A Low Insertion Loss Variation Trombone True Time Delay in GaAs pHEMT Monolithic Microwave Integrated Circuit

Abstract

A wideband true time delay is proposed based on 0.25- μm GaAs pHEMT technology. The novel trombone topology is adopted for achieving low variation in insertion loss of different delay states. The fourth-order and second-order inductive all-pass networks (APNs) are operating as delay cells between input and output lines. By selecting different transmission ways, 3 bit with the step of 14 ps and maximum delay range of 98 ps are realized. Measurement results show the insertion loss of 3.8-10.5 dB over the frequency bandwidth of 6-16 GHz. The variation in insertion loss is less than ±1.4 dB. The chip area with pads is 1.955 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the power consumption is 110 mW.