A Broadband On-Chip Bandpass Filter Using Shunt Dual-Layer Meander-Line Resonators

A miniaturized broadband on-chip bandpass filter (BPF) is presented based on shunt dual-layer meanderline resonators and several metal-insulator-metal (MIM) capacitors. To understand the operational mechanism of the proposed BPF structure, it is analyzed using a simplified LC equivalent circuit model for further investigation of the transmission zeros (TZs) distributions. To validate the proposed idea, the BPF with three TZs is implemented in a commercial 0.13-μm SiGe (Bi)-CMOS process. The measured results show that the BPF has a center frequency at 18 GHz with a very broad bandwidth of 66.7%, and the minimum insertion loss within the passband is 2.9 dB. The chip, excluding the GSG pads, is about 0.318 mm × 0.392 mm.