Dielectric waveguide resonator, dielectric waveguide filter, and method of adjusting the characteristics thereof

Abstract

A conducting film is formed on a dielectric block in a dielectric waveguide resonator, and a through-hole is formed in the dielectric block. The unloaded Q is set by selecting the outside dimensions of the dielectric block. The resonance frequency is set by selecting the size and location of the through-hole as well as the outside dimensions of the dielectric block. A terminal electrode is formed on the outer surface of the dielectric block. A coupling hole is formed in the dielectric block and a coupling electrode is formed on the inner surface of the coupling hole. One end of the coupling electrode is connected to the terminal electrode and the other end of the coupling electrode is either connected to the conducting film formed on the outer surface of the dielectric block or terminated inside the dielectric block. The above structure allows an increase in the degree of freedom in the design of the characteristics including the resonance frequency and unloaded Q of the dielectric waveguide resonator. The invention also provides a dielectric waveguide filter with a simple coupling mechanism whereby it is possible to couple to an external circuit without having to use an additional member and without electromagnetic leakage.

Description

1. This is a division of Ser. No. 09 / 464,154 filed Dec. 16, 1999, allowed, which is a division of Ser. No. 08 / 871,333 filed Jun. 9, 1997, now U.S. Pat. No. 6,020,800, the disclosures of which are incorporated by reference herein.2. 1. Field of the Invention3. The present invention relates to a dielectric waveguide resonator and a dielectric waveguide filter for use particularly in a microwave or millimeter wave range, and to a method of adjusting the characteristics thereof.4. 2. Description of the Related Art5. There are various types of dielectric resonators known for use in the microwave range. They include: a TE01.delta.-mode dielectric resonator consisting of a dielectric in the form of a solid circular cylinder or a hollow circular cylinder placed in a shield case; a TM110-mode dielectric resonator consisting of a prism-shaped dielectric which is placed in a metallic case or a case covered with a conducting film in such a manner that the dielectric extends from the upper to th...

AI Technical Summary

Problems solved by technology

However, these dielectric resonators have problems in design and production arising from their structure.

In the case of the TM110-mode dielectric resonator, it is not easy to connect a prism-shaped dielectric to a metallic case or a case covered with a conducting film through which a current flows.

When the prism-shaped dielectric and the outer conductor are combined in an integral fashion, a complicated and difficult molding technique is required.

This causes an increase in the cost of the production and assembly process.

Since only a certain number of dielectric materials are available in practical production, the unloaded Q is limited within a certain range.

However, this requires a complicated production process.

In practice, it is difficult to freely select the dielectric constant.

Thus, this type of resonator is difficult to design and adjust.

However, the long stub 9 can cause leakage of electromagnetic waves via the gap between the stub 9 and the conducting film 2.

The leakage of electromagnetic wave can cause interference in an external circuit.

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