A 1.7–2.7-GHz 4-bit Phase shifter based on packaged RF MEMS switches

Abstract

This study presents a 4-bit phase shifter with a maximum phase shift degree of 75° based on packaged metal-contact single-pole double-throw (SPDT) radio frequency microelectromechanical system (RF MEMS) switches mounted on a 20 mil RO4350 substrate and assembled with its driver module on a 4-layer printed circuit board (PCB) board. Electric length of 10° and characteristic impedance of 61.7 Ω are selected for T-stub matching. Standard PCB processing makes it easy to develop and suitable for taking place of mechanical tilt employed in recent base station. Measurements indicate a maximum insertion loss of 1.37 dB at 2.7 GHz and a minimum return loss of 11.71 dB. The phase accuracy is within 1.75° at 2.7 GHz.

Keywords:

• impedance matching
• MEMS switches
• modeling and measurement
• phase shifters

Acknowledgements

The authors acknowledge the innovative research program of HUAWEI Technologies Co. The authors thank Q. Wang, B. Wang and Z. Q. Liao of HUAWEI Technologies for their advice and support.