amplifiers using current state-of-the-art low noise This paper estimates the noise temperature as a function of frequency for amplifiers covering the 1 to 10 GHz range utilizing state-of-the-art HEMT transistors operating at temperatures of 300K, 80K, and 20K. The analysis includes the effect of loss and bandwidth of the input matching network.
—This paper describes a method for designing cryo-genic silicon–germanium (SiGe) transistor low-noise amplifiers and reports record microwave noise temperature, i.e., 2 K, measured at the module connector interface with a 50-generator. A theory for the relevant noise sources in the transistor is derived from first principles to give the minimum possible… (More)
Two packaged low noise amplifiers for the 0.3-4 GHz frequency range are described. The amplifiers can be operated at temperatures of 300-4 K and achieve noise temperatures in the 5 K range (<0.1 dB noise figure) at 15 K physical temperature. One amplifier utilizes commercially available, plastic-packaged SiGe transistors for first and second stages; the… (More)
2 Abstract-Design data, in the form of dimension tables, is presented for probe transitions for microstrip substrates with 4 dielectric constants (E, = 2.2, 6.0, 10.1, and 13) in two orientations relative to the waveguide (broadside and longitudinal). These dimensions have been optimized for full waveguide bandwidth with > 20 dB return loss using an… (More)
This paper describe a millimeter wave low noise amplifier with extraordinary low noise, low power consumption, and wide frequency range. These results are achieved utilizing state-of-the-art InP HEMT transistors coupled with CPW circuit design. The paper describes the transistor model, modeled and measured on-wafer and in-module results at both 300K and 24K… (More)
—A novel dual polarized ultrawide-band (UWB) feed with a decade bandwidth is presented for use in both single and dual reflector antennas. The feed has nearly constant beam width and 11 dBi directivity over at least a decade bandwidth. The feed gives an aperture efficiency of the reflector of 66% or better over a decade bandwidth when the subtended angle… (More)
Pre-HEAT is a 20 cm aperture submillimeter-wave telescope with a 660 GHz (450 micron) Schottky diode heterodyne receiver and digital FFT spectrometer for the Plateau Observatory (PLATO) developed by the University of New South Wales. In January 2008 it was deployed to Dome A, the summit of the Antarctic plateau, as part of a scientific traverse led by the… (More)
— A novel transition from coaxial cable to microstrip is presented in which the coax connector is perpendicular to the substrate of the printed circuit. Such a right-angle transition has practical advantages over more common end-launch geometries in some situations. The design is compact, easy to fabricate, and provides repeatable performance of better than… (More)