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Satellite tracking simultaneous-lobing monopulse receiving system utilizing polarization diversity in coherent and noncoherent operational modes
Electronic and mechanical scanning control system for monopulse tracking antenna
Multiplicative feed system for monopulse angle tracking antennas, discussing influence of sidelobe and backlobe responses on control function slope determining antenna bearing angle
Parabolic antenna properties generated by dual band circularly polarized focused two channel monopulse feed system, discussing tracking data from helicopter, Apollo 8 and Cassiopeia A
Polarization diversity monopulse tracking receiver design without radio frequency switches
Monopulse tracking system with antenna array of three radiators for deriving azimuth and elevation indications
Development and characteristics of low-noise multimode monopulse antenna feed system for use with microwave communication equipment
Monopulse scanning network for scanning volumetric antenna pattern
The Tracking and Data Relay Satellite with a set of circularly-polarized, amplitude-sensing monopulse patterns suitable for acquiring and tracking user spacecraft at Ku-band (15.0 GHz) is discussed. The possibility of increasing the less than 0.4-degree half-power beamwidth of the data beam to almost 1.0 degree during the acquisition phase is predicated on the use of feeds situated in the first bright-ring of the Airy diffraction structure. A complex-vector simulation equivalent to the Kirchhoff-Kottler or Franz formulations is used to compute transmitted and received field information for a dual-reflector (Cassegrain) antenna configuration in a three-dimensional space.
A monolithic azimuthal monopulse antenna for 94 GHz applications has been developed. The structure consists of a single dipole suspended in one plane of an integrated horn cavity to obtain the sum pattern, and an antiparallel pair of dipoles suspended in a different plane of the same horn cavity to achieve the difference pattern. Pattern measurements of microwave models and on the millimeter-wave antennas show good agreement with theory and exhibit symmetry with a sharp -30 dB null at broadside for the difference antenna. Microwave model measurements show input impedances close to 50 Ohms, with greater than -25 dB isolation between sum and difference antennas across a 10 percent bandwidth.
Terrain height variations in mountainous areas cause problems in radiometric corrections of synthetic aperture radar (SAR) images. To determine the elevation angle and the height at the different parts of an image, an application of the monopulse principle is proposed. From the ratios of images radiometrically modulated by the difference and sum antenna pattern in range it is possible to calculate the appropriate elevation angle at any point in the image. Design considerations for a corresponding airborne SAR-system are presented, and some estimates of error influences (e.g., ambiguities), expected performance and precision in topographic mapping are given.
This paper presents systems modeling, simulation and implementation of Ka-band monopulse tracking feed for antennas in NASA/DSN ground stations.
Ka-band (32-GHz) monopulse tracking has been chosen for the upcoming NASA missions.
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Explore the source record for details and available documents.
Analysis of comparators used in CSM high gain antenna tracking system
Scanning method involves separation of scanning capability into two independent degrees of freedom. One degree of freedom corresponds to azimuthal scanning and other to elevation scanning on spiral coordinate axes. Scanning of both prime-feed and mirrored patterns is accomplished with reduction of mechanical vibration damage to large antennas.
A time division multiplexing and a quadraphase combining dual channel system were analyzed, designed, and tested. Analyses performed include the following: (1) boresight error as a function of the error channel bandwidth; (2) error channel interference with the sum channel functions; (3) threshold performance; and (4) error channel crosstalk, linearity, and drift as a function of signal level, Doppler, and environment. Test results indicate that the time division multiplexing system meets the design goals of the program. However, careful selection and alignment of all gain controlled amplifiers are required along with temperature compensation of the angle channel gain. The quadraphase system crosstalk performance is comparatively poor (-15 dB) with respect to the -30 dB requirements and this consequently affects gain tracking performance. Gain tracking was found to be + or - 20 percent rather than the + or - 5 percent specification. Data for the two systems is compared and recommendations are presented.