Co-designed quasi-reflectionless low-noise amplifier with bandpass filter and RF switching functionalities

Cheng, Steven Matthew; Fontana, Andres; Psychogiou, Dimitra

Co-designed quasi-reflectionless low-noise amplifier with bandpass filter and RF switching functionalities

Files

Co-Designed_Quasi-Reflectionless_Low-Noise_Amplifier_With_Bandpass_Filter_and_RF_Switching_Functionalities.pdf(938.49 KB)

Date

2026-04-01

Authors

Cheng, Steven Matthew

Fontana, Andres

Psychogiou, Dimitra

Publisher

Institute of Electrical and Electronics Engineers Inc.

Published Version

10.1109/LMWT.2026.3676313

Abstract

In this letter, a reflectionless low-noise amplifier (LNA) filter (RLNAF) is presented, incorporating four distinct functions: 1) filtering; 2) reflection cancellation; 3) low-noise amplification; and 4) RF switching within a single component. It is comprised of a transmissive path and two absorptive paths. Specifically, a complex-termination methodology is applied to the transmissive path incorporating a bandpass filter (BPF) and LNA functionalities, removing the need for additional interstage matching networks (MNs). The absorptive paths are composed of a bandstop filter terminated with a loading resistor in one port to selectively dissipate the out-of-band reflected RF signals. Moreover, switch-off functionality is demonstrated by reconfiguring the bias of the transistor. For proof-of-concept validation purposes, two RLNAF prototypes are designed, manufactured, and measured at C-band. The RF characteristics are given as follows: RLNAF I: fcen=4.65 GHz, gain = 15.8 dB, noise figure (NF) = 2.07 dB, and quasi-reflectionless characteristics better than 10 dB from DC to 4.27 and 4.34 GHz to 6.42 GHz and at least 9.8 dB from 4.27 to 4.34 GHz; RLNAF II: fcen=3.7 GHz, gain = 15.3 dB, NF = 1.09 dB, and quasi-reflectionless characteristics better than 10 dB from DC to 4.75 and 5.75 GHz to 7.03 GHz and at least 6 dB from 4.75 to 5.75 GHz.

Keywords

Absorptive filter , Active filters , Band-pass filters , Bandstop filter , Circuits , Feeds , Filtering , Filters , Frequency modulation , Isolators , Notch filters , Radio broadcasting , Reflectionless filter , [EngineeringArchitecture] , [Tyndall] , bandpass filter (BPF) , low-noise amplifier (LNA)

Citation

Cheng, S M, Fontana, A & Psychogiou, D 2026, 'Co-designed quasi-reflectionless low-noise amplifier with bandpass filter and RF switching functionalities', IEEE Microwave and Wireless Technology Letters, vol. 36, no. 9, pp. 1-4. https://doi.org/10.1109/LMWT.2026.3676313