Magneto-electric Dipole Research Articles

3D printed propeller-like metamaterial for wide-angle and broadband microwave absorption

• A broadband wide-angle 3D meta-absorber was proposed based on the reciprocity theory. • The absorber was designed by characteristic mode analysis and dispersion engineering. • The absorber was fabricated of CB-PP composite by 3D printing technology. • Broadband and wide-angle absorption of the absorber was verified experimentally. It is a challenge to design an absorber which can simultaneously satisfy comprehensive demands of broad absorption band, wide incident angle range, and low-profile. In this work, we designed a metamaterial absorber (MMA) based on the antenna reciprocity theory to achieve the above goals. Firstly, a three-dimensional (3D) propeller-like structure with reference to a typical magneto-electric dipole (MED) antenna was proposed and analyzed by the characteristic mode (CM) theory to realize near-omnidirectional radiation. Then, the radiation-absorption conversion was realized by introducing lossy materials into this structure, and the absorption performance was further improved by optimizing the dispersion feature of the lossy materials. Finally, the propeller-like metamaterial absorber with a thickness of 0.113 λ L was manufactured efficiently and integrally through 3D printing technology. Simulation results showed that the proposed absorber can achieve broadband absorption with the efficiency more than 90% in the frequency band of 3.4-10 GHz. It also has excellent wide-angle absorption capacity, with Transverse Electric (TE) polarization of 0° to 50° and Transverse Magnetic (TM) polarization of 0° to 80°. With the increase of incident angle, the upper limit of absorption bandwidth can be gradually extended to 18 GHz. Moreover, the effectiveness in the range of 0° to 60° incident angle is verified by measuring the reflectivity of the 3D printed absorber.

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.

A novel wideband dual‐polarized heptagonal magnetoelectric dipole antenna loaded with inverted L‐shaped structures

AbstractA novel dual linearly‐polarized magnetoelectric (ME) dipole antenna with wide bandwidth is presented in this letter, where two orthogonally placed Г probes are utilized to realize dual polarizations. In particular, four heptagonal patches are first adopted in lieu of the four conventional rectangular patches to obtain a wider bandwidth. In the sequel, four inverted L‐shaped parasitic elements are loaded on the periphery of the four patches to further enhance the bandwidth of ME dipole antenna. A prototype is fabricated and measured to verify the properties of the proposed antenna. The simulated and measured results show that the overlapped 10 dB bandwidth of 99.2% can be achieved ranging from 1.2 to 3.56 GHz, and the available peak gain can be as high as 12 dBi. Meanwhile, its cross‐polarization level (CRPL) is lower than −22 dB, and the isolation between the two ports is larger than 20 dB across the operating frequency.

A 3-D Printed Ultrawideband Magnetoelectric Dipole Antenna With Ridged Waveguide Aperture-Coupled Feeding

A ultrawideband magnetoelectric dipole (MED) antenna fed by a ridged waveguide is presented in this letter. Different from the widely used Γ-shaped probe feeding structure, a novel ridged waveguide aperture-coupled feeding technology is employed to excite the MED antenna and an ultrawideband MED antenna with an impedance matching of 104% from 1.92 to 6.08 GHz and directional pattern is realized. To verify this design, an antenna prototype is fabricated using the metallic three-dimensional printing technology. The measured impedance bandwidth of VSWR < 2 is 104% from 1.99 to 6.14 GHz. The directional patterns with a stable gain varying from 5.5 to 7.5 dBi are achieved. Besides, high radiation efficiency of above 89% is obtained owing to its all-metallic structure, which avoids the dielectric loss.

A Ka-Band SLM Printed Filtering Divider-Fed Magnetoelectric Dipole Antenna Array Using Embedded Gap Waveguide

In this letter, a filtering divider-fed magnetoelectric (ME) dipole antenna array using embedded gap waveguide (GW) is investigated. The antenna array is fed by a 5th-order all-resonator 1-to-4 filtering power divider. 4 × 4 ME dipole antennas are excited with the same amplitude and in phase. The selective laser melting (SLM) and embedded GW technology are employed to reduce fabrication complexity. The measured results show that the proposed antenna array achieves an impedance bandwidth of 27.3 - 30.8 GHz ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$|S_{11}| &lt; -10$</tex-math></inline-formula> dB). The gain of the antenna array varies from 19.5 to 20.6 dBi with stable radiation patterns. The advantages of the proper filtering function together with high gain, high efficiency, large power capacity and compact size in the proposed design ensure a promising future in its applications for millimeter wave (mm-Wave) radars and communication systems.

Design of a compact magneto‐electric dipole antenna

AbstractIn this letter, a compact magneto‐electric (ME) dipole antenna is designed and analyzed without compromising too much good performance of the ME dipole. In particular, the second‐order Minkowski‐like fractal structure is loaded on the planar electric dipole to effectively miniaturize the aperture size of the antenna. A prototype was fabricated and measured. The antenna volume is reduced by 24.6% when compared with the counterpart before the fractal. Meanwhile, the proposed antenna can achieve a bandwidth of 56% in terms of −10 dB ranging from 1.58 to 2.81 GHz. The radiation pattern of E‐ and H‐planes are basically identical. The cross‐polarization level is less than −25 dB, and the front‐to‐back ratio is larger than 14 dB. The maximum antenna gain can be up to 10.1 dBi. The measured results are in good agreement with the simulated ones.

High Gain and Wideband Antenna-in-Package Solution Using Fan-Out Technology

AbstractThe technology of fan-out wafer level packaging (FOWLP) has been widely adopted for millimeter wave antenna-in-package (AiP) system integration with low interconnection parasitic parameters. Present AiP solutions using FOWLP technology generally form antenna pattern on redistribution layer, which brings design inconvenience. In our work, a low-cost printed circuit board RO4350B laminate for substrate-integrated waveguide (SIW) antenna with a relatively large size is integrated, forms a three-dimensional stacked structure. The AiP employs a right-angle transition board embedded in epoxy molding compound (EMC), which transmits millimeter-wave signal to the SIW antenna stacked on the backside of EMC. The SIW antenna consists of 4 × 4 radiation slots with modified magneto-electric dipole for bandwidth enhancement. The measured gain is 14dBi at 60 GHz with bandwidth beyond 55–65 GHz. The three-dimensional AiP structure improves heat dissipation, no extra thermal design is needed for applications under 0.5 W mm-wave chip power consumption. The AiP module is manufactured and measured on the test board. The proposed approach is a convenient solution for wide band and high gain millimeter wave AiP system integration.

Broadband Magnetoelectric Dipole Filtering Antenna for 5G Application

A magnetoelectric (ME) dipole filtering antenna with high out-of-band suppression level and high selectivity is proposed in this letter. The intrinsic radiation null of the traditional ME dipole antenna is used, which produces a good filtering response at the edge of the lower passsband. A pair of vertical parasitic metal planes are introduced between the shorted walls and fed through slot coupling, which can be equivalent to an additional magnetic dipole. The radiated electric field of the magnetic dipole is opposite to that of the original antenna at higher frequency, forming a wide stopband radiation null, which greatly improves the high-frequency stopband suppression level of the antenna. Furthermore, a pair of T-shaped coupling stubs are inserted between the shorted wall and electric dipole, producing another radiation null with high roll-off rate at higher frequency. The measurement results show that the −10 dB impedance bandwidth of the proposed antenna is 49.4% (3.2–5.3 GHz). Its low-frequency stopband suppression level is greater than 16.6 dB and high-frequency stopband suppression level is greater than 26.0 dB. Moreover, the antenna radiation pattern is stable and symmetrical in the whole operating passband, and the filtering response is desirable.

A Study on Millimeter-Wave Magneto-Electric Dipole Phased Arrays for 5G Dual-Band Applications

Beam steering characteristics of millimeter-wave substrate-integrated magneto-electric (ME) dipole phased arrays with large sizes are investigated in this article. The formation mechanism of the guided waves traveling along the planar ME-dipole array geometry is revealed with the use of a linear array model in simulation, which not only provides an effective method of predicting the blind angles for the ME-dipole phased arrays but also confirms the superior wide-angle scanning performance of the arrays. An 8 × 8 ME-dipole phased array is then designed, fabricated, and tested, whose measured beam scanning range without the blindness in both the E- and H-planes is ±60° over the frequency range between 23.5 and 27.5 GHz and is ±50° over the range between 27.5 and 29.5 GHz. A gain of up to 23.6 dBi and stable radiation patterns are also achieved. With the simple single-layered configuration and the wide-angle scanning ability over the wide operating band of 22.6%, the ME-dipole phased array would be an attractive candidate for the millimeter-wave dual-band applications in the fifth generation (5G) mobile communications.

Single-Layer Interconnected Magneto-Electric Dipole Antenna Array for 5G Communication Applications

A high-gain and wideband interconnected magneto-electric (ME) dipole on a single-layer PCB substrate is designed for 5G communication applications. Microstrip lines and coplanar striplines (CPSs) serve as transmission lines to connect the ME dipole elements along the E-plane and the H-plane directions, respectively. Impedance matching and sidelobe-level suppression are the key challenges to design a large-scale interconnected ME dipole antenna array. It is shown that impedance matching can be improved by introducing slots and adjusting the width of microstrip lines. Sidelobe level can be enhanced by properly choosing the length of the microstrip lines. A 5 × 5 interconnected ME dipole array is fabricated on a single layer of the RT/duroid 5880 substrate. The proposed antenna exhibits a measured −10 dB impedance bandwidth of 14.5 GHz (52% at 28 GHz) and a maximal peak realized gain of 20.44 dBi at 27.5 GHz with a 3 dB gain bandwidth of 3.5 GHz (12.5% at 28 GHz). The proposed antenna array is a good candidate for 5G communication applications due to its advantages of simple feeding structure, wide bandwidth, high gain, and low profile.

A Novel Dual-Polarized Magnetoelectric Dipole Antenna and Its Array for LTE and 5G Sub-6 GHz Base Station Applications

This study presents a novel dual-polarized magnetoelectric dipole antenna and its array with director and rectangular parasitic metal patches for LTE and 5G sub-6 GHz base station applications. This antenna is composed of L-shaped magnetic dipoles, planar electric dipoles, rectangular director, rectangular parasitic metal patches, and η-shaped feed probes. The gain and bandwidth were enhanced by using the director and parasitic metal patches. The measured impedance bandwidth of the antenna was 82.8% (1.62-3.91 GHz, VSWR < 1.5), and its gain was 10 ± 0.5 dBi. The profile of the antenna unit, operated at 1.7 GHz, was only 42 mm (0.227λ0, where λ0 represents the free space wavelength corresponding to the lowest resonance frequency point). Subsequently, four antenna units were arranged in a line array with 0.6λ0 spacing. Both the antenna and its array were fabricated and measured. The measurement results show that the array has good radiation characteristics, such as broad bandwidth covering 1.65-3.97 GHz (VSWR < 1.5), high gain (its gain was great than 15.2 dBi), and high radiation efficiency (>90%). Its HPBWs were 63° ± 4° and 15° ± 2° for H- and E-planes, respectively. The design can cover TD-LTE and 5G sub-6 GHz NR n78 frequency bands very well, meaning that this is a good candidate antenna for base station applications.

Wideband Co-Linearly Polarized Magneto-Electric Dipole Antenna for In-Band Full-Duplex Applications

A wideband co-linearly-polarized magnetoelectric (ME) dipole antenna is proposed for the in-band full-duplex (IBFD) application, having identical radiation properties in the operating frequency band. Good isolation between the transmitting and receiving ports is obtained over a wide frequency range by modifying the shared central part of the ME dipole without a complex feeding structure. The central part is a defected rectangular tube suspended above the ground. To validate the proposed antenna, a prototype is fabricated and measured. The measured port isolation is higher than 22 dB over the operating frequency band from 1.90 to 2.91 GHz (42.0%). The proposed antenna has a simple structure and good wideband radiation performance, with high potential for IBFD applications.

A Coupled-Fed Broadband Dual-Polarized Magnetoelectric Dipole Antenna for WLAN and Sub-6 GHz 5G Communication Applications

This paper presents a novel coupled-fed broadband dual-polarized magnetoelectric dipole antenna for wireless local area network (WLAN) and 5G communication applications. The proposed magnetoelectric dipole antenna is composed of a planar electric dipole and shorting pins as a magnetic dipole to obtain a broad operation frequency band. Two coupled microstrip lines perpendicular to each other are coupled through a cross-shaped slot to excite the vertical and horizontal polarizations. The proposed antenna features a simple structure, high gain, and high polarization isolation. The measured impedance bandwidth of the proposed antenna is 1.8–4.2 GHz (fractional bandwidth of 80%). The measured realized antenna gain value is 3.7–8.5 dBi, and polarization isolation level is 25 dB at the operation frequency band.

High‐gain miniaturized magnetoelectric dipole antenna array for millimeter‐wave applications

AbstractIn this paper, a miniaturized high gain magnetoelectric dipole (MED) antenna array is proposed, which is composed of a one‐to‐two‐way substrate‐integrated waveguide E‐plane T‐type waveguide power divider as the feeding network. The MED antenna consists of a pair of mirror‐symmetrical E‐patches and a pair of vertical metallized vias. The size of the antenna array is 1.2λ0× 1.6λ0× 0.17λ0. A bandwidth of 29.3% (25.6–34.4 GHz) for S11 &lt; −10 dB can be achieved and has unidirectional radiation performance in the operating frequency band. The peak gain of the antenna reaches 11 dBi, and the average gain can reach more than 10 dBi.

A Single-Fed Wideband Circularly Polarized Cross-Fed Cavity-Less Magneto-Electric Dipole Antenna.

In this paper, we proposed a new wideband circularly polarized cross-fed magneto-electric dipole antenna. Different from conventional cross-dipole or magneto-electric dipole antennas, the proposed simple geometry realizes a pair of complementary magnetic dipole modes by utilizing the two open slots formed between the four cross-fed microstrip patches for achieving circular polarization and high stable gain across a wide frequency band. No parasitic elements are required for extending the bandwidths; therefore, both the radiation patterns and in-band gain are stable. The simulated field distributions demonstrated the phase complementarity of the two pairs of magnetic and electric dipole modes. A parametric study was also performed to demonstrate the radiation mechanism between the electric and magnetic dipole modes. The radiating elements are realized on a piece of double-sided dielectric substrate fed and mechanically supported by a low-cost commercial semirigid cable. The overall thickness of the antenna is about 0.22λo at the center frequency of axial ratio bandwidth. The measured results show a wide impedance bandwidth (|S11| < -10 dB) of 70.2% from 2.45 to 5.10 GHz. The in-band 3-dB axial ratio bandwidth is 51.5% from 3.0 to 5.08 GHz. More importantly, the gain of the antenna is 9.25 ± 0.56 dBic across the 3-dB axial ratio bandwidth.

Design of Wideband Dual-Polarized ME Dipole Antenna With Parasitic Elements and Improved Feed Structure

A wideband dual-polarized antenna is proposed for base station applications. The proposed antenna is composed of two folded and hollowed out magnetoelectric dipoles placed crosswise, as well as a box-shaped reflector, the overall size is 0.97λ × 0.97λ × 0.27λ. Two Γ-shaped probes with a gradual change in size are used to excite the antenna. By adding parasitic elements to the feeding structure and box-shaped reflector, wide operating bandwidth from 1.59 to 3.65 GHz is realized, where the standing wave ratio is less than 2 and the fractional bandwidth is up to 78.6%. Meanwhile, stable radiation pattern, high front-to-back ratio, and steady boresight gain can also be seen over the whole band. Prototype is fabricated and the measured results verify that the proposed antenna could be a competitive candidate in base station applications.

A Broadband Circularly Polarized Planar Antenna Array Using Magneto-Electric Dipole Element With Bent Strips for Ka-Band Applications

This letter proposes a Ka-band broadband circularly polarized (CP) planar array based on the magneto-electric (ME) dipole structure. The antenna element consists of linearly polarized (LP) ME-dipole and two rotationally symmetrical bent strips. The two strips are connected to the opposite side of the LP ME-dipole to obtain a rotating electric field required by CP radiation. A feed structure of microstrip is implemented to excite the antenna element through an H-shaped coupling slot. The tightly coupled array technique is adopted to enhance the axial ratios (ARs) of the element. The proposed CP element realizes an AR bandwidth of 28%. Then, an 8 × 8 array with a 1-to-64 full-corporate feeding network is designed for experimental validation. The test results indicate that the 8 × 8 array prototype exhibits an impedance bandwidth of 50% covering 24 to 40 GHz, a 3 dB AR bandwidth of 28% covering 26.7–35.3 GHz, a gain between 20.6 and 22.1 dBic over the whole overlapped bandwidth, and a radiation efficiency higher than 75%. Attributed to the excellent CP performance and ease of integration with front-end circuits, the designed array is a good select for Ka-band wireless and satellite communications.

Broadband magneto-electric dipole antenna using circular quadrants with SIW technique

Broadband magneto-electric dipole antenna using circular quadrants with SIW technique

Broadband Dual-Polarized Magnetoelectric Dipole Antenna With Compact Structure for 5G Base Station

This paper presents a compact wideband dual-polarized magnetoelectric dipole antenna suitable for 5G base stations, which can cover 5G NR n77/78/79 band. The proposed antenna is configured with a cross ME dipole loaded with a rectangular slot, and two L-shaped feed lines are coplanar with the vertical patch, which makes the transverse size of the antenna more compact. The prototype size is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.57\,\,\lambda _{min} \times 0.57\,\,\lambda _{min}$ </tex-math></inline-formula> (length <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> width). According to the measured results, the operating band of the antenna is 3.06-5.28 GHz, and the impedance bandwidth is 53.2% of −10 dB. In the whole frequency range, the isolation between ports is less than −22 dB. Furthermore, metal baffles around the ground are used to stabilize the radiation pattern and improve the front-to-back ratio, achieving gains greater than 8dBi in the frequency band. However, the half power beam width (HPBW) exceeds 65°±5° for base station applications. The antenna has the advantages of broadband, high front-to-back ratio and low cross-polarization, and can be used as a good candidate antenna for 5G commercial small base stations.

Compact Magneto-Electric Dipole Array With Wide Beam Scanning Range for 5G NR Bands

Compact Magneto-Electric Dipole Array With Wide Beam Scanning Range for 5G NR Bands