JPH07122932A - Frequency adjustment method for dielectric oscillator - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding the frequency adjustment method of a dielectric oscillator, the work is simple and the cost is low, and the fluctuation of the oscillation frequency is small.
It is an object of the present invention to realize a frequency adjustment method for a dielectric oscillator that has flexibility in mounting a dielectric resonator. [Constitution] The dielectric resonator (10) is coupled to the line (21) of the oscillating element (20) by the magnetic field of its fundamental mode TE ₀₁ δ to obtain an oscillation frequency substantially equal to its resonance frequency. In the dielectric oscillator housed in the body (30), the metal casing (3
Make the walls of (0) close to each other and attach the dielectric resonator (10) to the oscillation element.
When approaching (20), at the same time, the wall of the metal casing (30) approaches the portion where the magnetic flux of the dielectric resonator (10) is dense and changes its resonance frequency to change its oscillation frequency. To configure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention couples a typical cylindrical dielectric resonator to the line of an oscillating element transistor by a magnetic field of its fundamental mode TE ₀₁ δ, and its resonance frequency is substantially equal to The present invention relates to a dielectric oscillator that obtains a predetermined oscillation frequency, and since this dielectric oscillator is used as a local oscillator of a microwave multiplex wireless device, a clock source of an optical transmission device, etc. A frequency adjustment method for setting the frequency needs to be established.

[0002]

2. Description of the Related Art The structure of a conventional dielectric oscillator is shown in FIG. First, insert the cylindrical dielectric resonator 10 into the strip line of the coupling line of the oscillation element 20 (Si transistor or GaAs FET).
21 is magnetically coupled to make an oscillator with an oscillation frequency approximately equal to its resonance frequency. Even when the dielectric resonator 10 is obtained by designating its resonance frequency, due to variations in the high-frequency characteristic parameters of the oscillation element 20, the dimensions of the metal housing 30, the etching parameters of the coupling line 21 on the circuit board, and the like, In order to set it at a predetermined frequency, it is necessary to adjust the oscillation frequency. Conventionally, there are the following three methods for adjusting the oscillation frequency. (1) Utilizing the fact that the resonance frequency of the dielectric resonator depends on the shape and size of the dielectric itself, and prepare a dielectric with a larger size in advance as shown in (a) of FIG. , A method of setting the oscillation frequency to a predetermined frequency by sequentially cutting the dielectric. (2) Utilizing the fact that the resonant frequency of the dielectric resonator changes depending on the distance when the conductor metal is brought close to the dielectric. As shown in FIG. A method of setting the oscillation frequency to a predetermined frequency by providing a metal screw and changing the insertion length of the metal screw. (3) As shown in (c) of FIG. 6, when the dielectric resonator 10 and the oscillating element 20 are brought close to each other, the oscillation frequency thereof increases and the method of the above (2) is used in combination. When the body resonator 10 is brought close to the oscillating element 20, at the same time, the wall of the metal housing 30 is laterally brought close to the cylindrical surface of the dielectric resonator 10 so that the dielectric resonator 10 comes close to the oscillating element 20. There was a method of setting the oscillating frequency to a predetermined frequency by moving it to and changing the oscillating frequency greatly.

[0003]

However, the above-mentioned prior art methods have the following drawbacks. That is, in the method (1), the work of sequentially cutting the dielectric 10 that serves as a resonator is complicated. In the method (2), not only the cost of the structure of the metal screw is high, but also since the screw is long and slender, it is easy to vibrate due to vibration, and the oscillation frequency also fluctuates accordingly. In the method (3), the magnetic flux around the cylindrical dielectric resonator 10 is dense in the upper and lower parts of the cylinder but sparse in the lateral part, as shown in the magnetic flux distribution diagram of FIG. Even if the cylindrical surface of the dielectric resonator 10 approaches the wall of the horizontal metal housing 30, a large frequency change does not occur, and the effect of frequency adjustment is small. Further, the mounting position of the dielectric resonator 10 must be on the side of the wall of the metal housing 30 without fail, and there is a drawback that the mounting flexibility is insufficient. An object of the present invention is to eliminate these drawbacks, to make the adjustment work simple and low cost, to reduce the fluctuation of the oscillation frequency during and after the adjustment, and to have a degree of freedom in mounting the dielectric resonator. It is to realize the frequency adjustment method of.

[0004]

To achieve this object, the basic structure of the present invention is that in the structure of FIG. 6 (c) of the above-mentioned prior art (3), the cylindrical dielectric body 10 has a horizontal metal housing. Even if the wall of 30 is approached, the magnetic flux in the lateral part of the dielectric 10 is sparse, so there is little change in the resonance frequency, but the magnetic flux in the upper or lower part of the cylinder is dense (focus on the magnetic flux distribution diagram in Fig. 7). Then, as shown in the principle diagram of the present invention in FIG. 1, the cylindrical dielectric resonator (10) is coupled to the line (21) of the oscillating element (20) by the magnetic field of its fundamental mode TE ₀₁ δ. In a dielectric oscillator whose whole to obtain an oscillation frequency substantially equal to the resonance frequency of the above is housed in a metal casing (30), a magnetic flux is dense in an upper portion or a lower portion of the cylindrical dielectric resonator (10). Then, when the dielectric resonator (10) is brought close to the oscillation element (20) by making the wall of the metal housing (30) close to each other, at the same time, the wall of the metal housing (30) becomes 10) porcelain Is constructed as to vary the oscillation frequency changing its resonance frequency in proximity to the upper or lower portion is dense.

[0005]

In the basic configuration of the present invention shown in FIG. 1, the dielectric resonator 10
When approaching the oscillator element 20, the wall of the metal housing 30
An oscillation element coupled to the dielectric resonator 10 due to the fact that the resonance frequency of the dielectric resonator 10 is greatly changed by approaching a portion where the magnetic flux at the upper part or the lower part of the cylinder of the dielectric resonator 10 is dense.
The oscillation frequencies of the 20 circuits greatly change, and the frequency adjustment to set the predetermined frequency is easily performed. In addition, the configuration of the present invention does not require the dielectric resonator 10 to be mounted near the wall of the metal housing 30, so there is flexibility in mounting, and it is not necessary to cut the dielectric 10 as a matter of course, and frequency adjustment is possible. This eliminates the need for metal screws for use and solves all the drawbacks of the prior art.

[0006]

EXAMPLES As concrete examples of the present invention, there are the following two methods. (1) In general, the metal lid of the housing for housing the sheet metal may be provided with so-called ribs in order to increase its bending strength. Therefore, as shown in FIG. 2 (corresponding to claim 2), When the metal lid 31 with a rib is used to bring the dielectric resonator 10 close to the oscillating element 20, the dielectric resonator is simultaneously
The structure is such that the upper portion of 10 approaches the rib portion of the metal lid 31. As shown in FIG. 3 as (2) (corresponding to claim 3),
The dielectric resonator 10 is placed on a substrate, and the upper surface of the substrate is provided with a ground pattern (GND surface) connected by a through hole that communicates with the ground GND on the lower surface. When the dielectric resonator 10 on the substrate is brought close to the oscillating element 20, the G
The metal conductor on the ND surface approaches the lower part of the dielectric resonator 10 to change the resonance frequency thereof, and as a result, the oscillation frequency is changed, and the frequency adjustment for setting the predetermined frequency is easily performed.

As a modification of FIG. 2, there are FIGS. 2 (a) and 2 (b). The configuration of FIG. 2 (a) is one in which the ribs of the metal lid 31 of FIG. 2 are slanted.
The direction of the strip line 21 of the 20 coupled lines is 0 ° and 90 ° with respect to the board, and the CAD (Computer
Aided Design) and automatic mounting at the factory can be facilitated. In the configuration of FIG. 2B, a plurality of ribs of the metal lid 31 of FIG. 2 are provided to increase the effect of frequency change. 3A and FIG. 4 (corresponding to claim 4) are modifications of FIG. The configuration of (a) of FIG. 3 is simply the GN of FIG.
A plurality of D planes are provided. In the configuration of FIG. 4, a multilayer substrate is used as a circuit board, and a GND plane is provided stepwise on each layer to obtain a larger frequency change effect.

[0008]

As described above, according to the present invention, it is possible to simplify or omit the frequency adjustment of the dielectric oscillator by eliminating the conventional scraping of the dielectric and the adjustment of the oscillation frequency by the metal screw. In addition, it is possible to obtain a larger frequency change than the conventional dielectric oscillator.

[Brief description of drawings]

FIG. 1 is a principle diagram of claim 1 showing a basic configuration of a frequency adjusting method for a dielectric oscillator according to the present invention.

FIG. 2 is a configuration diagram of an embodiment corresponding to claim 2 of the present invention.

FIG. 3 is a configuration diagram of an embodiment corresponding to claim 3 of the present invention.

FIG. 4 is a configuration diagram of an embodiment corresponding to claim 4 of the present invention.

FIG. 5 is a configuration diagram of a conventional dielectric oscillator.

FIG. 6 is a block diagram of a conventional frequency adjustment method for a dielectric oscillator.

[Fig. 7] Magnetic flux distribution diagram of the fundamental mode TE ₀₁ δ of the cylindrical dielectric resonator

[Explanation of symbols]

Reference numeral 10 is a dielectric resonator, 20 is an oscillating element, 21 is a coupling line and a strip line, 30 is a metal housing, and 31 is a lid of the metal housing.

Claims (4)

[Claims] 1. A dielectric resonator (10) is provided with its fundamental mode (TE
₀₁ δ) Magnetic field coupled to the line (21) of the oscillating element (20) to obtain an oscillation frequency approximately equal to its resonance frequency.
In the dielectric oscillator housed in (30), the wall of the metal casing (30) is made to be close to the portion where the magnetic flux is dense in the upper or lower part of the dielectric resonator (10). When the resonator (10) is brought close to the oscillating element (20), at the same time, the wall of the metal housing (30) approaches the portion where the magnetic flux of the dielectric resonator (10) is dense and changes its resonance frequency. A frequency adjusting method for a dielectric oscillator, characterized in that the oscillation frequency is changed. 2. The lid of the metal housing (30) is provided with a rib for increasing bending strength, and the dielectric resonator (10) is provided with an oscillating element (20).
2. The frequency adjustment of the dielectric oscillator according to claim 1, wherein the upper portion of the dielectric resonator (10) is brought closer to the rib portion of the lid of the metal casing (30) at the same time when the dielectric resonator (10) is brought closer to. Method. 3. The dielectric resonator (10) is placed on a circuit board, and a ground GND pattern is provided on the upper surface of the board, the ground GND pattern being connected by a through hole leading to the ground (GND) on the lower surface thereof. When the dielectric resonator (10) of (1) is brought close to the oscillating element (20), at the same time, the metal conductor of the ground GND pattern on the upper surface of the substrate comes close to the lower part of the dielectric resonator (10). Item 2. A frequency adjusting method for a dielectric oscillator according to Item 1. 4. A ground GND, wherein a multi-layer substrate is used as a circuit substrate on which the dielectric resonator (10) is placed, and the upper surface of each layer of the multi-layer substrate is connected to the ground (GND) through hole through the ground GND. The frequency adjusting method for a dielectric oscillator according to claim 3, wherein the patterns are provided stepwise.