Ultra-compacted sub-terahertz bandpass filter in 0.13 mm SiGe

The design of an ultra-compacted silicon-based bandpass filter in the sub-terahertz frequency range is explored. A filter with combline topology consisting of multilayered resonators and a cross-coupling capacitor has been designed in 0.13 μm SiGe. The dimensions of the implemented filter are 40 × 130 μm², which are even smaller than a ground-signal-ground probing pad with 100 μm pitch. Meanwhile, the filter achieves a 3-dB bandwidth of about 32.0-GHz (22.0%) and an insertion loss of -7.7 dB at the centre frequency of 143 GHz.