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.

Target Localization and Tracking in Noncoherent Multiple-Input Multiple-Output Radar Systems

Abstract: For a noncoherent multiple-input multiple-output (MIMO) radar system, the maximum likelihood estimator (MLE) of the target location and velocity, as well as the corresponding Cramer-Rao lower bound (CRLB) matrix, is derived. MIMO radar's potential in localization and tracking performance is demonstrated by adopting simple Gaussian pulse waveforms. Due to the short duration of the Gaussian pulses, a very high localization performance can be achieved, even when the matched filter ignores the Doppler effect by matching to zero Doppler shift. This leads to significantly reduced complexities for the matched filter and the MLE. Further, two interactive signal processing and tracking algorithms, based on the Kalman filter and the particle filter (PF), respectively, are proposed for noncoherent MIMO radar target tracking. For a system with a large number of transmit/receive elements and a high signal-to-noise ratio (SNR) value, the Kalman filter (KF) is a good choice; while for a system with a small number of elements and a low SNR value, the PF outperforms the KF significantly. In both methods, the tracker provides predictive information regarding the target location, so that the matched filter can match to the most probable target locations, reducing the complexity of the matched filter and improving the tracking performance. Since tracking is performed without detection, the presented approach can be deemed as a track-before-detect approach. It is demonstrated through simulations that the noncoherent MIMO radar provides significant tracking performance improvement over a monostatic phased array radar with high range and azimuth resolutions. Further, the effects of coherent integration of pulses are investigated for both the phased array radar and a hybrid MIMO radar, where only the pulses transmitted and received by colocated transceivers are coherently integrated and the other pulses are combined noncoherently. It is shown that the hybrid MIMO radar achieves significant tracking performance improvement when compared with the phased array radar, by using the extra Doppler information obtained through coherent pulse integration.

A Simple Alternative for Beam Reconfiguration of Array Antennas

Abstract: An innovative method for antenna arrays beam configuration is presented. In the proposed method, every element of the array is connected to its feed through a switch, so that it can be active or passive, depending on the switch position. Pattern reconfigurability is achieved by appropriately switching on or off the array elements. The optimal configuration of the switches for each of the radiated patterns, as well the common voltages of the active elements, is calculated by using a genetic algorithm. For each configuration, the currents in the driven and parasitic elements are determined, via their self and mutual impedances, by inversion of the impedance matrix. In the presented examples, the method has been applied to both linear and planar arrays of parallel dipoles that switch the power pattern from a pencil to a flat-topped beam (linear array) or to a footprint pattern (planar array). † Also with University of California, Los Angeles, USA 228 Ares, Franceschetti, and Rodriguez

Phased array beamformer module driving two elements

Abstract: A modular beamformer system for providing signals to at least two radiating elements of a phased array antenna is provided. The system includes a right-hand circular polarization beamformer module and a left-hand circular polarization beamformer module. The left and right circular polarization beamformer modules are coupled to two radiating elements. Each beamformer module includes two groups of beamforming circuitry, one per radiating element. At least one feeder line extends from each beamforming circuitry and is coupled to one of the radiating elements to transmit an output of each beamforming circuitry.

Phased array antenna and method for producing thereof

Abstract: A vertically stacked array antenna structure is described The structure comprises a radiating layer, a passive layer disposed under said radiating layer, an active layer disposed under said passive layer, and an interface assembly The radiating layer comprises an array of radiating elements The passive layer has only passive components At least a part of the passive components includes an array of RF duplexers corresponding to the array of radiating elements The active layer comprises RF amplifiers The interface assembly comprises at least one metallic frame which is in direct thermal coupling with the RF amplifiers The interface assembly is configured for providing thermal communication of the active layer with a heat exchanger

Antenna failure compensation

Abstract: A method for compensating for the failure of an element in a phased array antenna assembly is provided. After failure of an element of the assembly, a composite pattern is generated from signals received by respective elements in the antenna assembly. This generated pattern is then compared to a standard composite pattern which was generated prior to the failure. Thus the necessity for remedial action can be assessed. If necessary, initial values for parameters associated with each element are assumed and an optimisation is performed on the parameters. Consequently, a composite pattern can be generated which approximates the standard composite pattern. Once optimisation has been achieved, the optimised parameters are applied to base settings for the assembly and operation of the phased array antenna assembly can be continued.