Design Of Antenna Array Research Articles

Multi-pattern synthesis in fourth-dimensional antenna arrays using BGM-based quasi-Newton memetic optimization method

Abstract The advancement in wireless communication is fueling the growth of innovative antenna array designs toward cost-effective and performance-oriented solutions. This paper proposed unconventional methods to design antenna arrays for multi-pattern synthesis without using attenuators or phase shifters. A low-cost alternative is proposed with “Time-modulation”-based antenna array capable of electronic scanning and beam steering. Here, “Time” is utilized as a fourth-dimensional (4D) array parameter, and that is why “Time-modulated” arrays are also called as 4D antenna arrays. The idea is to control the high-speed switch attached with each antenna periodically to produce desirable current and phase tapering. This article expanded the “Time-modulation” concept to synthesize multiple radiation patterns like monopulse patterns, scanned beam patterns, shaped beam patterns, and cosecant-squared beam patterns for multifunctional radar systems. Suitable time schemes are developed to generate the narrowband sum–difference patterns useful for monopulse radars. Simultaneous scanned beam patterns are also proposed for narrowband communication. Furthermore, to address the wideband applications, shaped flat-top beam patterns and cosecant-squared beam patterns are also proposed. In this regard, 20- and 16-element “Time-modulated” linear array antennas are developed, and the parameters of the arrays are controlled by suitably designed objective functions with quasi-Newton method (QNM)-based memetic optimization method. For this purpose, first a well-known genetic algorithm is adopted to search the potential trust regions in the exploration stage and QNM is used for fine-tuning. Furthermore, the Broyden’s good method-based direction-updating equation is used with QNM to improve the performance.

Comparison of Microwave Hyperthermia Applicator Designs with Fora Dipole and Connected Array.

In microwave hyperthermia tumor therapy, electromagnetic waves focus energy on the tumor to elevate the temperature above its normal levels with minimal injury to the surrounding healthy tissue. Microwave hyperthermia applicator design is important for the effectiveness of the therapy and the feasibility of real-time application. In this study, the potential of using fractal octagonal ring antenna elements as a dipole antenna array and as a connected array at 2.45 GHz for breast tumor hyperthermia application was investigated. Microwave hyperthermia treatment models consisting of different fractal octagonal ring antenna array designs and a breast phantom are simulated in COMSOL Multiphysics to obtain the field distributions. The antenna excitation phases and magnitudes are optimized using the global particle swarm algorithm to selectively increase the specific absorption rate at the target region while minimizing hot spots in other regions within the breast. Specific absorption rate distributions, obtained inside the phantom, are analyzed for each proposed microwave hyperthermia applicator design. The dipole fractal octagonal ring antenna arrays are comparatively assessed for three different designs: circular, linear, and Cross-array. The 16-antenna dipole array performance was superior for all three 1-layer applicator designs, and no distinct difference was found between 16-antenna circular, linear, or cross arrays. Two-layer dipole arrays have better performance in the deep-tissue targets than one-layer arrays. The performance of the connected array with a higher number of layers exceeds the performance of the dipole arrays in the superficial regions, while they are comparable for deep regions of the breast. The 1-layer 12-antenna circular FORA dipole array feasibility as a microwave hyperthermia applicator was experimentally shown.

Innovation Design of High Gain Array Antenna for 5G Communication

The fifth-generation (5G) wireless communication system requires high gain antennas to support the growing demand for high-speed data transmission and low-latency connectivity. High gain antennas are crucial for enhancing the signal strength and extending the coverage area of 5G networks. By using multiple antenna elements, an array can achieve higher gain and directivity compared to a single element antenna. This improvement in gain enables better signal reception and transmission, leading to increased communication range, higher data rates, and improved reliability. In this paper, we discuss the design and implementation of antenna arrays for improving antenna gain in 5G communication systems at 3.5 GHz.The design of the array antenna incorporates single, dual, quad, and octal element structures to enhance the antenna's gain. The proposed antenna has been examined, and the results indicate that it has a return loss of -37.4 dB at the resonant frequency of 3.5 GHz, an antenna gain of 7.22 dB, and a bandwidth of 286.5 MHz. The use of a single, dual, quad, and octal element array configuration is anticipated to improve the gain performance of the antenna, making it a promising option for 5G communication systems.

Joint Precoding and Array Design for Broadcast in the Internet of Unmanned Aerial Vehicles

To promote energy and spectrum efficient communications in multi-antenna channels, broadcast can provide a substantial gain in system throughput. However, the hardware constraints and strong line-of-sight (LoS) limit the implementation and performance of multi-antenna broadcast in the Internet of unmanned aerial vehicles (UAVs). Based on the pseudo-Doppler principle, we propose a joint precoding and antenna array design to reduce the number of radio frequency (RF) chains required by the broadcast and free the LoS path from the inter-stream interference. The reduction of RF chains is realised by designing the precoding matrix that makes at least one of the transmit antennas have null inputs during any broadcast and, moreover, the LoS path is formed to match the obtained precoding matrix through antenna array design at the broadcasting UAV. The algorithms with low computational complexity for optimising this design are developed to minimise the transmit power within the UAV broadcast paradigms. Theoretical formulation and numerical results in the metrics of sum data rate and bit error rate substantiate the validity of our proposed design, specifically in the Internet of UAVs with strong LoS.

Design and analysis of multiple beams phased array microstrip antenna for 5G applications

The paper presents a novel and compact antenna array design fed through a 3 dB BLC for producing phase shift in the array. Beam steering is an attractive design feature for avoiding obstacles in the path of the beam. It is achieved by switching the beam to another path by simply varying the phase shift between elements. The proposed structure exhibits resonance in the frequency having range of 27.6 GHz −29.6 GHz with a minimal return loss value of −45 dB for frequency applications of 28 GHz, which can be further employed for 5G frequency applications, there are two multiple beams observed, with main beam at theta equal to −35 degrees, the main beam shifts to +28 degrees by changing the feed port of the coupler. A stable gain of around 11.5 dB is obtained for the entire frequency range. The input phase has been varied for different elements in the array, and best results were obtained for a 90 degree phase difference, which required the use of a 3 dB BLC. Rogers RT Duroid 5880, having a dielectric of 2.2 and a 0.51 mm dielectric height, was used as a substrate for antenna fabrication. The simulations were performed on the CST Microwave studio and the measurements were done on VNA (Agilent N5247A).

A Quad-Band Near-Field Antenna Array for a Multistatic Microwave Imaging Chamber

A new quad-band tapered patch transmit-receive antenna array designed for a multistatic microwave imaging cavity system is presented. The reverberating cube-shaped chamber is filled with a matching fluid emulsion and encompasses 64 antenna elements mounted on its sidewalls (16 per panel). Four resonant frequencies that lie in the range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.5 - 3$</tex-math></inline-formula> GHz are achieved. The design procedure is provided based on system constraints and performance requirements that need to be taken into account: (1) the near-field nature of the electromagnetic wave in the presence of a shielded chamber and (2) the propagation of waves into the immersion fluid within the imaging domain. The antenna array design was numerically verified, and its prototype was fabricated. Results show good agreement between measurements and simulations, achieving antenna system performance requirements.

Design and Implementation of 2x4 Octagonal Array Patch Microstrip Antennas using T-Slots at 2.4 GHz Frequency for Wifi Applications

Wireless communication requires a useful device to transmit and receive electromagnetic waves. WiFi is a particular kind of wireless communication device used to send data over the internet network. The bandwidth and signal coverage of WiFi have significant limitations. As a result, an antenna is utilized to enhance signal reception in order to solve this issue. The research method used is to compare the design of the 2x4 octagonal microstrip array antenna using a T-slot and without the T-slot to see the results of simulation and testing in terms of return loss, VSWR, gain, and bandwidth. The results of bandwidth testing for octagonal microstrip antennas without a 2x4 T-slot array are 32 MHz, while for octagonal microstrip antennas using a 2x4 T-slot array of 40MHz. The octagonal microstrip antenna without a 2x4 T-Slot array has Return Loss of -18.2 dB and a VSWR of 1.280. The 2x4 octagonal T-Slot array microstrip antenna has Return Loss of -17.6 dB and a VSWR of 1.303. The test results 2x4 octagonal array microstrip antenna gain without using T-slot produces the largest gain of 9.55dBi, and the antenna using T-slot produces the largest gain of 12.55dBi.

Design of Compact Fragment-Type Antenna Array for Microwave-Based Head Imaging Application

Specifically designed antennas are needed to meet the needs of head imaging applications where an antenna array is typically used. In this article, the design of a compact fragment-type antenna using a genetic algorithm is proposed. The proposed antenna is fabricated by a low-cost FR4 substrate and covers a 72.4% fractional bandwidth (1.92 to 4.1 GHz), with an average gain of more than 2.02 dBi. The overall structure of the proposed antenna is equivalent to 0.29 λ0 × 0.19 λ0, where λ0 is the corresponding wavelength at 1.92 GHz. The results indicate that the proposed antenna is compact and suitable for microwave-based head imaging. An effective microwave head imaging system with an array of 8 compact fragment-type antennas is designed, with one antenna working as a transmitter and the others working as a receiver in turn. The imaging performance is investigated with blood layer inside the head model using the Microwave Radar- Based Imaging Toolbox open-source software. The detection of the presence and location of stroke is done by analyzing the compact fragment-type antennas’ backscattered signal.

Design of Frequency Scanning Coupled-Resonator Two-Element Array Antenna

In this brief, we present one type of frequency scanning coupled-resonator two-element array antenna and its corresponding equivalent circuit synthesis method. This antenna consists of several series-coupled resonators, the non-radiating resonators are cascaded between two radiating resonators. Since the antenna only has resonators and coupling structures, the threeports coupled-resonator circuit model can be used to explain the working principle and predict the performance of this antenna. The analysis of circuits with different orders indicates that the fractional bandwidth can control the scanning rate and the scanning rate and range can be both affected by the number of non-radiating resonators. Finally, two antennas with three and four resonators are designed in PCB form to validate the method. The third-order (fourth-order) antenna can scan 54.1∘ (64∘) in a 5.87% (5.54%) bandwidth centered at about 3.5 GHz.

Received Antenna Array Design of GSSK-Based Antennas Selection for RIS-Assisted Communication

A wireless communication scheme named as the reconfigurable intelligent surface (RIS) assisted generalized space-shift keying (GSSK) based antennas selection (RIS-GKAS) is designed in this article. In this scheme, GSSK works at receiver and the reflected elements in the RIS can be adjusted to achieve the passive beamforming for the antennas selection to maximize the signal-to-noise ratio. This proposed scheme can be applied to a city with plenty of buildings. Specifically, the RIS is considered as an access point in this scheme and the received antennas are designed into a specific array for the antennas selection to achieve the passive beamforming. Besides, the performance analysis of the proposed scheme with maximum likelihood detector is presented. The results show that the RIS-GKAS has approving performance among various RIS-assisted index modulation schemes, and the designed pregreedy-aided maximum likelihood detector has the robustness among the multiple detectors under imperfect channel state information in RIS-GKAS scheme.

Design of microstrip patch antenna element and array on quartz glass wafer with suspended cavity based on MEMS technology

Design of microstrip patch antenna element and array on quartz glass wafer with suspended cavity based on MEMS technology

A novel helical antenna for high-power design in X-band

This paper describes a novel helical antenna for high-power design in X-band. Based on the advantages of miniaturization, high efficiency, and low-profile from helical antenna, firstly, by optimizing the primary parameters, the helical antenna obtains a significant axial ratio bandwidth and operational bandwidth in X-band. Then in array antenna design, metal frames are introduced to decrease the mutual coupling effects, reducing the lower-impedance bandwidth decrease from 9.77 GHz to 8.08 GHz. Meanwhile, to further realize high-power design, a novel curved feed structure is employed to boost the power capacity increase from 31.1KW to 43.8KW. The measured results show that the proposed helical antenna has an operating bandwidth across X-band (reflection coefficient < −10 dB), and the max power capacity of the antenna finally ascends to 43.8 kW.

Design of Millimeter Wave Radar Antenna Array with Flat-top Pattern

In this paper, a planar millimeter wave radar array antenna with flat-top pattern is proposed for wide detection angle. Firstly, the Chebyshev synthesis method is used to design the linear array with high gain and low sidelobe pattern which works in the 24 GHz frequency band. The maximum gain of the linear array is roughly 15 dBi, and the main-sidelobe ratio is close to 20 dB. By setting the excitations and phases distribution of the planar array feeding network, a 5××4 antenna array with a flat-top pattern is obtained. The simulated and measured results show that the radar antenna array has a wide half-power beamwidth of 88 degrees, which can ensure that the automotive radar has a longer detection range and a larger monitoring angle.

A Ku Wideband Circularly Polarized Microstrip Antenna Array with Low Profile Crossed-Dipole Element

This paper presents a novel Ku wideband circularly polarized (CP) antenna array composed of crossed-dipole element (CDE) and fed through sequential rotation (SR) feeding technique. Unlike the traditional CP-CDE fed by coaxial cable that usually works at low frequencies, the proposed CDE consists of two orthogonal heart-shaped patch dipoles that can work at frequencies as high as Ku-band, at the same time achieving a larger bandwidth. A feeding structure is proposed without welding, so potential errors in the antenna assembly process can be mitigated. A 2 × 2 CP antenna array with wideband SR feeding network is designed based on the CDE to further expand the axial ratio (AR) bandwidth. The designed antenna array is fabricated using the multilayer printed circuit board (PCB) technology and measured in anechoic chamber using the planar near-field measurement facility. The measured results show that −10 dB impedance bandwidth of 44% (11.6–18.15 GHz) along with 3 dB AR bandwidth of 38.7% (12–17.65 GHz) and 3 dB gain bandwidth of 34.6% (12.2–17.3 GHz) as well as 11.02 dBic peak gain have been achieved while maintaining a lower profile.

Direction of arrival estimation for BLE: Antenna array design and evaluation

The use of smart antenna arrays in wireless communication systems is becoming increasingly popular, as they improve the performance of the radio link and allow the integration of communication and sensing functions. In this paper, we present the design and performance evaluation of a uniform circular antenna array (UCAA) with 12 monopole antennas and RF switches to select the active antenna for the signal direction of arrival (DoA) estimation. The antenna configuration was optimized through simulations for a different number of antennas and antenna array radius. The frequency tuning of the antennas considered the coupling of the active antenna with adjacent antennas. The performance of the antenna array was evaluated by (1) simulations that examined the proximity of the antenna to the edge of the antenna array and the influence of adjacent antennas on the performance of the active antenna, and (2) measurements in outdoor and indoor environments. The results of the simulations show that antenna coupling can cause nulls in the radiation pattern, which affects the DoA estimation by reducing the signal-to-noise ratio. In a semi-controlled environment, we achieved a DoA estimation error of less than 1 degree by using the Bluetooth Low Energy (BLE) Angle of Arrival feature.

Modeling the effect of bend radius on the performance of a conformal dual-band mm-wave patch antenna array

There is growing interest in the use of additive manufacturing for the fabrication of RF devices due to fast prototyping capabilities and the use of less material as opposed to traditional fabrication techniques. In addition to the previously mentioned advantages, the aerosol jet printing method in particular allows for the conformal printing of RF components. This work models the effect of the bend radius on the return loss and radiation pattern of a dual-band (28 GHz and 39 GHz) mm wave patch antenna array design that will be aerosol jet printed. The antenna is modeled on a 5-mil thick flexible substrate (PET) and the simulation is run from 27 GHz to 40 GHz using HFSS. The return loss and radiation pattern results of the antenna are compared for various bend radii (0.25 in to 2 in) of the conformal surface the antenna is to be printed upon. Simulation results show a maximum frequency deviation of about 400 MHz on the return loss for the low (28 GHz) frequency band of the antenna when it is bent from a bend radius of 0 in to 2 in.

Analytical Approach to Parameter Determination in Kaiser Function for Power-weighted Antenna Array Design

Window methods that are frequently used in the design of finite impulse response filters are also applicable to antenna array designs. This paper explores the application of a Kaiser function in a power-weighted antenna array design, focusing on the determination of the Kaiser function’s β parameter. The determination, which includes the calculation, optimization, and validation of the β parameter, was carried out based on a specific configuration of a linear antenna array design. The observation of this exploration emphasized the suppression of the sidelobe level (SLL) and the width of main lobe (WML) performance. By changing the β parameter, the Kaiser function is capable of approximating different window methods, since it plays an important role in defining the set of weighting coefficients for a specifically targeted SLL. Kaiser function application in power-weighted antenna array designs with a linear arrangement indicates the need of β parameter optimization because of the disagreement between the obtained SLL and the targeted SLL. The optimized β parameter produced a smaller SLL error for even and odd numbers of elements. From the validation, the average SLL error percentage for a targeted SLL of 25 dB, 35 dB, and 45 dB was 6%, 4.31%, 6.10%, respectively.

Design of a High-Gain Hybrid Slot Antenna Array Based on Bulk Silicon MEMS Process for W-Band Applications

A W-band, high-gain, hybrid slot antenna array based on bulk silicon MEMS technology is proposed in this paper. The high-order-mode cavity is explored to excite the 2 × 2-slot basic unit, so as to reach the low-profile requirement of the bulk silicon MEMS process. To avoid the fragile structure of the large-scale antenna arrays based on the bulk silicon MEMS process, the ridge gap waveguide is employed to build the feed network for a large-scale array. A vertical transition between a rectangular waveguide and a ridge gap waveguide is designed to support the low-loss and low-cost assembling method between the radiation units and the feed network. An 8 × 8-slot hybrid antenna array is simulated and fabricated. The measured results show a relative bandwidth (VSWR &lt; 2) of 8.1% with the first side-lobe level less than −11 dB over the frequency band of 91–97 GHz. A maximum gain of 26.1 dBi with the radiation efficiency of 65.2% is achieved. With high gain and high fabrication efficiency, the proposed hybrid slot antenna array would be valuable for W-band radar applications.

Design of Microstrip Antennas Array for Wireless Applications by Using HFSS

The modern wireless communication desires high gain, wide bandwidth and minimal size antennas that are efficient to provide improved performance over a wide range of frequency spectrum. This requirement leads to the design of microstrip patch antenna. This paper presents the design of compact 1X2 microstrip patch antenna array which uses the corporate feed technique for excitation. The proposed antenna is designed on FR-4 substrate with dielectric constant 4.4 and thickness 1.6mm. Dielectric constant and parameters like Return Loss, Gain and Radiation pattern are calculated using high frequency simulation software. The fabricated antennas results are to be compared with Simulation results. The antenna has been designed for the range 2.4 GHz. Keywords: Microstrip antenna, corporate feed, FR-4 substrate, Microstrip antenna array

Design of Wideband High-Gain Patch Antenna Array for High-Temperature Applications.

A low-profile, wideband, and high-gain antenna array, based on a novel double-H-shaped slot microstrip patch radiating element and robust against high temperature variations, is proposed in this work. The antenna element was designed to operate in the frequency range between 12 GHz and 18.25 GHz, with a 41.3% fractional bandwidth (FBW) and an obtained peak gain equal to 10.2 dBi. The planar array, characterized by a feed network with a flexible 1 to 16 power divider, comprised 4 × 4 antenna elements and generated a pattern with a peak gain of 19.1 dBi at 15.5 GHz. An antenna array prototype was fabricated, and the measurements showed good agreement with the numerical simulations as the manufactured antenna operated in the range of 11.4-17 GHz, with a 39.4% FBW, and the peak gain at 15.5 GHz was 18.7 dBi. The high-temperature simulated and experimental results, performed in a temperature chamber, demonstrated that the array performance was stable in a wide temperature range, from -50 °C to 150 °C.