JPH0428163B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to an oscillator for a microwave integrated circuit or the like, and particularly to an oscillator that prevents a decrease in the Q of a dielectric resonator, which is a main component. Regarding.

In recent years, the frequencies of high-frequency bands used for communication have become higher (wavelengths shorter), and the oscillators used for this purpose are microstrip lines and dielectric resonators (hereinafter referred to as
(abbreviated simply as DR) is compact and efficient. In such a configuration, the presence of a dielectric substrate near the DR that causes high frequency loss in the resonant circuit reduces the Q of the DR. Therefore, it is necessary to minimize this decrease in Q.

(b) Prior Art FIG. 2 schematically shows a conventional oscillator, with Figure a being a side sectional view and Figure B being a plan view.

In FIG. 2, a dielectric layer is formed by arranging and forming a ground layer on the entire bottom surface of a metal substrate 1, a microstrip line 3 on the top surface, and a low-pass circuit 10 for supplying a DC bias to this from the outside. A semiconductor element 4 such as a Gunn diode is arranged and connected to the end of the body substrate 2 and the microstrip line 3.

On the other hand, a metal casing 6 made of steel or the like that includes the dielectric substrate 2 and covers it from above, on the metal substrate 1, has a screw hole cut through the upper surface and a dielectric material etc. on the lower end surface. A frequency adjustment screw 7 to which a DR 5 is attached via a spacer 8 is screwed into the screw hole. As clearly shown in Figure a, the lower end surface of the DR5, including a part of the microstripline 3, completely faces the dielectric substrate 2, and It is configured as a microwave integrated circuit (hereinafter simply abbreviated as MIC) that can finely adjust the resonant frequency by moving up and down in the directions of arrows A and B using a spiral spiral. . Note that the dielectric substrate 2
is constructed of ceramic material.

(c) Problems to be solved by the invention Microstripline 3 and
In the MIC due to coupled resonance with the DR5, due to the presence of the dielectric substrate 2 facing and close to the entire surface of the DR5, the tan δ (dielectric loss angle) of the dielectric substrate 2 and the dielectric substrate 2
Loss may occur due to solder or dielectric adhesive used to attach the
As a result, the Q of DR5 decreases, output loss increases, and the stability of the resonance frequency deteriorates.

As a solution to the above problem, it is possible to make the width of the dielectric substrate 2 closer to the width of the microstrip line 3, but it is also possible to configure other accessory circuits such as the low-pass circuit 10 on one ceramic substrate. The number of circuit boards increases and the degree of integration deteriorates. This not only increases the cost, but also reduces the reliability of the entire circuit because connection points between the boards are required. Furthermore, since the width of the substrate 2 becomes narrow, there are various problems such as insufficient mechanical strength.

In view of the above-mentioned problems, the present invention aims to solve the problem that the Q of the DR5 decreases without reducing the degree of integration of the MIC, and to reduce the interference between the electromagnetic field of the DR5 and the dielectric substrate 2 as much as possible. Less DR5
It is an object of the present invention to provide a new oscillator that can minimize the decrease in Q of the oscillator.

(d) Means for Solving the Problems To achieve the above object, the configuration means of the present invention has a configuration in which a dielectric resonator is coupled to face a microstrip line formed on a dielectric substrate. In the oscillator, the microstrip line of the coupling part is offset to the end of the dielectric substrate, and at least a part of the opposing end surface of the dielectric resonator is positioned so as to face outside the end of the dielectric substrate. This is an oscillator characterized by the following.

(e) Effect In the above configuration, the microstrip line is deflected to the end of the dielectric substrate, and at least a part of the opposing surface of the dielectric resonator facing the microstrip line is formed with the dielectric substrate. By not facing each other, preferably by locating most of the parts in a retracted position so that they do not face each other, the influence of the dielectric resonator's magnetic field by the dielectric substrate is minimized. Less loss, higher Q
This results in lower output loss and higher frequency stability.

(f) Embodiments Hereinafter, embodiments of the oscillator according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view for explaining an embodiment of an oscillator according to the present invention, and FIG. 1 is a side sectional view, and FIG.
It is. In FIG. 1, the oscillator of this embodiment has a metal substrate 1, a dielectric substrate 2,
It consists of a microstripline 3, DR5, metal housing 6, frequency adjustment screw 7, and others.
The feature is that the joint position of the microstripline 3 and DR5 has been moved (deviated).
For this reason, the same parts are given the same reference numerals as in FIG. 2, and explanations of these parts will be omitted, but it should be understood that they are equivalent.

In Figure 1, microstrip line 3
is a deflection coupling part 9 which is bent in a detour so as to be located at the end of the dielectric substrate 2 at the coupling part with the DR5.
form. Then, adjust the position of the frequency adjustment screw 7, on which the DR5 is adhesively fixed to the lower end surface via the dielectric spacer 8, so that the opposite end surface of the DR5 is on the dielectric substrate with respect to the deflection coupling part 9 of the microstripline 3. The dielectric substrate 2 is set so that at least a part thereof is opposed to the outside of the end of the dielectric substrate 2 . This can be achieved by deviating the position of the screw hole in the metal housing 6 to a predetermined position from that shown in FIG.

The amount of overlapping between the DR 5 and the substrate 2 is determined by various conditions such as the frequency band used, the allowable limit for Q setting, and the like.

With the above configuration, the magnetic field of DR5 is not affected by the dielectric substrate located at the opposing position.
Loss is lower than before.

(g) Effects of the invention As is clear from the above explanation, the oscillator according to the present invention enables high integration and high-density packaging without reducing the degree of MIC integration.
Since the reduction in the Q of the oscillator can be minimized, it greatly contributes to improving the characteristics of the oscillator, such as output and frequency stability. Furthermore, fine adjustment of the resonant frequency can be performed with low loss and high Q. Since the value of Q is small in the millimeter wave band, particularly remarkable effects can be obtained according to the present invention.

[Brief explanation of drawings]

FIG. 1 is for explaining one embodiment of the oscillator according to the present invention; FIG. 1A is a side sectional view, FIG. 1B is a plan view,
FIG. 2 is a side cross-sectional view and a plan view, respectively, for explaining a conventional oscillator. In the figure, 1 is a metal substrate, 2 is a dielectric substrate,
3 is a microstrip line, 4 is a semiconductor element, 5 is a DR, 6 is a metal housing, 7 is a frequency adjustment screw, 8 is a dielectric spacer, 9 is a deflection coupling part, 10
is a low-pass circuit.

Claims (1)

[Scope of Claims] 1. In an oscillator configured to couple a dielectric resonator 5 facing a microstripline 3 formed on a dielectric substrate 2, the microstripline 3 of the coupling portion is connected to the dielectric An oscillator characterized in that the dielectric resonator 5 is bent in a detour so as to be located at an end of the dielectric substrate 2, and at least a part of the opposing end surface of the dielectric resonator 5 is located outside the end of the dielectric substrate 2. . 2 Including the dielectric substrate 2 on the metal substrate 1,
A screw hole is cut through the top surface of the metal casing 6 that covers these from above, and an adjustment screw 7 is screwed into the screw hole.
The dielectric resonator 5 is connected to the lower end surface of the dielectric resonator 5 via a spacer.
2. The oscillator according to claim 1, wherein the oscillator is fixed and supported opposite to the microstrip line 3 so as to be able to come and go from a distance.