Viper RF (United Kingdom)

This paper describes the design and characterisation of two amplifiers from 81GHz to 86GHz. This chip set was designed as a part of a dual-redundant low-noise amplifier module for future W-band communication payload system. The first amplifier was designed using the D007IH GaAs metamorphic HEMT (mHEMT) technology from MACOM (formerly OMMIC) for low noise application. The gain of this amplifier was measured to be approximately 30dB with a noise figure of 2.2dB and a low power consumption of 30mW. The die measures 3.5mm x 1.2mm. The second amplifier was designed for better linearity using the PH10 GaAs process from UMS. The amplifier demonstrated of gain greater than 27dB with a third order output intercept point (OIP3) better than 17dBm. The die measures 4.5x1.5mm.

This paper describes the design, simulation, and measurement of a tuneable 9.365-GHz aperiodic Bragg resonator. The resonator utilizes an aperiodic arrangement of non ( /4) low-loss alumina plates ( , loss tangent of to ) mounted in a cylindrical metal waveguide. Tuning is achieved by varying the length of the center section of the cavity. A multi-element bellows/probe assembly is presented. A tuning range of 130 MHz (1.39%) is demonstrated. The insertion loss varies from -2.84 to -12.03 dB while the unloaded Q varies from 43 788 to 122 550 over this tuning range. At 10 of the 13 measurement points, the unloaded Q exceeds 1 00 000, and the insertion loss is above -7 dB. Two modeling techniques are discussed; these include a simple ABCD circuit model for rapid simulation and optimization and a 2.5-D field solver, which is used to plot the field distribution inside the cavity.

For the sake of brevity the references of all species appearing in the ac- companying list which are also mentioned in Dr. G. A. Boulenger's "Catalogues", have teer omitted, and for the others the only reference given is that of the publication in which the description of the species first appeared.