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Structural distortions in large antennas have impact on antenna gain, sidelobe level and adaptive interference rejection. Partial compensation for the distortion of space-based radar (SBR) phased-array antennas and array-fed reflectors can be achieved by adjusting the phase-shifter settings to compensate for the distortion, if it can be accurately measured. This approach is effective in regaining...
The primary motive for large transmit array of parabolic reflectors, also known as uplink array, was to explore alternate methods in order to replace the large 70m antennas of deep space network (DSN) such that the core capability for emergency support to a troubled spacecraft in deep space is preserved. Given that the Uplink Array is a new technology, the focus has always been on its feasibility...
This paper discusses the ongoing research being conducted in the RF Technology Division of the Applied Sensors, Guidance, and Electronics Directorate, US Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC) on the Redstone Arsenal in Huntsville, Alabama. The overall purpose of the research is to determine and overcome the technological barriers impinging upon enhancements...
This paper presents the architecture and initial measured performance of an X-band digital beamforming (DBF) plug-and-play receive array. This processor was designed to steer four independent simultaneous beams over the entire X-band with 32 independent channels, an instantaneous bandwidth of 15 MHz, and a spur-free dynamic range of at least 65 dB. Designed using commercial-off-the-shelf (COTS) components,...
The goal of this paper is to evaluate the impact of photonic beamformers on the amplitude and the signal-to-noise ratio (SNR) of RF signals received by a phased array antenna. To this end, the two-port definitions of RF gain and noise figure are generalized to include multiple-port combining devices such as beamformers. These metrics are then applied to several simple photonic and hybrid RF/photonic...
The development of a microstrip patch antenna array for an L-band repeat-pass interferometric synthetic aperture radar (InSAR) is discussed in this paper. The instrument will be flown on an unmanned aerial vehicle (UAV) and will provide accurate topographic maps for Earth science by 2007. The antenna operates at a center frequency of 1.2575 GHz and with a bandwidth of 80 MHz, consistent with a number...
This paper addresses key technologies under development at the NASA Glenn Research Center designed to provide architecture-level impacts. Specifically, we describe deployable antennas, a new type of phased array antenna and novel power amplifiers. The evaluation of architectural influence can be conducted from two perspectives where said architecture can be analyzed from either the "top-down"...
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