Millimeter-wave band-pass filters using spherical dielectric resonators are presented. The dielectric spheres are sandwiched between metal plates and are excited by a simple microstrip line structure on a thin-film circuit board. As such, these filters could also be implemented in the back-end-of-line layers of an integrated circuit. A single resonator, based on a diameter 0.6 mm alumina ceramic sphere, is shown to resonate with high unloaded Q-factor of 750 at 170 GHz. A three-sphere band-pass filter is measured showing <5 dB insertion loss and 0.4% bandwidth at 170 GHz. A concept for mechanically tuning of a two-sphere band-pass filter is demonstrated for a filter operating around 105 GHz. The measured filter shows approximately 5 dB insertion loss and <0.5% bandwidth and its passband can be varied over 3 GHz of frequency, or 3%. Technological challenges are discussed.

中文翻译：

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使用球形介电谐振器的低损耗和可调谐毫米波滤波器

介绍了使用球形介电谐振器的毫米波带通滤波器。介电球夹在金属板之间，由薄膜电路板上的简单微带线结构激发。因此，这些滤波器也可以在集成电路的后端层中实现。基于直径 0.6 mm 氧化铝陶瓷球的单个谐振器显示在高空载时谐振问- 在 170 GHz 时为 750。测得的三球带通滤波器在 170 GHz 处显示 <5 dB 插入损耗和 0.4% 带宽。为工作在 105 GHz 附近的滤波器演示了一种机械调谐双球带通滤波器的概念。测得的滤波器显示大约 5 dB 的插入损耗和 <0.5% 的带宽，其通带可在 3 GHz 频率范围内变化，即 3%。讨论了技术挑战。