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.
A G-band cryogenic MMIC heterodyne receiver module for astronomical applications
We report cryogenic noise temperature and gain measurements of a prototype heterodyne receiver module designed to operate in the atmospheric window centered on 150 GHz. The module utilizes MMIC InP HEMT amplifiers, a second harmonic mixer, and bandpass filters. Measurements show an average gain of 22 dB and an average noise temperature of 87 K over a 40 GHz band from 140 to 180 GHz when the module is cooled to 22 K. A spot noise temperature of 58 K was measured at 166 GHz and is a record for cryogenic noise from HEMT amplifiers. The compact housing features a split-block design that facilitates quick assembly and a condensed arrangement of the MMIC components and bias circuitry. DC feedthroughs and nano-miniature connectors also contribute to enabling the compact design, so that the total volume of the module is about 2.5 cm cubed.
Active Broad X-Band Circular Patch Antenna
This letter presents the results of experimental study of omnidirectional circular patch antenna operating in the TM010 mode. Antenna geometrical parameters have been selected on the basis of theoretical calculations. It has been shown that the antenna of this kind with VSWR les 2 and bandwidth of 18% has a conical radiation pattern with maximum oriented 36deg to the zenith. The antenna has a side radiation level of -15 dB and a cross-component level of less than -25 dB. The experimental results are in good agreement with the theoretical calculations. Employment of the one-stage HEMT amplifier makes it possible to obtain the total gain of an active antenna of no less than 10 dB. This antenna can be successfully used for mobile systems, wireless indoor communications, as well as for array applications