An SP10T Switch With Reconfigurable Matching and Symmetrical Routing Topologies Functioning From DC to 18 GHz

This article presents a broadband single-pole ten-throw (SP10T) switch with a low insertion loss (IL) performance. With the proposed three topologies, the design breaks the constraints between bandwidth (BW) and IL. The proposed three topologies include: 1) employing a one-for-all symmetrically routed structure that achieves similar transfer functions for all pole-to-throw paths, and hence, one matching network covers all branches impedance matching; 2) a series-transmission-line (TL)-shunt unit that optimizes the IL and matching; and 3) a 3-in-1 reconfigurable matching network that varies the conjugate impedance and achieves the best performance for the three subfrequency bands that composes the entire BW. The compact reconfigurable matching network is based on constructing a 50- $\Omega $ artificial transmission line (ATL) that compensates all parasitic and redundant components. The proposed reconfigurable SP10T switch is fabricated in a commercial 0.15- $\mu \text{m}$ GaAs pHEMT process. Experimental results show the SP10T switch achieves an impressive wide BW from dc to 18 GHz with a favorable IL of 1.1–3.2 dB. The input P1dB points and IP3 points are better than 21.2 and 35.1 dBm, respectively. The isolation is higher than 24 dB.

I. Introduction

Nowadays, evolving communication systems have increasingly stringent requirements on flexibility, multimode/multiband capabilities, and wide bandwidth (BW). In this regard, the switches are particularly crucial for switching RF system operation modes. To cope with the evolution of modern and future RF systems, more throw ports and wider BW capability are preferred for single-pole (SP) multithrow (MT) switch developments. However, due to the fundamental constrained tradeoff between the number of throws, insertion loss (IL), and BW, an ultrabroadband switch with more than ten throws faces difficulties in maintaining both desirable IL and well impedance matching.