JPH0244802A - resonator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a resonator using a strip or microstrip line used in filters, oscillators, etc.

Conventional technology Strip or microstrip line resonators used in high-frequency bands often use quarter wavelength 2. However, depending on the high-frequency grounding method, characteristics such as resonant frequency and no-load Q can be changed. It had drawbacks such as fluctuation. As a resonator that improves this problem, a ring-shaped resonator is known that does not have a high-frequency ground and can be miniaturized.

The structure of this ring-shaped resonator is known, for example, as described in Japanese Unexamined Patent Publication No. 6442674. below,
A conventional ring-shaped resonator will be explained with reference to FIG.

In FIG. 3, 1 is a single line formed of a micros IJ knob line and formed in a loop shape, and 2 is a lumped constant capacitor. In this figure, the shape is rectangular, but since the electrical characteristics are the same as the ring shape, the rectangular shape will be explained here. In addition, both strip and microstrip lines can be applied, but here, a microstrip (IJ knob line) will be described as a representative line.

With the above configuration, that is, the single line 1 formed in a loop shape and the lumped constant capacitor 2, a much smaller co-3\-1 resonator can be realized compared to a normal 1-wavelength ring resonator. . This resonator maintains the characteristics of a single-wavelength ring resonator, such as no high-frequency grounding and low radiation loss due to its loop configuration.
It is designed to be smaller.

Problems to be Solved by the Invention However, with the above configuration, it is possible to reduce the size of the single-wavelength ring resonator without impairing its characteristics, but in order to realize the resonant frequency with good reproducibility, Although it is necessary to realize lumped constant capacitance with high precision, adding a frequency adjustment function to absorb the difficulty of realizing it or to absorb variations in manufacturing accuracy increases the number of parts, resulting in performance deterioration. However, there were problems such as high costs. Further, since the shape is a loop, there is wasted space inside the loop.

The present invention solves the above-mentioned problems of the prior art, and suppresses variations in resonance frequency, improves reproducibility and accuracy of resonance frequency, and facilitates frequency adjustment.
The purpose is to provide a small, low-cost resonator.

Means for Solving the Problems The present invention replaces the lumped constant capacitance, which is essential to a conventional capacitively loaded ring resonator, with a coupled line, and forms this coupled line inside a loop-shaped single line. , which achieves the above objectives.

The present invention uses photo-etching technology with good manufacturing accuracy to simultaneously manufacture a single line and a coupled line forming distributed capacitance, thereby reducing the cost of the resonator and improving the reproducibility of the resonant frequency. This is intended to improve accuracy. Also,
By changing the length of this coupled line, frequency adjustment can be easily performed, and by forming this coupled line inside a loop-shaped single line, the resonator can be made smaller.

EXAMPLE A first example of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a resonator in a first embodiment of the present invention. In Figure 1, 1o is 5.\-.

A single line formed in a loop shape, 11 is a parallel coupled line provided inside the single line formed in a loop shape.

The operation of the above configuration will be explained below. The lumped constant capacitance shown in Fig. 3 is connected to the parallel coupled line 1
This parallel coupled line 11 is connected to the loop-shaped single line 1Q, and
By providing it inside, it operates as a small resonator at low cost. According to this configuration, when the frequency is high, the coupling interval of the parallel coupled lines can be designed to be wide, the reproducibility of manufacturing is good, and the variation in resonance frequency can be reduced. Further, even if the resonant frequency deviates from the desired frequency, the frequency can be easily adjusted by adjusting the length of the parallel coupled line formed inside the loop-shaped single line.

Furthermore, compared to the lumped constant capacitance, the loss generated in the parallel coupled line portion can be made extremely small, so that the no-load Q of the resonator becomes large. In actual design, the odd-even mode impeance (Zoo) of the parallel coupled line section.

between the impedance of the single line (Zoe) and the impedance of the single line (Zo),
When selected and designed to satisfy the relationship Zo2=Zoo ' Zoe, there will be less reflection in the parallel coupled line section and the single line section, and the characteristics of the resonator will become stable.

As is clear from the above description, according to this embodiment, the capacitance essential for downsizing the ring resonator is realized by distributed capacitance using parallel coupled lines, thereby promoting cost reduction of the resonator. Moreover, it is intended to improve the reproducibility of manufacturing, reduce variations in resonance frequency, and improve the no-load Q. Also, this parallel coupled line is
By forming it inside a loop-shaped single line, even if the resonant frequency deviates from the desired frequency, a small resonator can be realized that allows easy frequency adjustment by adjusting the length of the parallel coupled line. .

Next, a second embodiment of the present invention will be described.

FIG. 2 is a plan view of a resonator in a second embodiment of the invention. In FIG. 2, the difference from the configuration in FIG. 1 is that the coupling line is shaped like a comb. 20 is the first
A single loop-shaped 7P/-7 line similar to the one shown in the figure, 21 is a comb tooth-like coupled line.

The operation of the above configuration will be explained below. By forming the coupling line 21 into a comb-like shape, a large distributed capacitance can be obtained if the coupling line length and the coupling interval are the same, so that the resonator can be made smaller.

Furthermore, if the distributed capacitance remains the same (without changing the length of the coupling line), the coupling spacing increases, which increases the reproducibility of manufacturing and further reduces the variation in resonance frequency.

As described above, according to this embodiment, since the distributed capacitance per unit length can be increased compared to a single coupled line, the coupling length can be shortened.
The resonator can be made smaller. Furthermore, if the bond lengths are made the same, the bond spacing becomes wider, which improves the reproducibility of manufacturing and makes it possible to reduce variations in resonance frequency.

Effects of the Invention As described above, the present invention provides a lumped constant capacitance, which is essential to conventional capacitance-loaded ring resonators, by using the same manufacturing process as for a single line, that is, a highly accurate manufacturing method such as photo-etching technology. By replacing the resonator with a coupled line that can be used, the cost of the resonator can be reduced, and the reproducibility and accuracy of the resonant frequency can be improved. Also, this coupled line,
By forming the resonator inside a loop-shaped single line, the resonator can be made smaller, and by changing the length of the coupled line, frequency adjustment is facilitated, which has great industrial effects.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a resonator in a first embodiment of the present invention, FIG. 2 is a plan view of a resonator in a second embodiment of the present invention, and FIG. 3 is a plan view of a conventional resonator. be. 1o120...Single line, 11.21...Coupled line.

Claims (3)

[Claims] (1) A resonator comprising a single line composed of a strip or microstrip line and a coupled line, the coupled line being formed inside the single line. (2) The resonator according to claim 1, wherein the coupled line is a parallel coupled line. (3) The resonator according to claim 1, wherein the coupling line is a comb-like coupling line.