Dual-polarized Antenna Element Research Articles

LCP-Based Low-Cost Base Station Antenna for 3.7 GHz 5G Band

This paper presents a large-scale base station antenna assembly structure that is low-cost, reliable, and easy to manufacture. The antenna element is composed of a low-loss liquid crystal polymer based on a plastic molded module and a modified wideband stacked patch antenna. The base station antenna consists of a 4 × 8 antenna module, with each module comprising 3 × 1 subarrays along with dual-polarized antenna elements. The antenna element achieved an efficiency of 91% and an impedance bandwidth of 1.14 GHz within a height of 10 mm at 3.7 GHz. Furthermore, the fabricated array antenna structure was tested and verified to have an effective isotropic radiated power of 75.6 dBm at boresight and a steering range of less than ±60°. Therefore, the proposed structure meets the required antenna and beam-forming performance for commercial 5G active antenna systems.

Wide-Angle Scanning and High Isolation Dual-Polarized Base Station Antennas for Sub-6 GHz Applications

This paper presents a wide-angle scanning and high isolation base station antenna array. The antenna element employs a compact dual-polarized umbrella-shaped printed dipole with a small size of 0.23λ0 × 0.23λ0 × 0.26λ0, which provides the possibility for a small element spacing array. The antenna element possesses wide 3 dB beamwidth of 84.6∘ benefiting from the pulling down of the dipole arms. Then, a dual-layer metal superstrate structure and metal wall is adopted to mitigate different kinds of mutual coupling between the dual-polarized antenna elements in the array. Owing to the wide beamwidth of the element and the low mutual coupling between the elements, the final 4×6 antenna array can achieve a good beam-scanning capability with maximum scanning angle up to ±55∘ and a small gain variation of less than 3 dB over the operation band 3.3-3.8 GHz. The fabricated array shows the measured isolation between all ports of the antennas is increased to more than 20 dB. Scanning characteristics also agree well with the simulated results. With the merits of wideband, low-cost (simple design and easy fabrication), wide-angle beam-scanning capacity, and good radiation performance, the proposed design has potential for application in 5G base stationsystems.

Packaging and Antenna-Assembled Hybrid Stacked PCB with Novel Vertical Transition for 39 GHz 5G Base Stations

This paper proposes a novel packaging and large-scale antenna-assembled structure for a printed circuit board (PCB) that reinforces productivity, facilitates cost reduction, and maintains reliability. This was achieved by splitting the antenna from the main board and packaging it into a radio-frequency integrated circuit. In addition, two innovative solutions—an externally attachable flexible PCB antenna and a PCB-embedded coaxial line—are introduced to overcome the degradation in antenna performance and vertical RF transition loss in the proposed low-cost hybrid PCB. First, the proposed externally attachable flexible PCB antenna and a parasitic aircoupled antenna, which were easily assembled on the PCB, achieved an antenna efficiency of 95% and an impedance bandwidth of 7 GHz. Second, the fabricated coaxial line exhibited enhanced impedance matching over a wide frequency range of 30–40 GHz and improved insertion loss of approximately 1.4 dB. Furthermore, the packaged antenna, composed of 256 dual-polarized antenna elements per stream, incorporated a 39 GHz CMOS-based 16-channel phased-array transceiver IC. The set-level beam-forming measurements were verified considering an effective isotropic radiated power of 55 dBm at boresight and a steering range >±60°. In addition to being suitable for mass production in terms of cost and reliability, the proposed structures and solutions met the required antenna and beam-forming performance for commercial 39 GHz base stations without sacrificing performance.

A Wide-Beam Antenna Array With Spatially Variable-Orthogonal-Polarizations (SVOP) Achieved by Polarization-Mixing

This paper introduces a novel polarization-mixing strategy to significantly widen the beamwidth of dual-linear-polarized antenna arrays without changing the array topology. Instead of using the two polarizations separately as usual, it blends the orthogonal linearly-polarized radiations to achieve wider beamwidth. The proposed method is implemented on a typical ±45°-polarized base station antenna array with its thought process and working mechanism elaborated. Much wider beamwidth is achieved compared to the traditional pattern synthesis methods based on amplitude and phase weighting or sparse arrays. The beamwidth can be controlled by simply tuning one phase shifter. Importantly, this method allows all the elements to be fully excited with the same amplitude, thus avoiding using additional amplifiers or attenuators. In the meantime, the polarization-mixing method leads to spatially-variable polarizations (SVP). To obtain polarization diversity required in cellular communication systems, two SVP arrays with the same pattern shapes are designed to have their polarizations orthogonal to each other in all directions of interest. The conditions of achieving orthogonal patterns using this method are theoretically derived and thoroughly validated in theory and in simulation. It is shown that the obtained spatially-variable-orthogonal-polarization (SVOP) arrays have a much broader beam pattern and better polarization orthogonality (PO) than that of the dual-polarized antenna element.

Beam Shaping of Base Station Antenna Array by Using MMPTE

In this paper, a beam shaping scheme is presented for the optimal design of base station antenna array. The antenna array consists of four linearly arranged dual-band dual-polarized antenna elements, and it is designed to cover the LTE frequency band (2.3-2.69 GHz) and 5G frequency band (3.3-3.6 GHz). The shaped beams with possible maximum gain, suppressed sidelobe level smaller than -16 dB, front-to-back ratio larger than 18dB, and filled-up null point larger than -23 dB are accomplished through two steps by using the unconstrained methods of maximum power transmission efficiency (MMPET) and constrained MMPTE, respectively. In the proposed beam shaping scheme, all the realistic factors of the antenna array have been taken into account, such as the difference of element radiation patterns, complexity and tolerance of the element structure and spacing.

Millimeter-Wave Dual-Band Dual-Polarized SIW Cavity-Fed Filtenna for 5G Applications

This article presents a millimeter-wave (mmWave) dual-band dual-polarized filtenna, which can achieve desirable out-of-band rejection for 5G applications. The dual-band dual-polarized antenna element consists of two fully-shielded quarter-mode substrate integrated waveguide (FSD-QMSIW) cavities and a dual-band stacked ring antenna. Two parts are coupled through the slot on the ground. The cavities are completely enclosed by the metal holes and copper cover to eliminate radiation loss. The loaded slots can tune the frequencies of the first two modes in the FSD-QMSIW cavity for dual-band operation. The inherent transmission null between the dual modes is generated to improve the stopband attenuation. To verify the proposed method, a dual-band dual-polarized filtenna with a three-order filtering function and four radiation nulls is designed and fabricated. The −10 dB impedance bandwidth can effectively cover 5G n258 (24.25–27.5 GHz) and n260 (37–40 GHz) bands in the measurement. The gains of two polarizations drop over 20 dB between the two bands. A four-element filtenna array is constructed to test its beam-scanning ability and further integrated with active beamformer integrated circuits (ICs). The measured results show that the fabricated filtenna array maintains satisfactory out-of-band rejection performance and can be one of the most promising 5G communication candidates.

Millimeter-Wave Wideband Dual-Polarized LTCC Antenna Array Based on Metasurfaces for Beam-Scanning Applications

This communication presents a millimeter-wave wideband dual-polarized low-temperature cofired ceramics (LTCC) antenna array based on metasurfaces (MSs) for beam-scanning applications. Benefiting from the wideband and large-freedom property of MS-based structures, a novel ±45° dual-polarized wideband MS-based antenna (MSA) element with high isolation is designed. The antenna element is fed by two orthogonal striplines on different layers, through a crosslike dog-bone slot and a narrow slot, respectively, to realize the two polarizations. The feeding structure consists of slot–stripline–slot–stripline from top to bottom and is specially designed to improve the polarization isolation of the antenna element. The proposed MSA element is compactly arranged with a small distance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ &lt; 0.5\lambda$ </tex-math></inline-formula> ) to construct a 4 <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> 4 array integrated in an LTCC package, where via walls with metal ring strips are loaded between adjacent elements to reduce the gain fluctuation. Consequently, the array can achieve a good beam-scanning capability over a wide band of 19.5% with a maximum scanning angle up to ±55° and a small gain variation of less than 3 dB. Meanwhile, the active <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S$ </tex-math></inline-formula> parameters almost always remain below −10 dB, enabling good impedance matching when scanning at all angles. With these features, the proposed design has potential for application in 5G base-station systems.

Multiband Dual-Polarized Hybrid Antenna With Complementary Beam for Simultaneous RF Energy Harvesting and WPT

A novel hybrid antenna for simultaneous RF energy harvesting (RF-EH) and dedicated wireless power transfer (WPT) is proposed. The hybrid antenna consists of a multiband dual-polarized omnidirectional antenna element (covering GSM-1800, UMTS-2100, ISM-2400/5800, 5G-3500, and wireless local area network (WLAN) bands) and a 2.4 GHz dual-polarized high-gain directional patch array element. In the WPT band (ISM-2400), directional beams locate at the null of omnidirectional beams, and a pair of spatially complementary beams is obtained. The omnidirectional beams are capable of capturing the ambient RF energy from low-elevation space for low-power circuits, while the directional beams receive the power from a dedicated source to activate high-power modules. Also, the spatially complementary feature contributes low mutual couplings between ports that support the independent operation of WPT and RF-EH. For validation, an outdoor RF-EH test and an indoor WPT test are conducted. The measured results agree with the simulated ones.

A Broadband Dual-Polarized Magneto-Electric Dipole Antenna Element for Low-Frequency Astronomical Arrays

This paper presents simulation-based design and analysis of a broadband dual-polarized magneto-electric dipole antenna element that can be used to construct VHF astronomical antenna arrays. The antenna consists of two pairs of radiating structures, each fed by a Γ-shaped feeding section. The feeding section and radiating parts are physically disconnected from each other. The antenna is evaluated by simulation, and its −10 dB impedance matching bandwidth ranges from 115 to 340 MHz. The maximum gain of the antenna is about 8 dB over the operating range. Isolation of about 20 dB is observed between the two input ports.

Wideband Dual-Polarized Endfire Antenna Based on Compact Open-Ended Cavity for 5G Mm-Wave Mobile Phones

This article describes a compact dual-polarized endfire antenna array for fifth-generation (5G) millimeter-Wave (mm-Wave) mobile application. The dual-polarized endfire antenna element is constructed by a compact open-ended cavity with cavity mode for vertical polarization (VP) radiation and open-slot mode for horizontal polarization (HP) radiation. With the integrated design of VP and HP elements, the proposed antenna shows a much more compact size compared to existing schemes. To enhance the bandwidth of low-profile VP radiation, a slot is etched on the cavity to create a new mode for dual-resonance response, realizing a wide bandwidth of 24.5&#x2013;29.5 GHz for both polarizations. In addition, radiation pattern modification techniques are employed to achieve good endfire beams with a high front-to-back ratio for both polarizations, thus enabling a high peak gain of 10.3 and 11.3 dBi for VP and HP, respectively. A wide beam scanning range of &#x00B1;50&#x00B0; with realized gain above 7 dBi is realized at 27 GHz for both polarizations. In virtue of compact size, wide bandwidth, high gain, and good spatial coverage, the proposed design strategy is promising for future 5G mm-Wave mobile phones.

A Modular Dual-Polarized Ka-Band Vivaldi Antenna Array

A modular dual-polarized Vivaldi antenna array design for 18–30 GHz frequency is presented. The array module consists of the antenna and RF modules. The antenna module comprises <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> dual-polarized antenna elements with element spacing of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> /2 at 30 GHz. The RF module contains the amplifiers and phase shifters that control all the elements using commercial off-the-shelf (COTS) flip-chip components. The footprint of the RF module is the same as that of the antenna module allowing assembly of antenna arrays of almost any size and shape. Additionally, the interface between the antenna and the RF modules is connectorless, decreasing the number of components required in the assembly and decreasing the overall cost of the system. An array of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4\times 8$ </tex-math></inline-formula> dual-polarized antenna elements is constructed from two array modules to prove the seamless operation of the modular design. The prototype uses Anokiwave chips with a frequency range from 26.5 GHz to 29.5 GHz. The measured amplitude and phase of the electric field in front of the antenna aperture is uniform so as to equally feed the elements. Additionally, the demonstrated beam steering up to ±60° in the plane of the larger array dimension matches well with the simulations, proving the feasibility of the design.

Analysis of Wave Propagation Models With Radio Network Planning Using Dual Polarized MIMO Antenna for 5G Base Station Applications

Dual polarized printed multiple input multiple output (MIMO) antenna for Band 42 (3.4 - 3.6 GHz) with wave propagation models is presented. Polarization and spatial diversity are achieved by utilizing two printed bow-tie antennas in orthogonal orientation. The designed dual polarized antenna element with <inline-formula> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$8\times 8$ </tex-math></inline-formula> massive MIMO antenna configuration radiation patterns are deployed in selected geographical situation for detailed radio network planning using FEKO-WinProp platform. Knife edge diffraction, extended walfisch-ikegami and dominant path wave propagation models are implemented with designed MIMO antenna configurations. Modulation schemes of QPSK and QAM with corresponding data rates and throughput for all propagation models are presented. The signal strength and quality reflecting parameters reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), and signal to noise plus interference ratio (SNIR) are also evaluated for each model. From the simulation results dominant path model provides data rate and throughput of 3.827, 995 MBit/s and 3.577, 930.1 MBit/s for single stream of data in uplink and downlink respectively. The maximum data rate of 1.37 GBits/s is achieved for deployed base stations with <inline-formula> <tex-math notation="LaTeX">$8\times 8$ </tex-math></inline-formula> massive MIMO antenna configuration effectively covering the entire geographical site.

Antenna-in-Package Integration for a Wideband Scalable 5G Millimeter-Wave Phased-Array Module

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 8×8 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 ×42.5 mm ×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.

A 256-Element Ku-Band Polarization Agile SATCOM Transmit Phased Array With Wide-Scan Angles, Low Cross Polarization, Deep Nulls, and 36.5-dBW EIRP per Polarization

This article presents an ultralow-profile and lightweight Ku-band transmit phased array with 256 dual-polarized antenna elements for SATCOM on-the-move (SOTM) terminals. The antennas are placed in a square grid with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> /2 spacing at 14 GHz. At normal incidence, the phased array results in a measured effective isotropic radiated power (EIRP) of 64.5 and 66.5 dBm at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {1~dB}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {sat}}$ </tex-math></inline-formula> , respectively, per polarization. The measured patterns, in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$E$ </tex-math></inline-formula> - and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$H$ </tex-math></inline-formula> -planes, show almost ideal patterns with a wide scanning range of ±60°, a 3-dB instantaneous bandwidth of 13.0–14.6 GHz, and a cross-polarization isolation of 27 dB up to ±45° and 23 dB at ±60° scan angles. In the circular polarization mode, the measured axial ratio (AR) is <1.1 dB at 14–14.5 GHz. The phased array is also capable of synthesizing deep nulls (−30 to −40 dB) over a wide range of angles, thereby reducing unintended radiation to geostationary orbit (GEO) satellites. Transmit noise analysis is presented and shows that the array signal-to-noise ratio (SNR) is dominated by the block upconverter (BUC) and not by the beamformers. An error vector magnitude (EVM) of 2.8%–3.5% was achieved over a wide scan range for QPSK, 8-PSK, and 16-PSK waveforms with 100-MHz bandwidth. The array near-ideal performance, compact size, low profile with 3.5-mm thickness, and ultralightweight of 212 g make it ideal for affordable Ku-band SATCOM terminals.

Sequential 90° Rotation of Dual-Polarized Antenna Elements in Linear Phased Arrays with Improved Cross-Polarization Level for Airborne Synthetic Aperture Radar Applications

In this work, a novel rotation approach for the antenna elements of a linear phased array is presented. The proposed method improves by up to 14 dB the cross-polarization level within the main beam by performing a sequential 90° rotation of the identical array elements, and achieving measured cross-polarization suppressions of 40 dB. This configuration is validated by means of simulation and measurements of a manufactured linear array of five dual-polarized cavity-box aperture coupled stacked patch antennas operating in L-Band, and considering both uniform amplitude and phase distribution and beamforming with amplitude tapering. The analysis is further extended by applying and comparing the proposed design with the 180° rotation and non-rotation topologies. This technique is expected to be used for the next generation L-Band Airborne Synthetic Aperture Radar Sensor of the German Aerospace Center (DLR).

A Differentially Fed Dual-Polarized Filtering Patch Antenna With Good Stopband Suppression

A differentially-fed dual-polarized filtering patch antenna with no extra filtering circuits involved is proposed. The filtering response is realized by symmetrically loading four short strips and a long cross-type strip, and a square ring slot to insert radiation zeros on the dual-polarized antenna element. The short and long strips can generate two transmission zeros at lower and upper band edges, respectively, leading to a sharp skirt selectivity. In addition, the long cross-type strip and the square ring slot can respectively introduce an extra resonance close to the original one, broadening the impedance bandwidth. Also, the equivalent circuit is presented to show that the two zeros can be brought by the two equivalent series resonant circuits extracted from the short/long strips resulting in the bandpass response. We may note that the proposed filtering structure owns the merits of simple, compact and complete symmetry, thus it can be well integrated with the dual- polarized antenna. Consequently, a compact and high-gain dual- polarized filtering antenna with good stopband suppression, low cross-polarization level and symmetrical radiation patterns is obtained. It can achieve an impedance bandwidth about 15% and a maximum gain of 8.4 dBi. The simulated cross-polarization level is below -40 dB, and the measured one is lower than -22 dB. Moreover, the upper stopband can be up to 2.6 f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the center frequency of the antenna), where the stopband radiations from all the directions can be suppressed and the measured suppression ratio can reach 90%.

Compact Millimeter-Wave Endfire Dual-Polarized Antenna Array for Low-Cost Multibeam Applications

A compact multibeam endfire dual-polarized antenna array for low-cost millimeter-wave (mmWave) applications is proposed in this letter. Multimode substrate-integrated waveguide (SIW) section with interactions is applied as the basic beamformer. The dual-mode SIW is used in the beamforming network to support dual-polarization application without occupying an extra area. The printed dipole antenna with integrated balun and the open-ended SIW antenna with metallic strips are integrated to realize an endfire dual-polarized antenna element. Based on this endfire antenna element, a multibeam dual-polarized antenna array is developed. The proposed antenna array includes a four-element antenna array, an SIW beamforming network, and transitions. Additional air gaps between antenna elements are designed for mutual coupling reduction. The fabricated multibeam endfire dual-polarized antenna array achieves an impedance bandwidth of 11.3%, and the overlapped 3 dB beamwidth of the four generated beams in two polarizations are able to cover a wide range between ± 41°. The proposed low-cost multibeam antenna array can be a good candidate for 5G mmWave wireless applications.

Low‐profile dual‐polarised metasurface‐enabled antenna array for base‐station applications

This Letter presents a dual linearly polarised microstrip antenna for base station applications. Firstly, a dual-polarised metasurface-based antenna element employing differential feeding technology is proposed. The proposed antenna element achieves a simulated bandwidth of 11.6% for |S 11 | < −15 dB, mutual coupling better than 30 dB, and the cross-polarisation discrimination level over 35 dB. Secondly, based on the antenna element, a 3 × 3 antenna array is eventually presented, which was fabricated and characterised. The measured bandwidth is 12% for |S 11 | < −10 dB, and the port-isolation is over 25 dB. The superiorities of low-profile and high port isolation indicate that the proposed design is a promising candidate for sub-6G base-station applications.

Mitigation of mutual coupling in 2 X 2 dual slant polarized MIMO antennas using periodic array of SRRs loaded with transmission line for LTE band 40

2 X 2 dual slant polarized multiple input multiple output (MIMO) antennas with reduced mutual coupling is presented for polarization and spatial diversity. The design of printed periodic array of split ring resonators (SRRs) loaded with horizontal strip transmission line is proposed to mitigate the mutual coupling among the MIMO antenna elements. An equivalent circuit model, characterizes the effect of coupling between the array of SRRs and the loaded transmission line, which together reduces the near field coupling between the adjacent antenna elements. The additional horizontal strip at the bottom is utilized to seek the return current path to the ground plane. Polarization and spatial diversity is achieved by utilizing dual slant 450 polarized antenna elements with eight independent channels. All four dual polarized antenna elements are designed to operate with a VSWR of <2 for (2.3-2.4 GHz) Band 40. Dual slant 450 polarization is achieved by utilizing two printed planar bow-tie antennas in orthogonal orientation. Measured and simulated results shows by incorporating periodic array of SRRs loaded with transmission line a considerable mutual coupling reduction of 25 to 50 dB is achieved in E-plane, H-plane, and D-plane over the required band 40. An isolation of 30 dB and an average gain of 7.5 dB is measured for dual slant 450 polarized antenna elements. MIMO performance metrics in terms of envelope correlation coefficient and diversity gain are also investigated.

Isolation Improvement of Compact Microbase Station Antenna Based on Metasurface Spatial Filtering

A compact high-isolation multiple-input multiple-output (MIMO) microbase station antenna consisting of two dual-polarized antenna elements is presented. The symmetrical magnetic coupling feeding network is used to feed the radiation patch of the dual-polarized antenna and to improve the isolation of the antenna element. By introducing parasitic square patches, the radiation characteristics and isolation of the dual-polarized antenna are improved. In addition, a modified closed-loop metasurface unit is designed and used to construct an isolation wall. When dual-polarized antenna elements are used to assemble a MIMO antenna, the proposed metasurface structure is inserted between them to reduce the coupling between MIMO antenna elements, regarded as a spatial band-stop filter to suppress the spatial electromagnetic waveform of the elements. After loading the metasurface isolation wall, the maximum increase of isolation is 9.17 dB at the center frequency point of 2.6 GHz. For antenna element ports and cross-polarized ports, the isolations are greater than 30 dB, and the isolation of the same polarized ports is better than 25 dB within the frequency band from 2.45 to 2.8 GHz. At the same time, the reflection coefficients of the ports of the elements are less than -15 dB. Finally, a prototype of the proposed MIMO microbase station antenna was fabricated and tested, and the experimental results are proximity with the simulation responses.