An efficient mutual coupling reduction method is introduced in this letter for extremely closely placed dual-element microstrip antennas positioned on a finite-sized ground plane WLAN MIMO application at 5.8 GHz. High isolation can be achieved through simple slot structure the between antennas. The position, length, and width of have been optimized maximizing isolation. It found that more than 40 dB two parallel sharing common plane. space distance these 17.5 mm ≈ 0.33λ <sub...

A novel single-fed low-cost wideband and high-gain slotted cavity antenna based on substrate integrated waveguide (SIW) technology using high-order modes is demonstrated in this paper. High-order resonant (TE130, TE310, TE330) inside the are simply excited by a coaxial probe which located at center of antenna. Energy coupled out 3 × slot array etched top surface cavity. Two antennas with different polarizations designed tested. Measured results show that linearly polarized prototype achieves...

A novel DOA flnding method for conformal array applications is proposed. By using sub-array divided and interpolation technique, ESPRIT-based algorithms can be used on arrays 1-D 2-D estimation. In this paper, the circular mounted a metallic cylindrical platform to several sub- arrays, each transformed virtual uniform linear or planar through technique. direction of arrivals estimated accurately quickly by LS-ESPRIT DFT-ESPRIT algorithms, respectively. This applied not only but also any...

This paper aims to present an up-to-date overview of the state-of-the-art about time-modulated arrays (TMAs). Starting from a description TMA fundamentals and basic theory in time frequency domain, most popular techniques for synthesizing TMAs are revised. Afterwards, survey main application contexts which have been proposed is reported. Finally, current research trends discussed future developments envisaged.

A novel amplitude-only measurement method is proposed to measure the signals (complex fields) of individual antenna elements for phased array calibration. The has minimum measuring time among known methods. total number power measurements with this about twice array. Phase shifters are required implement only three phase shifts (0°, 90°, and 180°). Array signal measured when setting an element one shifts. According superposition principle electromagnetic field, a linear combination signals....

In this communication, a novel wideband magnetoelectric (ME) dipole antenna is proposed and investigated. A microstrip line aperture-coupled feeding structure used to excite the antenna. This simple can significantly enhance impedance bandwidth. An prototype fabricated exemplified validate concept. Measured results show that ME with excitation achieves an bandwidth of 85% for VSWR <; 2 from 2.5 6.2 GHz. Further, measured maximum boresight gain up 8 dBi obtained 1 dB about 67% 5 The radiation...

Abstract 3D ground penetrating radar (GPR) is the main method for detection of underground cavities in urban roads. The number road cavity samples detected by small, whereas intelligent identification model require a large learning training, resulting inadequate training. This causes to be less accurate identifying cavities, many misses and misjudgments. Given above problems, combined with characteristics vertical, horizontal, crossed slices obtained one process GPR, GPR recognition based on...

A synthesis technique for the optimization of element excitations conformal phased array with improved NSGA-II (INSGA-II) algorithm is introduced in this communication. Firstly, patterns all elements are measured a microwave chamber when they terminated by their own characteristic impedances. As these called as active experimentally obtained, have already included mutual coupling information environment. Then pattern antenna can be obtained superposition various weights. And because each has...

In this letter, a single-fed low-profile high-gain circularly polarized slotted cavity antenna using high-order mode, i.e., TE440 is proposed. The proposed has simple structure that consists of radiating linearly and linear-to-circular polarization converter. An prototype operating at WLAN 5.8-GHz band fabricated with low-cost standard printed circuit board (PCB) process exemplified to validate the concept. Measured results compared their simulated counterparts are presented, good agreement...

An efficient pattern synthesis approach is proposed for the of large-scale 4-D antenna arrays in this paper. A array separated into two dependent "conventional arrays" with identical structures, whose far-field radiation patterns correspond to at center frequency and sidebands, respectively. It demonstrated that problem can be formulated as a nonconvex programming problem. Mathematical transformation then applied change nonconvexity respect excitation coefficients. Therefore, reduced convex...

The synthesis of irregular phased arrays subject to constraint on directivity is fulfilled by convex optimization. In particular, based the membership between antenna elements and subarrays, dictionary matrix, resulting sparse excitation vector, binary vector are introduced describe array pattern exact tiling aperture. Therefore, without overlaps holes satisfying given maximum sidelobe level (SLL) minimum can be summarized as a mixed integer nonconvex programming problem, where both subarray...

An effective optimization method is proposed for the synthesis of sparse antenna arrays subject to constraint on directivity in this letter. Based framework thinned synthesis, a real-value mixed integer programming problem minimization number elements under given maximum sidelobe level, scan range, and minimum limited array aperture established. In order solve efficiently, an iterative convex proposed, where strategies weighted l <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

A novel design of the passive license plate radio frequency identification tag antenna in UHF band based on characteristic mode theory (CMT) is proposed this paper. The operated as a since it conductor (made aluminum). desired up-tilted pattern beam achieved successfully by using direct CMT-based radiation synthesis procedure. can be expanded superposition some specific modes pattern, which identified according to analysis plate. Four coupling slots are exploited excite selected current...

This paper introduces a hybrid genetic algorithm and particle swarm optimization (GA-PSO) dedicated to pattern synthesis of conformal antenna arrays. Taking advantages both methods, the proposed GA-PSO has fast convergence speed high accuracy when applied array synthesis. To show performance algorithm, several typical test functions examples linear are illustrated. Finally, 4 × 2 cylindrical microstrip as practical example is studied demonstrate algorithm. The simulated measured results have...

A novel low‐profile single‐fed circularly polarised single‐layer metasurface antenna for wideband operation is proposed in this Letter. The consists of nine unit cells arranged a 3 × layout. Four slits are incorporated into four them, respectively, to form two orthogonal currents with 90° phase difference; hence, fields excited. Moreover, modified L‐type slot etched on the middle lattice improve impedance bandwidth and axial ratio performance. dielectric‐filled ( ɛ r = 3.5, tan δ 0.001) low...

A new technique based on the multiple measurement vectors FOCal Underdetermined System Solver (M-FOCUSS) for synthesis of pattern reconfigurable sparse arrays is presented. The method, MMVs recovery theory, used finding common element positions and individual excitations patterns in guidance collaborative strategy. reasonable tradeoff between number active antenna elements characteristics can be achieved. Numerical examples show high efficiency robustness proposed method. Furthermore,...