Design of Reliable Analog DMTL Phase Shifter with Improved Performance for Ku Band Applications

Abstract

An analog phase shifter based on distributed MEMS transmission line (DMTL) is designed for Ku band applications. Traditional RF MEMS phase shifter comprising 6 switches has limited phase shift of 37.75° due to instability region. A new concept of stopper is incorporated to achieve high phase shift. In the present paper, optimisation of the analog phase shifter is done to increase its phase shift upto 88.63°. Phase shift is a strong function of capacitance ratio which is increased from 1.75 to 2.95. The maximum operating voltage and mechanical resonant frequency for the phase shifter are 16 V and 8.3 KHz, respectively. The switching time is calculated to 56 μs. The simulated insertion loss of the phase shifter is -1.75 dB with return loss of -20.49 dB at 17 GHz. The simulated results are verified with analytical modelling which are in close match.