JPH0794946A - Frequency-variable microwave oscillator - Google Patents

Abstract

PURPOSE:To provide a frequency-variable microwave oscillator capable of switching the oscillation frequency of a microwave. CONSTITUTION:This microwave oscillator is constituted a supporting means consisting of microstrip lines 12, 14 provided on a dielectric substrate 2 and connected to an FET 11, a dielectric resonator 10 arranged close to the lines 12, 14, a metallic rod 4 supported on the upper part of the resonator 10 and a locking part 6 fixed to a shield case 1 with a locking piece 5 provided on the side face part of the rod 4, a magnet piece 3 provided integrally with the upper part of the rod 4, and an electromagnet constituted of an iron core 7 arranged on the upper part of the magnet piece 3 and a winding coil. The distance between the rod 4 and the resonator 10 is switched to plural stages by controlling the direction of a current flowing through the winding coil to switch oscillation frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FET (field effect transistor) oscillator using a dielectric resonator used in a microwave circuit, and particularly to a BS (satellite broadcast) and CS (communication satellite) receiving antenna. Related to the converter used.

[0002]

2. Description of the Related Art FIG. 4 is a partially cutaway perspective view of a microwave oscillator using a dielectric resonator, showing a conventional example, and a dielectric substrate 2 provided inside a shield case 25 of the oscillator.
The dielectric resonator 10 is attached to the upper surface of the dielectric using an adhesive or the like, and the microstrip line 12 connected to the drain terminal of the FET 11 and the microstrip line 14 connected to the gate terminal are It is placed at a position where it is electromagnetically coupled with. Between the drain circuit and the gate circuit of the FET 11, a capacitance between both circuits and a feedback circuit by the dielectric resonator 10 are formed, and the dielectric resonator 1
0 resonates at a predetermined frequency and negatively feeds back a signal to the gate circuit side, and thus oscillates a microwave having a predetermined frequency.

Regarding the resonance frequency of the dielectric resonator 10, a through hole is provided in a portion of the shield case 25 above the dielectric resonator 10 and a metal screw 26 is screwed into the through hole, so that the dielectric resonator 10 and By changing the distance between the metal screws 26, the number of magnetic fluxes of the dielectric resonator 10 blocked by the metal screws 26 is changed, the resonance frequency of the dielectric resonator 10 is changed, and the microwave oscillation frequency is changed. I was trying to adjust it. In order to prevent the oscillation frequency from changing during use, after adjusting the oscillation frequency, the metal screw 26 is fixed to the shield case 25 using a screw lock or the like.

[0004]

Therefore, since the oscillation frequency of the microwave is a single frequency and the switching of the oscillation frequency is not possible, for example, in the BS and CS common converter, for the BS for the oscillation frequency 10.678 GHz and the oscillation frequency Since two microwave oscillators for CS having a frequency of 11.2 GHz are provided, there is a problem that the converter becomes large and the cost becomes high. The present invention makes it possible to switch the microwave oscillation frequency so that one microwave oscillator can be shared for BS reception and CS reception, thereby making the converter compact and reducing the cost. The purpose is to

[0005]

A variable frequency microwave oscillator according to the present invention is provided on a dielectric substrate and has a microstrip line connected to an FET and a dielectric strip provided close to the microstrip line. A body resonator, a metal rod supported above the dielectric resonator, and a switching means for switching the distance between the metal rod and the dielectric resonator in a plurality of steps. .

[0006]

As described above, the present invention comprises the switching means for switching the distance between the metal rod supported on the upper part of the dielectric resonator and the dielectric resonator in a plurality of steps. If the distance is increased, the resonance frequency of the dielectric resonator can be lowered, and it is 10.67 for BS reception.
It is possible to oscillate at an oscillating frequency of 8 GHz, and if the distance between the metal rod and the dielectric resonator is made short, the resonant frequency of the dielectric resonator can be increased, and oscillation at 11.2 GHz for CS reception. Since it can oscillate at a frequency, it becomes possible to use one microwave oscillator in common.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway perspective view showing an embodiment of a variable frequency microwave oscillator of the present invention.
The same components as those shown in FIG. 4 are designated by the same symbols. The dielectric resonator 10 is attached to the upper surface of the dielectric substrate 2 provided inside the shield case 1 of the oscillator using an adhesive or the like, and connected to the microstrip line 12 and the gate terminal connected to the drain terminal of the FET 11. The microstrip line 14 that is formed is the dielectric resonator 10
It is placed at a position where it is electromagnetically coupled with. Between the drain circuit and the gate circuit of the FET 11, a feedback circuit is formed by the capacitance between the two circuits and the dielectric resonator 10, and the dielectric resonator 10 resonates only at a predetermined frequency to apply negative feedback to the gate circuit side. , Oscillates a microwave of a predetermined frequency.

A through hole is provided in a portion of the shield case 1 directly above the dielectric resonator 10, and a metal rod 4 is inserted from the outside of the shield case 1 into the inside through the through hole, and a metal rod outside the shield case 1 is inserted. The locking piece 5 provided on the side surface of the metal plate 4 and the locking portion 6 provided on the upper surface of the shield case 1 constitute a supporting means for the metal rod 4 to support the metal rod 4. The magnet piece 3 is integrally provided on the upper portion of the metal rod 4, and an electromagnet including an iron core 7 fixed to another fixing portion and a winding wound on the iron core 7 is provided on the upper portion of the magnet piece 3. Are arranged.

Connection terminals 8 and 9 of the winding wound around the iron core 7.
When a DC voltage is applied between them and a current is caused to flow from the connection terminal 8 to the connection terminal 9, the side of the iron core 7 facing the magnet piece 3 is magnetized to the N pole, and the direction from the connection terminal 9 to the connection terminal 8 is increased. When an electric current is applied by applying a current, the side of the iron core 7 facing the magnet piece 3 becomes S
Magnetized to poles. If the surface side of the magnet piece 3 is the S pole, the metal rod 4 will be first pulled up and pushed down in the next operation, and the tip of the metal rod 4 inserted in the shield case 1 will be pushed. The distance between the dielectric resonator 10 and the dielectric resonator 10 can be switched.

When the number of magnetic fluxes of the dielectric resonator 10 blocked by the metal rod 4 is changed by switching the distance between the tip of the metal rod 4 and the dielectric resonator 10, the relative permittivity of the dielectric resonator 10 is changed. In other words, if the resonance frequency of the dielectric resonator 10 is changed and the distance between the metal rod 4 and the dielectric resonator 10 is increased, the resonance frequency of the dielectric resonator 10 can be lowered, and it can be used for BS reception. It is possible to oscillate at an oscillation frequency of 10.678 GHz. Further, if the distance between the metal rod 4 and the dielectric resonator 10 is made short, the resonance frequency of the dielectric resonator 10 can be increased, and it is possible to oscillate at an oscillation frequency of 11.2 GHz for CS reception. As a result, the frequency variable microwave oscillator can be provided.

FIG. 2 is an enlarged cross-sectional view of the metal rod supporting means shown in FIG. For example, a cylindrical case is used as the case 15, and an elastic member and a locking piece 5 supported by the elastic member are incorporated inside the cylindrical shape. For example, a spring 16 is used as the elastic member. Part of the locking piece 5 is exposed from the tip of the shield case 1
Fix the locking portion 6 having a plurality of concave portions on the upper surface of the
The tip of the locking piece 5 is locked in the recess of the locking portion 6 so that the metal rod 4
Support. When the elastic force of the spring 16 is adjusted and the metal rod 4 is pulled up to the upper portion, the locking piece 5 can be locked by the recessed portion provided on the upper portion of the locking portion 6, and the metal rod 4 is moved downward. When it is pushed down, the locking piece 5 can be locked by the recessed portion provided in the lower part. In the embodiment of FIG. 1, the engagement pieces 5 and the engagement portions 6 are replaced with each other, and a plurality of recesses are provided on the surface of the metal rod 4 to form the engagement portions.
The locking piece may be fixed to the upper surface of the shield case 1.

FIG. 3 is an electric circuit block diagram showing an embodiment of the variable frequency microwave oscillator of the present invention. F
The gate electrode of ET11 is connected to one end of the microstrip line 14, and the other end of the microstrip line 14 is
It is connected to the earth via a resistor 21 and is non-reflectively terminated. The drain electrode of the FET 11 is connected to the power supply terminal 18 through the microstrip line 12 and the voltage adjusting resistor 19 in this order, and the source electrode of the FET 11 is connected between the ground and the impedance adjusting resistor 20. It is connected to the line 13 and outputs the oscillated microwave through the microstrip line 13.

[0013]

As described above, according to the present invention,
The distance between the dielectric resonator and the metal rod supported on the upper part of the dielectric resonator can be switched in multiple steps. By switching the distance between the dielectric resonator and the metal rod, microwave oscillation can be performed. It becomes possible to switch the frequency,
If the variable frequency microwave oscillator of the present invention is incorporated into a converter, the oscillation frequencies can be switched and used for BS and CS reception, which greatly contributes to downsizing and cost reduction of the converter. .

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a frequency variable microwave oscillator of the present invention.

FIG. 2 is an electric circuit block diagram showing one embodiment of the frequency variable microwave oscillator of the present invention.

FIG. 3 is an enlarged sectional view of the locking means shown in FIG.

FIG. 4 is a partially cutaway perspective view of a microwave oscillator using a dielectric resonator, showing a conventional example.

[Explanation of symbols]

 1 Shield Case 2 Dielectric Plate 3 Magnet Piece 4 Metal Bar 5 Support Piece 6 Support Part 7 Iron Core 8 Connection Terminal 9 Connection Terminal 10 Dielectric Resonator 11 FET 12 Microstrip Line 13 Microstrip Line 14 Microstrip Line 15 Case 16 Spring 18 power supply terminal 19 resistor 20 resistor 21 resistor 25 shield case 26 screw

Claims (3)

[Claims] 1. A microstrip line provided on a dielectric substrate and connected to an FET, a dielectric resonator provided in proximity to the microstrip line, and supported above the dielectric resonator. And a switching means for switching the distance between the metal rod and the dielectric resonator in a plurality of steps. 2. The supporting means provided on the side surface of the metal rod, the magnet piece integrally provided on the upper side of the metal rod, and the iron core arranged on the upper side of the magnet piece. And an electromagnet composed of a winding coil, and by controlling the direction of the current flowing through the winding coil, the distance between the metal rod and the dielectric resonator can be switched in a plurality of steps to oscillate at different frequencies. The variable frequency microwave oscillator according to claim 1, wherein: 3. The supporting means includes an elastic member, a locking piece supported by the elastic member, and a locking portion having a plurality of recesses on a surface for locking the locking piece, one of which is provided. 3. The frequency variable microwave oscillator according to claim 2, wherein the metal rod is provided on a side surface and the other is provided on a fixed portion.