Preliminary design of 18-45 GHz radio astronomy receiver

The preliminary design and system simulation of an 18 - 45 GHz radio astronomy receiver is presented, planned for installation on the 26 m radio telescope at the Hartebeesthoek Radio Astronomy Observatory in South Africa. The receiver utilizes a sideband separating architecture with two local oscillator settings to cover the full frequency range. The receiver will deliver a 4-11 GHz output IF for each sideband. An analysis of the frequency plan and simulated performance using off-the-shelf components and target custom design specifications are discussed. A discussion on multi-chip module (MCM) and full monolithic integration towards miniaturized packaged ultra- wideband receivers for radio astronomy is also given. System simulations show ultra-wideband operation using two LO settings with the largest spurious signal at -40 dBc relative to the fundamental and an average noise figure of 1.8 dB at room temperature within the IF band. The simulated results show a minimum image rejection between the sidebands of 12 dB at the band edge of the IF.