Distributed Phase Shifter with Enhanced Variability and Impedance Matching

A reconfigurable phase shifter has been developed with enhanced phase variation without compromising the impedance matching performance. The phase shifter is based on a distributed MEMS transmission line (DMTL). A slow-wave structure is coupled with the DMTL to improve the phase shift and to reduce the dimensions of the device. The optimisation process has been performed using a lumped element model extracted from electromagnetic simulations. The proposed structure has been studied in order to validate the theoretical analysis. A significant increase of 2 times in the effective dielectric constant improves the phase variability by 42% compared to a traditional design with a similar MEMS capacitive ratio. The proposed concept offers an attractive solution for applications demanding low return loss and a wide degree of phase variability.