Beampattern Synthesis Research Articles

Retraction Note: Investigation on broad beam pattern synthesis

Retraction Note: Investigation on broad beam pattern synthesis

Beampattern Synthesis With Dynamic Range Ratio Constraint via Sequential Convex Optimization

Beampattern Synthesis With Dynamic Range Ratio Constraint via Sequential Convex Optimization

Eigenvector method for array pattern synthesis

AbstractA novel equation for array beam pattern synthesis is presented. The expected pattern total power is set to a fixed value, under this constraint, the difference between the main beam total power and the other part total power is maximized to achieve the array pattern synthesis. To solve the proposed pattern synthesis equation, which cannot be solved by any published traditional method, based on the Lagrange multiplier method, it is transformed into a new equation in which the array element excitation vector is the eigenvector of a matrix. Thus, the array element excitation vector can be obtained by matrix eigenvalue decomposition. Three array architectures using the method are taken as examples to show its advantages. Simulation results of the examples show that the method has better performance than other methods. The method is a noniterative approach, so it requires less computational volume to complete the pattern synthesis process. In addition, through eigenvalue decomposition, multiple eigenvectors can provide other different solutions of array elements current excitations, which can be applied in different areas.

Low-complexity frequency-invariant beampattern synthesis using accurate response control for speech extraction

Beampattern synthesis generally designs weight parameters to form a main beam towards the direction of interest while suppressing interference and environmental noise simultaneously, playing a critical role in fixed beamforming techniques. In practical applications, when the position of the interference source changes, the filter design requirements will correspondingly change, thus necessitating accurate response control and rapid update capabilities. A low-complexity method is also highly desired in broadband beampattern synthesis, especially for time-domain beamformers with a relatively large number of weight parameters. To achieve rapid update and reduce the complexity for time-domain beamformers, this paper proposes a low-complexity frequency-invariant beampattern synthesis method using accurate response control. By introducing the null-forming scheme of adaptive beamformers, a virtual interference-plus-noise covariance matrix is constructed to precisely control the beampattern. Additionally, the spatial response variation is considered in the optimization problem for a constant mainlobe pattern, avoiding the complexity of determining a desired beampattern. Compared with the existing algorithms based on the interior-point method and the alternating direction method of multipliers, the proposed method reduces the computational complexity of each iteration, showing higher efficiency in broadband beampattern synthesis. Furthermore, the proposed method adjusts the beamformer flexibly on the basis of a pre-designed beampattern, achieving fast beampattern update when the acoustic environment changes. Numerical simulations on beam patterns and experimental results on speech extraction demonstrate better interference suppression performance of the beamformers designed by the proposed method.

Frequency-Invariant Beampattern Synthesis for Wideband MIMO Radar Under Nulling and PAPR Control

Frequency-Invariant Beampattern Synthesis for Wideband MIMO Radar Under Nulling and PAPR Control

Frequency diversity array joint radar jamming system shared signal design method

A new design method of shared signal is proposed for the Frequency Diversity Array (FDA) joint radar jamming system (JRJS). Each array element of FDA JRJS transmits the same shared signal, converts the beam pattern synthesis into spectrum design through the mapping relationship between beam pattern and shared signal frequency, and focuses energy on detecting and jamming targets. The essence of the jamming caused by the shared signal to the enemy radar is the mismatch of the frequency modulation slope, which forms the dense jamming, improves the detection threshold of the enemy radar's constant false-alarm rate (CFAR), and protects its platform from detection. The simulation results show that the shared signal can cause jamming to the enemy radar while aiming the beam at the detection target and the jamming target, which realizes the integration of detection and jamming.

Beampattern Synthesis and Optimization Method Based on Circular Frequency Diverse Array Engineering Model

The frequency diverse array (FDA) is capable of generating range-angle-dependent beampatterns by introducing a tiny frequency offset to the transmit carrier frequency of each array element. However, the beam-scanning potential of conventional linear FDA applications is limited, notably in their incapacity for 360° omnidirectional scanning. This paper introduces a method that leverages the geometric configuration of circular frequency diverse arrays (CFDAs) for synthesizing and optimizing beampatterns through a practical engineering approach. Initially, we compute the structural parameters and configurations of CFDA. Subsequently, the isophase plane is utilized to adjust the phase of each array element. Ultimately, the CFDA structure is used to optimize the non-uniform frequency offset, and the beampattern, which is capable of 360° omnidirectional scanning, is realized by low sidelobe optimization. Simulation results affirm that the CFDA antenna, as per the actual engineering model, possesses precise dot-shaped beampattern scanning abilities across both range and angle dimensions.

Phase-only beampattern synthesis for maximizing mainlobe gain via Riemannian Newton method

Beampattern synthesis with phase-only weights is extensively utilized in phased-array systems due to the virtue of low-cost and high power efficiency. It is always a non-convex optimization problem having constant modulus constraints (CMCs) and the performance significantly depends on the employed solvers. This paper discusses the phase-only beampattern synthesis for maximizing the mainlobe gain with the constraints on the mainlobe ripple and the relative sidelobe level. As CMC is equivalent to a complex circle manifold, the proposed beampattern synthesis is considered as a manifold optimization problem, and then decomposed into several subproblems under the framework of manifold alternating direction method of multipliers (ADMM). In particular, the subproblem for updating phase-only weights is efficiently tackled by a second-order Riemannian Newton method, which has faster convergence speed and no requirement on line search compared to widely-used first-order Riemannian manifold methods. The explicit convergence condition is derived and the computational complexity is also analyzed. Numerical results show that the proposed method has better performance on the mainlobe gain and sidelobe control accuracy, or less computational cost compared to several representative approaches, such as convex relaxation, standard ADMM, Riemannian gradient descent-based ADMM and Riemannian conjugate gradient methods.

A multi‐objective optimization approach for beam pattern synthesis ofUAVvirtual rectangular antenna array

AbstractVirtual antenna array (VAA) formed by unmanned aerial vehicle (UAV) antenna units using collaborative beamforming (CB) technology plays an important role in the air communication system, and can be used in radar, military, disaster rescue and other places. However, there are still some issues with the beam pattern formed by this method, such as high sidelobe level (SLL), high cost and low efficiency. In this article, each UAV carries an omnidirectional antenna unit, and a large number of UAVs form a UAV virtual rectangular antenna array (UVRAA) to communicate with the ground base station (BS). We formulate an overhead minimization and efficient communication multi‐objective optimization problem (OMECMOP) which jointly optimize the excitation current weights of the UVRAA and reduce the number of UAVs in operation to improve the beam pattern, enhance the communication efficiency and decrease the overhead of UVRAA. In addition, we also propose an improved multi‐objective multi‐verse optimization algorithm based on the inverse decline curve type (ISDT‐MOMVO) which introduces a strategy optimization initialization solution with quasi‐opposition based learning (QBL) and a hybrid solution updating operators to solve the OMECMOP. The simulation results show that compared with other traditional swarm intelligence (SI) optimization algorithms the ISDT‐MOMVO algorithm produces better beam pattern and the thinning rate can reach 50%.

MIMO radar partially correlated waveform design based on chirp rate diversity

Waveform design is a significant topic in multiple-input-multiple-output (MIMO) radar. In this paper, we address the problem of waveform design for colocated narrowband MIMO radar transmit beampattern synthesis. The existing methods have not comprehensively considered the transmit beampattern synthesis under multiple practical constraints, such as constant modulus constraint, Doppler tolerance, high range resolution and low auto-correlation sidelobe. We consider these practical constraints and propose a novel chirp rate diversity-based linear frequency modulated (CRD-LFM) waveform design for approximating the desired MIMO radar transmit beampattern. To tackle the problem, we improve the classical two-step approach. Firstly we design the covariance matrix using the existing closed-form solution. Then we model the problem of obtaining the waveforms from the covariance matrix as a nonlinear optimization problem, and we utilize the Sequential Quadratic Programming (SQP) algorithm to solve it. The simulations demonstrate that the waveforms obtained by this method can well approximate the desired transmit beampattern and have higher range resolution. Furthermore, we verify that the suppression of auto-correlation sidelobe can be achieved using amplitude weighting, which is easily realizable in practical engineering.

Frequency Diverse Array Beampattern Synthesis With Sinc- and Weighted-Sinc-Function-Based Frequency Offsets

Frequency Diverse Array Beampattern Synthesis With Sinc- and Weighted-Sinc-Function-Based Frequency Offsets

Beam Pattern Synthesis for Both Low Inter-Beam Interference and Enhanced EIRP in Millimeter-Wave Multi-Beam Phased Arrays

Beam Pattern Synthesis for Both Low Inter-Beam Interference and Enhanced EIRP in Millimeter-Wave Multi-Beam Phased Arrays

Enhanced Precision in Beam Pattern Synthesis for Compact Transmitarray Antenna Design: Integrating Comprehensive Unit Cell and Measurement Environment Models

Enhanced Precision in Beam Pattern Synthesis for Compact Transmitarray Antenna Design: Integrating Comprehensive Unit Cell and Measurement Environment Models

Phase-Only Transmit Beampattern Synthesis With Maximum Mainlobe Gain via Manifold ADMM

Phase-Only Transmit Beampattern Synthesis With Maximum Mainlobe Gain via Manifold ADMM

Wideband MIMO Radar Transmit Beampattern Synthesis in a Spectrally Crowded Environment

Wideband MIMO Radar Transmit Beampattern Synthesis in a Spectrally Crowded Environment

Transmit Beampattern Synthesis for Active RIS-Aided MIMO Radar via Waveform and Beamforming Optimization

Transmit Beampattern Synthesis for Active RIS-Aided MIMO Radar via Waveform and Beamforming Optimization

Optimal Function-Based Frequency Offset Design Based on Polynomial Fitting for Frequency Diverse Array Beampattern Synthesis

Optimal Function-Based Frequency Offset Design Based on Polynomial Fitting for Frequency Diverse Array Beampattern Synthesis

Synthesis of Concentric Circular Antenna Array Employing Jaya Algorithm

In the present scenario, Sidelobe Level (SLL) is treated as the most important parameter of the antenna array as it assists in suppressing interference and adjacent noise in wireless communication systems. As the maximum SLL value examined higher power wastage in unwanted signal direction, a transmitter of the communication system encounters major hitches. In this article, the optimum design of four various groups of Concentric Circular Antenna Array (CCAA) of the array antenna has been to lower SLL as much as possible. Optimum beam pattern synthesis of the proposed array antenna has been carried out by optimizing the standardized current distribution of the array antenna elements, all elements placed with fixed inter-element spacing. The work proposed algorithm is the Jaya optimization algorithm, the main aim of this technique is to describe the credibility of a currently chosen human social behaviour-based optimization algorithm known as Jaya. This very easy algorithm with lower complexity to synthesize Concentric Circular Antenna Array (CCAA) which is thoroughly utilized in the present scenario communication systems. The obtained results of the Jaya algorithm compared with Particle Swarm Optimization (PSO) and previously published articles. The Jaya algorithm achieved an improved side lobe level reduction as correlated to the PSO algorithm, finally getting results to examine the improved ability of Jaya as the best suitable method and achieve better sidelobe level suppression.

A General Approach to the Design of the Fractional-Order Superdirective Beamformer

The superdirective beamformer (SD) with a linear array exhibits the maximum directivity factor (DF) in the isotropic noise field. Previously, a fractional-order SD (FO-SD) has been designed to achieve a compromise between the robustness and the DF. However, this method may suffer from two limitations. First, it only considers the Jacobi-Anger expansion-based beampattern synthesis. Second, it cannot control the DF in spherically isotropic noise field. To address these problems, we propose a general approach to the design of the FO-SD, which is a linear combination of two SDs with the integer order that can be designed with any beampattern synthesis method. Moreover, the proposed approach is able to control the WNG and the DF in both spherically and cylindrically isotropic noise field. Computer simulations substantiate the effectiveness of the proposed FO-SD over the existing SDs.

Optimal audio beam pattern synthesis for an enhanced parametric array loudspeaker

A parametric array loudspeaker (PAL) generates highly directional audible sound in air with a small aperture size compared to a conventional loudspeaker. But in indoor applications, the long propagation distance of a PAL causes reflections, which disturbs the reproduction of narrow audio beams. Moreover, sound distortion appears along the off-axis direction due to the frequency dependence of the beam width. This study proposed an optimal audio beam pattern synthesis for a PAL-based convex optimization, which can design the audio beam of a PAL with an optimal solution. The proposed method overcame the mentioned limitations by applying it to a length-limited PAL for audio spot control and a multichannel PAL array for a constant beam width audio beam. In a length-limited PAL, the proposed method restricts the audio spot to a smaller region and weakens the sound leakage along the off-axis direction. Whereas in a multichannel PAL array, the proposed method also achieves a constant beam width near the radiator axis. Simulations and experiments verify the effectiveness of the proposed method, which will enhance the performance of a PAL in scenarios where control of the audio beam is required.