Accession Number : ADA299864

Title :   Quasi-Optical Constrained Lens Amplifiers.

Descriptive Note : Doctoral thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Schoenberg, Jon S.

PDF Url : ADA299864

Report Date : 20 SEP 1995

Pagination or Media Count : 222

Abstract : A major goal in the field of quasi-optics is to increase the power available from solid state sources by combining the power of individual devices in free space, as demonstrated with grid oscillators and grid amplifiers. Grid amplifiers and most amplifier arrays require a plane wave feed, provided by a far field source or at the beam waist of a dielectric lens pair. These feed approaches add considerable loss and size, which is usually greater than the quasi-optical amplifier gain. In addition, grid amplifiers require external polarizers for stability, further increasing size and complexity. This thesis describes using constrained lens theory in the design of quasi optical amplifier arrays with a focal point feed, improving the power coupling between the feed and the amplifier for increased gain. Feed and aperture arrays of elements, input/output isolation and stability, amplifier circuitry, delay lines and bias distribution are all contained on a single planar substrate, making monolithic circuit integration possible. Measured results of X band transmission lenses and a low noise receive lens are presented, including absolute power gain up to 13 dB, noise figure as low as 1.7 dB, beam scanning to +/-30 deg, beam forming and beam switching of multiple sources, and multiple level quasioptical power combining. The design and performance of millimeter wave power combining amplifier arrays is described, including a Ka Band hybrid array with 1 watt output power, and a V Band 36 element monolithic array with a 5 dB on/off ratio.

Descriptors :   *OPTICAL CIRCUITS, *LASER AMPLIFIERS, *RADIOFREQUENCY LENSES, COUPLING(INTERACTION), OSCILLATORS, OUTPUT, OPTICAL PROPERTIES, THEORY, GRIDS, DIELECTRICS, ISOLATION, THESES, INPUT OUTPUT PROCESSING, INTEGRATED CIRCUITS, MILLIMETER WAVES, SUBSTRATES, FAR FIELD, TRANSMITTANCE, PLANAR STRUCTURES, BEAM FORMING, HYBRID SYSTEMS, MONOLITHIC STRUCTURES(ELECTRONICS), OPTICAL SWITCHING, BIAS, PLANE WAVES, X BAND, NOISE(RADIO), SOLID STATE ELECTRONICS, ANTENNA APERTURES, KA BAND, DELAY LINES, LOW NOISE, ANTENNA FEEDS, V BAND, POWER GAIN, POLARIZERS.

Subject Categories : Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE