Phased array

About: Phased array is a research topic. Over the lifetime, 19428 publications have been published within this topic receiving 229231 citations. The topic is also known as: Phased Array Radar, PAR.

Coherent optical monolithic phased-array antenna steering system

Abstract: An optical-based RF beam steering system for phased-array antennas comprising a photonic integrated circuit (PIC). The system is based on optical heterodyning employed to produce microwave phase shifting by a monolithic PIC constructed entirely of passive components. Microwave power and control signal distribution to the antenna is accomplished by optical fiber, permitting physical separation of the PIC and its control functions from the antenna. The system reduces size, weight, complexity, and cost of phased-array antenna systems.

MIMO radar: Snake oil or good idea?

Abstract: MIMO communication is theoretically superior to conventional communication under certain conditions, and MIMO communication also appears to be practical and cost-effective in the real world for some applications. It is natural to suppose that the same is true for MIMO radar, but the situation is not so clear. Researchers claim many advantages of MIMO radar relative to phased array radars (e.g., better detection performance, better angular resolution, better angular measurement accuracy, improved robustness against RFI, ECM, multipath, etc.). We will evaluate such assertions from a system engineering viewpoint. In particular, there are serious trade-offs of MIMO vs. phased array radars relative to cost, system complexity, and risk considering numerous real world effects that are not included in most theoretical analyses. Moreover, in many cases one can achieve essentially the same radar system improvement with phased array radars using simpler, less expensive, and less risky algorithms. We evaluate roughly a dozen asserted advantages of MIMO radar relative to phased arrays.

Cognitive radar antenna selection via deep learning

Abstract: Direction-of-arrival (DoA) estimation of targets improves with the number of elements employed by a phased array radar antenna. Since larger arrays have high associated cost, area and computational load, there is a recent interest in thinning the antenna arrays without loss of far-field DoA accuracy. In this context, a cognitive radar may deploy a full array and then select an optimal subarray to transmit and receive the signals in response to changes in the target environment. Prior works have used optimisation and greedy search methods to pick the best subarrays cognitively. In this study, deep learning is leveraged to address the antenna selection problem. Specifically, they construct a convolutional neural network (CNN) as a multi-class classification framework, where each class designates a different subarray. The proposed network determines a new array every time data is received by the radar, thereby making antenna selection a cognitive operation. Their numerical experiments show that the proposed CNN structure provides 22% better classification performance than a support vector machine and the resulting subarrays yield 72% more accurate DoA estimates than random array selections.

Multiwavelength-Integrated Optical Beamformer Based on Wavelength Division Multiplexing for 2-D Phased Array Antennas

Abstract: A novel, hardware-compressive architecture for broadband and continuously tunable integrated optical truetime- delay beamformers for phased array antennas is proposed and experimentally demonstrated. The novel idea consists in employing the frequency-periodic response of optical ring resonator (ORR) filters in conjunction with on-chip wavelength division multiplexing (WDM), in order to create multiple signal paths on an individual beamformer channel. This novel idea dramatically reduces the network complexity and, in turn, its footprint on the wafer. This allows the integration of an unprecedented number of delay channels on a single chip, ultimately overcoming the main limitation of integrated optical beamformers, that is, the difficulty to feed antenna arrays with many elements using a single integrated chip. A novel beamformer has been realized based on this technique, using the ultra-low-loss TriPleXTM waveguide platform with CMOScompatible fabrication equipment, and its functionality is demonstrated over an instantaneous bandwidth from 2 to 10 GHz. This result, at the best of our knowledge, represents at the same time the record instantaneous bandwidth (8 GHz) for an optical beamformer based on optical ring resonators (ORR), and the first demonstration of an integrated beamformer where the periodic response of ORRs is exploited to process signals from different antenna elements, simultaneously, using a single delay line.

Wideband interference suppressor in a phased array radar

Abstract: A phased array radar antenna uses time-steering subarray notch weightings to produce a wideband notch in the direction of interference for Electronic-Counter-Measure (ECM) interference suppression. A predetermined set of subarray notch weightings, each set being identical for each subarray, is stored in controllers each of which is coupled to a plurality of phase shifters and attenuators for feeding radiating elements of the antenna. Interference suppressors operate from a plurality of controllers to produce a subarray pattern having a notch in the direction of interference. Beamformers then combine outputs of all time-steering subarrays in the antenna so as to produce an antenna pattern having a wideband notch in the direction of interference.