Magneto-electric Dipole Research Articles

Wideband low‐profile magneto–electric dipole antenna stacked with patch and metasurface

AbstractHere, a novel low‐profile wideband and high‐gain magnetoelectric dipole antenna with metasurface superstrate is proposed. The magnetoelectric dipole antenna printed on single layer consists of a probe fed patch with four shorted patches arranged symmetrically. Gain enhancement is achieved by placing two side walls and metasurface superstrate with an air gap. Additional rectangular patch connected to the same probe is placed above the magnetoelectric dipole antenna within an air gap. This improves impedance bandwidth, gain and efficiency significantly. Overall profile of antenna is 0.15 λ0, which is lower compared to conventional magnetoelectric dipole antennas with a profile of 0.25λ0. The proposed antenna fabricated on FR4 substrate shows 57% of wide impedance bandwidth from 3.63 to 6.57 GHz with overall size of 1λ0 × 1λ0 × 0.15λ0. The maximum gain in the operating band is 10.2 dBi.

Modulation of antenna beam in both elevation and azimuth planes by reflective phase gradient metasurface

ABSTRACT A broadband low profile magneto-electric dipole (ME-dipole) antenna is proposed which can control the steering of the antenna beam in the elevation plane and azimuth plane. A reflective phase gradient metasurface (RPGMS) is designed to act as the partially reflecting surface of the antenna and provides two different phase shifts for it. By rotating and translating RPGMS around the center of the antenna can reshape the wavefront shape, realize beam steering with directions (, )= (±40°, 0°), (±30°, 0°), (±20°, 0°), (±20°, 90°). The results of full wave simulation are in good agreement with the measured results, the beam tilted range of ± 40° in E-plane and ± 20° in H-plane are obtained at 8 GHz. The bandwidth is between 42.5% and 48.4%, with a maximum gain of 6.29dBi.

Design of High-Gain Magneto-Electric Dipole Antenna by Loading a Magneto-Electric Dipole Director

A high-gain magneto-electric dipole (ME-Dipole) antenna has been designed by adding a ME-Dipole director on top of a conventional cavity-backed ME-Dipole antenna. The purpose of adding the ME-Dipole director is to significantly enhance the gain of the antenna. The proposed design has been both measured and simulated, with an average gain of 12.5 dBi and 12.4 dBi, respectively, demonstrating the design's high gain capabilities. Additionally, the measured and simulated impedance bandwidth (VSWR ≤ 2) are 29.21% (1.90 GHz - 2.55 GHz) and 30.70% (1.93 GHz - 2.63 GHz), respectively, confirming the wideband nature of the design. Other outstanding performance metrics, such as low cross-polarization of - 25 dB and the stable antenna gain of 11.8 ± 1.7 dBi as measured and 12.0 ± 1 dBi as simulated, have also been observed in the current design.

Analysis and Design of Dual-Polarized Millimeter-Wave Filtering Magneto-Electric Dipole Antenna

A wideband dual-polarized millimeter-wave filtering magneto-electric dipole (ME-dipole) antenna design is proposed based on a transmission line model with multiple open-circuited loads. Based on the transmission line theory, the input impedance of a quarter-wavelength open-circuited transmission line is zero. Thus, a transmission line terminated with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> open-circuited loads has <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> transmission zeros. Inspired by this conclusion, the proposed antenna structure is developed which consists of three parts: the microtrip feedlines, the ME-dipole radiator and a printed branch structure. The former three parts can be regarded as three open-circuited loads of an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> -stub-loaded transmission line model while the last part is utilized for bandwidth improvement. By optimizing the length parameters of these three parts, three antenna radiation nulls can be generated as predicted. For verification, a dual-polarized antenna is implemented. Measurement results show that the proposed antenna has an operation bandwidth of 42.1% and an average realized gain of 7.5 dBi. In addition, it has three controllable radiation nulls and a better than 16 dB out-of-band suppression level. Above features make the proposed antenna a good candidate for 5G millimeter-wave (mm-wave) applications.

A Broadband Circularly Polarized Magneto-Electric Dipole Antenna

A novel broadband low-profile circularly polarized (CP) magneto-electric (ME) dipole antenna is proposed in the paper. Sharing the same aperture, a pair of electric dipoles (E-dipoles) and a pair of magnetic dipoles (M-dipoles) are combined through four bulges in the corners of the ring. The arms of the ring work as dipole antennas, i.e., E-dipoles, while the slots formed by the ring with bulges and the central patch work as slot antennas, i.e., M-dipoles. To realize CP radiation, a pair of vacant-quarter printed rings with short-end microstrip lines are utilized to excite the dipole and slot antennas simultaneously. The measurement results indicate that a wide overlapped impedance bandwidth (IMBW) and axial ratio bandwidth (ARBW) of 2.15-3.35 GHz (1.2 GHz, 43.6%) and a low height of 0.18 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> at the center frequency of 2.7 GHz are achieved. Moreover, a high gain of 8.5-10.3 dBic and stable radiation patterns with no side lobes and low back lobes of less than -20 dB are realized for wireless communication.

A Wideband Circularly Polarized Magnetoelectric Dipole Transmitarray Antenna Based on Element Rotation Techniques

In this article, a wideband circularly polarized (CP) transmitarray antenna (TA) operating at the X-band is reported. A receive-and-transmit type anisotropic magneto-electric (ME) dipole is proposed as the broadband TA unit cell with low-insertion-loss characteristic. By employing the element rotation methodology, the continuous transmissive phase compensation is achieved, thus producing the high-gain directive radiation. The 16×16-element CP TA implemented using the designed ME-dipole structure not only possesses wide measured 1-dB and 3-dB gain bandwidths of 24.5% (10.75-13.75 GHz) and 33.3% (10-14 GHz), respectively, but also yields a notable 1.5-dB axial ratio (AR) bandwidth of 37.4% (9.25-13.5 GHz). Peak gain of 24.3 dBic and aperture efficiency of 46% are experimentally measured. The proposed CP TA shows attractive advantages including wide bandwidth, high-purity circular polarization and stable gain, which makes it a competitive candidate for many applications including satellite communication (SatCom).

An Ultrawideband Compact Magneto-Electric Dipole Antenna and Its Coupled Array

A novel magneto-electric dipole antenna with compact structure and unidirectional radiation is proposed. The electrical connection between the U-shaped floor and the electric dipole (E-dipole) was cut off to reduce the profile height, and the straight-line edges of the original dipoles were replaced with an arc-shaped one to stabilize the VSWR. Furthermore, when the antenna element is employed as the coupled array unit, the altering of the element number and the way the array is assembled has no significant impact on the radiation performance, which is almost the same as that of a single antenna. The modified prototype of a 2×2 array with the dimension of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.33 \lambda_{L} \times 0.28 \lambda_{L} \times 0.10 \lambda_{L}$</tex-math></inline-formula> is fabricated and measured. Results indicate that the antenna array exhibits a band ratio of 30.9 with VSWR≤ 2.3 in 98 MHz-3.03 GHz, realized gain of 4.1-14.9 dBi and unidirectional pattern with SLL<-10 dB from 98 to 700 MHz.

A Wideband Full-Metal Sidewall-Loaded Magnetoelectric Dipole Array Based on Combined Ridge and Groove Gap Waveguides in the Q-Band

A wideband full-metal sidewall-loaded magnetoelectric (ME) dipole array antenna fed by combined ridge-groove gap waveguide is proposed. Three promising full-metal aperture-coupled 2×2-element ME-dipole subarrays are investigated and compared in detail. By introducing sidewalls around the metal pillars and increasing their height to 0.36λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , the bandwidth of the subarray is substantially enhanced to 33% for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> < -15 dB. An eigenmode analysis is performed to explain and validate the broadband property of the proposed subarray with taller pins and sidewalls. The combined ridge gap waveguide and E-plane groove gap waveguide are employed in the feeding layer for a compact array as well as for lower losses and better isolation between the gap waveguides. Wideband ridge-to-groove (RG) and groove-to-ridge (GR) junctions are designed using stepped transformers for bandwidth enhancement. For verification, an 8×8-element sidewall-loaded ME-dipole array is designed and fabricated by computer numerical controlled (CNC) milling technique in the Q-band. The bandwidth for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> < -10 dB is widened to 35.9% from 34.5 to 49.4 GHz. From 34.3 GHz to 34.7 GHz and 35.6 GHz to 48.7 GHz, the antenna efficiency is better than 75%, with a bandwidth of 32.5%. The proposed design is attractive for wideband and higher-frequency wireless applications.

Miniaturized Dual-Wideband Millimeter-Wave Filtenna in Package for 5G Applications

This letter presents a miniaturized dual-wideband millimeter-wave (mm-wave) antenna in package with filtering function. The proposed antenna mainly consists of four radiation patches and metallized vias. By introducing a pair of shorting pins underneath each radiation patch, the proposed antenna realizes dual-band operation in different modes. The upper band operates in the magnetoelectric dipole mode, while the lower band radiates through a new magnetic dipole. Besides, a radiation null is generated in-between the two operating bands to suppress signals. Furthermore, another pair of shorting pins is loaded on both sides of the probe, which generates two radiation nulls in the upper stopband. The dimensions of antenna are only 0.28 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ_l</i> × 0.28 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ_l</i> × 0.075 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ_l</i> at 24 GHz. To verify the proposed approach, a prototype of 1×4 array is fabricated using a high density interconnection (HDI) process. The measured −10 dB bandwidth of the array covers 24−30 GHz and 37−43.5 GHz with an average gain of 8 dBi and 9.1 dBi, respectively. Besides, three radiation nulls are formed, suppressing the out-of-band gain by more than 13dB. The proposed antenna with such superior performance demonstrates great potential for millimeter-wave applications.

A stacked dielectric magnetoelectric dipole antenna with embedded ceramics

Abstract A stacked dielectric magnetoelectric antenna with embedded ceramics (SDMEA-EC) is proposed. The antenna consists of a stacked dielectric resonator antenna with embedded ceramics and a leaf-shaped electric dipole (LSE-Dipole). To improve the performance of the magnetoelectric dipole antenna, a novel verification method is proposed by analyzing equivalent magnetic currents to meet the Huygens element principle. The stacked structure with embedded ceramics is helpful for expanding the impedance bandwidth. The electric dipole not only participates in the radiation but also is a part of the feed network, which simplifies the overall structure. The prototype of the proposed stacked dielectric resonator magnetoelectric antenna achieves an impedance bandwidth of 20.2 % in the high frequency band (5.35 GHz–6.55 GHz) and 13.4 % in the low frequency band (4.54 GHz–5.19 GHz), an over 6.7 dBi gain, and a cross-polarization discrimination (XPD) of greater than 30 dB.

A wideband magnetoelectric dipole antenna for 4G/5G communication

AbstractIn this letter, a wideband magnetoelectric (ME) dipole antenna for 4G/5G communication is proposed. The bandwidth of the antenna is greatly enhanced by loading two pairs of metallic circular loops on the planar electric dipole. With the loops, the antenna impedance bandwidth in terms of 10 dB is improved from 48.3% (1.98–3.24 GHz) to 86.8% (1.465–3.71 GHz), that is, 79.7% bandwidth enhancement is achieved. The surface current of the proposed antenna is analyzed in detail. It shows that when the length of the loops approaches half a wavelength, the loops contribute new resonant modes, thereby increasing the impedance bandwidth. A prototype is fabricated and measured. The measured results are in good agreement with the simulated counterparts. Meanwhile, the antenna gain ranges from 7.42 to 12.8 dBi across the operational frequency region. Stable radiation patterns with low crosspolarization levels are obtained in both E‐ and H‐plane.

Impact of dielectric substrate on the performance of an 8 × 8 magneto-electric dipole phased array antenna for 5G mmWave applications

The impact of the substrate dielectric material on the performance of a wideband magneto-electric dipole (MED) phased array antenna is systematically studied in this article. Four commercially available dielectric substrates for mmWave applications, i.e., Rogers RO 5880, RO 3003, RO 4350B, and Panasonic Megtron-6, are considered in the design investigation of the proposed MED phased array antenna. First, the influence of the dielectric constant on the operating frequency of the unit cell MED antenna is explored in the broadside direction (θ = 0°). Second, the scanning impedance is assessed at various scanning angles for both E- and H-plane scanning. Finally, the radiation performance of the proposed design of a finite 8 × 8 MED phased array antenna is examined. This study gives a foundational understanding of the impact of dielectric characteristics on the performance of MED phased arrays. The analysis revealed that the MED phased array antenna based on substrates with a higher dielectric constant exhibited a smaller scanning angle than the substrate with a lower dielectric constant. The findings may serve as practical guidelines for selecting the dielectric substrates for the 5G mmWave phased array antenna in order to adapt their design to an application’s specifications.

Dual-Wideband Dual-Polarized Magnetoelectric Dipole Antenna for Sub-6 GHz Applications

This letter presents a dual-wideband dual-polarized magnetoelectric dipole (ME) antenna, which works at the prominent frequency bands of 1.7 - 2.7 GHz and 3.3 - 5.0 GHz in Sub-6 GHz. A cross ME dipole excites dual-polarized radiation, and a cross-strip under the cross-dipole embeds a notched band from 2.7 - 3.3 GHz. Further, a cross-patch above the cross-dipole and a metal baffle around the ground improve the wideband impedance matching and stable the radiation pattern. As a result, a prototype of the proposed antenna is fabricated and measured. The measured results exhibit dual-wideband and dual-polarized characteristics of 1.66 GHz - 2.6 GHz (44.13%) and 3.12 GHz - 5.08 GHz (47.8%), 1.74 GHz - 2.64 GHz (41.09%) and 3.34 GHz - 5.08 GHz (42.08%), and the realized gains of 7 dBi and 9 dBi for the two ports, respectively. The proposed antenna is state-of-the-art for base-station applications in Sub-6 GHz.

A Low-Profile Dual-Polarized Substrate Integrated Magneto-Electric Dipole MIMO Antenna

A magneto-electric dipole (MED) MIMO antenna with low-profile, dual-polarized, and substrate integrated properties is proposed. The antenna element is composed of four fan-shaped patches lying on the radiation plane and four vertical metal vias linking the patches and the ground. Compared with the common MED antennas, the proposed MED antenna element has a lower profile of 0.1λ. Besides, it is fed by microstrip lines via two orthogonal H-shaped slots, resulting in a broad impedance bandwidth of 40% (3-4.5 GHz) and a steady gain in the entire operational band. The ports isolation is higher than 27 dB, the cross-polarization discrimination (XPD) is higher than 37 dB, and the measured radiation efficiency is greater than 70%. Furthermore, four antenna elements are utilized to form a MIMO antenna, which can obtain better ports isolation characteristics under the condition that the element spacing is half wavelength. Finally, the MIMO antenna is simulated, fabricated and measured. The results verify the rationality of the design.

Filtenna-Filter-Filtenna-Based FSS With Simultaneous Wide Passband and Wide Out-of-Band Rejection Using Multiple-Mode Resonators

A novel Filtenna-Filter-Filtenna (FA-F-FA)-based frequency selective surface (FSS) technique is proposed using multiple-mode resonators (MMRs). Based on this method, a bandpass FSS with simultaneous wide passband and wide out-of-band rejection is validated. The MMR unit cell consists of two back-to-back magneto-electric (ME-) dipole antennas and a filter-embedded GND plane. Four modes are analyzed and used to acquire a wide passband of the FSS. At the same time, wide out-of-band rejections in both lower and upper bands are controlled by the filter-embedded GND plane with four rotationally symmetric quarter-wavelength transmission lines (QWTLs). Moreover, the GND plane plays a crucial role in the impedance matching of the proposed FSS. As a result, four transmission poles (TPs) and three transmission zeros (TZs) of the proposed FSS can be obtained, leading to a fourth-order filtering response and wide out-of-band rejection. An equivalent circuit model, current distributions, and electric field distributions are introduced to illustrate the working mechanism of the FSS. Finally, the proposed FA-F-FA-based FSS with a 50.2% 3-dB fractional bandwidth ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FBW</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3dB</sub> ) in the passband, 53.5% and 119.2% of the 20-dB fractional bandwidth ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FBW</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20dB</sub> ) respectively in the lower and upper rejection bands is achieved. The S-parameters are stable under an oblique incident angle of 50 degrees. The measured and simulated results are in good agreement. In addition, the proposed FSS has the advantages of low profile, assembly free, and dual-polarization application, which verify the versatility of the FA-F-FA-based MMR FSS.

Gain enhancement for low‐profile broadband dual‐polarized magnetoelectric dipole using impedance surface walls

AbstractA broadband dual‐polarized magnetoelectric (ME) dipole is proposed with gain enhancement by impedance surface walls (ISWs). The proposed antenna has a dimension of 140 × 140 × 45 mm3 (0.4 × 0.4 × 0.12 λ3) and operates from 0.87 to 3.0 GHz (110%), which can be applied on the on board UWB communications. The ISWs are designed for the band from 2.6 to 3.0 GHz to counter the high‐mode radiated waves of the ME dipole while maintaining the size of the antenna. The proposed antenna is fabricated and measured, and there is a good agreement between the simulated results and the measured ones. Compared to the antenna without ISWs, the gains of the proposed design are enhanced at 4.5 dBi at 2.6 GHz and 3 dBi at 3.0 GHz.

Wideband Circularly Polarized Magneto-Electric Dipole Antenna Array with Metallic Walls for Millimeter-Wave Applications

This work proposes a new circularly polarized (CP) 4 × 4 magneto-electric (ME) dipole antenna array using metallic walls for 28 GHz band applications. The ME dipole element is surrounded by eight metallic walls and is excited fed by microstrip line. By introducing metallic walls, the 3-dB axial ratio (AR) bandwidth of the element is increased from 23% to 36.5%. The 4 × 4 array is fed by a simple 1-to-16 microstrip power divider. In contrast to the conventional substrate integrated waveguide (SIW) power divider using two layers, the proposed microstrip divider only needs one substrate layer. The experimental 3-dB AR bandwidth of the array achieves 30.1%, ranging from 22.5 to 30.5 GHz, which falls inside the −10 dB impendence bandwidth. The measured maximum gain is 19.2 dBic.

Stereoscopic UWB Yagi-Uda Antenna with Stable Gain by Metamaterial for Vehicular 5G Communication.

In this paper, a stereoscopic ultra-wideband (UWB) Yagi-Uda (SUY) antenna with stable gain by near-zero-index metamaterial (NZIM) has been proposed for vehicular 5G communication. The proposed antenna consists of magneto-electric (ME) dipole structure and coaxial feed patch antenna. The combination of patch antenna and ME structure allows the proposed antenna can work as a Yagi-Uda antenna, which enhances its gain and bandwidth. NZIM removes a pair of C-notches on the surface of the ME structure to make it absorb energy, which results in two radiation nulls on both sides of the gain passband. At the same time, the bandwidth can be enhanced effectively. In order to further improve the stable gain, impedance matching is achieved by removing the patch diagonally; thus, it is able to tune the antenna gain of the suppression boundary and open the possibility to reach the most important characteristic: a very stable gain in a wide frequency range. The SUY antenna is fabricated and measured, which has a measured -10 dBi impedance bandwidth of approximately 40% (3.5-5.5 GHz). Within it, the peak gain of the antenna reaches 8.5 dBi, and the flat in-band gain has a ripple lower than 0.5 dBi.

Ultrawideband Compact Magnetoelectric Dipole Antenna/Array With Dual-Polarization

Design of ultra-wideband (UWB) dual-polarized antenna with compact size is presented in this communication, which is composed of a triple-layer magnetoelectric (ME) dipole, a pair of cross-placed Γ-shaped feeding structure and a box-shaped reflector. Three layers of the ME dipole cover low (around 1.5 GHz), middle (3.5 GHz) and high (4.5 GHz) bands respectively, leading to an ultra-wide operating band from 1 to 5 GHz. The total size of the design is 75mm (0.75λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) × 75mm (0.75λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) × 55mm (0.55λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ). An array that consists of 8 such antenna elements is designed, fabricated, and measured. Results show that the voltage standing wave ratio (VSWR) is less than two over the whole operating band for all ports. As for the radiation characteristics, boresight gain ranging from 5.3 to 8.8 dBi is achieved for each antenna element, when it comes to the array, a peak gain of 17.23 dBi occurs at 4 GHz when all the antenna elements are excited with identical amplitude and phase. Beam scanning is also realized in the whole operating band through phase disposing, the scanning range is up to ±45° from 1 to 2 GHz and ±30° from 2 to 5 GHz.

Gain-Improved Wideband Circularly Polarized Magnetoelectric Dipole Antenna With Parasitic Helix

This communication presents a magnetoelectric (ME) dipole antenna with wideband circularly polarized (CP) and gain-improved performance. Two pairs of perpendicular sub-ME dipoles which are realized by horizontal and vertical patches constitute the original ME dipole. By connecting one pair of sub-ME dipole with metallic strip, CP operation is achieved at lower band firstly. Then, we change the coupling slot from rectangle to cross which leads to the enhancement of impedance and axial-ratio (AR) bandwidth. Furthermore, a helix with different turn radii and uniform turn spacing is introduced to improve the gain in the whole band. Performance of the proposed design is verified by measured results. The fabricated antenna exhibits an -10-dB impedance bandwidth of 3.33-6.75 GHz, corresponding to 67.9%. Besides, the measured 3-dB AR bandwidth and 3-dB gain bandwidth are 3.6-6.25 GHz (53.8%) and 3.4-5.8 GHz (52.2%), respectively. The proposed design could provide promising application values for wideband wireless communication systems.