Bandwidth-optimal single shunt-capacitor matching networks for parallel RC loads of Q ≫ 1

In this paper we demonstrate an optimized matching network that maximizes the matching bandwidth for parallel RC loads with quality factors greater than unity. The matching network includes a transmission line and a single shunt capacitor. We systematically investigate the dependance of the network's bandwidth on the impedance and electrical length of the transmission line. Results show that high impedance lines always yield maximum bandwidth for parallel RC loads with Q > 1. A 4.3:1 MEMS varactor-based tunable matching network is measured as a vehicle to demonstrate these results. In particular, we find that up to a two-fold increase in the 10-dB reflection bandwidth is possible by utilizing high impedance lines. Wih a single 4.3:1 MEMS varactor a measured bandwidth of over 136% is obtained.