High-gain Antenna Research Articles

Design of a Flexible Cylindrical Antenna with Rotatable Curved Frequency Selective Surface for Omnidirectional High-Gain Applications

In this paper, a high-gain flexible cylindrical antenna with rotatable curved frequency selective surface (FSS) is presented, which is designed for the 2.4 GHz industrial scientific medical (ISM) band. The array of 3 × 3 optimized FSS unit cells (102 × 102 mm2) is applied to improve the gain of the antenna (50.4 × 28 × 0.1 mm3). Through the rotation of the FSS, omnidirectional gain enhancement is realized. The simulation and measurement results demonstrate the feasibility of this work. The measured antenna with the FSS has omnidirectional high-gain in the operational band of 2.18–2.90 GHz, and the gain can be increased by 5.31 dBi at most. The antenna can be used in cylindrical conformal devices, and the proposed design method provides a new solution for gain enhancement of cylindrical omnidirectional antennas.

High-Gain Millimeter-Wave Beam Scanning Transmitarray Antenna

In this article, a high-gain millimeter-wave transmitarray antenna (TAA) maintaining scanning ability is developed, integrating an array feed as the primary emitter. The work is achieved within a limited aperture area, avoiding the replacement or extension of the array. The addition of a set of defocused phases along the scanning direction to the phase distribution of the monofocal lens allows the converging energy to be dispersed into the scanning scope. The beam forming algorithm proposed in this article can determine the excitation coefficients of the array feed source, and is beneficial to improve the scanning capability in array-fed transmitarray antennas. A transmitarray based on the square waveguide element illuminated by an array feed is designed with a focal-to-diameter ratio (F/D) of 0.6. A 1-D scan with a scope of −5° to 5° is realized through calculation. The measured results show that the transmitarray can achieve a high gain, 37.95 dBi at 160 GHz, although a maximum 2.2 dB error appears compared with the calculation in the operating band of 150–170 GHz. The proposed transmitarray has been proven to generate scannable high-gain beams in the millimeter-wave band and is expected to demonstrate its potential in other applications.

Circularly Polarized Antenna with Metallic Reflector for High-Gain Satellite Communication

This paper describes the design and performance of a circularly polarized antenna for satellite communication applications. The antenna design includes a monopole patch antenna, split ring resonator, defective ground surface and a metallic reflector. The antenna is designed to operate in multiple frequency bands and to have high gain. The metallic reflector is used to enhance the antenna gain by reflecting the signal in the same phase as the transmitted signal, thereby strengthening the signal. The antenna resonates in 4.4 GHz and 7.6 GHz frequency bands, making it suitable for satellite communication applications. The paper presents both simulated and measured results of the antenna's performance, including return loss, gain, VSWR and polarization characteristics. The paper provides a detailed analysis of antenna's performance, demonstrating its suitability for satellite communication applications. The use of a metallic reflector, the split ring resonator and defective ground surface design results into antenna's high gain and multiband operation.

A Wideband GRIN Dielectric Lens Antenna for 5G Applications.

This paper proposes a graded effective refractive indexes (GRIN) dielectric lens for 5G applications. The inhomogeneous holes in the dielectric plate are perforated to provide GRIN in the proposed lens. The constructed lens employs a collection of slabs that correspond to the specified graded effective refractive index. The thickness and the whole lens dimensions are optimized based on designing a compact lens with optimum lens antenna performance (impedance matching bandwidth, gain, 3 dB beamwidth, and sidelobe level). A wideband (WB) microstrip patch antenna is designed to be operated over the entire band of interest from 26 GHz to 30.5 GHz. For the 5G mm-wave band of operation, the behavior of the proposed lens along with a microstrip patch antenna is analyzed at 28 GHz for various performance parameters, including impedance matching bandwidth, 3 dB beamwidth, maximum gain, and sidelobe level. It has been observed that the antenna exhibits good performance over the entire band of interest in terms of gain, 3 dB beamwidth, and sidelobe level. The numerical simulation results are validated using two different simulation solvers. The proposed unique and innovative configuration is well-suited for 5G high gain antenna solutions with a low-cost and lightweight antenna structure.

Design and Optimization of a High-Gain Filtering Antenna Based on Parasitic Pixel Layer

A novel high-gain filtering antenna based on the parasitic pixel layer is designed and optimized in this paper. Initially, a circular patch surrounded by a shorted concentric annular ring one is proposed as the radiation source, such a design is able to realize an upper radiation null. Afterward, a parasitic pixel layer is placed upon the radiation source with an air gap. Another radiation null at the lower band is then obtained by optimizing the connection status between adjacent pixel elements based on the internal multi-port method. Besides that, the parasitic pixel layer can enhance the realized broadside gain. Finally, a high-gain filtering antenna with a bandpass response is obtained. The antenna is validated by a full-wave simulation study followed by the experimental verification. Measured results indicate that the antenna can operate from 4.7 to 5.4 GHz with an average gain of 9.6 dBi and two radiation nulls at the lower and upper band edges of the reflection coefficient curve.

A novel fan beam and high gain antenna array for outdoor applications

This paper introduces a novel high gain and wideband antenna array at 5 GHz for outdoor applications. The proposed array consists of a 2×9 elements planar array and a reflector. This antenna has a gain peak of 15.7 dBi and a bandwidth of 2 GHz from 4.0 GHz to 6.0 GHz. The angle coverage of 240° in the azimuth plane with gain 2 dBi higher. The total dimension of the antenna array is 31.5×13.4×1.2 cm3 which is fabricated on RO4003C substrate. The antenna has been fabricated and measured, the measurement and the simulation results are in good agreement.

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 < 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.

5G Communication: High Gain Array Antenna Operating at 3.5GHz

—5G technology is leverages advanced antenna technology and wider bandwidth to improve the potential of wireless communication that enables a significant increase in the amount of information that can be transmitted through the wireless system. With its ability to deliver higher data rates and lower latency, 5G promises to support a wide range of applications, from immersive virtual reality to autonomous vehicles.However, 5G communication systems are characterized by poor radiation features, which limit their usefulness in wider operational ranges. To overcome these issues, this project will focus on designing a high-gain array antenna operating at 3.5GHz specifically for 5G communication. A directional patch antenna will be designed for a specific base station to provide high radiation network connectivity and superior communication quality. Moreover, the high-gain array antenna at 3.5GHz will be optimized for long-distance point-to-point connections. In this project, a 4x4 patch antenna will be designed and fabricated using FR4 epoxy material to achieve high gain for long-distance signal transmission.

응답시간이 개선된 액정 기반 능동 반사 배열 안테나 단위 셀 구조

This paper presents a unit cell structure for liquid crystal (LC)-based reconfigurable reflective arrays, aimed at improving the imbalance in response time. Conventional LC-based reflectarray antenna unit cells, which have been widely used as high-gain beam-steerable antennas, have an imbalance in response time because of different alignment of LC molecules during the rise and decay times. By separating the metal layers in contact with the LC layer and applying four bias voltages, we generated both horizontal and vertical electric field. Accordingly, the decay time was improved by unifying the methods in which the LC molecules were aligned during the rise and decay times. Our measurements confirm that the decay time can be reduced to approximately 1/3 compared to the conventional structure, indicating the possibility of resolving the imbalance.

Analysis of On-Antenna Power Combining for Realization of Pattern-Reconfigurable Multifeed Microstrip Antennas

This article explores an on-antenna power combining concept for multifeed microstrip antennas. We incorporated different radiation modes of multifeed antennas, thereby optimally exploiting the given space of a single radiator. The analytical cavity model is revisited to facilitate analysis of the on-antenna power combining mechanism in planar topologies. The analytical modeling is first aimed to apply to conventional patch structures and offers an in-depth design methodology. As the analytical method is facing limitations in irregular-shaped antennas we proposed a reliable and computationally cheap numerical method based on the eigenvalue analysis of the scattering matrix. The proposed method can be used to extract the optimum excitation and impedance of each port of resonant-type multifeed antennas. Due to the proposed numerical method, one can examine the excitation vector and the active impedance values for different radiation modes of multifeed antenna concurrently. Next, the reliability of the solutions of the proposed numerical method is evaluated against the analytical solutions through some examples. A multifeed structure not only can furnish on-antenna power combining but also assist with tailoring reconfigurable antennas. Finally, a practical planar radiator topology featuring multifeed excitations exhibiting a high-gain reconfigurable antenna with sum and difference patterns is devised.

High-Gain Transmissive Array Antenna with Broadband Cross-Polarisation Isolation

A transmissive metal unit working in the range of 18 GHz-29 GHz is designed in this paper. This is a three-layer metal circular slit unit with promising cross-polarization isolation properties. A planar lens antenna with a center operating frequency of 28 GHz is designed based on the unit utilizing a phase compensation algorithm. The numerical simulation results show that the antenna can improve the gain of the horn antenna from 22.9 dB to 25.6 dB, which can effectively advance the development of 5G communication technology.

Endfire Circularly Polarized Planar Antennas: A review of their development

This article reviews and summarizes the developments of endfire circularly polarized (CP) planar antennas. The difficulty in designing such antennas is that there is not a large radiating aperture on a substrate to produce strong enough vertically polarized (VP) radiation to match the horizontally polarized (HP) radiation. Mainly based on the structures of radiation and feeding, endfire CP planar antennas are classified into several groups. The mechanisms of these antennas are identified, their performance is compared with tables, and the relation between performance and structures is explored. It is indicated that the distance between the phase centers of VP and HP radiators is a crucial parameter to affect the axial ratio (AR) bandwidth and beamwidth of an endfire CP antenna. It is addressed that it is essential to have strong VP radiation for a high-gain and wideband endfire CP antenna when substrates are thin.

High-Gain Dual-Circularly Polarized Leaky-Wave Antenna for Point-to-Point Communications

In this letter, a high-gain low-profile dual-circularly polarized (CP) leaky-wave antenna (LWA) with fixed beam is presented. The proposed LWA comprises only two-layered substrates, in which the top layer constructs the annular LWA array while the bottom layer realizes the feeding network. To obtain the fixed beam, the differential excitation generated by the proposed coupler is employed. Furthermore, the dual-CP feeding network provides two sequentially rotated phase excitations for the slot coupler, then the dual-CP radiation with fixed beam is realized. The profile height of the proposal is only 0.15 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> at 28 GHz, while the measured peak gain is up to 27.2 dBic; this could be attractive for point-to-point communications.

Design of Low-Profile Transmitarray Antennas With Wide Mechanical Beam Steering at Millimeter Waves

Mechanical beam steering using a single transmitarray (TA) can be a cost-effective solution for a high-gain antenna with wide-angle scanning. Elevation scanning can be achieved by a linear displacement of the feed in the focal plane parallel to the aperture of diameter D. When designing compact terminals with a short focal length F and with high gain, the aberrations caused by this mechanical movement become the main limiting factor for the maximum scanning range. This work presents a novel design method for devising the TA phase correction with an even distribution of these aberrations among all beam directions. A significant improvement in the scanning performance is achieved when compared with the conventional single-focus phase correction approach. To validate the proposed approach, we consider a TA design at the Ka-band (30 GHz) F/D <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cong ~0.34$ </tex-math></inline-formula> . A multifocal TA design was manufactured using 3-D printed unit cells. To highlight the proposed concept, the antenna configuration is stripped to the bare minimum: a perforated dielectric slab with in-plane mechanical movements in front of an open-ended standard waveguide used as feed. This antenna scans up to 50°, with a gain of 25 dBi at 30 GHz, 2.5 dB of scan loss, sidelobe level (SLL) <–10, and 1 dB bandwidth of 6.7%.

Wideband, High-Gain, and Compact Four-Port MIMO Antenna for Future 5G Devices Operating over Ka-Band Spectrum

In this article, the compact, ultra-wideband and high-gain MIMO antenna is presented for future 5G devices operating over 28 GHz and 38 GHz. The presented antenna is designed over substrate material Roger RT/Duroid 6002 with a thickness of 1.52 mm. The suggested design has dimensions of 15 mm × 10 mm and consists of stubs with loaded rectangular patch. The various stubs are loaded to antenna to improve impedance bandwidth and obtain ultra-wideband. The resultant antenna operates over a broadband of 26.5–43.7 GHz, with a peak value of gain &gt;8 dBi. A four-port MIMO configuration is achieved to present the proposed antenna for future high data rate devices. The MIMO antenna offers isolation &lt;−30 dB with ECC of &lt;0.0001. The antenna offers good results in terms of gain, radiation efficiency, envelop correlation coefficient (ECC), mean effective gain (MEG), diversity gain (DG), channel capacity loss (CCL), and isolation. The antenna hardware prototype is fabricated to validate the performance of the suggested design of the antenna achieved from software tools, and good correlation between measured and simulated results is observed. Moreover, the proposed work performance is also differentiated with literature work, which verifies that the suggested work is a potential applicant for future 5G compact devices operating over wideband and high gain.

A Compact Size Antenna for Extended UWB with WLAN Notch Band Stub

An ultra-wideband (UWB), geometrically simple, compact, and high-gain antenna with a WLAN notch band is presented for future wireless devices. The antenna is printed on the top side of the Rogers RT/Duroid 5880 substrate and has a small dimension of 10 mm × 15 mm × 0.254 mm. The primary radiator of the proposed coplanar waveguide-fed monopole antenna is comprised of a rectangular-shaped structure initially modified using a slot, and its bandwidth is further enhanced by loading a Y-shaped radiator. As a result, the antenna offers a –10 dB impedance matching bandwidth of 11.55 GHz ranging from 3–14.55 GHz, covering globally allocated C-, S-, and X-band applications. Afterward, another rectangular stub is loaded in the structure to mitigate the WLAN band from the UWB spectrum, and the final antenna offers a notched band spanning from 4.59 to 5.82 GHz. Moreover, to validate the simulated results, a hardware prototype is built and measured, which exhibits good agreement with the simulated results. Furthermore, the proposed work is compared to state-of-the-art antennas for similar applications to demonstrate its design significance, as it has a compact size, wider bandwidth, and stable gain characteristics.

Design of high gain base station antenna array for mm-wave cellular communication systems

Millimeter wave (mm-Wave) wireless communication systems require high gain antennas to overcome path loss effects and thereby enhance system coverage. This paper presents the design and analysis of an antenna array for high gain performance of future mm-wave 5G communication systems. The proposed antenna is based on planar microstrip technology and fabricated on 0.254 mm thick dielectric substrate (Rogers-5880) having a relative permittivity of 2.2 and loss tangent of 0.0009. The single radiating element used to construct the antenna array is a microstrip patch that has a configuration resembling a two-pronged fork. The single radiator has a realized gain of 7.6 dBi. To achieve the gain required by 5G base stations, a 64-element array antenna design is proposed which has a bore side gain of 21.2 dBi at 37.2 GHz. The 8 × 8, 8 × 16, and 8 × 32 antenna array designs described here were simulated and optimized using CST Microwave Studio, which is a 3D full-wave electromagnetic solver. The overall characteristics of the array in terms of reflection-coefficient and radiation patterns makes the proposed design suitable for mm-Wave 5G and other communication systems.

Multimarker Approach to Evaluate the Exposure to Electromagnetic Fields at 27 GHz on Danio rerio Larvae

5G technology aims to satisfy several service requirements, leading to high data-rate connections and lower latency times than current ones. 5G systems use different frequency bands of the radio wave spectrum, taking advantage of higher frequencies than previous mobile radio generations. To guarantee capillary radio coverage, it will be necessary to install a huge number of repeaters since electromagnetic waves at higher frequencies, and especially microwaves at higher bands, exhibit lower capacity to propagate in free space. Since the introduction of this new technology, there has been growing concern about possible harmful effects on human health. The aim of this study was to investigate the possible short-term effects induced by 5G-millimeter waves on the embryonic development of zebrafish (Danio rerio). Fertilized eggs were exposed to 27 GHz using a non-commercial high-gain pyramidal horn antenna, and several endpoints were monitored every 24 h. As a result, exposure to electromagnetic fields at 27 GHz caused no significant impacts on mortality or on morphology since the exposed larvae showed normal detachment of the tail, the presence of a heartbeat, and well-organized somites. Exposure to 27 GHz caused an increase in the heart rate in exposed embryos compared to that in the control group at 48 h. However, this increase was not observed at 72 and 96 h. Finally, very weak positivity regarding exposed larvae was highlighted by immunohistochemical analysis.