Coupled waveguide antennas.
Coupled waveguide antenna analyzed based on coupled-mode theory
WAVEGUIDE ANTENNA↗
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Coupled waveguide antennas.
Coupled waveguides structure proposed as leaky- wave antenna, extending previous coupled-mode theory
COUPLED MODE↗
Cup Cylindrical Waveguide Antenna
The cup cylindrical waveguide antenna (CCWA) is a short backfire microwave antenna capable of simultaneously supporting the transmission or reception of two distinct signals having opposite circular polarizations. Short backfire antennas are widely used in mobile/satellite communications, tracking, telemetry, and wireless local area networks because of their compactness and excellent radiation characteristics. A typical prior short backfire antenna contains a half-wavelength dipole excitation element for linear polarization or crossed half-wavelength dipole elements for circular polarization. In order to achieve simultaneous dual circular polarization, it would be necessary to integrate, into the antenna feed structure, a network of hybrid components, which would introduce significant losses. The CCWA embodies an alternate approach that entails relatively low losses and affords the additional advantage of compactness. The CCWA includes a circular cylindrical cup, a circular disk subreflector, and a circular waveguide that serves as the excitation element. The components that make it possible to obtain simultaneous dual circular polarization are integrated into the circular waveguide. These components are a sixpost polarizer and an orthomode transducer (OMT) with two orthogonal coaxial ports. The overall length of the OMT and polarizer (for the nominal middle design frequency of 2.25 GHz) is about 11 in. (approximately equal to 28 cm), whereas the length of a commercially available OMT and polarizer for the same frequency is about 32 in. (approximately equal to 81 cm).
Acosta, Roberto J.↗
Antenna noise temperatures of the 34-meter beam-waveguide antenna with horns of different gains installed at F1
This article presents a set of theoretical and measured zenith-antenna noise temperatures at 8.45 GHz for the DSS-13 34-m beam-waveguide antenna when horns of different gains are installed at F1. The methodology for calculations is shown in detail. The major differences between calculated and measured values are attributed to changes in subreflector support leg scattering when illuminated by the various horns.
Otoshi, T. Y.↗
Cup waveguide antenna with integrated polarizer and OMT
A cup waveguide antenna with integrated polarizer and OMT for simultaneously communicating left and right hand circularly polarized electromagnetic waves is adjustable to obtain efficient propagation and reception of electromagnetic waves. The antenna includes a circular waveguide having an orthomode transducer utilizing first and second pins longitudinally spaced apart and oriented orthogonally with respect to each other. Six radially-oriented adjustable polarizer screws extend from the exterior to the interior of the waveguide. A septum intermediate the first and second pins is aligned with the first pin. Adjustment of the polarizer screws enables maximized propagation of and/or response to left hand circularly polarized electromagnetic waves by the first pin while simultaneously enabling maximized propagation of and/or response to right hand circularly polarized electromagnetic waves by the second pin.
Acosta, Roberto J.↗
Correcting for Beam Aberrations in a Beam-Waveguide Antenna
A method for correcting the aim of a beam-waveguide microwave antenna compensates for the beam aberration that occurs during radio tracking of a target that has a component of velocity transverse to the line of sight from the tracking station. The method was devised primarily for use in tracking of distant target spacecraft by large terrestrial beam-waveguide antennas of NASA's Deep Space Network (DSN). The method should also be adaptable to tracking, by other beam-waveguide antennas, of targets that move with large transverse velocities at large distances from the antennas.
Franco, Manuel↗
A Novel Design Technique for Beam-Waveguide Antennas
Paper covers the poor low-frequency performance of geometrically designed beam-waveguide antennas,and a novel design technique for solving this poor performance. A unique application was made of the conjugate phase-matching techniques to obtain the desired solution.
beam-waveguide↗
The 1- to 4-K refrigeration techniques for cooling masers on a beam waveguide antenna
The status of technology is reported for various 1- to 4-K commercially available refrigeration systems capable of producing 1.5-K refrigeration to cool masers and superconducting cavity oscillators on the proposed beam waveguide antenna. The design requirements for the refrigeration system and the cryostat are presented. A continuously operating evaporation refrigerator that uses capillary tubing to provide a continuous, self-regulating flow of helium at approximately 1.5 K has been selected as the first refrigerator design for the beam waveguide antenna.
Johnson, D. L.↗
Compensation of Gravity-Induced Structural Deformations on a Beam- Waveguide Antenna Using a Deformable Mirror
At the NASA Deep Space Network (DSN) Goldstone Complex, a 34-meter- diameter beam-waveguide antenna, DSS-13, was constructed in 1988-1990 and has become an integral part of an advanced systems program and a test bed for technologies being developed to introduce Ka-band (32 GHz) frequencies into the DSN. A method for compensating the gravity- induced structural deformations in this large antenna is presented.
technologies DSN↗
Initial pointing calibrations for the DSS 13 34-meter beam-waveguide antenna
The beam pointing of the Deep Space Station (DSS) 13 beam-waveguide antenna at the Goldstone Venus site was calibrated during the postconstruction performance testing period from Jul. 1990 through Jan. 1991. The pointing calibrations were based on errors measured on radio sources at both the Cassegrain and centerline beam-waveguide focal points. The blind pointing performance goal of 5.0 mdeg, 3-sigma at Ka-band (32 GHz) was demonstrated to be met for low (less than 10 mph) wind conditions.
Alvarez, L. S.↗
Efficiency calibration of the DSS 13 34-meter diameter beam waveguide antenna at 8.45 and 32 GHz
Efficiency measurements at 8.45 and 32 GHz (X and Ka bands, respectively) were carried out on the new 34 m diameter beam waveguide antenna now in use at the NASA Goldstone Deep Space Communications Complex. The use of portable test packages enabled measurements at both the Cassegrain and beam waveguide focal points. Radio sources (quasars and Venus) were used as calibrators, and updated determinations of flux and source size correction were made during the period of the measurements. Gain and efficiency determinations as a function of elevation angle are presented, and the effects of the beam waveguide system and antenna structure are clearly seen. At the beam waveguide focus, an 8.45 GHz peak efficiency of 72.38 pct. was measured; at 32 GHz, 44.89 pct. was measured.
Slobin, S. D.↗
Efficiency measurement techniques for calibration of a prototype 34-meter-diameter beam-waveguide antenna at 8.45 and 32 GHz
Efficiency measurements at 8.45 and 32 GHz (X and Ka bands, respectively) were carried out on the new 34 m diameter beam waveguide antenna now in use at the NASA Goldstone Deep Space Communications Complex. The use of portable test packages enabled measurements at both the Cassegrain and beam waveguide focal points. Radio sources (quasars and Venus) were used as calibrators, and updated determinations of flux and source size correction were made during the period of the measurements. Gain and efficiency determinations as a function of elevation angle are presented, and the effects of the beam waveguide system and antenna structure are clearly seen. At the beam waveguide focus, an 8.45 GHz peak efficiency of 72.38 pct was measured; at 32 GHz, 44.89 pct was measured.
Slobin, Stephen D.↗
Structural design options for the new 34 meter beam waveguide antenna
In addition to the successful network of 34 m High Efficiency antennas recently built by JPL, the Deep Space Network (DSN) is embarking on the construction of a 34 m high performance, research and development antenna with beam waveguide optics at the Venus site. The construction of this antenna presents many engineering challenges in the area of structural, mechanical, RF, and pointing system design. A set of functional and structural design requirements is outlined to guide analysts in the final configuration selection. Five design concepts are presented covering both the conventional center-fed beam optics as well as the nonconventional, by-pass beam configuration. The merits of each concept are discussed with an emphasis on obtaining a homologous design. The preliminary results of structural optimization efforts, currently in progress, are promising, indicating the feasibility of meeting, as a minimum, all X-band (8.4 GHz) requirements, with a goal towards meeting Ka-band (32 GHz) quality performance, at the present budget constraints.
Katow, S.↗
A Novel Design Technique for Beam-Waveguide Antennas
The new 34-m beam-waveguide (BWG) antenna at Goldstone has a beam magnifier ellipse below ground level that transforms a 22-dB gain feedhorn into a high-gain 29-dB gain pattern for input to a standard four-mirror BWG system. It was initially designed for the X- an Ka-bands, and has a loss of less than 0.2 dB.
antenna↗
Slotted antenna waveguide plasma source
A high density plasma generated by microwave injection using a windowless electrodeless rectangular slotted antenna waveguide plasma source has been demonstrated. Plasma probe measurements indicate that the source could be applicable for low power ion thruster applications, ion implantation, and related applications. This slotted antenna plasma source invention operates on the principle of electron cyclotron resonance (ECR). It employs no window and it is completely electrodeless and therefore its operation lifetime is long, being limited only by either the microwave generator itself or charged particle extraction grids if used. The high density plasma source can also be used to extract an electron beam that can be used as a plasma cathode neutralizer for ion source beam neutralization applications.
Foster, John↗
A portable X-band front-end test package for beam-waveguide antenna performance evaluation. Part 2: Tests on the antenna
Results are given for an X-band (8.45 GHz) test package for testing the new 34-m beam-waveguide antenna at Goldstone in an 'on-the-antenna' configuration. Included are X-band zenith noise temperature values and tipping-curve data obtained at the Cassegrain focal point F1 as well as at the pedestal room focal point F3. Subreflector Z-defocus test results for both F1 and F3 are also presented. The X-band test package operated well in all of the different test configurations and exceeded expected performance.
Otoshi, T. Y.↗
A portable Ku-band front-end test package for beam-waveguide antenna performance evaluation
A 34-m beam-waveguide (BWG) antenna has been built a Deep Space Station 13 (DDS 13) in the Goldstone Deep Space Communications Complex. This antenna is designed to be efficient at X-, Ku-, and Ka-bands, and it is the first NASA tracking antenna to use a BWG design. The design of a Ku-band test package for the new BWG antenna at 11.7-12.2 GHz is presented. Results of linear polarization measurements with the test package on the ground are also presented. This report is the fifth in a series of articles concerned with test package design and performance.
Otoshi, T. Y.↗
Environmental Projects: Biological Assessment, Opinion, and New 34-Meter Beam-Waveguide Antenna (DSS 24) at Apollo Site - Volume 17
This report deals with the Biological Assessment, Biological Opinion and Final Report on the construction of a high- efficiency 34-meter, multifrequency beam-waveguide antenna at the Apollo Site of the Goldstone Deep Space Communications Complex, operated by JPL. According to the Endangered Species Act of 1973, a Biological Assessment must be conducted and a Biological Opinion, with terms and conditions, rendered (the Opinion by the U.S. Department of the Interior) before construction of any federal project that may affect endangered or threatened flora or fauna. After construction, a final report is filed with the Department. The desert tortoise, designated "threatened" by the U.S. Fish and Wildlife Service, and the Mojave ground squirrel and the Lane Mountain milk vetch, both designated "candidate threatened," required the reporting specified by the Act. The Assessment found no significant danger to the animal species if workers are educated about them. No stands of the plant species were observed in the surveyed construction area. The Department issued a Biological Opinion to safeguard the two animal species. The Service and the California Department of Fish and Game both issued a Biological Concurrence that JPL had satisfied all environmental criteria for preserving threatened species.
Bengelsdorf, Irving↗