Phase error and associated cross-polarization effects in cassegrainian-fed microwave antennas

Phase error and cross-polarization effects in Cassegrainian and microwave antenna

Applications of two-dimensional integral equation theory to reflector antenna analysis

Applying method of moments to solution of integral equations for current induced on conducting cylinders in two-dimensional fiel

Millimeter-wave radiometry for radio astronomy Final report, Nov. 1965 - 31 Dec. 1967

Noise, gain, and antenna data for millimeter wave radiometers, and lunar eclipse observation

Symmetrical two dimensional scattering program

Computer program solves integral equation for currents induced by electric or magnetic plane wave incident upon one or more conducting cylinders with a midplane of symmetry. Program utilizes symmetry of the geometry. Restrictions on the program are given

Millimeter-wave radiometry for radio astronomy Final report

Lunation study using millimeter wave radiometry for radio astronom

Millimeter-wave radiometry for radio astronomy Final report

Millimeter wave radiometry for radio astronom

Millimeter-wave radiometry for radio astronomy Final report, 1 Aug. 1964 - 15 Sep. 1966

Instrumentation and antenna development, solar observations, and lunation observations in study of millimeter wave radiometry for radio astronom

Structural Test and Analysis of a Hybrid Inflatable Antenna

NASA is developing ultra-lightweight structures technology for communication antennas for space missions. One of the research goals is to evaluate the structural characteristics of inflatable and rigidizable antennas through test and analysis. Being able to test and analyze the structural characteristics of a full scale antenna is important to enable the simulation of various mission scenarios to determine system performance in space. Recent work completed to evaluate a Hybrid Inflatable Antenna concept will be discussed. Tests were completed on a 2-m prototype to optimize its static shape and identify its modal dynamics that are important for analytical model validation. These test results were used to evaluate a preliminary finite element model of the antenna, and this model development and correlation activity is also described in the paper

Field Scanner Design for MUSTANG of the Green Bank Telescope

MUSTANG is a bolometer camera for the Green Bank Telescope (GBT) working at a frequency of 90 GHz. The detector has a field of view of 40 arcseconds. To cancel out random emission change from atmosphere and other sources, requires a fast scanning reflecting system with a few arcminute ranges. In this paper, the aberrations of an off-axis system are reviewed. The condition for an optimized system is provided. In an optimized system, as additional image transfer mirrors are introduced, new aberrations of the off-axis system may be reintroduced, resulting in a limited field of view. In this paper, different scanning mirror arrangements for the GBT system are analyzed through the ray tracing analysis. These include using the subreflector as the scanning mirror, chopping a flat mirror and transferring image with an ellipse mirror, and chopping a flat mirror and transferring image with a pair of face-to-face paraboloid mirrors. The system analysis shows that chopping a flat mirror and using a well aligned pair of paraboloids can generate the required field of view for the MUSTUNG detector system, while other systems all suffer from larger off-axis aberrations added by the system modification. The spot diagrams of the well aligned pair of paraboloids produced is only about one Airy disk size within a scanning angle of about 3 arcmin.Comment: 7 pages, 9 figure