A compact and low loss V-band lowpass filter using coplanar waveguide structure

This paper presents a compact finite width ground planes coplanar waveguide (FG- CPW) low-pass filter (LPF) for V-band wireless personal area network (WPAN) communication systems. The FG-CPW equivalent circuit is constructed by a series inductor at both ends with two shunted inductor-capacitor (LC) resonators at the center of the circuit, which the series inductor can be realized as a series-short-stub in CPW line. The shunted series LC resonator is realized as a high impedance CPW line series with a low impedance CPW open stub. The full wave EM simulation was performed by Agilent Momentum^TM to predict the frequency response. The CPW LPF was implemented in WIN-semiconductor ^TM 0.15-μm pHEMT technology. The simulated results show a good agreement with measurement, the obtained insertion loss is small than 0.5 dB with a return loss better than 20 dB. The 3-dB bandwidth is from 0 to 70 GHz. A better than 20-dB rejection is obtained from 95 to 110 GHz. The measured frequency responses agree well with the simulated ones. The chip size is very compact of 0:45 × 0:4mm².