Polarisation performance and calibration of the digital beamforming system for 2-PAD
IEEE International Symposium on Phased Array Systems and Technology (2010) 686-689
Abstract:
In this paper, we report on calibration and polarisation performance of the 2PAD digital beamforming system, a pathfinder instrument for large-N, high-frequency phased-array radio instruments, in particular the Square Kilometre Array (SKA) radio telescope. We review the design of the digital system, and report on instrumental calibration approaches. © 2010 IEEE.A 43-GHz VLA survey in the ELAIS N2 area
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 408:2 (2010) 657-668
Infrared-correlated 31-GHz radio emission from Orion East
\mnras 407 (2010) 2223-2229
A 700 GHz unilateral finline SIS mixer fed by a multi-flare angle smooth-walled horn
Proceedings of SPIE - The International Society for Optical Engineering 7741 (2010)
Abstract:
We present the design of a broadband superconductor-insulator- superconductor (SIS) mixer operating near 700 GHz. A key feature of our design is the utilisation of a new type of waveguide to planar circuit transition comprising a unilateral finline taper. This transition is markedly easier to design, simulate and fabricate than the antipodal finline we employed previously. The finline taper and the superconducting circuitry are deposited on a 15 μm thick silicon substrate. The employment of the very thin substrate, achieved using Silicon-On-Insulator (SOI) technology, makes it easy to match the incoming signal to the loaded waveguide. The lightweight mixer chip is held in the E-plane of the waveguide using gold beam leads, avoiding the need for deep grooves in the waveguide wall. This new design yields a significantly shorter chip, free of serrations and a wider RF bandwidth. Since tuning and all other circuits are integrated on the mixer chip, the mixer block is extremely simple, comprising a feed horn and a waveguide section without any complicated mechanical features. We employ a new type of smooth-walled horn which exhibits excellent beam circularity and low cross polarisation, comparable to the conventional corrugated horn, and yet is easier to fabricate. The horn is machined by standard milling with a drill tool shaped into the horn profile. In this paper, we describe the detailed design of the mixer chip including electromagnetic simulations, and the mixer performance obtained with SuperMix simulations. We also present the preliminary measurements of the smooth-walled horn radiation patterns near the mixer operating frequencies. © 2010 SPIE.The C-Band All-Sky Survey: Instrument design, status, and first-look data
Proceedings of SPIE - The International Society for Optical Engineering 7741 (2010)