A Low-Loss and Full-360° Reflection-Type Phase Shifter for WLAN Wireless Backhaul Applications

Abstract

This paper presents a reflective-type phase shifter (RTPS) capable of full 360° phase shift range with low-loss and compact for 5.47-5.85 GHz WLAN wireless backhaul. Intuitive and concise analyses of common reflective loads, including single-element single-tunable (SEST), dual-element single-tunable (DEST) and there-element single-tunable (TEST), are analyzed, elaborating their limitations. The fourelements dual-tunable (FEDT) load technique is proposed to increase the phase shift range. In addition, the influence factors of phase shift step and insertion loss (IL) are comprehensively discussed. Measurement results show that the proposed RTPS provides a phase shift range greater than 360°, a phase shift step less than 15°, an IL less than 2.3 dB in the entire frequency band. Meanwhile, the size of this RTPS is just only 9.5×8.2 mm 2 . Compared to other RTPS, this design has the advantages of low IL, compact size, wide-band, high precision, and easy to control.INDEX TERMS Digital tunable capacitor (DTC), reflective-type phase shifter (RTPS), WLAN wireless backhaul