Showing papers on "Dipole antenna published in 2021"
TL;DR: In this article, a general decoupling method based on a new perspective of common mode (CM) and differential mode (DM) cancellation is proposed for two closely spaced antennas, where the mutual coupling effect can be analyzed and solved by exciting them simultaneously with in-phase and out-of-phase signals.
Abstract: In this article, a general decoupling method based on a new perspective of common mode (CM) and differential mode (DM) cancellation is proposed. For two closely spaced antennas, the mutual coupling effect can be analyzed and solved by exciting them simultaneously with in-phase (CM) and out-of-phase (DM) signals. It is theoretically proved that, if CM and DM impedances are the same, the mutual coupling effect between two separated antennas can be totally eliminated. Therefore, we can solve the coupling problem by CM and DM impedance analysis and exploit the unique field properties of characteristic modes to assist in antenna decoupling in a physical intuitive way. To validate the feasibility of this method, two practical design examples, including the decoupling between closely spaced dipole antennas and planar inverted-F antennas, are proposed. Both design examples have demonstrated that the proposed method can provide a systemic design guideline for antenna decoupling and achieve better decoupling performance compared to the conventional decoupling techniques. We forecast the proposed decoupling scheme, with a simplified decoupling procedure, has great potential for the applications of antenna arrays and multi-input multi-output (MIMO) systems.
105 citations
TL;DR: In this paper, a superstrate-based decoupling method was proposed to reduce the mutual coupling between two closely packed dipole antennas while maintaining cross-polarization suppression.
Abstract: A ceramic superstrate-based decoupling method (CSDM) is proposed to reduce the mutual coupling between two closely packed dipole antennas while maintaining cross-polarization suppression. Compared with other superstrate-based methods, this proposed method can effectively reduce the mutual coupling between the antennas without using any periodic structures on the superstrate. The ceramic superstrate is a 2 mm thin slab with a relative dielectric constant of 20.5 and is suspended over the antennas coupled in H-plane with the spacing of only 0.28 wavelength at 3.5 GHz. It is demonstrated by both simulation and measurement that the isolation between two dipole antennas can be improved from 10 to more than 25 dB within the operation band while their reflection coefficients remain to be below −10 dB after the ceramic superstrate is introduced. The radiation patterns of the antenna maintain stable at different operation frequencies within the band of interest and the peak gain has increased by around 1.5 dB. Meanwhile, the total efficiency is enhanced by about 15% and the envelope correlation coefficient (ECC) between the two antennas is reduced from 0.7 to 0.4.
82 citations
TL;DR: In this paper, a limited number of works have surveyed, compared and categorised the proposed antenna designs for CubeSats based on their operating frequency bands, e.g., VHF, UHF, L, S, C, X, Ku, K/Ka, W and mm/sub-mm wave antennas.
Abstract: Cube Satellites, aka CubeSats, are a class of nano satellites that have gained popularity recently, especially for those that consider CubeSats as an emerging alternative to conventional satellites for space programs. This is because they are cost-effective, and they can be built using commercial off-the-shelf components. Moreover, CubeSats can communicate with each other in space and ground stations to carry out many functions such as remote sensing (e.g., land imaging, education), space research, wide area measurements and deep space communications. Consequently, communications between CubeSats and ground stations is critical. Any antenna design for a CubeSat needs to meet size and weight restrictions while yielding good antenna radiation performance. To date, a limited number of works have surveyed, compared and categorised the proposed antenna designs for CubeSats based on their operating frequency bands. To this end, this paper contributes to the literature by focusing on different antenna types with different operating frequency bands that are proposed for CubeSat applications. This paper reviews 48 antenna designs, which include 18 patch antennas, 5 slot antennas, 4 dipole and monopole antennas, 3 reflector antennas, 3 reflectarray antennas, 5 helical antennas, 2 metasurface antennas and 3 millimeter and sub-millimeter wave antennas. The current CubeSat antenna design challenges and design techniques to address these challenges are discussed. In addition, we classify these antennas according to their operating frequency bands, e.g., VHF, UHF, L, S, C, X, Ku, K/Ka, W and mm/sub-mm wave bands and provide an extensive qualitative comparison in terms of their size, −10 dB bandwidths, gains, reflection coefficients, and deployability. The suitability of different antenna types for different applications as well as the future trends for CubeSat antennas are also presented.
66 citations
TL;DR: In this paper, an end-fire dual-polarized phased antenna array with small ground clearance is proposed for the 5G millimeter-wave (mmW) applications with a wide bandwidth in which each antenna element consists of a dipole fed by a microstrip line for horizontal polarization and an H-plane horn using substrate-integrated waveguide (SIW) for vertical polarization.
Abstract: In this article, an endfire dual-polarized phased antenna array with small ground clearance is proposed for the fifth-generation (5G) millimeter-wave (mmW) applications with a wide bandwidth In this array, each antenna element consists of a dipole fed by a microstrip line for horizontal polarization and an H-plane horn using substrate-integrated waveguide (SIW) for vertical polarization To achieve a wide bandwidth for vertical polarization, two metal vias are added at the aperture of the horn antenna Then, a four-element antenna array is designed by partially overlapping the aperture of each horn element A prototype has been fabricated using multilayer printed circuit board (PCB) process The measured results agree well with the simulated ones The antenna is with an impedance bandwidth of $\vert \text{S}_{11}\vert dB from 244 to 295 GHz for both polarizations The maximum gains of vertical and horizontal polarizations are 916 and 927 dBi, with the scanning angle from −34° to 33° for both polarizations with gain deterioration less than 3 dB The proposed antenna is a promising solution for 5G mmW cellphones or antenna-in-package applications
63 citations
TL;DR: In this paper, a dual-polarized planar phased array with high polarization isolation and low crosspolarization is presented operating from 4 to 18 GHz, i.e., 4.5:1.
Abstract: In this article, a dual-polarized planar phased array with high polarization isolation and low cross-polarization is presented operating from 4 to 18 GHz, i.e., 4.5:1. The proposed array is comprised of tightly coupled dipoles with integrated coupled-Marchand baluns. To improve the uniformity of fields distributed on the array, the center-feeding dipole is used in this design instead of the conventional edge-feeding one at first. Then, the outer conductors of the feed are composed of a group of shorted vias with the proper number and position. Based on these methods, the output balance of the balun is significantly improved, resulting in high isolation between ports with different polarization modes. Furthermore, this feed has a natural ability to suppress the D-plane common mode resonance. The capacitive metallic annular plate over adjacent radiating elements and the thick aluminum plate with an air cavity placed under the array are employed together to suppress the in-band coupled-loop modes. The infinite array simulation indicates that the array can achieve transmit (Tx)/receive (Rx) isolation more than 48 dB at broadside. Isolation better than 32 and 30 dB can be achieved when scanning to 45° in E-/H-planes and 60° in E-plane, respectively. The cross-polarization level is below −54 dB at broadside and remains below −29 dB when scanning to 60° in E-plane as well as 45° in H-plane. A $12\times12$ dual-polarized antenna array is fabricated and measured to validate the correctness of this design. This type of antenna can be applied in wideband simultaneous transmit and receive (STAR) monostatic systems.
55 citations
TL;DR: In this article, a planar dual-polarized phased array for 5G cellular communications is proposed, which contains two eight-element subarrays including horizontally polarized end-fire dipole antennas and vertically polarized endfire periodic slot antennas, employed on the PCB ground plane of the 5G mobile platform.
Abstract: A planar dual-polarized phased array is proposed for 5G cellular communications. The array has the properties of dual-polarization, wideband, and quasi-endfire radiation, which is printed on one side of a single-layer substrate. The design contains two eight-element subarrays including horizontally polarized endfire dipole antennas and vertically polarized endfire periodic slot antennas, employed on the PCB ground plane of the 5G mobile platform. Both subarrays provide wide bandwidth to cover 28 and 38 GHz (promising 5G candidate bands). The −10 dB impedance bandwidth of the proposed CPW-fed dipole and slot antennas are 26.5–39.5 GHz and 27.1–45.5 GHz, respectively. Moreover, for −6-dB impedance bandwidth, these values could be more than 20 GHz (24.4–46.4 GHz for the dipole antenna) and 70 GHz (22.3–95 GHz for the slot antenna). The fundamental characteristics of the proposed dual-polarized 5G antenna array in terms of the impedance bandwidth, realized gain, polarization, radiation pattern, and beam steering are investigated and good results are obtained. The clearance of the proposed dual-polarized 5G antenna array is less than 4.5 mm which is sufficient for cellular applications.
51 citations
TL;DR: In this paper, an eight-element linear phased array with frequency selective surface (FSS) operating in the $S$ -band was designed for a wide-angle scanning conformal phased array antenna for an UAV platform.
Abstract: Conformal antennas are practicable candidates to the aerodynamic platforms. A wide-angle scanning conformal phased array antenna for an unmanned aerial vehicle (UAV) platform is designed and presented in this article. An eight-element linear phased array loaded with frequency selective surface (FSS) operating in $S$ -band is investigated. The horizontally polarized antenna element is designed based on a tapered slot feeding dipole. The antenna aperture can be easily conformed to the front wing airframe of the UAV due to the flexibility of the employed polyimide film. To fulfill the requirement of the airborne communication system, two kinds of FSSs are loaded on the dipole antenna to enhance the gain and reduce the 3 dB beamwidth of the main lobe in the elevation plane. To improve the active impedance matching when the beam scans to the large angles, a novel parasitic structure is proposed. Finally, a $1 \times 8$ linear conformal array prototype is simulated, fabricated, and measured. The experimental results indicate that the antenna array achieves a fractional bandwidth of 22.1% with ±70° scanning along the E-plane. The measured results validate the performance of the proposed conformal array and the design.
50 citations
TL;DR: In this paper, a millimeter-wave (mmW) low profile wideband magneto-electric (ME) monopole antenna with the vertically polarized endfire radiation is presented by combining a pair of top-loaded electric monopoles with a thin open-ended substrate integrated waveguide (SIW) with the extended lower broad wall.
Abstract: A millimeter-wave (mmW) low-profile wideband magneto-electric (ME) monopole antenna with the vertically polarized endfire radiation is presented by combining a pair of the top-loaded electric monopoles with a thin open-ended substrate integrated waveguide (SIW) with the extended lower broad wall. The antenna has a profile of 0.19 wavelength at the center frequency of the operating band, a wide bandwidth of 60.7% (from 23.5 to 44 GHz) covering all the fifth-generation (5G) mmW bands in the Ka -band, a stable gain of around 7 dBi, and a tilted radiation pattern. Then a $1 \times 8$ ME-monopole array is designed to investigate the beam scanning properties and the effects of the metallic ground and the polycarbonate radome, which should be considered in practical applications. As a sample, a $1 \times 8$ array fed by an SIW feed network, assembled on a metallic ground plane, and covered by a polycarbonate radome is finally designed, fabricated, and measured. The prototype achieves promising radiation features with a gain up to 15.3 dBi. Owing to the compact low-profile structure with good performance, the proposed design would be valuable to the mmW applications.
48 citations
TL;DR: A dual circularly polarized (CP) magnetoelectric dipole antenna was devised to form a circular ring shape and fabricated using 3-D printing technology to overcome the conflict between high (broadside) gain and wide (half-power) beamwidth, a new beamwidth broadening technique was proposed.
Abstract: A dual circularly polarized (CP) magnetoelectric dipole antenna is presented in this article. The dual-CP antenna was devised to form a circular ring shape and fabricated using 3-D printing technology. To overcome the conflict between high (broadside) gain and wide (half-power) beamwidth, a new beamwidth broadening technique was proposed. Twelve meta-columns were placed evenly along the circumference close to the ring-shaped dipole. A design approach is elaborated, where the number and size of meta-columns were decided according to the design curves. Symmetrical beamwidth of 108° in orthogonal planes with a broadside gain of 6 dBic was achieved across a wide effective bandwidth from 3.2 to 5.4 GHz (51%), sufficiently covering the 5G new radio (NR) bands: $n77, n78, n79$ . The antenna owns a compact size of $0.83 \times 0.83 \times 0.18\lambda ^{3}$ at 4.15 GHz. A planar subarray composed of four dual-CP elements was also investigated and compared with the existing arrays.
43 citations
TL;DR: In this article, a 1-bit transmit array element design at Ku-band was proposed, which adopts the receiver-transmitter structure with an active receiving dipole and a passive asymmetric transmitting dipole.
Abstract: Reconfigurable transmitarray antennas with independent dual-linear polarization phase controlling capability are essential for wireless communications applications. This work proposes a novel 1 bit transmitarray element design at Ku -band, which adopts the receiver–transmitter structure with an active receiving dipole and a passive asymmetric transmitting dipole. The 1 bit phase shift is achieved by alternating two p-i-n diodes integrated on the active dipole to reverse its current direction. To mitigate the influence of p-i-n diodes and reduce the element insertion loss, a parasitic bypass dipole is added next to each dipole. Element simulations show that a low loss of only 1.0 dB is achieved. The dual-linear polarization capability is obtained by orthogonally interlacing two sets of proposed receiver–transmitter structures. A 100-element transmitarray prototype is designed, fabricated, and measured. The measured gain is 18.3 dB at 12.2 GHz, corresponding to an aperture efficiency of 22.6%. The 2-D beam-scanning capability for independent dual-linear polarization is experimentally verified and the scan angle covers ±50°. The measured maximum scan gain loss is 2.9 and 3.5 dB in the two principal planes, respectively.
42 citations
TL;DR: In this article, a magnetoelectric (ME) dipole was used to achieve wideband and low cross-polarization transmitarray design for 1-bit transmit arrays.
Abstract: The application of magnetoelectric (ME) dipole to achieve wideband and low cross-polarization transmitarray design is presented in this article. First, a novel meandering-probe-fed ME dipole that exhibits a wideband matching, central feeding configuration, and symmetrical antenna structure is developed. These preferred features are borrowed to address the narrowband and potential element-displacement issues in 1 bit transmitarray element design. Numerical simulations of the proposed 1 bit ME-dipole transmitarray element show a wide 1 dB insertion-loss bandwidth of 47% and a low cross-polarization level of −40 dB. Measured results of the transmitarray designed using the proposed ME-dipole elements indicate an operating bandwidth of 47% and a cross-polarization discrimination (XPD) around 35 dB. In addition, a dual-layer phase compensation scheme for cross-polarization synthesis is described. The effectiveness of this method is demonstrated with a cross-polarization cancelation scheme that further improves the measured XPD to 40 dB. The proposed transmitarrays show advantages of remarkable bandwidth, low cross-polarization, and comparatively high aperture efficiency over most reported 1 bit designs.
TL;DR: In this article, an ultrathin, electrically small, single-substrate Huygens dipole rectenna with exceptional physical and radiation performance characteristics is reported, which consists of two metamaterial-inspired near-field resonant parasitic (NFRP) elements, an Egyptian axe dipole (EAD) and a capacitively loaded loop (CLL).
Abstract: An electrically small, single-substrate Huygens dipole rectenna with exceptional physical and radiation performance characteristics is reported. A highly efficient rectifier circuit is seamlessly integrated with an ultrathin, electrically small, Huygens dipole antenna (HDA) on a single piece of Rogers 5880 substrate. It consists of two metamaterial-inspired near-field resonant parasitic (NFRP) elements, an Egyptian axe dipole (EAD) and a capacitively loaded loop (CLL) that are etched on the top and bottom metallization layers of the substrate, respectively. A printed receiving dipole is amalgamated tightly with the rectifier on the CLL layer. This ultracompact rectenna system has a large electromagnetic wave capture capability and achieves nearly complete conversion of the incident energy into dc power. The HDA prototype has a realized gain of 4.6 dBi and a half power beamwidth (HPBW) greater than 130°. The entire rectenna is electrically small with ka =0.98, is low cost and easy to fabricate, and has a measured 88% ac-to-dc conversion efficiency. The developed rectenna system is the ideal candidate for ultracompact far-field wireless power transfer (WPT) applications.
TL;DR: In this article, a planar circularly polarized (CP) planar array antenna is proposed for the upcoming 5G millimeter-wave (mm-wave) applications, where the antenna element is fed by a slot etched on the substrate integrated waveguide (SIW) for convenient integration.
Abstract: A novel wideband circularly polarized (CP) planar array antenna is proposed in this article for the upcoming fifth-generation (5G) millimeter-wave (mm-wave) applications. The antenna element is fed by a slot etched on the substrate integrated waveguide (SIW) for convenient integration. It consists of two additional semicircle patches and two suspend metal posts which are working as the newly proposed polarizers for broadband CP operation. The combined patch, post, and slot generate totally four CP modes which greatly expand the antenna 3 dB axial ratio (AR) bandwidth. The antenna operating mechanism and the design procedure are illustrated in detail. The simulated results for the antenna element show an AR bandwidth of 41.28% from 25.66 to 39.01 GHz, an impedance bandwidth of wider than 44.62% from 24.41 to 38.43 GHz, and a gain of 7.25 ± 1 dBic over the frequency band. The antenna shows a stable pattern and wide AR/impedance overlapping bandwidth (25.66–38.43 GHz), which covers most of the current 5G mm-wave bands. To enhance the antenna gain for practical application, a planar $4 \times 4$ antenna array fed by a fully incorporated SIW network is designed, fabricated, and measured. The measured results for the array demonstrate an AR bandwidth of 36.51% from 25.3 to 36.6 GHz, an impedance bandwidth of 40.21% from 24.42 to 36.71 GHz, and a peak gain of 19 dBic. The proposed antenna features a novel broadband CP working principle, low profile, and good radiation performance, which is well suited for 5G mm-wave applications.
TL;DR: The proposed shared-aperture phased array antenna with wide-angle scanning capability (WASC) is a good candidate for the base station in the mobile environment, and WASC is realized in both the C- and S- bands with low mutual coupling.
Abstract: A dual-band shared-aperture phased array antenna with wide-angle scanning capability (WASC) is presented in this paper for mobile communications. Each shared-aperture antenna element consists of two wideband microstrip antenna units with air-cavity for the C -band and one wide beam magnetic-electro dipole antenna unit for the S -band. To achieve the wide-angle scanning, a phased array should have low inter-element mutual coupling and wide array-element beam-width. A simple metallic strip (MS), comprising four metal stubs and one rectangle shaped metal pillar, is utilized to improve the inter-element isolation of the array in and between the C - and S -bands. Furthermore, the metal strip can also broaden the beam-width of the C -band antenna units without distorting the wide-beam property of the S -band units. The shared-aperture array with a simple metallic strip is designed based on the above elements, and WASC is realized in both the C - and S - bands with low mutual coupling. To verify the proposed method, the shared-aperture array is fabricated and characterized, yielding good performance within the overall operating bandwidth. The measured results align very well with the simulated. The proposed array realizes the scanning coverage of ±60° with realized gain reduction of less than 3 dB in both the C - and S -bands, which is a good candidate for the base station in the mobile environment.
TL;DR: A dual-broadband dual-polarized magnetoelectric dipole (ME-dipole) antenna with a shared aperture for 5G applications is proposed in this paper.
Abstract: A dual-broadband dual-polarized magnetoelectric dipole (ME-dipole) antenna with a shared aperture for 5G applications is proposed in this communication. The antenna is operated at the 2.35–3.93 GHz (N41 and N78) and 24–34 GHz (N257 and N258) dual fifth-generation (5G) bands. Each band exhibits a dual-polarized radiation, and more importantly, the two bands shared the same radiation aperture. In the millimeter-wave (MM-wave) band, the proposed antenna can generate two-dimensional (2-D) multiple beams with dual-polarization, and the switching range at each plane is about ±20°. The antenna is composed of two kinds of ME-dipole. The MM-wave band uses an ME-dipole feeding through the substrate-integrated waveguide (SIW) as the source to excite four horn antennas with inclined inner walls to achieve high-gain 2-D switching with dual-polarization. The lower frequency band combines the four horn antennas to achieve a large dual-polarized ME-dipole antenna. The antenna operating mechanism and the design procedure are illustrated in detail. The measured results show that a −10 dB impedance bandwidth of 33.91% (24–33.91 GHz) and 50.31% (2.35–3.93 GHz) is achieved. The peak gain of the proposed antenna in the two bands is 10.67 dBi (3.8 GHz) and 14.85 dBi (32.2 GHz), respectively. Due to the robust characteristics of the ME-dipole and horn antenna, the antenna shows a stable pattern and a wide impedance bandwidth, which covers most of the current 5G microwave and MM-wave bands. The antenna features a shared aperture, large frequency ratio, dual-broadband, dual-polarization, and 2-D multiple beams, which are well suited for the 5G base station applications.
TL;DR: This communication presents a novel surrogate-assisted quasi-Newton enhanced global optimization (SA-QNEGO) algorithm that finds a more accurate minimum value with less computational time than direct optimization using DE.
Abstract: This communication presents a novel surrogate-assisted quasi-Newton enhanced global optimization (SA-QNEGO) algorithm. In this proposed method, the heuristic hypersphere sampling (HHS) method is used to obtain representative samples. The surrogate model is built based on the low-fidelity model. The quasi-Newton enhanced differential evolution (DE) method is designed to optimize the surrogate model. Finally, the optimal design of a high-fidelity model is obtained through a space mapping procedure. The proposed algorithm is verified through two antenna design examples including a dipole antenna with balun and an SIW cavity-backed slot antenna. The results show that the proposed algorithm finds a more accurate minimum value with less computational time than direct optimization using DE.
TL;DR: In this paper, a pattern-reconfigurable Yagi-Uda antenna based on liquid metal is presented, which consists of a balunfed active dipole and a pair of stretchable passive parasitic dipoles, which are implemented by eutectic gallium-indium (EGaIn) alloy embedded in microfluidic channels.
Abstract: A pattern-reconfigurable Yagi–Uda antenna based on liquid metal is presented. The antenna consists of a balun-fed active dipole and a pair of stretchable passive parasitic dipoles, which are implemented by eutectic gallium-indium (EGaIn) alloy embedded in microfluidic channels. The parasitic dipoles are driven at each end by two low-cost, three-dimensional printed media rods. Afterward, spinning the rods at different angles leads to varying degrees of stretching upon the stretchable dipoles. Note the length of passive parasitic dipoles is a vital factor for antenna radiation reconfiguration. The antenna exhibits bidirectional radiation if the parasitic dipoles are equal in length. Otherwise, directional radiation toward the shorter parasitic dipole direction can be obtained. Based on the above-mentioned working principle, a pattern-reconfigurable antenna working in wireless local area network (WLAN) band is fabricated and measured. Apart from the reconfigurable capability, the proposed antenna keeps operating in the WLAN band of 2.4–2.48 GHz during the whole shape deformation.
TL;DR: A batteryless, wearable knitted ultrahigh frequency (UHF, 902–928 MHz) radio frequency identification compression sensor (Bellypatch) antenna is presented and its applicability as an on-body respiratory monitor and the antenna radiation efficiency is satisfactory in both free-space and on- body operations.
Abstract: One of the major challenges faced by passive on-body wireless Internet-of-Things sensors is the absorption of radiated power by tissues in the human body. We present a batteryless, wearable knitted ultrahigh frequency (UHF, 902–928 MHz) radio frequency identification compression sensor (Bellypatch) antenna and show its applicability as an on-body respiratory monitor. The antenna radiation efficiency is satisfactory in both free-space and on-body operations. We extract radio-frequency (RF) sheet resistance values of three knitted silver-coated nylon fabric candidates at 913 MHz. The best type of fabric is selected based on the extracted RF sheet resistance. Simulated and measured performance of the antenna confirm the suitability for on-body applications. The proposed Bellypatch antenna is used to measure the breathing activity of a programmable infant patient emulator mannequin (SimBaby) and a human subject. The antenna is highly sensitive to respiratory compression and relaxation. Fluctuations in the backscatter power level/received signal strength indicator in both cases range from 6 to 15 dB. The improved on-body read range of the proposed sensor antenna is 5.8 m, about ten times higher than its predecessor wearable knitted strain sensing Bellyband antenna (0.6 m). The maximum simulated specific absorption rate on a human torso model is 0.25 W/kg, lower than the maximum allowable limit of 1.6 W/kg.
TL;DR: In this paper, the authors proposed a reflector-back cavity-low-band (LB)/highband (HB) configuration for the dual-band dual-polarized base station antenna array design.
Abstract: In this article, we propose a novel reflector-back cavity-low-band (LB)/high-band (HB) configuration for the dual-band dual-polarized base station antenna array design. The HB antennas are embedded in the opening sections of the loop radiating arms of the LB antennas. Clear and independent radiating environments are fulfilled by using two different types of reflectors (large planar reflector and back cavity). The mutual effects between the LB and HB antennas help to acquire good impedance matching and stable radiation patterns. Loop-like LB radiators work as directors in the HB, thereby effectively suppressing the side and back radiations of the HB antennas. Dual-function open slots are loaded on the ground stubs of the LB baluns, serving as impedance transformer in the LB but filtering structures in the HB. The experimental results validate that the proposed antenna array successfully covers bandwidths of 0.69–0.96 and 3.3–3.8 GHz (VSWR < 1.5) for 4G/5G applications. The port isolations are higher than 38 and 25 dB in the LB and HB, respectively. With the two independent radiating environments formed in the two bands, both LB and HB antennas exhibit stable unidirectional radiation patterns. The antenna gains and HPBWs are also satisfactory in both bands.
TL;DR: In this article, an aperture coupled magnetoelectric (ME) dipole antenna with wideband and low profile was proposed for millimeter-wave applications, where transverse slots were added to miniaturize the antenna and the antenna was finally miniaturized to $2.5\times3.3$ mm2.
Abstract: A wideband compact magnetoelectric (ME) dipole antenna is investigated for millimeter-wave applications. First, an aperture coupled ME dipole is proposed with wideband and low profile. Next, transverse slots are added to miniaturize the antenna. The radiation performance of the higher-order mode is also improved. The antenna is finally miniaturized to $2.5\times3.3$ mm2 ( $0.27\,\,\lambda _{0} \times 0.35\,\,\lambda _{0}$ , where $\lambda _{0}$ is the wavelength in free space at center frequency) when it is used in the array environment. A bandwidth of 48.8% (24.3–40 GHz) for SWR $1 \times 8$ linear array is designed, fabricated, and measured. Good beam scanning capability is also verified by active simulation. With the advantages of wide bandwidth, compact size, promising radiation pattern and wide-angle beam scanning potential, the proposed antenna would be attractive for millimeter-wave devices and antenna in package (AiP) applications.
TL;DR: The design achieves wideband operation with a minimal cost or a complexity overhead (e.g., air cavities or additional substrates) by integrating a novel magnetoelectric dipole antenna in the package.
Abstract: This work introduces a multilayered organic package with embedded antennas that enables the integration of a scalable wideband phased array module supporting the n257, n258, and n261 5G frequency bands (24.25–29.5 GHz). The package comprises: 1) an $8\times 8$ array of dual-polarized antenna elements with 5.1-mm spacing; 2) RF, intermediate frequency (IF), dc, and digital interconnects to support radio-frequency integrated circuits (RFICs), filters, and combiners; and 3) a ball-grid array (BGA); it is implemented in a compact 42.5 mm $\times 42.5$ mm $\times 1.65$ mm form factor. The design achieves wideband operation with a minimal cost or a complexity overhead (e.g., air cavities or additional substrates) by integrating a novel magnetoelectric dipole antenna in the package. Direct probing and radiation pattern measurements of three antenna variants in two prototype antenna array packages demonstrate >6-GHz bandwidth with 0–5-dBi gain. Measurement results for associated liquid crystal polymer-based bandpass filters and power combiners are also presented.
TL;DR: A novel topology of combining a stacked patch antenna at 2.4/5 GHz bands and a magnetic-electric (ME) dipole antenna at 60-GHz with shared-aperture is developed, featuring the same linear polarization and broadside radiation patterns.
Abstract: Integrated antenna systems that support multiple wireless standards (microwave and millimeter-wave bands) have become a pivotal issue in future wireless networks. The joint implementation of these frequency bands that can provide long-range and short-range radio accesses within a wireless system is desired. However, due to the large frequency difference between different bands, it is hard to realize with limited space. To solve this problem, a novel topology of combining a stacked patch antenna at 2.4/5 GHz bands and a magnetic-electric (ME) dipole antenna at 60-GHz with shared-aperture is developed in this article. Based on the methodology of aperture reuse, a highly-integrated tri-band antenna system with a large frequency ratio and good isolation is reasonably designed, featuring the same linear polarization and broadside radiation patterns. For experimental demonstration, an elaborate prototype is fabricated and tested. The measured -10-dB impedance bandwidths among the three bands can satisfy the criterions of the IEEE 802.11 b/a/ad for wireless local area networks (WLANs, 2.4-2.485 GHz and 5.15-5.85 GHz) and wireless gigabit (WiGig, 57-64 GHz) operations
TL;DR: In this article, a dual-band dual-circularly polarized magneto-electric dipole antenna array for full-duplex communication systems is presented in this communication, which can simultaneously achieve left-hand circular polarization (LHCP) around 20 GHz with a low-loss feed network using the printed ridge gap waveguide (PRGW).
Abstract: A dual-band dual-circularly polarized magneto-electric dipole antenna array for full-duplex communication systems is presented in this communication. The proposed array can simultaneously achieve left-hand circular polarization (LHCP) around 20 GHz and right-hand circular polarization (RHCP) around 30 GHz with a low-loss feed network using the printed ridge gap waveguide (PRGW). The antenna is composed of two sets of stacked interconnected short-circuit patches operating at different frequencies and fed by the same gap. The LHCP at the 20 GHz band and RHCP at the 30 GHz band are realized by exciting the corresponding orthogonal electric-dipole mode and magnetic-dipole mode with −90°/90° phase difference. A cylindrical cavity consists of a series of metalized vias with a top metal strip used for surface wave inhibition. Using the PRGW, a four-way power divider with a low transmission loss is designed. Finally, the simulated $2 \times 2$ array was fabricated and measured. The measurement results show that the impedance bandwidths are 18.85–20.8 and 29.5–30.9 GHz. The 3 dB axial ratio bandwidths are 19.4–20.4 and 28.5–31.4 GHz, with the peak gains of 13.2 and 11.5 dBic, respectively.
TL;DR: In this paper, a millimeter-wave high-gain dual-polarized antenna array with an enhanced bandwidth is presented, which uses an innovative air-filled differential feeding cavity loaded with a short-ended cross-shaped waveguide.
Abstract: A millimeter-wave high-gain dual-polarized antenna array with an enhanced bandwidth is presented. An innovative air-filled differential feeding cavity loaded with a short-ended cross-shaped waveguide is investigated to serve as the feed network and the mode splitter simultaneously of the 2 × 2 dual-polarized sub-arrays. Wideband characteristics and a compact planar size that are desirable for the wideband array design are achieved. Moreover, a wideband dual-polarized waveguide-fed magneto-electric (ME) dipole antenna with a lightweight self-support geometry and wideband H-plane parallel feed networks with modified dual-layered configurations are proposed, which are convenient to connect with the differential feeding cavity directly. With the use of a commercial metallic three-dimensional (3D) printing facility, the proposed radiating elements, feeding cavities, and feed networks can be combined successfully in a whole piece with a lightweight geometry. The printed 8 × 8 array prototype operating in the Ka-band confirms a wide bandwidth of about 30%, a gain of up to 28.5 dBi, and stable unidirectional radiation patterns for the two polarizations. Benefitted from the advantages of the promising wideband dual-polarized radiations and convenience of fabrication, the proposed antenna array would be attractive for millimeter-wave polarization diversity applications.
TL;DR: In this article, a 5.8 GHz band highly efficient 1-W rectenna was proposed, which consists of a bridge diode, directly connected to a short-stub-connected high-impedance dipole antenna.
Abstract: This article describes a 5.8-GHz band highly efficient 1-W rectenna that consists of a bridge diode, directly connected to a short-stub-connected high-impedance dipole antenna, with a designed antenna resistance of $580~\Omega $ . The proposed antenna topology realizes circuit functionalities of impedance transform, impedance matching, harmonic reaction, and dc blocking while maintaining a high antenna radiation efficiency. Lossy circuit components between the antenna radiator and the bridge diode can be eliminated for a highly efficient rectification. In experimental investigations, the measured rectification efficiency of the 5.8-GHz band rectifier is 92.8% at an input power of 1 W, and the estimated antenna radiation efficiency from the measured antenna gain is 96.9%, including loss due to circuit functionalities and interconnection. With lesser additional losses, the proposed antenna can be integrated with circuit functionalities to achieve a highly efficient rectenna. The measured rectification efficiency is almost the same as the fundamental limitation restricted by the rectifier diodes’ performance.
TL;DR: A compact dual-port dual-frequency planar shared-aperture antenna with large frequency ratio that can be used on vehicular platforms for providing V2V communications and 5G millimeter-wave connections simultaneously.
Abstract: This paper presents a compact dual-port dual-frequency planar shared-aperture antenna with large frequency ratio. It consists of a microwave magneto-electric (ME) dipole antenna and a millimeter-wave parallel-plate resonator antenna (PPRA). It has two vertical conducting walls that form an upper-band parallel-plate resonator and meanwhile provide a magnetic source to the lower-band ME dipole. The design is a shared-aperture structure and is therefore very compact. For demonstration, a dual-frequency antenna simultaneously covering the 5.9-GHz vehicle-to-vehicle (V2V) band (5.855–5.925 GHz) and the 28-GHz 5G band (27.5–28.35 GHz) was designed, fabricated, and measured. Good agreement between the measured and simulated results was found. The lower and upper bands have the measured 10-dB impedance bandwidths of 41.6% (5.30–8.08 GHz) and 6.66% (27.15–29.02 GHz), and measured peak antenna gains of 5.80 dBi and 8.46 dBi, respectively. The antenna can be used on vehicular platforms for providing V2V communications and 5G millimeter-wave connections simultaneously.
TL;DR: In this paper, a novel shared aperture planar quasi-Yagi antenna with complementary pattern diversity performance is presented for 5G-NR application, where a shared aperture antenna with high port isolation and a compact size is first proposed by the even-odd mode feedings.
Abstract: A novel shared aperture planar quasi-Yagi antenna with complementary pattern (as well as polarization) diversity performance is presented for fifth generation (5G)-new radio (NR) application. A shared aperture antenna with high port isolation and a compact size is first proposed by the even–odd mode feedings. Then, by combining the monopole and dipole modes, the novel pattern reconfigurable method is studied step by step using the surface current distribution. By controlling the feeding states of the monopole and dipole elements, a pattern reconfigurable Yagi antenna with four modes (omnidirectional, broadside, and two tilted patterns) is realized. The quasi-Yagi antenna, which exhibits a compact size of $0.511\lambda _{0} \times 0.244\lambda _{0} \times 0.005\lambda _{0}$ , is fabricated and measured for experimental verification. The measured −10 dB bandwidth of the four modes all basically covers the 5G-N78 band 3.3–3.8 GHz (14.1%). The measured peak radiation efficiency is greater than 80%. The proposed compact antenna, with the advantages of low-cost, simple design, good bandwidth, and radiation performance, and pattern/polarization reconfigurability, is well situated for 5G-NR communication.
TL;DR: In this paper, a method of designing a printed filtering dipole antenna using codesign of bandpass filter (BPF) and antenna is proposed, which consists of two identical arms, which are placed on the opposite sides of the substrate.
Abstract: A method of designing a printed filtering dipole antenna using codesign of bandpass filter (BPF) and antenna is proposed in this article. The printed dipole antennas consist of two identical arms, which are placed on the opposite sides of the substrate. One arm of the dipole is used to construct the half-wavelength resonator of a typical BPF, and thus filtering and radiation performance can be obtained simultaneously. A third-order filtering dipole antenna is designed and analyzed in detail to demonstrate the codesign method. The measured S11 of the filtering dipole antenna is less than −11 dB in the range of 0.94–1.094 GHz and the peak gain is 7.8 dBi. To extend this design method, a third-order ±45° dual-polarized filtering dipole antenna is designed and measured. The measured S11 and S22 of the ±45° dual-polarized filtering dipole antenna are both less than −11 dB in the range of 0.94–1.08 GHz. Besides, the isolation between them is higher than 20 dB in the passband. The measured radiation patterns show that the dual-polarized filtering dipole antenna would be a potential candidate for base stations.
TL;DR: In this article, the authors proposed a parasitic decoupling technique (PDT) for increasing antenna isolation in the multiple-element multiple-input multiple-output (M-MIMO) array.
Abstract: This paper presents a systematic and accurate calculation method to design the parasitic decoupling technique (PDT) for increasing antenna isolation in the multiple-element multiple-input multiple-output (M-MIMO) array. The mutual coupling among antennas is suppressed by incorporating the parasitic decoupling structure (PDS) to generate the desired interference against the original antenna coupling. The designed PDS is composed of the parasitic scatterers, transmission lines (TLs), and reactive loads. A general network model is developed to determine the TL lengths and load reactances to satisfy the criteria derived from antenna impedances for high isolation. The decoupling methodology is further verified by two benchmarks. The simulation and measurement results demonstrate that isolation over 25 dB, efficiency above 72%, and envelop correlation coefficient below 0.02 can be achieved for both examples after using the proposed PDT. Besides, the PDT leads to improved pattern diversity, suitable for MIMO applications.
TL;DR: In this article, a self-isolated 10-element antenna array operating in the long-term evolution 42 (LTE42) frequency band is proposed for 5G massive MIMO smartphone applications.
Abstract: A self-isolated 10-element antenna array operating in the long-term evolution 42 (LTE42) frequency band is proposed for 5G massive MIMO smartphone applications. The proposed antenna elements are placed in a 2D array configuration; they are placed symmetrically along the two long edges of the mobile chassis. The proposed antenna structure is a shorted loop antenna resonating at half-wavelength mode, which is rarely deployed by researchers due to its large size compared to other quarter wavelength antenna structures. It is a printed, shorted, and compact loop antenna of a total footprint area of $6\times6.5$ mm2 ( $\lambda /14.3\times \lambda $ /13.2, where $\lambda $ is the free space wavelength at 3.5 GHz). A small capacitive coupling flag-shaped strip is used to excite the proposed loop antenna. The compactness is achieved using an inward meandering that forms an internal loop in the element. The position and the dimensions of this loop are used to tune the resonant frequency and matching level at 3.5 GHz. The results (theoretical, simulated, and measured) show that the 3.5 GHz band (3.4-3.6 GHz) is achieved with impedance matching better than −10 dB, and total efficiency higher than 65%. A $10\times10$ MIMO system is formed and it has an excellent MIMO and diversity performance in-terms of the envelope correlation coefficient (below 0.055), and apparently it has the highest channel capacity (about 54.3 bps/Hz) among other MIMO systems of the same order. Simulation results of the specific absorption rate (SAR) demonstrates that the proposed antenna solution satisfied SAR criterion. Thus, the proposed ten-element MIMO antenna represent an excellent candidate for sub-6 GHz 5G smartphone applications.