High-Powered RF SOI Switch With Fast Switching Time for TDD Mobile Applications

Abstract

This paper presents a fast switching and high-powered single-pole double-throw (SPDT) switch for RF switch circuits, such as TRx antenna switches and frequency band (or operation mode) selection switches in mobile handset applications. For fast switching time and performances of the RF switch, we proposed a novel method that can “selectively” control the impedance of a gate biasing circuit (“high” or “low” impedance). The proposed SPDT switch use the low impedance of the gate biasing circuit for fast switching time and use the high impedance of the gate biasing circuit to avoid the degradation of the insertion loss and harmonics. The proposed SPDT switch has no additional bias and no large payment for size consumption. According to measurement results, the turn-on switching time of the proposed SPDT switch was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.35~\mu \text{s}$ </tex-math></inline-formula> (at 2 GHz). The insertion loss, isolation, and return loss at 2 GHz were 0.16 dB, 47.1 dB, and 24 dB respectively. 2nd and 3rd harmonic levels at 25 dBm input power at 2 GHz were −88.7 dBm and −78.9 dBm, respectively. Power handling capability was 39.5 dBm of input power at 2 GHz. The designed SPDT switch was implemented in a 0.13- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> partially depleted silicon-on-insulator (PD-SOI) process.