<inline-formula> <tex-math notation="LaTeX">$K$ </tex-math> </inline-formula>-Band 4-Bit Phase Shifter Using Two Back to Back MEMS SP16T Switching Networks

Abstract

This paper presents a $K$ -band 4-bit phase shifter using micro-electromechanical system-based dc contact single-pole-sixteen-throw (SP16T) switching networks. The circuit is fabricated on 635- $\mu \text{m}$ alumina substrate using surface micromachining process. Compact circular type SP16T switch is the primary functional building block of the 4-bit phase shifter. SP16T switch demonstrates an average insertion loss of ~1.9 dB, isolation of better than 14 dB and average return loss of better than 14 dB in the 18–26-GHz band. Total area of the fabricated SP16T switch is only ~2.5 mm2. Finally, two SP16T switches are cascaded with different delay lines to develop the complete 4-bit phase shifter. The 4-bit phase shifter demonstrates an average insertion loss of 3.47 dB in the 19.75–20.25-GHz band with a return loss of better than 14 dB and average phase error is less than ~1.77 °at 20 GHz. Total area of the fabricated 4-bit phase shifter is ~13.5 mm2. The reliability of the SPST and SP16T switches show more than 1 billion (B) cycles with an RF power of 0.1–1 W. Finally, device demonstrates >1 B cycles with cold switched and >~600 million cycles with hot switched conditions. To the best of our knowledge, this is the first reported high reliable and more compact MEMS 4-bit phase shifter in the literature that has undergone extensive measurement stages with minimum number of switching elements per phase state. [2018-0014]