Side Lobe Level Reduction Research Articles

Efficient side lobe level reduction technique for planar antenna arrays

This paper presents a novel array synthesis technique based on the virtual antenna array (VAA) concept for side lobe level (SLL) reduction of uniform planar antenna arrays (UPAA). The VAA decomposes the (M×N) UPAA into vertical and horizontal uniform linear antenna arrays (V–ULAA and H–ULAA) consisting of M and N antenna elements, respectively. The V-ULAA and H-ULAA are positioned perpendicularly and closely enough apart to form a new (M+N) virtual UPAA. Consequently, the number of antenna elements is significantly reduced, which in turn minimizes the computational complexity and signal processing time required to synthesize the desired radiation pattern. Therefore, instead of reducing the SLL of the entire UPAA, we simply reduce the SLL of each ULAA using the well-known hybrid Method of Moments/Genetic Algorithm (MoM/GA) array synthesis technique, which adjusts both the excitation coefficients and element spacings to achieve low SLL. The MoM/GA results in non-uniform V-LAA and H-LAA having two non-uniform excitation vectors AV and AH, respectively, and much lower SLLs than the corresponding V-ULAA and H-ULAA. Finally, the synthesized excitation vectors AV and AH are used to synthesize either the virtual (M+N) planar antenna array (V-PAA) or the physical (M×N)PAA with more than two-fold reductions in the SLL.

Sidelobes and sideband minimization in time-modulated array antenna based on chaotic exchange nonlinear dandelion optimization algorithm

Time-modulated array antenna (TMAA) is a new type of array antenna based on time modulation technology. By introducing "time" as the fourth dimensional design freedom into the design of conventional array antennas in three-dimensional space, the array antenna has time modulation characteristics, which better controls the radiation characteristics of the array antenna and achieves the best far-field radiation pattern synthesis. This paper designs a Time-modulated linear array (TMLA) with low sidelobe level (SLL) and low sideband level (SBL) based on the chaotic exchange nonlinear dandelion optimization (CENDO) algorithm. Three optimization methods are studied: firstly, determining the optimal on-time (τnn) for each array element; The second is to determine the optimal on-time (τnn) and optimal uniform array element spacing (d) for each array element; The third is to determine the optimal opening time (ton), closing time (toff), and optimal uniform array element spacing (d) for each array element. To achieve simultaneous reduction of sidelobe level and suppression of harmonic interference. The same array model contains different harmonic frequency radiation. In this article, we only considered two harmonic frequencies, namely the first sideband frequency and the second sideband frequency. Because the harmonic of other sideband frequencies has a very small impact on the radiation of the fundamental wave, it can be ignored. To demonstrate the stronger ability of the CENDO algorithm in optimizing Time-modulated array antennas, and in line with the principle of fairness and impartiality, this paper also simulates different Time-modulated array models and compares the results of the CENDO algorithm with other published literature. It is concluded that this study shows lower SLL and lower SBL in different models. This provides a more scientific and accurate explanation of the superiority of the CENDO algorithm compared to other algorithms in the field of antenna optimization in electromagnetics. At the same time, this also provides great research value and fundamental support for designing high-performance Time-modulated array antennas in subsequent engineering applications.

Performance improvement of slot antenna with metamaterial for modern wireless communication

A slot antenna has been widely used for multifunction in modern wireless communication technologies such as WLAN, WiMAX, IoT, and GSM. Generally, slot antennas can operate in wideband. Nevertheless, this antenna type was limited in terms of lower gain because of wideband operation. Therefore, this paper presents a slot antenna designed for operation frequencies between 1.8 GHz and 6.5 GHz and a study of the performance improvement of slot antennas with metamaterials to increase antenna quality. The utilization of metamaterials can improve the performance of slot antennas by increasing gain levels, reducing sidelobe levels, and optimizing reflection coefficients (S11). As a result, determine the metallic hole structure and wire medium structure put behind the slot antenna for comparing performance. All of them act like reflectors for reflected radiation from the back to the front, which improved the average gain of all operating frequencies from 3.41 dBi to 7.33 dBi for metallic hole structure and 7.42 dBi for wire medium structure. Moreover, the simulation and measurement gave great results. These proposed metamaterials provided enhanced gain and reduced sidelobe level.

Gain Enhancement and Sidelobe Level Reduction of Microstrip Patch Antenna Under Operation of TM50-Like Mode

Gain Enhancement and Sidelobe Level Reduction of Microstrip Patch Antenna Under Operation of TM₅₀-Like Mode

Synthesis of elliptical cylindrical antenna array using craziness particle swarm optimization for suppressing sidelobe level

This paper introduces Craziness-based particle swarm optimization (CRPSO), an enhanced Particle Swarm Optimization method, to study the best antenna design for an Elliptical Cylindrical Array (ECA). Heuristic methods such as the PSO algorithm has two key benefits: it employs minimal control parameters and converges quickly. However, PSO performance can be, hampered by early convergence and stagnation. This study modifies the PSO algorithm to address these issues by a “craziness” factor represented by a craziness variable. The CRPSO approach to minimizing the Side Lobe Level (SLL) by determining the optimal configuration of active and inactive elements without preset, First Null Beam Width (FNBW) parameters. Additionally, SLL variation with various element spacings. Results show a significant decrease in SLL up to −42.83 dB, and comparing the results to PSO and existing literature shows superior SLL reduction.

Unequally-spaced slot strategy for radiation null reduction in single SIW-embedded antenna element

The incorporation of higher-order modes (HOMs) can substantially augment the antenna gain and bandwidth, but this improvement is typically accompanied by compromised radiation performance including radiation nulls and higher side lobe levels. In this study, an inventive strategy is introduced to reduce the radiation nulls and the side lobe levels of a single antenna element by positioning multiple slots of the radiating element at unequal spacing. Dual hybrid HOMs are analyzed inside a substrate integrated waveguide-based cavity to design a wide band, enhanced gain dual-polarized antenna. The radiating element of the antenna is designed with multiple slots positioned at unequal spacing but symmetrical along the origin. This methodology provides three-fold advantages: a reduction of side lobes, an adjustment of phase center, and a significant reduction of radiation nulls. The antenna has been fabricated, and experimentally validated. The antenna exhibits a reduction in radiation null to − 0.5 dB, a phase adjustment of the main lobe to 0°, and a reduction in side lobe level from − 14.4 dB (N = 2, equal spacing) and − 15.5 dB (N = 4, equal spacing) a maximum of − 19.7 dB (N = 4, unequal spacing) at 12.35 GHz in the phi-0 plane. Excellent agreement between measured and simulated results corroborates the efficacy of the proposed approach. The significant improvement in the radiation performance of the single-element antenna design sets the antenna design apart from the state-of-the-art solutions.

Radiation Pattern Correction of Faulty Planar Phased Array using Genetic Algorithm

The probability of antenna array failure or malfunctioning cannot be ruled out, and hardware replacement of faulty elements is not always a viable solution. Therefore, academic and industrial interest in self-healing phased arrays are on the rise. In this work, the phase-only genetic algorithm (GA) optimization flow for the radiation pattern correction of a 4 × 4 phase faulty planar antenna array is proposed. Initially, a reference array pattern at the desired scan angle is generated. Then random phase faults are introduced across the 1 × 4 antenna elements in any one of 4 sub-arrays to produce maximum distortion in the reference radiation pattern of 4 × 4 planar array. The proposed GA re-computes the new excitation weights for the remaining non-faulty 3 sub-arrays to correct the overall radiation pattern of 4 × 4 array. This is achieved by calculating the array output power for reference and GA computed weights. The GA corrected patterns fairly follow the desired array patterns in terms of peak gain and reducing sidelobe levels for the desired scan angle. The efficiency of the optimized radiation patterns was evaluated in full-wave HFSS model and measurements validation. In this way, maintenance cost can be reduced with recovery of acceptable level of radiation pattern using software instead of physically replacing faulty antenna elements in the array.

Concentric Elliptical Antenna Array Synthesis using Sine Cosine Algorithm for Reducing the Sidelobe level

This paper employs the Sine Cosine Algorithm, a recent meta-heuristic method, to enhance the radiation properties of concentric elliptical antenna arrays in far-field applications, such as smart grid wireless communication and the Internet of Things. It focuses on minimizing the Sidelobe Level, a key parameter in antenna radiation, to mitigate unwanted signals and interference. The proposed method, known for its global optimization effectiveness, tackles the challenge of designing sparse multiple concentric elliptical arrays. By using the Sine Cosine Algorithm, the inter-element spacing and optimal determination of amplitude coefficients are achieved, resulting in a radiation pattern with reduced sidelobe level. To showcase the adaptability and superior performance of our proposed algorithm, we systematically evaluated its effectiveness across four distinct sets of concentric elliptical antenna arrays. These arrays comprise varying numbers of elements: (6, 12, 18 elements, 6, 12, 18, 24 elements, 6, 12, 18, 24, 30 elements and 6, 12, 18, 24, 30, 36 elements) with and without a central element. Using the sine cosine algorithm, we synthesize arrays and compare their sidelobe level and First Null Beam Width values with those from recent methods. Our findings consistently shows that the proposed algorithm consistently outperforms alternatives, yielding significantly lower sidelobe level values in all comparisons.

Virtual Antenna Arrays with Frequency Diversity for Radar Systems in Fifth-Generation Flying Ad Hoc Networks

This paper proposes the design of virtual antenna arrays with frequency diversity for radar systems in fifth-generation flying ad hoc networks. These virtual arrays permit us to detect targets from the sky with flying drones. Each array element is composed of a microstrip antenna mounted on quadcopter drones and is virtually connected with the other elements. The antennas are tuned to work at the lower fifth-generation frequency band of 3.5 GHz. The design process considers the optimization of frequency offsets and positions for each element to obtain a side lobe level reduction. This methodology is carried out by particle swarm optimization. Several design examples are presented with random frequency offsets and non-uniform positions. These designs are compared to uniform-spaced arrays excited with Hamming frequency offsets. The simulation results show that using random frequency offsets and non-uniform positions provides a minor side lobe level reduction. This research demonstrates the feasibility of using virtual arrays for radar systems in fifth-generation flying ad hoc networks.

Low sidelobe planar electrically large sparse array antenna with element number reduction based on genetic algorithm

AbstractConventionally, both electrically larger (EL) arrays and sparse arrays offer the advantage of element number reduction but disadvantage of high sidelobe levels. A new scheme of planar EL sparse array antenna based on a genetic algorithm (GA) to achieve low sidelobe with element number reduction is proposed. To begin with, EL sparse array antenna optimisation models based on GA for both linear and planar arrays are analysed. Then, an EL slot antenna element based on a 3 × 3 substrate integrated waveguide cavity is designed. An 8‐element linear EL sparse array antenna is designed and compared with a uniform array antenna, demonstrating a reduction in the maximum sidelobe level (MSLL) by nearly 4.6 dB. After that, a 4 × 8 element planar EL sparse array antenna is fabricated and measured. Compared to an 8 × 16 element planar EL uniform array antenna, the number of antenna elements is reduced by 75%, while the MSLL is reduced by approximately 3 dB. The measured −10 dB impedance bandwidth ranges from 25.3 to 27.8 GHz. At the central frequency, the radiation pattern achieves a peak gain of 29.6 dBi, exhibiting low sidelobe levels below −15.0 dB.

Application of Dandelion Optimization Algorithm in Pattern Synthesis of Linear Antenna Arrays

This paper introduces an application of the dandelion optimization (DO) algorithm in antenna arrays. This is the first time that the DO algorithm has been used for optimizing antenna arrays. For antenna array optimization, sidelobe level (SLL) and deep nulls are key technical indicators. A lower SLL can improve the signal-to-noise ratio and reduce the impact of clutter signals outside the main beam. Deep nulls need to be aligned with the direction of interference to eliminate the influence of interference sources. The combination of the two can effectively improve the anti-interference ability of the entire system. Therefore, antenna arrays with ultra-low sidelobes and ultra-deep nulls are currently hot in the field of antenna array design and are also some of the key technologies needed to achieve modern high-performance radar systems. As a new type of evolutionary algorithm inspired by nature, the DO algorithm is inspired by the wind propagation behavior of dandelions in nature. This algorithm iteratively updates the population from three stages of ascent, descent, and landing, ultimately finding the optimal position. It has good optimization ability in solving complex problems such as those involving nonlinearity, discreteness, and non-convexity, and the antenna array pattern synthesis optimization problem belongs to multivariate nonlinear problems. Therefore, the DO algorithm can be effectively applied in the field of antenna array optimization. In this work, we use the following method to obtain an optimized pattern of a linear array with the lowest sidelobe level (SLL), null placement in particular directions, and a lower notch in particular directions: by controlling the antenna array’s element spacing and leaving the phase unchanged to optimize the current amplitudes and by controlling the excitation current and phase fixation of the antenna array and changing the element spacing. In the first and second examples, different algorithms are used to reduce the SLL of the antenna. In the first example, the DO algorithm reduces the SLL to −33.37 dB, which is 2.67 dB, 2.67 dB, 3.77 dB, 2.74 dB, and 2.52 dB lower than five other algorithms. In the second example, the SLL optimized by the DO algorithm is −42.56 dB, which is 5.04 dB and 1.48 dB lower than two other algorithms. In both examples, the DO algorithm reduces the SLL lower than other algorithms when the main lobe of the antenna is not significantly widened. Examples 3, 4, and 5 use the DO algorithm to optimize the amplitude of the current, generating deep nulls and deep notches in specific directions. In Example 3, the DO algorithm obtains a depth of nulls equal to −187.6 dB, which is 66.7 dB and 44.3 dB lower than that of the flower pollination algorithm (FPA) and the chaotic colony predation algorithm (CCPA), respectively. In Example 4, the deep null obtained by the DO algorithm is as low as −98.69 dB, which is 6.67 dB lower than the deep null obtained by the grey wolf optimization (GWO) algorithm. In Example 5, the deep notch obtained by the DO algorithm is as low as −63.1 dB, which is 6.4 dB and 1.9 dB lower than the spider monkey optimization (SMO) algorithm and the grasshopper optimization algorithm (GOA), respectively. The data prove that the DO algorithm produces deeper nulls and notches than other algorithms. The last two examples involve reducing sidelobe levels and generating deep nulls by optimizing the spacing between elements. In Example 5, the SLL obtained using the DO algorithm is −22.8766 dB, which is 0.1998 dB lower than the lowest SLL of −22.6768 dB among other algorithms. In Example 6, the SLL obtained using the DO algorithm is −20.1012 dB, and the null depth is −125.1 dB, which is 1.592 dB lower than the SLL obtained by the cat swarm optimization (CSO) algorithm and 19.1 dB lower than the deep null obtained by the GWO algorithm, respectively. In summary, the results of six simulation experiments indicate that the DO algorithm has better optimization ability in linear array optimization than other evolutionary algorithms.

Cost-effective horn antennas; from E-plane sectionalized to octagonal shapes

ABSTRACT In this paper, low-cost methods of improving horn antennas are studied based on the recently introduced E-plane sectionalized rectangular horn antennas. In the beginning, application of E-plane sectionalizing of the rectangular horn antennas on open-boundary E-plane sectoral horn antennas is reexamined and a simple method for obtaining high gain and low sidelobe levels (SLLs) is introduced. Subsequently, effects of removing the conductive sheets from the modified E-plane sectionalized horn antenna are studied and a simple horn antenna with octagonal aperture is obtained with slightly reduced efficiency. Finally, an ultra-low-cost method of improving simple rectangular horn antennas is introduced based on this study. The purpose is to compensate the destructive effects of high SLLs of reference antennas in the antenna measurements, since a common reference antenna type is the rectangular horn antenna, which has high SLLs on the E-plane. In particular, efficiency improvement and SLL reduction of rectangular horn antennas are achieved by adding only four triangular conductive sheets to construct octagonal horn antennas.

Efficient methods for iterative ultrasound image reconstruction using L1 and L2 norm regularization

Ultrasound image reconstruction can be posed as an inverse problem, with image pixels as parameters to a model of wave propagation that are estimated from raw ultrasound channel data. Such framework allows one to make assumptions about channel signals and image properties in form of regularization that can be used to improve reconstruction accuracy in the presence of electronic and acoustic noise. A simple model assumes spherical wave propagation from point sources in a homogeneous medium, similar to delay-and-sum (DAS) beamforming; solving such problems numerically can require many iterations and can result in blurred images when traditional L2 norm regularization is used. We use Fast Iterative Shrinkage Thersholding Algorithm (FISTA) to reduce the number of iterations to less than 10, and to apply L1-norm regularization to the data, which improves edge sharpness and image contrast. We demonstrate the concept using FIELD II simulated ultrasound signals from point, speckle, and anechoic targets with controlled levels of electronic and speckle noise. The FISTA-reconstructed point targets show reduced sidelobe levels by 15 dB compared to the traditional DAS image, and the reduction in full-width at half maximum by a factor of 2. We also implement iterative reconstruction in omega-k frequency domain, which allows factoring the forward and adjoint operators at each spatial frequency and paves the way for an intuitive and more memory efficient, multi-threaded implementation of the method.

Synthesis of Antenna Array Radiation Pattern at Large Scanning Angles Using Genetic Algorithm

At present, in most modern communication systems, for example, in modern satellite terminals, the use of scanning beam antennas, i. e. antenna arrays is assumed. At the same time, at large scanning angles, the side lobe level (SLL) increases strongly and decrease in the gain is observed. In this regard, the problem of finding a procedure for synthesizing an amplitude-phase distribution (APD) with low SLL and high gain (G) at large scanning angles comes up. One of the ways to reduce SLL and compensate for the decrease in G is to synthesize the optimal APD (in terms of the maximum G and minimum SLL) using optimization algorithms. At the same time, taking into account the characteristics of the radiation pattern of the array emitters requires numerical electrodynamic calculation. The goal of this paper is to develop a procedure for the synthesis of APD with low SLL for linear and rectangular antenna arrays at various, including large, scanning angles and compensation for G reduction using a genetic algorithm and numerical electrodynamic calculation. The methods for studying the characteristics of antenna radiators are numerical electrodynamic modeling by the finite element method (FEM) in Ansys HFSS computer-aided design system and optimization of the APD for a given radiation pattern(RP) by a random search method using partial diagrams of antenna elements. The novelty is the combination of accurate numerical electrodynamic calculation of the RP of antenna elements and optimization search for APD for the synthesis of the required RP using partial diagrams. As a result, a procedure for APD synthesis of linear and uniform rectangular equidistant (for example, 8- and 64-element) antenna arrays has been developed, taking into account the exact electrodynamic characteristics of antenna elements and their mutual resistance. Radiation patterns were obtained taking into account the effect of neighboring elements, with the help of which, using a genetic algorithm, APDs on emitters were found at different scanning angles. The change in SLL and G of the antenna array is analyzed at different scanning angles using different APDs. The proposed algorithm allows to synthesize APD for a RP with low SLL and high G at scanning angles up to 40° for linear antenna array and up to 80° in the case of a uniform rectangular antenna array. The results of this work are relevant in the problems of radiation pattern synthesis, since the proposed solution provides a significant gain in the radiation pattern synthesis rate of APD of linear and rectangular antenna arrays, especially for systems with a large number of antenna elements. At the same time, it is possible to maintain a high G at large scanning angles, and achieve a significant reduction of SLL.

A segmented periodic slot array leaky‐wave antenna for beamforming applications

AbstractA segmented periodic slot array leaky‐wave antenna (LWA) is proposed for beamforming applications. The LWA consists of segments, each with a unique propagation constant achieved through varying periodicity and slot size. By using segments with different propagation constants, the proposed LWA can achieve beamforming such as flat‐top beams and side‐lobe level (SLL) reduction. The LWA is based on a substrate‐integrated waveguide with periodic double transverse slots in the broad wall of the waveguide. The double slots allow for reflection‐canceling to suppress the broadside stopband and hence can achieve beamforming capabilities in the backward, broadside, and forward directions. Full‐wave simulations are used to demonstrate the proposed concept for flat‐top beamforming in the mm‐wave band at 30 GHz. Experimental demonstration is conducted using two prototypes for flat‐top beams and SLL reduction, with good agreement with full‐wave simulations.

DESIGN OF AMPLITUDE AND PHASE CONTROLLED BUTLER BEAMFORMING NETWORK FOR X/KU-BAND AIRBORNE SYNTHETIC APERTURE RADAR APPLICATIONS

Beamforming networks play an important role in today's communication systems. The Butler matrix network is one of the most useful networks used to feed array antennas and generate multi-beamforming systems. Its complexity increases with an increase in the number of input and output ports. This research work presents simulated results of an unequal amplitude 8 × 8 Butler matrix network, in which the Taylor series synthesis technique was employed to generate unequal amplitudes (-9.626, -9.125, -8.798, -8.636, -8.636, -8.798, -9.125, and -9.626 dB). The design of the Butler matrix beamforming network is based on two frequency bands, i.e., the X-band and Ku-band, with center frequencies of 9.3 and 13.265 GHz, respectively. The design mainly involves 12 hybrid couplers and eight phase shifters that can generate beams in eight different directions (-32.4°, -26.5°, -15.5°, -10.3°, 10.3°, 15.5°, 26.5°, and 32.4°). This design is based on the Taylor series expansion, which has the advantage of sidelobe level reduction of -17 dB. All of the simulations were done using advanced design system software key sight technologies. The simulations results were in line with the theoretical calculations.

Thinned Smart Antenna of a Semi-circular Dipole Array for Massive MIMO Systems

Massive MIMO (multiple-input multiple-output) is a multi-user MIMO technology that can provide high-speed multimedia services in 5G wireless networks using sub-6 GHz and millimeter wave bands. The massive MIMO (MMIMO) installs array antennas in the base stations, using hundreds of transceivers with other RF modules. One of the drawbacks of the MMIMO system is its huge power consumption, and the beamforming network with RF modules for a large number of antennas is the main contributor to the power consumption. In this paper, a novel beamforming method is proposed for the low power consumption of an MMIMO system. The proposed thinned smart antenna (TSA) of a semi-circular array produces a secure beam toward the user’s terminal with reduced interference. By thinning the antenna array, some of the antenna elements are kept off, resulting in less power consumption, while the array pattern remains the same as a fully populated array with a reduced side lobe level (SLL). The sub-6 GHz band of 5 GHz is used for the design of thinned array antennas. The genetic algorithm (GA) is used to determine the array sequence in thinning, and the adaptive signal processing algorithms least mean square (LMS), recursive least square (RLS), and sample matrix inversion (SMI) are used for the beamforming of the TSA, and the corresponding algorithms are GA-LMS, GA-RLS, and GA-SMI. The power saving of 40% to 55% is achieved using TSA. The maximum SLL reductions of 13 dB, 12 dB, and 14 dB are achieved for TSA using GA-LMS, GA-RLS, and GA-SMI algorithms, respectively.

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.

Antipodal Vivaldi Antenna with Star Trek insignia-based side slot edge for ultra-wideband applications

This article presents a Vivaldi Antipodal Antenna (AVA) with lens and radiating side cavities based on the Star Trek insignia, called Star Trek Side Edge Radiation (STSER-AVA). The objective was to improve parameters to make the radiation of the proposed antenna more directive. To this aim, the development is focused on reducing the squint of the central radiation beam and the side lobe level (SLL), as well as increasing the gain compared to a Conventional AVA. To achieve the objective, using an optimized design. The proposed antenna with or without a lens reached the target with a squint of -2.0 degrees, at 3.90 GHz the antenna with a lens achieved better gain (9.42 dB), but with a greater reduction in SLL of -10.73 dB compared to the lens less antenna. The results were obtained with computational electromagnetic simulations and experimental measurements.

A distributed subarray position optimization method based on DE-MIFT algorithm

Distributed array radar is a next generation radar that has been a hot research direction due to its high maneuverability, low cost, and high reliability. However, the synthesized beam pattern of the distributed array usually has some high sidelobes and grating lobes, which reduce the system performance. In this paper, a hybrid algorithm based on the differential evolution algorithm and modified iterative Fourier transform algorithm called DE-MIFT is proposed for optimizing subarray positions in a distributed array model. This distributed array model is based on a uniform linear subarray with equal amplitude excitation. Moreover, an integer coding method based on the minimum spacing between subarrays is adopted in the proposed algorithm to encode and initialize population, then the two algorithms are used to optimize in parallel. Then a variable selection factor is used to select dominant individuals from the parallel optimization results, and the subarray position design of distributed array is obtained through iterations. It is shown by simulation results that the proposed algorithm can effectively suppress system grating lobes, reduce sidelobe levels, and has powerful global search capability and fast convergence speed.