JPS62183202A - stripline 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 Industrial Application The present invention relates to strip line (including Micros IJ tube line) resonators used in high frequency filters and oscillators of various communication equipment, measuring instruments, etc. It is related to.

Conventional technology: As a small resonator with low loss using strip lines, microstrip lines, and strip lines, Japanese Patent Laid-Open No. 54-4
A ring-shaped or loop-shaped resonator described in Japanese Patent No. 2574 is known. An example is shown in FIG.

In FIG. 3, 101 is a microstrip line configured in a rectangular loop shape, and 107 is a lumped constant capacitive element.

In this case, although the shape is rectangular, the electrical characteristics are the same as those of the ring shape, so only the rectangular shape will be explained here.

Furthermore, since both strip and microstrip lines can be applied, the explanation will be made without making any particular distinction between them.

This resonator is much smaller than a normal single-wavelength ring resonator due to the fact that there is no high-frequency grounding, the radiation loss due to the loop shape is reduced, and the capacitive element 107 is installed. It has the following features.

Problems to be Solved by the Invention However, with the configuration shown in FIG. 3, unless the capacitance is made with high precision and good reproducibility, the resonance frequency may vary.

Furthermore, as the frequency becomes higher (TGHz or higher), it is extremely difficult to accurately achieve the capacitance value of the capacitive element 107 shown in Fig. 3, and some kind of frequency adjustment is required, which increases the number of parts. However, there are problems in that the cost is high and deterioration such as loss cannot be ignored.

In view of the problems of the prior art described above, the present invention aims to reduce variations in resonance frequency and reduce loss, as well as eliminate adjustment and reduce loss when used in a filter or the like.

Means for Solving the Problems The present invention provides an annular SL-IJ tube line with both ends open, and is provided with parallel connecting portions that are connected in parallel to each other at both end portions of the open ends.

Function The present invention replaces the lumped constant capacitor, which is indispensable to the conventional structure of the resonator, with a parallel coupled line.
While retaining the features of a capacitor-mounted resonator, the variation in resonance frequency is suppressed and no adjustment is required.

In addition, since the parallel coupling portion can be processed with high precision using photo-enochinking technology, reproducibility is extremely good and variations in resonance frequency can be significantly reduced.

Embodiment FIG. 1 is a plan view of a sl-IJ tubular line resonator in an embodiment of the present invention.

In FIG. 1, reference numerals 101 and 102 are a single strip trunk line section and a parallel coupled strip I-IJ tube line section, both of which are patterned on a dielectric substrate such as alumina.

This parallel coupled strip line section 102 based on distributed coupling can be considered by replacing the capacitive element 107 in FIG. 3. When the frequency is high, the coupling length can be shortened and the coupling spacing can be designed to be wide, which reduces frequency variation. Furthermore, the loss occurring in the coupling strip section 102 is also extremely small compared to the lumped constant.

In the actual design, the parallel coupled strip line section 10
2 odd-even mode impedance and 7. oo, Zoe
When the line impedance of the single stub l-IJ tubular line section 101 is Zo, if the line impedance of the single stub IJ tubular line section 101 is chosen to be Zoe -Zoo and designed, the parallel coupled strip IJ tubular line section 102 and
The reflection at the connection part of the IJ tube line section 101 is reduced, and the characteristics of the resonator are stabilized.

FIG. 2 shows an embodiment in which the resonator of FIG. 1 is applied to a bandpass filter. In Figure 2, 103
, 104 is a resonator in an embodiment of the present invention, 105
, 106 are input/output terminals.

According to the configuration shown in FIG. 2, since both the input/output coupling and the inter-resonator coupling are realized by distributed coupling, a low-loss filter can be constructed without adjustment.

Effects of the Invention As described above, the present invention replaces the capacitive element of the conventional lumped-capacitance mounted link resonator with a parallel coupled line, thereby making it possible to reduce variations in resonance frequency and reduce loss, thereby making it possible to improve filters, etc. When used for this purpose, no adjustment and low loss can be achieved, and its industrial value is extremely high.

[Brief explanation of drawings]

Fig. 1 is a plan view of a strip line resonator according to an embodiment of the present invention, Fig. 2 is a plan view of a band pass filter using the strip line resonator using the strip line resonator, and Fig. 3 is a plan view of a conventional ring type resonator. It is a top view of a container. 101... Single strip line section, 102... Parallel coupled strip line section. Name of agent: Patent attorney Toshi Nakao (1 name)
Figure 2 Figure 1LJ5 to G
Figure 3 θ7

Claims (2)

[Claims] (1) A strip line resonator characterized in that a ring-shaped strip line with both ends open is provided with a parallel coupling portion that connects the ring-shaped strip line in parallel to each other at both end portions of the open ends. (2) When the odd-even mode impedances of the lines in the parallel coupled portion are respectively Zoo and Zoe, and the line impedance in the non-parallel coupled portion is Zo, the feature is that these impedances have the relationship Zo^2≒Zoo・Zoe. A stripline resonator according to claim 1.