Highly Linear K-/Ka-Band SPDT Switch Based on Traveling-Wave Concept in a 150-nm GaN pHEMT Process

Abstract

This letter presents a highly linear 18–42 GHz single-pole double-throw (SPDT) switch based on the traveling-wave concept for 5G applications. An RF switch for 5G applications requires low insertion loss, high isolation, and high linearity in both Tx/Rx modes. To achieve wideband performance and high linearity, the traveling-wave concept and a 150-nm GaN high electron mobility transistor (HEMT) process were used. The equivalent circuit of the SPDT switch was analyzed using the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S$ </tex-math></inline-formula> -parameter to suppress the loss and improve the isolation. The proposed SPDT switch operates with less than 2.0-dB of insertion loss and higher than 32.1-dB of isolation in a frequency range of 18–42 GHz, in both Tx/Rx modes. The measured input 1-dB compression point (IP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> ) is 47.5–49.5 dBm at 26–30 GHz. The chip size of the proposed SPDT, including pads, is 3.7 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 0.51 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .