Automated Linear Crosstalk Reduction System for European Spallation Source Cavity Simulator

Multichannel radio frequency (RF) devices often suffer from signal crosstalk between channels. This article presents an active automated crosstalk reduction solution. It was designed for a Cavity Simulator for the European Spallation Source (ESS)—a device with seven independent RF outputs operating at a 704.42-MHz carrier. This solution utilizes digital correction techniques to reduce the effective crosstalk between the channels. The worst case was improved from −44.2 to −73.3 dB, resulting in a 29.1-dB improvement. The first part of the article provides an overview of the Cavity Simulator. The theory of operation for the crosstalk reduction follows. Section V discusses the hardware used for self-calibration. The software controlling the calibration and operation of the crosstalk reduction is also discussed. Section VII presents the system operation measurements. It is followed by conclusions, and plans for further improvements.