Engineering topics

Bathker, D.

Publications and source records attributed to Bathker, D..

5 records

NASA NTRS1990

Design and performance analysis of the DSS-13 beam waveguide antenna

A new 34 m research and development antenna is currently being constructed prior to introducing beam waveguide (BWG) antennas and Ka-band (32 GHz) frequencies into the NASA/JPL Deep Space Network. The new 34 m antenna, fed with either a center or bypass BWG, will lose less than 0.2 dB (excluding surface root mean square and mirror misalignment losses), as compared with a standard-fed Cassegrain antenna a X- (8.4 GHz) and Ka-bands. The antenna is currently under construction and is scheduled to be completed July 1990. Phase 1 of the project is for independent X- and Ka-band receive-only tests. Phase 2 of the project is for simultaneous S- (2.3 GHz) and X-band or X- and Ka-band operation, and the design is currently under way.

Veruttipong, T.↗

NASA NTRS1987

Design considerations for the beamwaveguide retrofit of a ground antenna station

A primary requirement of the NASA Deep Space Network (DSN) is to provide for optimal reception of very low signal levels. This requirement necessitates optimizing the antenna gain to the total system operating noise level quotient. Low overall system noise levels of 16 to 20 K are achieved by using cryogenically cooled preamplifiers closely coupled with an appropriately balanced antenna gain/spillover design. Additionally, high-power transmitters (up to 400 kW CW) are required for spacecraft emergency command and planetary radar experiments. The frequency bands allocated for deep space telemetry are narrow bands near 2.1 and 2.3 GHz (Ka-band), 7.1 and 8.4 GHz (X-band), and 32 and 34.5 GHz (Ka-band). In addition, planned operations for the Search for Extraterrestrial Intelligence (SETI) program require continuous low-noise receive coverage over the 1 to 10 GHz band. To summarize, DSN antennas must operate efficiently with low receive noise and high-power uplink over the 1 to 35 GHz band.

Veruttipong, T.↗

NASA NTRS1986

Design considerations for the beam-waveguide retrofit of a ground antenna station

Retrofitting an antenna that was originally designed without a beam waveguide introduces special difficulties because it is desirable to minimize alteration of the original mechanical truss work and to image the actual feed without distortion at the focal point of the dual-shaped reflector. To obtain an acceptable image, certain Geometrical Optics (GO) design criteria are followed as closely as possible. The problems associated with applying these design criteria to a 34-meter dual-shaped DSN (Deep Space Network) antenna are discussed. The use of various diffraction analysis techniques in the design process is also discussed. GTD and FFT algorithms are particularly necessary at the higher frequencies, while Physical Optics and Spherical Wave Expansions proved necessary at the lower frequencies.

Veruttipong, T.↗

NASA NTRS1979

A prototype DSN X-S band feed: DSS 13 application

A prototype X-S band horn feed for future use at various DSN sites, dealing with the testing of the final fabricated feed at DSS 13 are discussed. Measured feedhorn patterns are presented, and efficiencies calculated. Preliminary results of system noise temperature and 26-m antenna system gain measurements are presented. Some measurements leading to an improved second generation feed are described. The results of the field measurements indicate that this horn will perform as originally specified and required. The tests for the second generation feed have indicated the potential cause of minor X-band moding.

Williams, W.↗

NASA NTRS1967

Radiation pattern programs

Computer programs for numerically evaluating scalar far field radiation pattern integral, and obtaining secondary radiation pattern of large paraboloidal antenna

ANTENNA↗