Engineering topics

Bhasin, Kul B.

Publications and source records attributed to Bhasin, Kul B..

59 records · Page 4

NASA NTRS1987

Monolithic Microwave Integrated Circuit (MMIC) technology for space communications applications

Future communications satellites are likely to use gallium arsenide (GaAs) monolithic microwave integrated-circuit (MMIC) technology in most, if not all, communications payload subsystems. Multiple-scanning-beam antenna systems are expected to use GaAs MMIC's to increase functional capability, to reduce volume, weight, and cost, and to greatly improve system reliability. RF and IF matrix switch technology based on GaAs MMIC's is also being developed for these reasons. MMIC technology, including gigabit-rate GaAs digital integrated circuits, offers substantial advantages in power consumption and weight over silicon technologies for high-throughput, on-board baseband processor systems. For the more distant future pseudomorphic indium gallium arsenide (InGaAs) and other advanced III-V materials offer the possibility of MMIC subsystems well up into the millimeter wavelength region. All of these technology elements are in NASA's MMIC program. Their status is reviewed.

Connolly, Denis J.↗

NASA NTRS1987

Optically controlled microwave devices and circuits: Emerging applications in space communications systems

Optical control of microwave devices and circuits by an optical fiber has the potential to simplify signal distribution networks in high frequency communications systems. The optical response of two terminal and three terminal (GaAs MESFET, HEMT, PBT) microwave devices are compared and several schemes for controlling such devices by modulated optical signals examined. Monolithic integration of optical and microwave functions on a single semiconductor substrate is considered to provide low power, low loss, and reliable digital and analog optical links for signal distribution.

Bhasin, Kul B.↗

NASA NTRS1987

Monolithic Microwave Integrated Circuit (MMIC) technology for space communications applications

Future communications satellites are likely to use gallium arsenide (GaAs) monolithic microwave integrated-circuit (MMIC) technology in most, if not all, communications payload subsystems. Multiple-scanning-beam antenna systems are expected to use GaAs MMICs to increase functional capability, to reduce volume, weight, and cost, and to greatly improve system reliability. RF and IF matrix switch technology based on GaAs MMICs is also being developed for these reasons. MMIC technology, including gigabit-rate GaAs digital integrated circuits, offers substantial advantages in power consumption and weight over silicon technologies for high-throughput, on-board baseband processor systems. For the more distant future pseudomorphic indium gallium arsenide (InGaAs) and other advanced III-V materials offer the possibility of MMIC subsystems well up into the millimeter wavelength region. All of these technology elements are in NASA's MMIC program. Their status is reviewed.

Connolly, Denis J.↗

NASA NTRS1987

Optical RF distribution links for MMIC phased array antennas

Conventional methods to distribute RF signals to GaAs Monolithic Microwave Integrated Circuits Phased Array Antennas are inadequate for arrays having large numbers of elements. Optical RF distribution links have been proposed as a lightweight, mechanically flexible, and low volume solution. Three candidate techniques for providing optical RF distribution are discussed along with the electro-optic devices required to configure them. A discussion of the present status of applicable electro-optics devices is also included.

Kunath, Richard R.↗

NASA NTRS1986

Analysis of optically controlled microwave/millimeter-wave device structures

The light-induced voltage and the change in the source-to-drain channel current under optical illumination higher than the semiconductor bandgap for GaAs MESFET, InP MESFET, Al0.3Ga0.7As/GaAs high electron mobility transistor (HEMT) and GaAs permeable base transistor (PBT) were analytically obtained. The GaAs PBT and GaAs MESFET have much higher sensitivity than InP MESFET. The Al0.3Ga0.7As/GaAs HEMT is observed to have the highest sensitivity. Variation in device parasitics due to optical illumination and its effect on the cutoff frequencies f sub T and f sub max are also investigated.

Simons, Rainee N.↗