JP2989427B2 - High frequency signal generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency signal generator used in a millimeter-wave band FM radar device mounted on a vehicle.

2. Description of the Related Art As a millimeter-wave band FM radar device mounted on a vehicle, a device using a nonradiative dielectric line has been developed. This non-radiative dielectric line is composed of upper and lower parallel conductor plates and a rod-shaped dielectric (dielectric rod) interposed between them, and is a simple and compact type that propagates a high-frequency signal along the dielectric rod. and it has a Do configuration. A high-frequency FM signal generator for a millimeter-wave band FM radar using such a simple and small non-radiative dielectric line is disclosed in Japanese Patent Application No. 4-269627 filed by the present applicant. Thus, the configuration is as shown in FIG. FIG. 2A is a plan view of a peripheral portion of such a high-frequency FM signal generator, and FIG.
2B is a cross-sectional view, and FIG. 2C is a cross-sectional view along CC ′ in FIG. However, the plan view (A) shows a state in which the upper conductive plate constituting the non-radiative dielectric waveguide is removed.
X, Y, and Z in FIG. 2A are orthogonal three-dimensional coordinates added for description.

A non-radiative dielectric line extending parallel to the Z-axis is formed by a lower conductor plate 11, an upper conductor plate 12, and a dielectric rod 13 held therebetween.
Diode mount 1 composed of metal block 14a and printed wiring board 14b held on the side surface
4 is held between the upper and lower conductor plates 11 and 12. As shown in the cross-sectional view of FIG. 2C, the upper and lower portions of the diode mount 14 have upper and lower conductor plates 11 and 12 respectively.
Is positioned in the Z-axis direction by being inserted into the concave portion 14c formed at the bottom. A heat radiation stud of a gun diode GD is screwed into the center of the metal block 14a of the diode mount 14, and one electrode of this gun diode is kept at the ground potential through a screwing mechanism of the metal block 14a and the heat radiation stud. At the same time, a bias voltage is supplied to the other electrode via a microstrip low-pass filter formed on the printed wiring board 14b. A varactor diode for frequency modulation is also mounted on the printed wiring board 14b.

A millimeter-wave band FM signal generated by the Gunn diode GD is coupled via a resonator 15 to an end of a dielectric rod 13 constituting a non-radiative dielectric line, and the direction in which the dielectric rod 13 extends. (Z-axis direction)
It is supplied to a transmission antenna and the like via an isolator, a coupler, etc., not shown.

The resonator 15 is composed of a dielectric plate 15b and a metal foil 15a formed on the surface of the dielectric plate 15b.
The rear surface of the dielectric plate 15b on the base side is held by bonding to the end surface of the dielectric rod 13 in a state where it is positioned so as to face the Gunn diode GD held by 4. The center frequency of the FM signal to be generated is 60 GHz
It is controlled within a range of about ± 5 GHz. The control of the center frequency depends on the oscillation characteristics of the Gunn diode GD and the resonator 15.
This is performed in combination with the resonance characteristics of The resonance characteristics of the resonator 15 depend on the dimensions of the metal foil 15a,
5 depends on the length along the signal propagation direction (X-axis direction).

The length of the metal foil 5a in the X-axis direction is FM
When the center frequency of the signal is 60 GHz, 1.5 mm ±
It is set in the range of 0.5 mm. Specifically, the metal foil 15
A lot of resonators are prepared in advance with the length L changed in increments of 0.05 mm (50 μm), and the resonators having different metal foil lengths are exchanged to repeat the trial and error of actually measuring the center frequency. By doing so, the resonator to be finally used is selected. The distance between the dielectric rod 13 and the Gunn diode GD is equal to the length of the metal foil 15a, that is, the side of the dielectric rod 13 facing the Gunn diode GD matches the end of the metal foil 15a. , The distance between the diode mount 14 and the Gunn diode GD is determined. Since the dielectric rod 13 is bonded and fixed to the lower conductor plate 11, the metal block 14a held in the recess 14c is slid in the X-axis direction each time the length of the metal foil 15a is changed. After that, it is fixed by screws from outside the upper and lower conductor plates. To enable this sliding, the length of the concave portion 14c is longer than the length of the metal mount 14a in the X-axis direction.

[0007]

According to the above prior art, in order to change the length of the metal foil 15a of the resonator 15 of the FM signal generator by trial and error, the recess 14c is formed in the X-axis direction. The length is longer than the length of the metal mount 14a. As a result, the printed wiring board 14b and the recess 14c
A gap may be formed between the end portion of the first member and the second member. Since such a gap affects the oscillation characteristics of the Gunn diode, there is a problem that frequency adjustment becomes difficult. Accordingly, it is an object of the present invention to provide a high-frequency signal generator in which a gap that makes frequency adjustment difficult is not formed.

Further, according to the above-mentioned prior art of the present applicant, the resonator 15 is fixed to the dielectric rod 13 by bonding the back surface of the dielectric plate 15 b of the resonator 15 to the end surface of the dielectric rod 13. doing. For this reason, if the adhesive layer is broken by vibration or impact generated during running of the vehicle, there is no possibility that the resonator 15 will be separated from the end face of the dielectric rod 13. Accordingly, another object of the present invention is to provide a high-frequency signal generator in which the resonator 15 is prevented from being separated from the dielectric rod 13.

[0009]

According to the high frequency signal generator of the present invention, the upper and lower conductor plates constituting the non-radiative dielectric line have step portions whose thickness changes along the extending direction of the dielectric rod. An outer conductor plate and an inner conductor plate having a thickness equal to the depth of the step and slidable in a direction orthogonal to the extension direction of the dielectric rod, and one or both of the inner conductor plates are provided with a mount. A recess for inserting a metal block is formed. Further, according to the high-frequency signal generator of the present invention, the dielectric plate of the resonator is bonded to the end face of the dielectric rod constituting the non-radiative dielectric line, and one or both of the upper and lower sides of the dielectric plate The end is inserted into a groove formed in one or both of the upper and lower conductor plates constituting the non-radiative dielectric waveguide.

[0010]

The structure in which the entire inner conductor plate in which the recess for inserting the metal block of the mount is formed is slid with respect to the outer conductor plate, so that a space is formed between the mount and the recess. And frequency adjustment becomes easier. Also, since at least one of the upper and lower ends of the dielectric plate of the resonator is inserted into the groove formed in the conductor plate,
Displacement in the direction perpendicular to the extension direction is prohibited,
As a result, peeling of the bonding surface between the dielectric substrate and the dielectric rod of the resonator is effectively prevented. Hereinafter, the present invention will be described in more detail with reference to examples.

[0011]

FIG. 1A is a diagram showing a high-frequency F according to an embodiment of the present invention.
FIG. 4B is a plan view showing the configuration of the M signal generator, FIG. 4B is a cross-sectional view taken along line BB ′ in FIG.
FIG. 14 is a sectional view taken along the line C ′. However, the plan view (A) is shown with the upper conductor plate constituting the non-radiative dielectric waveguide removed. X, Y, and Z in the plan view (A) are:
These are orthogonal three-dimensional coordinates added for the purpose of explanation. In FIG. 1, the components denoted by the same reference numerals as those in FIG.
Are the same as those already described with respect to, and redundant description of these components will be omitted.

In the high-frequency FM signal generator according to this embodiment, the upper and lower conductor plates constituting the non-radiative dielectric line have outer conductor plates 11b and 12b each having a step which changes the thickness in the Z-axis direction.
And internal conductor plates 11a and 12a having a thickness equal to the depth of the step and slidable in the X-axis direction. The inner conductor plates 11a and 12a have metal mounts 14a.
A concave portion 14c is formed for inserting the hole. The upper end and the lower end of the metal block 14a of the diode mount 14 are inserted into grooves 14c formed in the upper and lower internal conductor plates 11a and 12a, so that the metal blocks 14a in the X-axis direction and the Z-axis direction. Displacement is prohibited, and rotation about the Y axis is also prohibited.

In the process of adjusting the oscillation frequency, the bottom surface of the dielectric rod 13 is adhered and fixed only to the surface of the outer conductor plate 11b, and is slidable on the surfaces of the inner conductor plates 11a and 12a. ing. Therefore, every time the length of the metal foil 15a of the resonator 15 is changed, the internal conductor plate 11a
And 12a are slid on the outer conductor plates 11b and 12b, so that the distance between the Gunn diode GD and the side surface of the dielectric rod 13 on the mount 14 side is adjusted. A long hole 16 whose longitudinal direction is the X-axis direction is formed in the lower internal conductor plate 11a. After the adjustment of the distance by the above-mentioned sliding is completed, the screw 17 is passed through the long hole 16 to the lower side. The lower inner conductor plate 11a is coupled to the lower outer conductor plate 11b by being screwed into a screw hole formed at a predetermined position of the outer conductor plate 11b. Further, the bottom surface of the dielectric rod 13 is bonded and fixed to the surface of the internal conductor plate 11a.

A groove 15c extending in the Y-axis direction is formed in the internal conductor plate 11a at the place where the resonator 15 is installed, and the lower end of the dielectric plate 15b forming the resonator 15 is formed in the groove 15c. Is inserted into. Thereby, displacement of the resonator 15 bonded and fixed to the end surface of the dielectric rod 13 in the Z-axis direction is prohibited, and peeling of the bonded portion due to vibration or impact is effectively prevented.

In the above, the configuration in which the groove for inserting the lower end of the dielectric plate of the resonator is formed in the lower conductor plate has been exemplified.
A groove for inserting the upper end of the dielectric plate may be formed in the upper conductive plate. In addition, metal block 1
Although the configuration in which the concave portion 14c for inserting the 4a is formed in both the upper and lower internal conductor plates has been illustrated, the configuration in which such a concave portion is formed in only one of the upper and lower internal conductor plates may be adopted.

Further, although the FM signal generator has been exemplified as the high frequency signal generator, it goes without saying that the present invention can be applied to a simple high frequency signal generator for generating a high frequency signal of a constant frequency.

[0017]

As described in detail above, the high-frequency signal generator of the present invention has a structure in which the entire inner conductor plate in which the recess for mounting is formed is slid with respect to the outer conductor plate. There is no room to form a gap between the mount and the recess that affects the oscillation characteristics of the Gunn diode, and the frequency can be easily adjusted.

Further, since the high-frequency signal generator of the present invention has a configuration in which at least one of the upper and lower ends of the dielectric plate of the resonator is inserted into the groove formed in the conductor plate, the bonding surface of the dielectric rod to the dielectric rod is formed. The effect of effectively preventing peeling and significantly improving reliability is achieved.

[Brief description of the drawings]

FIG. 1 is a plan view (A) and cross-sectional views ((B), (C)) showing the configuration of a high-frequency FM signal generator according to one embodiment of the present invention.

FIG. 2 is a plan view (A) and a cross-sectional view ((B), (C)) showing a configuration of a high-frequency FM signal generator according to the prior art of the present applicant.

[Explanation of symbols]

 11a, 12a Inner conductor plate 12b, 12b Outer conductor plate 13 Dielectric rod 14 Diode mount 14a Metal block 14c Recess for inserting metal block 15 Resonator 15a Metal foil 15b Dielectric plate 15c Insert lower end of dielectric plate Grooves 16 Slots 17 Screws

──────────────────────────────────────────────────続 き Continuing from the front page (56) References Real Opening Sho-59-183002 (JP, U) Tsutomu Yoneyama, "Millimeter-Wave Integrated Circuits Using Nonradiative Dielectric Lines," IEICE Transactions C-1 vol. J73-C-1 No. 3 pp. 87-94, March 1990 (58) Fields investigated (Int. Cl. ⁶ , DB name) H03B 9/12-9/14 H01P 3/16 G01S 7/282 G01S 13/34

Claims (3)

(57) [Claims] 1. A non-radiative dielectric line comprising a mount including a metal block for mounting a high-frequency oscillation element, an upper and lower conductor plate and a dielectric rod interposed therebetween, and a high-frequency wave generated by the high-frequency oscillation element. A resonator for propagating a signal to the non-radiative dielectric line, wherein the upper and lower conductor plates constituting the non-radiative dielectric line extend along the extension direction of the dielectric rod. An outer conductor plate having a step portion having a variable thickness, and an inner conductor plate having a thickness equal to the depth of the step portion and slidable in a direction orthogonal to an extending direction of the dielectric rod, A high-frequency signal generator, wherein the mount is held on one or both of the conductor plates. 2. The dielectric rod according to claim 1, wherein the resonator comprises a dielectric plate and a metal foil formed on the dielectric plate, and the dielectric plate constitutes the non-radiative dielectric line. And an upper or lower end or both ends are inserted into grooves formed in the upper and lower inner conductor plates. 3. A mount for mounting a high-frequency oscillator, a non-radiative dielectric line comprising upper and lower conductor plates and a dielectric rod interposed therebetween, a dielectric plate and a surface formed on the front or back surface thereof. A resonator made of metal foil and transmitting a high-frequency signal generated by the high-frequency oscillation element to the non-radiative dielectric line, wherein the dielectric plate of the resonator includes the non-radiative dielectric. are inserted above and below the one or both of the ends the nonradiative dielectric line is formed above and below the conductor plate constituting the groove while being adhered to the end face of the dielectric rod which constitutes the body line, the groove Along
By moving the dielectric plate back and forth,
A high-frequency signal generator capable of fine-tuning the oscillation characteristics of the signal generator.