A 43-GHz AlInAs/GaInAs/InP HEMT grid oscillator

A 36-element hybrid grid oscillator has been fabricated. The active devices are InP-based High Electron Mobility Transistors (HEMT's). The grid oscillates at 43 GHz with an effective radiated power of 200 mW. Measurements show the E and H-plane radiation patterns have side lobes 10 dB below the main beam. These results are a significant improvement over a previous millimeter-wave grid oscillator, which had a divided beam because of substrate mode

Low-cost high-performance W-band LNA MMICs for millimeter-wave imaging

The main limitation to the sensitivity of a radiometer or imager is its equivalent noise temperatures, T_e. Placing a low noise amplifier (LNA) at a radiometer's front end can dramatically reduce T_e. LNA performance has steadily improved over recent years, and here we report on a W-band LNA with the lowest T_e measured at room temperature. Furthermore, we present statistical RF data showing high yield and consistency for future high volume production that is needed for commercial radiometric imaging array applications such as security screening, aircraft landing, and other systems

Low-cost high-performance W-band LNA MMICs for millimeter-wave imaging

The main limitation to the sensitivity of a radiometer or imager is its equivalent noise temperatures, T_e. Placing a low noise amplifier (LNA) at a radiometer's front end can dramatically reduce T_e. LNA performance has steadily improved over recent years, and here we report on a W-band LNA with the lowest T_e measured at room temperature. Furthermore, we present statistical RF data showing high yield and consistency for future high volume production that is needed for commercial radiometric imaging array applications such as security screening, aircraft landing, and other systems

MEMS-Based Communications Systems for Space-Based Applications

As user demand for higher capacity and flexibility in communications satellites increases, new ways to cope with the inherent limitations posed by the prohibitive mass and power consumption, needed to satisfy those requirements, are under investigation. Recent studies suggest that while new satellite architectures are necessary to enable multi-user, multi-data rate, multi-location satellite links, these new architectures will inevitably increase power consumption, and in turn, spacecraft mass, to such an extent that their successful implementation will demand novel lightweight/low power hardware approaches. In this paper, following a brief introduction to the fundamentals of communications satellites, we address the impact of micro-electro-mechanical systems (MEMS) technology, in particular micro-electro-mechanical (MEM) switches to mitigate the above mentioned problems and show that low-loss/wide bandwidth MEM switches will go a long way towards enabling higher capacity and flexibility space-based communications systems

Ultra broadband low power MMIC amplifier

A low power two-stage InP HEMT MMIC amplifier has been developed. The amplifier utilizes 0.12 µm T-gate InP HEMTs with 225 µm gate periphery. This compact microstrip MMIC is only 1.5 mm 2 in size. It exhibits gain of 12.51 dB at 15 mW of dissipated power over an operating range from 1 to 50 GHz. The gain bandwidth/dissipation figure of merit is 40 dB GHz/mW. The average noise figure is 3 to 3.8 dB over the Ka band