Experiments with Calibrated Digital Sideband-Separating Downconversion

ABSTRACT.This article reports on the first step in a focused program to reoptimize radio astronomy receiver architecture to better take advantage of the latest advancements in commercial digital technology. Specifically, an L-Band sideband-separating downconverter has been built using a combination of careful (but ultimately very simple) analog design and digital signal processing to achieve wideband downconversion of an RFI-rich frequency spectrum to baseband in a single mixing step, with a fixed-frequency local oscillator and stable sideband isolation exceeding 50 dB over a 12°C temperature range.