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The purpose of this study is to achieve the low-cost, light-weight and compact antenna array with wide bandwidth and low side lobe levels for synthetic aperture radar (SAR) applications in Ku frequency band.

A compact design of a rectangular microstrip patch antenna array using multilayered dielectric structure is presented in Ku-band for advanced broadband SAR systems. In this design, stepped pins are used to connect the microstrip feed lines to the radiating patches.

The simulation and fabrication results of the multilayered antenna and a 1×16-element linear array of the antenna with Taylor amplitude distribution in the feeding network are presented. The antenna element has a 10-dB impedance bandwidth of more than 26%, and the linear array shows reduction in bandwidth percentage (about 15.4%). Thanks to Taylor amplitude tapering, the side lobe level (SLL) of the array is lower than −24 dB. The maximum measured gains of the antenna element and the linear array are 7 and 19.2 dBi at the center frequency, respectively.

In the communication systems, a high gain narrow beamwidth radiation pattern achieved by an array of multiple antenna elements with optimized spacing is a solution to overcome the path loss, atmospheric loss, polarization loss, etc. Also, wideband characteristics and compact size are desirable in satellite and SAR systems. This paper provides the combination of these features by microstrip structures.

The purpose of this paper is to discuss and analyze a microstrip feed equilateral triangular microstrip array antenna (ETMPAA) that is proposed for S band (3 GHz) applications.

The ETMPAA comprises three equilateral triangular patches with equal distance. The size of the antenna is 49.4 mm (0.0494 m)×18.4 mm (0.184 m). The proposed antenna has been designed by etching triangular shape structure on glass epoxy substrate (FR4).

The simulated result shows that ETMPAA has the impedance bandwidth of 900 MHz and the bandwidth can be achieved by controlling the gap between the patch antennas. The antenna is fed by microstrip feeding technique. Design of an antenna using advanced design system (ADS), based on finite element methods (FEM) has been used to analyze and optimize the antenna. Based on the measurement results an antenna proposed with maximum efficiency and maximum gain.

This paper fulfils an identified need to study a microstrip feed ETMPAA is proposed for S band (3 GHz) applications.

This paper aims to introduce a new novel microstrip monopulse comparator system to reduce the spurious radiation from the comparator and the feed network for achieving better radiation performance.

Two substrate layers have been used for the microstrip monopulse comparator system. The feed network and the comparator circuits are on the first substrate layer and the microstrip array antenna is on the second layer. The elements of the array antenna are novel square four-sided narrow rectangular slot antennas built on a conducting plane. A commercially available computational software, CST microwave studio, has been used for the analysis of the system.

Two substrate layers have been used for the microstrip monopulse comparator system. The feed network and the comparator circuits are on the first substrate layer and the microstrip array antenna is on the second layer. The elements of the array antenna are novel square four-sided narrow rectangular slot antennas built on a conducting plane. A commercially available computational software, CST microwave studio, has been used for the analysis of the system.

The system is proposed for tracking moving targets.

Novel slot radiators are introduced as radiating elements in this paper. The antenna arrangement shields the comparator and the feed network circuits, reducing the spurious radiation significantly.

This paper aims to propose a laser micro-machined 4 × 4 elements microstrip array antenna suitable for 5 G millimeter wave (mm-wave) applications. Each patch element of the array is excited with same amplitude and phase that is achieved with proper novel impedance matching stub. The proposed antenna achieves a simulated gain of 13.15 dBi and a measured return loss of −24.80 dB at 28.73 GHz with a total bandwidth of 7.48 GHz. The designed antenna is directional with a directivity of 15.1 dBi at 28.73 GHz, whereas fabricated on a low cost FR4 substrate with a substrate thickness of 0.074 λ mm. The antenna is realized with an aperture size of 2.24λ × 3.26λ.

The antenna structure starts from the design of single element called unit cell. The single element is designed using the transmission line model equations of a rectangular patch. To design a 28 GHz microstrip patch antenna, a dielectric material with lower permittivity and having thickness (h) less than 1 mm is required. This specification gives better gain and efficiency by reducing surface waves and mutual coupling between elements. The inset width is optimized to achieve the minimum reflection coefficient (S11). The single element has been arranged with a minimum spacing of λ/2 (5.3571 mm) in an H plane and E plane. It is connected using the microstrip lines with proper impedance matching. The four 2 × 2-sub array cell subsystems are connected with a corporate feed together formed the 4 × 4-array cell. Rectangular planar array method is used to arrange the elements in the 4 × 4 array cell.

The design concept is simple which includes the combination of corporate feed and insect feed. It is compact in size and easy to fabricate. The bandwidth of fabricated prototype antenna array is achieved as 7.48 GHz from 24.98 GHz to 32.46 GHz. The mutual coupling is very less though the antenna array is placed with minimum spacing between adjacent elements. This is because of the microstrip feeding structure with minimum phase shift. The gain can be further enhanced with increasing number of array element and proper designing of feed line. Owing to the advantages of low profile, wide bandwidth and high gain, the designed array will be potentially useful in 5 G wireless communications.

The measured antenna offers bandwidth 7.48 GHz (24.98 GHz-32.46 GHz) with centered frequency 28.73 GHz. The agreement between simulated and measured results is good. The VSWR is observed 0.32 < 2, offers good impedance matching and low mutual coupling. It gives better E-Field and H-field radiation patterns of the 4 × 4 array antenna structure at 28 GHz. The total gain of 13.14 dBi is achieved at the center frequency. The total efficiency of 63.42 per cent is achieved with FR4 substrate.

Millimeter wave spectrum represents new opportunities to add capacity and faster speeds for next-generation services as fifth generation (5G) applications. In its Spectrum Frontiers proceeding, the Federal Communications Commision decided to focus on spectrum bands where the most spectrums are potentially available. A low profile antenna array with new decoupling structure is proposed and expected to resonate at higher frequency bands, i.e. millimeter wave frequencies, which are suitable for 5G applications.

The presented antenna contains artificial magnetic conductor (AMC) surface as decoupling structure. The proposed antenna array with novel AMC surface is operating at 29.1GHz and proven to be decoupling structure and capable of enhancing the isolation by reducing mutual coupling as 8.7dB between the array elements. It is evident that, and overall gain is improved as 10.1% by incorporating 1x2 Array with AMC Method. Mutual coupling between the elements of 1 × 2 antenna array is decreased by 39.12%.

The proposed structure is designed and simulated using HFSS software and the results are obtained in terms of return loss, gain, voltage standing wave ratio (VSWR) and mutual coupling. The S-Parameters of each stage of design is tabulated and compared with each other to prove the decoupling capability of AMC surface in antenna arrays.

The proposed structure is designed and simulated using HFSS software, and the results are obtained in terms of return loss, gain, VSWR and mutual coupling. The S-Parameters of each stage of design is tabulated and compared with each other to prove the decoupling capability of AMC surface in antenna arrays.

A class of robust and efficient beamforming methods is developed in this paper for the optimised design of realistic microstrip antennas on arbitrarily curved substrates. More specifically, this paper aims to focus on the formulation of an effective and computationally light beamforming algorithm and its implementation on a novel realistic cylindrical-substrate microstrip array antenna with significantly decreased size, wideband operation and enhanced radiation characteristics.

The proposed multi-parametric schemes introduce an efficient null-steering concept, which drastically annihilates the undesired beamformer waveform artefacts, while retaining the real output signal undistorted. In particular, the key objective is the accurate calculation of the appropriate complex feeding weights, required to set nulls along the propagation directions of the unwanted signals and a maximum towards the propagation direction of the desired incoming signal. The featured technique, combined with a modified finite element method, is applied to the design of a new family of cylindrical-substrate microstrip array antennas.

Numerical results, mainly concerning customisable three-dimensional radiation patterns and attributes, certify the merits of the algorithm and its limited system demands. The introduced beamforming algorithms are applied to a variety of different inputs (desired radiation patterns), which indicate that the designed cylindrical-substrate antenna overwhelms existing designs in terms of computational cost for the beamforming algorithm, while retaining acceptable values for radiation characteristics, such as gain, directivity and side-lobe suppression. In this manner, the effectiveness of the prior methodology and the benefits of this newly shaped array antenna are comprehensively revealed and substantiated.

Rigorous beamforming techniques in conjunction with a class of contemporary array antennas are developed for potential use in high-end communication systems, such as 5G configurations. The proposed cylindrical-shaped structures are systematically designed, with an emphasis on space efficiency and wideband radiation effectiveness to offer fully adjustable setups. To this aim, the cylindrical-substrate microstrip antenna, because of its inherent azimuthal symmetry and confined overall dimensions, provides reliable operation and promising performance.

In this work, a microstrip antenna array for wireless power transfer (WPT) application is reported. The proposed 4 × 4 antenna array operating at 16 GHz is designed using a flexible Kapton polyimide substrate for a far-field charging unit (FFCU).

The proposed antenna is designed using the transmission line model on a flexible Kapton polyimide substrate. The finite element method (FEM) is used to perform the full-wave electromagnetic analysis of the proposed design.

The antenna offers −10 dB bandwidth of 240 MHz with beam width and broadside gain found to be 29.4° and 16.38 dB, respectively. Also, a very low cross-polarization level of −34.23 dB is achieved with a radiation efficiency of 36.67%. The array is capable of scanning −15° to +15° in both the elevation and azimuth planes.

The radiation characteristics achieved suggest that the flexible substrate antenna is suitable for wireless charging purposes.

Microstrip patch antenna is generally used for several communication purposes particularly in the military and civilian applications. Even though several techniques have been made numerous achievements in several fields, some systems require additional improvements to meet few challenges. Yet, they require application-specific improvement for optimally designing microstrip patch antenna. The paper aims to discuss these issues.

This paper intends to adopt an advanced meta-heuristic search algorithm called as grey wolf optimization (GWO), which is said to be inspired by the hunting behaviour of grey wolves, for the design of patch antenna parameters. The searching for the optimal design of the antenna is paced up using the opposition-based solution search. Moreover, the proposed model derives a nonlinear objective model to aid the design of the solution space of antenna parameters. After executing the simulation model, this paper compares the performance of the proposed GWO-based microstrip patch antenna with several conventional models.

The gain of the proposed model is 27.05 per cent better than WOAD, 2.07 per cent better than AAD, 15.80 per cent better than GAD, 17.49 per cent better than PSAD and 3.77 per cent better than GWAD model. Thus, it has proved that the proposed antenna model has attained high gain, leads to cause superior performance.

This paper presents a technique for designing the microstrip patch antenna, using the proposed GWO algorithm. This is the first work utilizes GWO-based optimization for microstrip patch antenna.

Application of electromagnetic band gap (EBG) i.e. electromagnetic band gap technique and its use in the design of microstrip antenna and MIC i.e. microwave integrated circuits is becoming more attractive. This paper aims to propose a new type of EBG fractal square patch microstrip multi band fractal antenna structures that are designed and developed. Their performance parameters with and without EBG structures are investigated and minutely compared with respect to the resonance frequency, return loss, a gain of the antenna and voltage standing wave ratio.

The fractal antenna geometries are designed from the fundamental square patch and then EBG structures are introduced. The antenna geometry is optimized using IE3D simulation tool and fabricated on low cost glass epoxy FR4, with 1.6 mm height and dielectric materials constant of 4.4. The prototype is examined by means of the vector network analyzer and antenna patterns are tested on the anechoic chamber.

Combining the square fractal patch antenna with an application of EBG techniques, the gain of microstrip antenna has been risen up and attained good return loss as compared to the antennas without EBG structures. The designs exhibit multi-frequency band characteristics extending in between 1.70 and 7.40 GHz. Also, a decrease in antenna size of 34.84 and 59.02 per cent for the first and second iteration, respectively, is achieved for the antenna second and third without EBG. The experimental results agree with that of simulated values. The presented microstrip antenna finds uses in industrial, scientific and medical (ISM) band, Wi-Fi and C band. This antenna can also be used for satellite and radio detection and range devices for communication purposes.

A new type of EBG fractal square patch microstrip antenna structures are designed, developed and compared with and without EBG. Because of the application of EBG techniques, the gain of microstrip antenna has been risen up and attained good return loss as compared to the antennas without EBG structures. The designs exhibit multi-frequency band characteristics extending in between 1.70 and 7.40 GHz, which are useful for Wi-Fi, ISM and C band wireless communication.

The purpose of this paper is the analysis of the radiation and impedance characteristics of cavity backed patch antennas embedded in a curved surface. Single patch elements and small scale array antennas are considered. The impact of curvature on the performance of the patch antenna is investigated, and the effect of mutual coupling between the elements in an array is examined.

A finite element‐boundary integral procedure has been implemented to accurately determine the performance characteristics of the patch radiators on planar and cylindrical surfaces. Simulated results will be shown to be in good agreement with measurements.

Mutual coupling effects between array elements are examined and it can be observed that an active element primarily interacts with the nearest neighbour elements. A comparison of an array element with a single patch radiator shows that the mutual coupling effects cause no significant mismatch between a patch and a feed network in practical applications.

The characteristics of conformal microstrip antennas are investigated for single patch radiators and patch elements in array environments. Simulations are supported by measurements.