A W-Band Digitally Controlled Bidirectional Transmission Line Phase Shifter in 22-nm FDSOI

Abstract

In this letter, a passive bidirectional integrated tunable transmission line (TL) phase shifter (PS) is proposed and demonstrated in the W-band (75–110 GHz). The PS is based on a modified coplanar waveguide (CPW) structure with a conditional meandering ground return path located below the coplanar metal layer on the ground wall. The modified CPW structure achieves a wide phase shift tuning range with a compact PS unit cell A 5-bit digitally controllable PS based on the proposed topology is implemented in the 22-nm fully depleted silicon-on-insulator (FDSOI) process. The PS achieves a worst case phase resolution and loss of 4.4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^\circ$</tex-math> </inline-formula> and 11.5 Db, respectively, in the W-band for a total phase shift of up to 115 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^\circ$</tex-math> </inline-formula> . To the authors’ knowledge, this represents the highest frequency range for a constant length integrated tunable TL PS in a silicon-based integrated circuit (IC) technology.