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.

M-Cube: a millimeter-wave massive MIMO software radio

Abstract: Millimeter-wave (mmWave) technologies represent a cornerstone for emerging wireless network infrastructure, and for RF sensing systems in security, health, and automotive domains. Through a MIMO array of phased arrays with hundreds of antenna elements, mmWave can boost wireless bit-rates to 100+ Gbps, and potentially achieve near-vision sensing resolution. However, the lack of an experimental platform has been impeding research in this field. This paper fills the gap with M3 (M-Cube), the first mmWave massive MIMO software radio. M3 features a fully reconfigurable array of phased arrays, with up to 8 RF chains and 288 antenna elements. Despite the orders of magnitude larger antenna arrays, its cost is orders of magnitude lower, even when compared with state-of-the-art single RF chain mmWave software radios. The key design principle behind M3 is to hijack a low-cost commodity 802.11ad radio, separate the control path and data path inside, regenerate the phased array control signals, and recreate the data signals using a programmable baseband. Extensive experiments have demonstrated the effectiveness of the M3 design, and its usefulness for research in mmWave massive MIMO communication and sensing.

Mimo radar waveform design for transmit beamforming and orthogonality

Abstract: Coherent multiple-input multiple-output (MIMO) radar is capable of forming a specific transmit beam pattern favorable for radar operation, but the transmitted waveforms from different antenna elements need to be orthogonal for coherent beamforming. In this work, an innovative approach is developed for MIMO radar waveform design in space-time domain, rendering MIMO radar able to satisfy transmit beamforming constraint in space-domain as well as the waveform orthogonality requirement in time domain. The approach is validated through simulations.

Improving the Performance of Wide-Angle Scanning Array Antenna With a High-Impedance Periodic Structure

Abstract: In this letter, the performance of wide-angle scanning phased array is analyzed. A high-impedance periodic structure (HIPS) is applied to improve radiation pattern of the antenna element in an array. The working mechanism of HIPS array is investigated. The structure could improve the surface-wave and the broad-beam radiation performance of the individual antenna element as well as the wide scan performance of the phased array. By the comparison to the metal ground plane, the gain of the array antenna is improved approximately 4.5 dB when the main beam scans at ±60°. A nine-element array antenna with a periodic structure is fabricated and measured. The measured results of the array coincide with the simulated results.

Ultrasonic arrays for monitoring cracks in an industrial plant at high temperatures

Abstract: A piezoelectric linear array structure has been designed to operate at temperatures up to 400/spl deg/C for nondestructive testing of steel components of a hot industrial plant. It is intended that these arrays be fixed permanently to the test subject so that known defects can be monitored by comparing measurements taken over a period of time without needing to shut down the plant. The arrays are used in pairs: the transmitter is a phased array producing a variable angle steered beam, and a second array is used for receiving. The defect can be identified from a series of scans collected from individual elements of the second array. A simple monolithic array structure was used, based on a single crystal of lithium niobate and operating in the frequency range 3 to 5 MHz. Prototype devices have 64 elements on a 0.5 mm pitch. Simulated defects in steel blocks have been scanned at high temperatures to illustrate the arrays' capability for nondestructive testing. The results suggest an accuracy better than 1 mm in finding the location of crack tips.

Synthesis of Conformal Phased Array With Improved NSGA-II Algorithm

Abstract: A synthesis technique for the optimization of the element excitations of conformal phased array with improved NSGA-II (INSGA-II) algorithm is introduced in this communication. Firstly, the patterns of all the elements are measured in a microwave chamber when they are terminated by their own characteristic impedances. As these patterns called as active patterns are experimentally obtained, they have already included the mutual coupling information of the environment. Then the pattern of the conformal antenna array can be obtained by a superposition of all these active patterns with various weights. And because the pattern of each element has been pre-stored, one can avoid the full-wave numerous computations in the optimization process. Using the optimization algorithm, the weights including amplitude and phase of each element can be optimized quickly. Therefore this treatment has the advantages of less computation and high accuracy. In order to further accelerate the optimization, INSGA-II algorithm is applied. By using this algorithm, the entire optimal solutions, i.e., the optimal solutions of the main beam of the conformal phased array directing to different angles, can be solved at once. The idea is demonstrated through the designs of two conformal antenna arrays mounted on hemisphere and cylinder-hemisphere platforms, respectively. Comparisons between the experimental and simulated results show the effectiveness of the proposed approach.