency bandwidth, the input / output reflection characteristics, and the isolation ® emission characteristics are improved, good circulator characteristics. Also, because the gap is small,
The influence of collision between the ferrite disk and the dielectric line due to vibration or shock is reduced, cracks and chips are less likely to occur in the ferrite disk, and a highly reliable product can be obtained.

A millimeter wave transceiver having a transmitting and receiving antenna using the circulator of the present invention has improved transmission loss and isolation characteristics of a millimeter wave signal in a high frequency band and a wide bandwidth, and as a result, is applied to a millimeter wave radar and the like. In that case, the detection distance can be increased. Also,
The millimeter wave transceiver using the circulator of the present invention, in which the transmitting antenna and the receiving antenna are independent, has improved transmission loss and isolation characteristics of the millimeter wave signal in a higher frequency band and a wider bandwidth, and has a millimeter wave received by the transmitting antenna. Wave signal does not mix into the millimeter wave signal oscillator,
Therefore, 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 detection distance can be further increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an embodiment of a circulator of the present invention.

FIG. 2 is an enlarged plan view of a main part of the circulator shown in FIG.

FIG. 3 is a graph showing the results of measuring isolation characteristics of the circulator of the present invention and the circulator of the comparative example.

FIG. 4 is a plan view showing an example of an embodiment of a millimeter wave radar module of the present invention.

FIG. 5 is a plan view showing another example of the embodiment of the millimeter wave radar module of the present invention.

FIG. 6 is a perspective view showing a millimeter wave signal oscillator for the millimeter wave radar module of the present invention.

FIG. 7 is a perspective view of a wiring board provided with a varactor diode for the millimeter wave signal oscillator of FIG.

FIG. 8 is a perspective view showing a basic configuration of a conventional NRD guide and partially seeing through the inside.

FIG. 9 is a perspective view of a conventional circulator.

FIG. 10 is a perspective view showing another example of a conventional circulator.

[Explanation of symbols]

1a, 1b, 1c: Mode suppressor 2a, 2b: Ferrite disk 4a, 4b, 4c: Dielectric line 5a, 5b, 5c: Connection part

Claims (3)

[Claims] 1. Between two parallel flat plate conductors arranged at intervals equal to or smaller than ½ of the wavelength of a millimeter wave signal, and two opposing ferrite discs arranged in parallel to the inner surfaces of the parallel flat plate conductors. Is provided, and a plurality of dielectric lines whose one ends are close to the peripheral edges of the two ferrite discs are arranged substantially radially. The discs have an outer diameter difference of 200 μm or less, a circularity of 200 μm or less, and a distance from one end of each of the plurality of dielectric lines of 300 μm or less. Circulator for dielectric line. 2. A first wave-propagating millimeter-wave signal output from a high-frequency generating element, which is output from a high-frequency generating element, is propagated between parallel plate conductors arranged at intervals of ½ or less of a wavelength of the millimeter-wave signal. A dielectric line and a high-frequency signal output from the high-frequency generating element, which is attached to one end of the first dielectric line, is periodically frequency-modulated or pulsed to output as a millimeter-wave signal for transmission. A millimeter wave signal oscillator that propagates in the first dielectric line, and one end side of the first dielectric line are arranged close to each other so as to be electromagnetically coupled, or one end of the first dielectric line is joined to the first dielectric line. And a second dielectric line for propagating a part of the millimeter-wave signal to the mixer side, and a ferrite disk arranged in parallel with the parallel plate conductor, arranged at predetermined intervals on the peripheral edge of each of the ferrite plates, and Millimeter wave signal It has a first connecting portion, a second connecting portion and a third connecting portion which are output terminals, and rotates the millimeter wave signal inputted from one of the connecting portions in a plane of the ferrite disk. Alternatively, a circulator that outputs from another adjacent counter-clockwise connection portion, the circulator having the first connection portion connected to the output terminal of the millimeter wave signal of the first dielectric line, and the circulator. And a third dielectric line that is connected to the second connection part of the above and that propagates the millimeter-wave signal and that has a transmission / reception antenna at the tip part, and propagates through the third dielectric line that is received by the transmission / reception antenna. A fourth dielectric line for propagating the received wave output from the third connection part of the circulator to the mixer side; a midway point of the second dielectric line line and a midway point of the fourth dielectric line line. Close A millimeter wave transceiver provided with a mixer section for electromagnetically coupling or joining the millimeter wave signals and mixing a part of a millimeter wave signal with a received wave to generate an intermediate frequency signal, wherein the circulator is the circulator. A millimeter wave transmitter / receiver, which is the circulator described. 3. A millimeter-wave signal output from a high-frequency generator and frequency-modulated or pulsed is propagated between parallel plate conductors arranged at intervals of ½ or less of the wavelength of the millimeter-wave signal. A first dielectric line, and a millimeter wave signal for transmission, which is attached to one end of the first dielectric line and periodically frequency-modulates or pulses the high-frequency signal output from the high-frequency generating element. And a millimeter-wave signal oscillating section that outputs as a signal and propagates in the first dielectric line, and is arranged in proximity to the first dielectric line so that one end side is electromagnetically coupled or to the first dielectric line. A second dielectric line having one end joined to propagate a part of the millimeter wave signal to the mixer side, and arranged at a predetermined interval on a peripheral edge of a ferrite disk arranged in parallel with the parallel plate conductor. And each of the above In the plane of the ferrite disk, the millimeter-wave signal input from one of the connecting portions has a first connecting portion, a second connecting portion, and a third connecting portion which are used as signal input / output terminals. A circulator for outputting from another connection portion that is clockwise or counterclockwise adjacent to each other, wherein the first connection portion is connected to the output end of the millimeter wave signal of the first dielectric line, A third dielectric line which is connected to the second connection part of the circulator and which propagates the millimeter wave signal and has a transmitting antenna at the tip, a receiving antenna at the tip, and a mixer at the other end. The fourth dielectric line provided is connected to the third connection part of the circulator, propagates the millimeter wave signal received and mixed by the transmission antenna, and is forwarded by a non-reflection terminal part provided at the tip part. The fifth dielectric line for attenuating a millimeter wave signal and the middle of the second dielectric line and the middle of the fourth dielectric line are close to each other to be electromagnetically coupled or bonded to each other. A millimeter wave transceiver provided with a mixer section for mixing a part of a millimeter wave signal and a received wave to generate an intermediate frequency signal, wherein the circulator is the circulator according to claim 1. Wave transceiver.