A wideband receiver-module for passive MM wave imaging array: Optimization and test results
Results of noise and impedance optimization of a W-band receiver-module are given. A wideband compact receiver-module for MM wave passive imaging array has been developed on the basis of InP MMIC LNA and a highly sensitive impedance matched low-barrier detector diode. Achieved bandwidth is 85–100 GHz, the gain factor is 30 dB that was sufficient to provide 15 mK/Hz1 temperature sensitivity of the receiver-module. Tests results of the receiver-module are presented.
Characteristics of Smooth-Walled Spline-Profile Horns for Tightly Packed Feed-Array of RATAN-600 Radio Telescope
In this paper we present a design of highly packed multi-beam receiving array. The requirements to the individual element of antenna array are formulated and the smooth-walled spline-profile horn as the adequate candidate is proposed. The utilization of such array in the RATAN-600 radio telescope will allow for providing the minimum beam spacing about (1.16-1.32) HPBW that is close to the best results in the highly packed multi-beam receiving array.
Bolometer array development at the Max-Planck-Institut für Radioastronomie
Abstract Continuum radiometers based on bolometers have a long tradition at the Max-Planck-Institut fur Radioastronomie (MPIfR) in Bonn, Germany. Arrays of bolometers have been under development since the early 1990s. A small seven-element system, operating at 300 mK, saw first light in 1992 at the IRAM 30-m telescope and has been used successfully by numerous observers at that facility since then. While this array had a conventional `composite' design, it was obvious that larger arrays, especially for higher frequencies, could take advantage of microfabrication technology. The recent MPIfR bolometer arrays employ a hybrid approach. They combine a single-mode horn array with a planar bolometer array on a single crystal Silicon wafer with Silicon–Nitride membranes. With efficient absorbing structures, the bolometers couple to the single mode of the radiation field collected by the horns, without needing integrating cavities. Readout is provided by NTD-Germanium thermistors that are attached to the absorbers. This paper covers the history of this development, the design aspects of the bolometer arrays, including the coupling to the telescope, and the status of work in progress.