Wide Beamwidth Research Articles

Novel corrugated rectangular dielectric resonator antenna with wide half power beam width

ABSTRACT In this work, a dielectric resonator antenna element is corrugated in a specific way, which led to increase its half power beam width (HPBW). The HPBW of the antenna is investigated for different values of corrugation depth and it has been concluded that HPBW can be increased by increasing this depth. By embedding periodic grooves in the DRA walls, it is possible to adjust the radiation intensity ratio of the upper wall to the side walls. By increasing this ratio, the HPBW of the antenna can be increased. To confirm the concept of beam widening method, a prototype of the corrugated DRA is fabricated and measured. Measured results show an impedance bandwidth of 23% (3.8–4.8 GHz). The measured E- and H-plane HPBWs at 4.1 GHz are 137° and 123°, respectively. Measured and simulated results are in a good agreement.

Multi-users different rates visible light communication system for sixth-generation multimedia applications

The two most significant issues that communication engineers have been confronting since the development of fifth-generation wireless networks are bandwidth increase and energy-saving techniques in data transmission. We present an innovative solution for utilizing a multi-user different-rates visible light communication (VLC) system for sixth-generation applications. Such a solution takes advantage of orthogonal frequency division multiple access (OFDMA) with orthogonal codes as multiple access communication networks. For the achievement of energy-saving and wide beam width of the optical source, the light emitting diode is often used as a transmitter. Furthermore, one of the most popular orthogonal codes in use is the double length modified prime code, which has been utilized for enhancing communication network security and network capacity. Most importantly, the performance of the network is evaluated versus the number of users, taking into consideration the amount of noise resulting from the multiple access interference, shot noise, and thermal noise. The error vector magnitude has also been considered for performance analysis and results. Significantly, the obtained results show the possibility of accommodating 110 users at an error rate of no more than 10 − 9 and a data rate per user of 50 Gbps.

Millimeter-wave Wideband High-isolation Antenna Array Based on End-fire Magnetoelectric Dipole Antenna for 5G Applications

In this paper, a millimeter-wave (mmW) wideband high-isolation wide-angle scanning antenna is presented. The end-fire magnetoelectric (ME) dipole with wideband impedance characteristic and wide beamwidth is selected. Based on the ME dipole, a 1×4 subarray with a stripline feed network is constructed to get higher antenna efficiency. Then, four 1×4 subarrays are adopted to form a 4×4 array to realize the wide-angle scanning performance. Furthermore, to get better isolation between the subarrays, the beam is tilted on the non-scanning plane; in addition, the resonant split rings are added on the background of the subarrays. With these two measures, the isolation between the subarrays can be effectively reduced, with more than 20 dB over the entire bandwidth. Owing to the wide beamwidth of ME dipole and high isolation between the subarrays, the 4×4 array can obtain the wide-angle scanning characteristic. The final antenna covers an operating bandwidth of 19.5% (24.25-29.5 GHz) with return loss more than 10 dB, which can meet the band in the 5G standard. The beam can scan approximately ±55∘ with a realized gain reduction under 3 dB within the wide operating bandwidth. Also, the simulated radiation efficiency of the array is more than 77% over almost the entire band. The antenna will be a potential candidate to be applied in 5G applications.

The Use of Machine Learning Techniques for Optimal Multicasting in 5G NR Systems

Multicasting is a key feature of cellular systems, which provides an efficient way to simultaneously disseminate a large amount of traffic to multiple subscribers. However, the efficient use of multicast services in fifth-generation (5G) New Radio (NR) is complicated by several factors, including inherent base station (BS) antenna directivity as well as the exploitation of antenna arrays capable of creating multiple beams concurrently. In this work, we first demonstrate that the problem of efficient multicasting in 5G NR systems can be formalized as a special case of multi-period variable cost and size bin packing problem (BPP). However, the problem is known to be NP-hard, and the solution time is practically unacceptable for large multicast group sizes. To this aim, we further develop and test several machine learning alternatives to address this issue. The numerical analysis shows that there is a trade-off between accuracy and computational complexity for multicast grouping when using decision tree-based algorithms. A higher number of splits offers better performance at the cost of an increased computational time. We also show that the nature of the cell coverage brings three possible solutions to the multicast grouping problem: (i) small-range radii are characterized by a single multicast subgroup with wide beamwidth, (ii) middle-range deployments have to be solved by employing the proposed algorithms, and (iii) BS at long-range radii sweeps narrow unicast beams to serve multicast users.

A 3-D-printed Wideband Millimeter-Wave Fan-Beam Antenna With Flat-Top, Sharp Cutoff Patterns, and Beam-Scanning Capability

This article presents a wideband millimeter-wave (MMW) fan-beam antenna with a flat-top, rapid cutoff radiation pattern, and beam-scanning capability through the use of 3-D printer technology. The proposed antenna, consisting of several periodic structures that composed of dielectric and air slabs, is fed by the WR-28 waveguide. By tuning the ratio of dielectric slab thickness to that of unit cell, the effective permittivity is controlled flexibly. The phase distribution on the aperture is carefully modulated in this way to devote high-quality flat-top patterns. In addition, the beam can be continuously scanned within the angle range of 70° without scarifying the gain performance dramatically. For demonstration, a prototype with boresight fan-beam radiation is first fabricated and measured. The proposed antenna achieves an impedance bandwidth of 50% from 24 to 40 GHz. Measured results indicate that the wide beamwidth patterns show flat-top and sharp cutoff performance. Both E-plane and H-plane patterns draw low cross polarization (smaller than −22 dB). Another prototype, aiming to verify the beam-scanning capability, is investigated. Measured results demonstrate the performances of the proposed antennas. With such favorable electrical performance, simple structure, and low-cost fabrication, the proposed antenna is a promising candidate for 5G MMW and satellite applications.

A low‐profile planar end‐fire broadband antenna with wide beamwidth

AbstractA low‐profile planar end‐fire broadband antenna with wide beamwidth is presented. The proposed antenna consists of a grounded coplanar waveguide (GCPW), an antipodal dipole, and a pair of directors. A transition from the GCPW to the substrate integrated waveguide (SIW) with tapered coupling slots is designed to achieve a wide impedance bandwidth. Wide beamwidths of the proposed antenna are realised through the antipodal dipole with bilaterally symmetrical sector arms. A pair of directors are symmetrically located on both sides of the sector arms to further widen the beamwidth. An antenna prototype operating at Ka band with a size of 2.18 λ0 × 0.77 λ0 × 0.06 λ0 (λ0 is the wavelength of the centre frequency) is fabricated based on the conventional printed circuit board process. The measurement results show that the reflection coefficient is lower than −12.5 dB in the frequency range of 32.2–37.0 GHz. At 35.5 GHz, the peak gain is 3.8 dBi, and the half‐power beamwidths (HPBWs) in E‐plane and H‐plane are 116° and 215°, respectively.

Periodic Asymmetric Trapezoidal Perturbation Microstrip Antenna for Millimeter-Wave Automotive Radar Sensors

This article presents a new design and experimental verification of a broadband wide-beam microstrip array antenna for short-range automotive radar sensors. The antenna is designed based on a pure microstrip transmission line, by inserting short inverted trapezoidal stubs alternately on both sides of the microstrip line periodically to generate a trapezoid-cascaded electric field, which enables the proposed antenna to radiate effectively. Therefore, the proposed antenna has the advantage of a simple structure. The antenna has a larger effective radiation aperture, which leads to a smaller quality factor, so the antenna has a broad bandwidth of 13% (74.02–85.08 GHz), completely covering 76–81 GHz automotive radar frequency band. The peak gain is up to 10.4 dBi. Based on the proposed antenna, a three transmitting antennas and four receiving antennas (3T4R) multiple-input-multiple-output (MIMO) radar antenna array is designed. To reduce the influence of strong surface waves on the radiation pattern, a design conception of a dummy array with an absorbing load is introduced. The array antenna of each transmitting (TX)/receiving (RX) channel can achieve a wide half-power beamwidth (HPBW) of 120° in the azimuth plane. Besides, the MIMO array exhibits good consistency, with the absolute amplitude error of TX-RX channels less than 3 dB and the phase error less than 20° in the azimuth plane.

Dual-Band Antenna With Omni/Unidirectional Radiation Realized by Single Metal Plate

This letter proposes a novel dual-band antenna realized by single metal plate. The basic antenna structure is a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</i> /2 dipole with omnidirectional radiation pattern, operating at 1.4 GHz. To obtain a second working band with directional radiation, this dipole is folded, therefore forming an open-end slot in-between its two arms, serving as a magnetic dipole. Then, by properly exciting these two dipoles with 90° phase difference in time domain, the inherent 90° phase difference formed between the slot and the electric dipole is cancelled. As a result, cardioid radiation pattern is obtained at 3.7 GHz. The measured results show that an impedance bandwidth of 10.3% and 18.1% is achieved at these two bands, respectively, with omnidirectional radiation pattern at 1.4 GHz band, and unidirectional radiation with at 3.7 GHz with wide beamwidth.

Circularly Polarized Cross-Dipole Antenna for UHF RFID Readers Applicated in the Warehouse Environment

In this paper, we proposed a broadband circularly polarized antenna with wide beamwidth. The main structure of the proposed antenna is a combined cross-polarized dipole antenna with four metal arms feeding by a single coaxial cable and two 90° phase delay lines. In order to attain a wide beamwidth antenna performance that can be used in a warehouse environment, we innovatively bent the metal arms and added a metal plane at a specific location to gain maximum beamwidth and the highest achievable gain. Especially, the application of folded metal arms not only reduce the space size of antenna, but also possess good axial ratio characteristic. The measurement illustrates that the antenna prototype achieves S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> < -10 dB impedance bandwidth (IBW) of 40% (820 - 1230 MHz), a 3-dB axial ratio bandwidth (ARBW) of 7.3% (895 - 970 MHz), and a maximum half-power beamwidth (HPBW) of 104° (@915 MHz). In addition, the good radiation characteristics of a gain of 6.33 dBic and an average radiation efficiency of 76.3% were measured in the operating bandwidth, in which make the antenna a good candidate for the hasty logistics radio frequency identification (RFID) system.

Study of Phantom Length Correction for kV-Cone Beam CT Dose Evaluation Method Using Farmer-type Ionization Chamber and Cylindrical Phantom

In this study, we investigated the necessary phantom length for dose evaluation of kV-CBCT mounted on the linear accelerator using a Farmer-type ionization chamber and cylindrical PMMA phantom, which many radiotherapy facilities own. Furthermore, a phantom length correction factor was proposed to compensate for the lack of scattered radiation contributed from the craniocaudal direction due to the inadequate phantom length. The air-absorbed dose at the center of a cylindrical PMMA phantom measured by a Farmer-type ionization chamber indicated that the contribution of scattered radiation saturates when the phantom length is 300 mm or longer. The phantom length correction factor was calculated from an approximate curve showing the relationship of the charge ratio measured using phantoms of 300 mm and 150 mm in length to the X-ray beam width. The air-absorbed dose measured with the 150-mm length phantom, corrected by the phantom length correction factor, showed a 1.61% dose difference from the air-absorbed dose measured with the 300-mm length phantom. In this study, the air-absorbed dose at the center of the phantom could be estimated over a wide X-ray beam width only using a 150-mm length cylindrical PMMA phantom. The method proposed in this study could be used in any radiation therapy facility.

On-Glass Grid Structure and Its Application in Highly-Transparent Antenna for Internet of Vehicles

In this paper, a low-cost printed-circuit-board (PCB) technology-based on-glass grid structure and its application in highly-transparent antenna for the internet of vehicles are presented. Firstly, a diamond-shaped grid structure on a glass substrate for high optical transparency (OT) is studied. To show the feasibility, two equal-length co-planar waveguide (CPW) transmission lines (TMLs) with conventional solid and the proposed grid structure are compared. It is found that identical electrical length and comparable performance of the two TMLs are obtained. The relationship between OT and electrical performance is also derived. In the next place, the application of the on-glass grid structure in the highly-transparent antenna design is explored, and the detailed fabrication process is presented. Finally, for demonstration, a CPW-fed wideband end-fire on-glass highly-transparent antenna covering the 5.8-GHz vehicle-to-vehicle band is designed, fabricated, and measured. Ultra-broad impedance bandwidth of 64.6% (3.08–6.02 GHz), wide H-plane beamwidths of over 146°, high antenna efficiencies of over 71.9%, and high OT of 69.8% are achieved. Easily fabricated with mature PCB technology and integrated on the vehicle windows, the proposed structure provides a low-cost highly-transparent solution for the internet of vehicles.

Beamwidth Enhancement of Microstrip Antennas Using Capacitive Via-Fence Loading

In this paper, a general approach to enhance the beamwidth of microstrip antennas is proposed for wide beam coverage in both E- and H-planes. A microstrip antenna loaded with two arrays of capacitive via fences is propounded and systematically studied. By introducing the vertical currents brought by the capacitive metalized vias, the half-power beamwidth (HPBW) is effectively broadened compared with the regular microstrip antennas. In addition, by utilizing the air medium with low loss, the microstrip antenna can be supported by the two arrays of via fences, maintaining a high radiation efficiency. To validate the proposed design, a prototype is fabricated and tested. The measurement results agree well with the simulated ones, with enhanced HPBWs of 100° and 90° in E- and H-planes, respectively. Compared with the existing 2.4-GHz antennas, the propounded antenna is with the advantages of wide beamwidth and high radiation efficiency, exhibiting the potential applications for space-limited mobile devices with wide coverage requirement.

Design and build a digital TV receiver double biquad antenna for the Greater Malang region and its surroundings

Many types of antennas can be used for digital TV receivers; in this article we try to design a double biquad antenna. This is due to a simple form, easy to make, a wide beamwidth. In designing a digital TV receiver for the Malang area, an STB device is needed, so that analog TV can still receive digital TV broadcasts. In this study, the antenna is made of copper wire, each side length: ¼ ? , with a working frequency: 650 MHz. In order to match the impedance of the 75? coaxial cable with the antenna, a balun 4:1 is required. The research place is in the Polinema Telecommunications laboratory. The test results show that the lowest return loss (RL) occurs at a frequency of F=605 MHz, namely RL: -17.8 dB, for a frequency of F=650 MHz, the magnitude of RL: -11.3 dB. The large VSWR antenna at the working frequency F: 650 MHz is 1.46. So that it can be said that it has fulfilled the antenna parameters, namely VSWR &lt; 2. It means that there is a power loss of less than 10%. The largest antenna gain occurs at a frequency: 400 MHz namely: 14.85 dB,. While the average gain of the antenna is 2.21 dB. The antenna radiation pattern is omni directional. The double biquad antenna is very good for use as a digital TV receiver for the Greater Malang area, either without using a reflector or with a reflector.

Design of a Wide-Bandwidth, High-Gain and Easy-to-Manufacture 2.4 GHz Floating Patch Antenna Fed with the Through-Wire Technique

This paper presents a feasibility study for designing a floating patch antenna structure fed with a probe from a microstrip. The main premise is to eliminate the dielectric in the patch design, which is equivalent to having an air dielectric and leads to the necessity of proper support to fasten the patch in the air. The novelty of this paper is that this new device, apart from being fed with the though-wire technique directly from the microstrip line, has to be, by design, robust and easy to manufacture, and, at the same time, it has to present, simultaneously, good values in all of the performance indexes. A prototype has been designed, manufactured, and measured with good performance results: a bandwidth higher than 10% around 2.4 GHz, a radiation efficiency higher than 96%, a 9.63 dBi gain, and a wide beamwidth. The main advantages of this prototype, together with its good performance indexes, include its low fabrication cost, low losses, light weight, robustness, high integration capability, the complete removal of the dielectric material, and the use of a single post for feeding the patch while simultaneously fixing its floating position.

Design of a wide beamwidth spherical conformal antenna array for ship‐borne applications

AbstractThis study presents the phase setting method for a spherical conformal antenna array to achieve a wide beamwidth circularly polarized radiation pattern. A dodecahedral spherical array was fabricated and measured to validate the phase setting method. The array adopts a regular dodecahedron spatial distribution structure composed of 11 dual‐polarization elements. By exciting 11 elements simultaneously with designed phase distributions, the proposed spherical array can achieve a wide beamwidth of more than 210° with circular polarization by selecting the radius of the dodecahedron. In addition, the power division network of the array is designed and processed, and the feed network is simplified by rotating the antenna element port to control the phase. Measurements agree well with the simulations. The measured results show that the proposed spherical antenna array achieves a half‐power beamwidth of more than 210° and an axial‐ratio beamwidth of larger than 240°.

Integrated Module Antenna for Automotive UWB Application

In this paper, an integrated module antenna for automotive UWB application is proposed. The target applications of the proposed antenna are for UWB localization and rear passenger detection. The purpose of this work is to design an antenna with a wide and narrow beamwidth that can be attached to the exterior/interior of a vehicle for simultaneous UWB localization and a rear passenger detection sensor with a single-module substrate in a limited space. For UWB localization, the wide beam coverage is required so the antenna receives the signal from any incident angle in horizontal plane. Meanwhile, the rear passenger detection sensor requires a relatively narrower beamwidth than the localization antenna for accurate detection within the vehicle. To integrate two different antennas into a single compact module substrate, modified ground stubs and parasitic radiators are applied. The size of the entire antenna structure is 35 mm × 65 mm × 1.156 mm. The proposed antenna designed on the multi-layered FR-4 substrate with a dielectric constant of 4.3. The bandwidth of the monopole is 6.14~8.24 GHz, and the patch array is 6.95~8.47 GHz. The isolation between the monopole and the patch array is less than −23 dBi in the target band. The performance of the proposed antenna is verified with simulation and measurement. In addition, a simulation of the proposed antenna with the real vehicle model is also conducted to verify the feasibility on actual vehicle. Based on this work, the proposed antenna can be applied to multi-function antenna for automotive application with low cost.

Design and Study of the Performance of Patch Antenna with Double C Slot for MIMO-OFDM Based Communications Systems for Media Technology

Mobile phones, server stacks, and other high-bitrate devices demand greater bandwidth from antennas. More bandwidth means higher bitrates and more data sent. MIMO antennas simultaneously deliver and receive data. MIMO antennas can broadcast data to unreachable places with little noise. Multiple data streams and multipath propagation boost performance and data quality. Many antennas allow MIMO systems to send and receive data at regular intervals. These antennas can perform beamforming and determine a signal's 3-D route. OFDM increases bitrates at the same frequency by multiplexing without guard bands. Multiple orthogonal carrier frequencies increase data in the same bandwidth and avoid carrier distortion. Air gaps, parasitic patches, and substrate modifications are methods to increase bandwidth and beam width for patch antennas. The conventional patch pattern has been modified and refined for maximum success. This article proposes a patch antenna with double C slots. This new design features a large bandwidth, wide beamwidth, and multidirectional transmission pattern. The gain, VSWR, and reflection coefficient of this patch antenna meets the MIMO-OFDM systems with 5G standard. Hence the proposed antenna design is recommended to employ in the MIMO-OFDM system for 5G applications.

Design and Characterization of a Planar Structure Wideband Millimeter-Wave Antenna With Wide Beamwidth for Wearable Off-Body Communication Applications

This letter presents the design of a planar single-layer wideband antenna featuring wide beamwidth has well as high and stable in-band gain. The proposed antenna is a planar monopole fed by a bottom-grounded coplanar waveguide to realize wide beamwidth in both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">xz</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">yz</i> -planes. Simultaneous optimization of all adjustable antenna parameters, carried out at the full-wave electromagnetic simulation level. The constructive interference of the radiated fields resulting in impedance bandwidth of more than 2 GHz, from 27 to 29 GHz. Along with a stable realized gain (>11 dBi) in the operating frequency band. The proposed antenna maintains a directional radiation pattern in the broadside direction. Merging the radiated modes of the slots and the parasitic patch elements also extends the antenna beamwidth to roughly ±35° with respect to the broadside direction. Following a detailed theoretical analysis, the antenna is validated numerically and experimentally, both in the free space and on a human volunteer chest and arm.

Metamaterial-Based Wide-Beam Dielectric Resonator Antenna for Broadband Wide-Angle Beam-Scanning Phased Array Applications

A novel metamaterial-loaded, miniaturized, broadband, wide-beam dielectric resonator (DR) antenna is presented for low-cost wide-angle beam-scanning applications. The mushroom structure is loaded on the DR structure, so the proposed DR radiator reduces the size reduction (low profile, 0.09 &#x03BB;0) and achieves a broadened bandwidth with a dual-mode response. The realized 3 dB beam-width of the DR radiator is widened from 90&#x00B0; to 194&#x00B0; by introducing a pair of miniaturized equal-amplitude and out-of-phase Huygens sources. Owing to its compact size and wide beam-width, a five-element low-cost wide-angle beam-scanning phased array is presented by using the proposed wide-beam DR elements. The measured -10 dB impedance bandwidth covers the 5G-78 band well (3.30-3.80 GHz, 14.1 %). The realized scanning angle of the fabricated linear array can be extended from &#x00B1;36&#x00B0; to &#x00B1;65&#x00B0;, and its 3 dB beam-width scanning coverage can up to &#x00B1;90&#x00B0;. In virtue of miniaturized size, wideband, low-cost, and good beam-scanning ability, the presented element, and the resulting wide-angle beam-scanning array are promising candidates for wireless communication and low-cost phased array applications.

Auxiliary antenna design for anti‐interference of satellite communication earth station

AbstractIn this study, a novel elliptical widebeam auxiliary antenna is proposed for anti‐interference of satellite communication earth station. The wide beam width of about 180° in horizontal plane (H‐plane) is achieved by increasing the width of the substrate, reducing the size of the ground plane and adding a V‐shaped aluminum frame. And the narrow beam width of about 30° in elevational plane (E‐plane) is achieved by designing a binary element array. Only two auxiliary antennas are needed for sampling to cover interference from any azimuth direction in H‐plane. The antenna is fabricated and measured, and the results are in good agreement with simulation. The corresponding −10 dB impedance bandwidth is about 17% with maximum gain of 6.5 dBi. The 3 dB beam widths are respectively 33° and 178° in E‐plane and H‐plane. Furthermore, simulation and experiment of the proposed auxiliary antenna in interference cancelation system verify its anti‐interference performance. According to sidelobe canceler, an average interference cancelation ratio of about 27 dB is achieved.