On the Design of Compact and Tight-Matching Exponential Tapered Networks for Wideband Applications

Abstract

We present a comprehensive study on ultra-wideband impedance matching using exponential tapering of transmission line characteristic impedance. The analysis models the tapered region as cascaded sections represented by ABCD matrices and evaluates the reflection performance across a broad frequency range. A shaping factor is introduced to optimize the taper profile, minimizing the required physical length to maintain VSWR < 1.1. The study spans multiple load-to-source impedance ratios from 1.5 to 10, determining the optimal shaping factor for minimum exponentially tapered profile, which consistently outperforms linear profiles in impedance matching and compactness. Our study offers clear, ready-to-use taper parameters for microwave designers.