Development of a low-loss Whispering-Gallery mode filter for the millimeter wave integrated circuits.

为研制低损耗毫米波滤波器而开展的研究结果总结如下：(1)针对实际的谐振器结构，详细研究了所提出的谐振器与外部电路的耦合特性。研究发现，利用具有与圆盘相同的相位常数的介质波导可以有效地激励高介电常数介质圆盘谐振器。(2)设计了一种由两个Whispering-Gallery模谐振器组成的70 GHz毫米波带通滤波器。在通带效率方面，观察到了良好的滤波性能。在500 MHz带宽下，插入损耗降至1.8dB.为了进一步改进所提出的滤波器，还需做以下工作：(1)抑制通带外的杂散响应.(2)研制一种适用于这类滤波器的计算机辅助设计系统.

The results of this study which was carried out for development of a low-loss millimeter wave filter are summarized as follows ;(1) The coupling characteristics between the presented resonator and the external circuits are investigated in detail for an actual resonator configuration. It was found that the high permittivity dielectric disk resonator can be excited with a good efficiency by using the dielectric wave guides having the phase constant which is equal to ones of the disk.(2) A millimeter wave bandpass filter which consists of two Whispering-Gallery mode resonators was designed at 70 GHz. A good filter performance was observed in regard to the efficiency in the pass band. The insertion loss was reduced to 1.8 dB in case of 500 MHz bandwidth.In order to improve the presented filter, furthermore, the following subjects remain,(1) Suppression of the spurious responses outside the passband.(2) Development of a CAD (Computer Aided Design) system for this type of filters.