Design & Simulation of Low Loss 5-Bit Ku Band Switched Line MEMS Phase Shifter on Gaas

Abstract

As the requirement for the low loss phase shifter increases, so does the development of RF MEMS as a solution. This paper presents the design & simulation of Switched line MEMS phase shifter for Ku band using GaAs substrate. The phase shift can be achieved by varying the lengths in delay path to the reference path for the same phase velocity. The electromagnetic & electromechanical simulations were carried out with various structural parameters to optimize the design. The novelties like low insertion loss, low actuation voltage with distributed actuation pads for DC and RF are used to make the design unique. The EM simulations are carried out using 3D simulator HFSS and a phase shift of 172.6 deg./dB for a total Phase shift of 348.75deg was achieved with return loss of 15.5dB over a frequency band from 16-18 GHz and a phase shift error less than ±2 degree in the 32 states. The electromechanical simulations are carried to achieve the low actuation voltage of 15.3V. These parameters make these suitable for the Phased array applications [1, 2].

A Ku band 5 bit MEMS phase shifter for active electronically steerable phased array applications

“…There are many published reports of MEMS phase shifters but reports of their practical applications are scarce. To the authors' knowledge, this study and development is one of the first few monolithically fabricated 5 bit microstrip version MEMS phase shifters in the Ku band (16)(17)(18). This paper presents the development of the optimized digital microstrip version of a 5 bit MEMS phase shifter for implementation into an active phased array antenna.…”

“…The proposed phase shifter can be used as a drop in device in the transmit/ receive (T/R) module section as this does not require any additional transition and it has a compatible interface with other monolithic microwave integrated circuits (MMICs) in the subsystem. A hybrid architecture of switched and loaded line topologies has been implemented in this work due to the linear and wideband performance along with a large phase shift requirement [17,18]. The fabrication was performed using the Fondazione Bruno Kessler (FBK) RF MEMS process.…”