Receiver Bandwidth Extension Beyond Nyquist Using Channel Bonding

TL;DR

This paper explores channel bonding techniques to extend receiver bandwidth beyond Nyquist limits, demonstrating practical implementations on Xilinx RFSoC with high IRR performance.

Contribution

It introduces and evaluates two novel joint front-end and converter design approaches for bandwidth extension using channel bonding.

Findings

Achieved 5 GHz instantaneous bandwidth with high IRR

Demonstrated practical implementation on Xilinx RFSoC

Realized near-theoretical IRR performance within 4-8 dB margin

Abstract

Current and upcoming communication and sensing technologies require ever larger bandwidths. Channel bonding can be utilized to extend a receiver's instantaneous bandwidth beyond a single converter's Nyquist limit. Two potential joint front-end and converter design approaches are theoretically introduced, realized and evaluated in this paper. The Xilinx RFSoC platform with its 5 GSa/s analog to digital converters (ADCs) is used to implement both a hybrid coupler based in-phase/quadrature (I/Q) sampling and a time-interleaved sampling approach along with channel bonding. Both realizations are demonstrated to be able to reconstruct instantaneous bandwidths of 5 GHz with up to 49 dB image rejection ratio (IRR) typically within 4 to 8 dB the front-ends' theoretical limits.