Wide Band Switched Delay Line using MEMS Switches

This paper presents a high precision wide band switched delay line with fine tuning capability and low insertion loss. The circuit is designed to operate in the frequency range from 1 GHz to 5 GHz and tuned using MEMS switches targeting a minimum delay step of 7 ps. The delay line uses a single layer of a high permittivity substrate (εr =10), and the MEMS devices are interconnected using conventional coplanar waveguide technology (CPW). The circuit was designed and simulated using CST Microwave Studio. The simulated group delay shows a small deviation from the linear phase of less than 1 over a wide bandwidth compared to the performance of SAW and ceramic filters [1]. The simulation results shows an insertion loss and a return loss of better than 1 dB and 20 dB respectively.