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Huang, John

Publications and source records attributed to Huang, John.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1999

Ka-Band Beam Steering Reflectarray Study

A one-meter diameter, 32 GHz active microstrip reflectarray capable of electronic beam steering has been studied. The 15_500 element array consists of rnicrostrip patch antennas, microstrip phase shifters, and dc bias lines. Specifically, the study focused on the solid-state devices and dc bias layouts for scanning the beam linearly 45 from boresight using 2-bit phase shifters. Three configurations are recommended for the reflectarray with integrated 2-bit phase shifters where the total substrate and cladding mass varies from 8 kg to 14 kg. Additionally, dc power requirements for p-i-n diodes in 1-bit, 2-bit and 3-bit phase shifting circuits are approximately 19 W, 19 W, and 39 W, respectively. The dc power requirement for phase shifters using passive MESFETs is much less than 1 W.

McSpadden, James O.↗
NASA NTRS1999

Inflatable Microstrip Reflectarray Antennas at X and Ka-band Frequencies

Inflatable antenna technology is being developed by JPL/NASA to enable the capabilities of low mass, high packaging efficiency, and low-cost deployment for future spacecraft high-gain and large aperture antennas. One of the technologies being considered is the inflatable microstrip reflectarray. A conventional inflatable parabolic reflector antenna will offer similar advantages with the added capability of wide electrical bandwidth. However, it suffers from the difficulty of maintaining its required large, thin, and curved-parabolic surface in the space environment. Since the microstrip reflectarray has the "natural" flat reflecting surface, it is much easier to maintain the required surface tolerance using an inflatable structure. This is the primary reason, despite its narrow bandwidth characteristic, that the inflatable microstrip reflectarray is being studied. This article discusses an already-developed one-meter X-band inflatable microstrip reflectarray and a three-meter Ka-band inflatable microstrip reflectarray which is currently under development. Both antennas' RF structures are designed at JPL and their mechanical inflatable structures are designed and manufactured at ILC Dover, Inc.

Huang, John↗
NASA NTRS1999

A Dual Polarization, Active, Microstrip Antenna for an Orbital Imaging Radar System Operating at L-Band

A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radar system was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radar systems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radar system which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L-Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.

Kelly, Kenneth C.↗
NASA NTRS1999

A Dual-polarized Microstrip Subarray Antenna for an Inflatable L-band Synthetic Aperture Radar

Inflatable technology has been identified as a potential solution to the problem of achieving small mass, high packaging efficiency, and reliable deployment for future NASA spaceborne synthetic aperture radar (SAR) antennas. Presently, there exists a requirement for a dual-polarized L-band SAR antenna with an aperture size of 10m x 3m, a center frequency of 1.25GHz, a bandwidth of 80MHz, electronic beam scanning, and a mass of less than 100kg. The work presented below is part of the ongoing effort to develop such an inflatable antenna array.

Zawadzki, Mark↗
NASA NTRS1998

Inflatable Microstrip Reflectarray Antennas At X and Ka-Band Frequencies

Introduction: Inflatable antenna technology is being developed by JPL/NASA to enable the capabilities of low mass, high packaging efficiency, and low-cost deployment for future spacecraft high-gain and large aperture antennas. One of the technologies being considered [11 is the inflatable microstrip reflectarray. A conventional inflatable parabolic reflector antenna will offer similar advantages with the added capability of wide electrical bandwidth. However, it suffers from the difficulty of maintaining its required large, thin, and curved-parabolic surface in the space environment. Since the microstrip reflectarray has the "natural" flat reflecting surface, it is much easier to maintain the required surface tolerance using an inflatable structure. This is the primary reason, despite its narrow bandwidth characteristic, that the inflatable microstrip reflectarray is being studied. This article discusses an already-developed one-meter X-band inflatable microstrip reflectarray and a three-meter Ka-band inflatable microstrip reflectarray which is currently under development. Both antennas' RF structures are designed at JPL and their mechanical inflatable structures are designed and manufactured at ILC Dover, Inc.

Huang, John↗
NASA NTRS1998

Ultra-Wideband UHF Microstrip Array for GeoSAR Application

GeoSAR is a program sponsored by DARPA (Defense Advanced Research Projects Agency) and NASA (National Aeronautics and Space Administration) to develop an airborne, radar- based, commercial terrain mapping system for identification of geologic, seismic, and environmental information, it has two (dual-band at X and UHF) state-of-the-art interferometric synthetic aperture radar (SAR) ground mapping systems. The UHF interferometric system is utilized to penetrate the vegetation canopy and obtain true ground surface height information, while the Xband system will provide capability of mapping the top foliage surface. This paper presents the UHF antenna system where the required center frequency is 350 MHz with a 160 MHz of bandwidth (46% from 270 MHz to 430 MHz). The antenna is required to have dual-linear polarization with a peak gain of 10 dB at the center frequency and a minimum gain of 8 dB toward two ends of the frequency band. One of the most challenging tasks, in addition to achieving the 46% bandwidth, is to develop an antenna with small enough size to fit in the wing-tip pod of a Gulfstream II aircraft.

Thomas, Robert F.↗
NASA NTRS1997

NASA's Mobile and Telecom Antenna Development at JPL

Chartered by NASA to develop and demonstrate enabling technologies for mobile and satellite telecommuniation systems, JPL has developed various antenna technologies throughout the microwave spectrum in the past two decades.

Telecom Antenna Mobile↗
NASA NTRS1997

Microstrip Reflectarray with Elements Having Variable Rotation Angles

Two Ka-band, half-meter diameter, circularly polarized microstrip reflectarrays have been developed. Although both antennas demonstrated excellent efficiencies, adequate bandwidths, and low average sidelobe and cross-pol levels, the one with variable rotation angles achieved superior overall performance. It is believed that these are electrically the largest microstrip reflectarrays (6924 elements with 42 dB gain) ever developed. It is also the first time that circular polarization has been actually demonstrated using microstrip patch elements. All these reflectarrays have dual-linear and dual-circular polarization capabilities, but only linear polarizations were demonstrated.

antennas↗
NASA NTRS1997

(abstract) Microstrip Reflectarray and its Applications

The microstrip reflectarray antenna, being in the form of a flat reflector, has recently been investigated by several antenna researchers. To demonstrate that such an antenna can be developed with relatively large electrical aperture, a half-meter-diameter microstrip array has been designed and constructed at 32 GHz with circular polarization. It is believed that this is the largest microstrip reflectarray ever built.

antenna reflectarray microstrip↗
NASA NTRS1997

(abstract) A Ka-Band 0.5 m Circularily Polarized Microstrip Reflectarray

The microstrip reflectarray antenna, being in the form of a flat reflector, has recently been investigated by several antenna researchers. This antenna, when compared to the conventional parabolic reflector, not only has the potential advantages of achieving smaller mass, smaller volume, simpler deployment mechanism, but also has the capability of scanning its main beam to larger angles from the broadside direction. Without any power divider and its associated large insertion loss, a phased reflectarray may not need the high cost T/R modules and can still remain to be an efficient array antenna.

antennas reflectarray parabolic reflector↗
NASA NTRS1997

Microstrip Reflectarray with Elements Having Variable Rotation Angles

Two Ka-band, half-meter diameter, circularly polarized microstrip reflectarrays have been developed. One has identical square patches with variable-length phase delay lines. The other uses identical square patches and delay lines with variable element rotation angles. Although both antennas demonstrated excellent efficiencies, adequate bandwidths, and low average sidelobe and cross-pol levels, the one with variable rotation angles achieved superior overall performance. It is believed that these are electrically the largest microstrip reflectarrays (6924 elements with 42 dB gain) ever developed. It is also the first time that circular polarization has been actually demonstrated using microstrip patch elements. Recent advances in reflectarray technology include the following: An X-band 0.75 m diameter microstrip reflectarray using variable-length phase delay lines which demonstrated a relatively high efficiency of 70% with peak gain of 35 dB; a partial microstrip reflectarray with beam scanning capability; A 27 GHz 0.23m diameter microstrip reflectarray using variable-size patches which achieved a gain of 31 dB at an efficiency of 31%. All these reflectarrays have dual-linear and dual-circular polarization capabilities, but only linear polarizations were demonstrated.

Huang, John↗
NASA NTRS1996

Phased Arrays of Ground and Airborne Mobile Terminals for Satellite Communications

Phased array antenna is beginning to play an important in the arena of mobile/satellite communications. Two examples of mobile terminal phased arrays will be shown. Their technical background, challenges, and cost drivers will be discussed. A possible solution to combat some of the deficiencies of the conventional phased array by exploiting the phased reflectarray technology will be briefly presented.

communication satellites mobile phased array refle↗
NASA NTRS1996

Capabilities of Printed Reflectarray Antennas

This article presents an advanced antenna technology, namely the printed reflectarray, that has the potential for providing an enhanced communication capability with relatively low cost, small size and small mass. It has applicaiton in the commercial and military arenas as well as in space exploration.

advanced↗
NASA NTRS1996

Microstrip Reflectarray and its Applications

ct given. Paper discusses antennas in general, and a new microstrip reflectarray antenna, and its better performance than parabolic, or other types.

antenna parabolic antenna microstrip reflectarray ↗
NASA NTRS1996

Antennas For Receiving Signals Broadcast Via Satellites

Four different antennas designed for use in receiving radio AM and FM signals broadcast via Earth-orbiting satellites at carrier frequency of 2.05 GHz in right-hand circular polarization. Antennas small, lightweight, inexpensive units with low-to-medium-gain, quasi-omnidirectional radiation patterns. Designed for outdoor and indoor uses.

Wu, Te-Kao↗
NASA NTRS1995

Parallel and series FED microstrip array with high efficiency and low cross polarization

A microstrip array antenna for vertically polarized fan beam (approximately 2 deg x 50 deg) for C-band SAR applications with a physical area of 1.7 m by 0.17 m comprises two rows of patch elements and employs a parallel feed to left- and right-half sections of the rows. Each section is divided into two segments that are fed in parallel with the elements in each segment fed in series through matched transmission lines for high efficiency. The inboard section has half the number of patch elements of the outboard section, and the outboard sections, which have tapered distribution with identical transmission line sections, terminated with half wavelength long open-circuit stubs so that the remaining energy is reflected and radiated in phase. The elements of the two inboard segments of the two left- and right-half sections are provided with tapered transmission lines from element to element for uniform power distribution over the central third of the entire array antenna. The two rows of array elements are excited at opposite patch feed locations with opposite (180 deg difference) phases for reduced cross-polarization.

Huang, John↗
NASA NTRS1995

Circular-Loop-Element Microwave Frequency-Selective Reflectors

Double or single planar arrays of circular loops laminated with dielectric sheets. Reflectors designed for use in multiplexing signals at several frequencies in microwave antenna system. Well suited to both circularly and linearly polarized radiation. Transmission and reflection characteristics relatively insensitive to angle of incidence. Similar device described in "Triband Circular-Loop Frequency-Selective Microwave Reflector" (NPO-18714).

Huang, John↗