5G Base Station Applications Research Articles

A Wideband Base Station Antenna Loaded with Bow-Tie-Like Parasitic Elements

A ±45° dual-polarization wideband antenna for 5G base station application is proposed using cross dipoles, bow-tie-like parasitic elements and baluns. The antenna is modeled, simulated and optimized to get an optimal size of 115mm × 115mm × 27.8mm. The antenna has a -10dB bandwidth of 2.24GHz-3.75GHz and a fractional bandwidth of 50.4% and its isolation of two orthogonal ports is exceed than 25dB over the operating frequency band. The dual-polarized antenna is fabricated and measured to get a result that it has wide bandwidth, good directional radiation patterns, and high peak gain of 8.1±1.1dBi, making it suitable for 5G base station applications.

A Novel Differentially Fed Dual-Polarized Filtering Magneto-Electric Dipole Antenna for 5G Base Station Applications

In this article, a compact differentially fed ±45° dual-polarized filtering magneto-electric (ME) dipole antenna with improved harmonic suppression is proposed and analyzed. First, the fusion of loop-slot dipole and half-wave vibrator is calculated and mentioned to furnish theoretical guidance. Then, by reasonably placing two pairs of second-order step impedance feedlines and a loop-slot patch, a corresponding two-mode loop-vibrator combination filtering antenna with an upper radiation null is naturally constructed. Moreover, simply by loading four open-circuit stubs at the center of octagonal slot patch edge, another extra resonance mode and radiation null in the upper band can be simultaneously obtained. Later, through hiring the reconstructed third-order stub-loaded-resonator (SLR) feedlines, wideband harmonic suppression along with a third radiation null is unaffectedly achieved. Finally, the optimized antenna is fabricated and tested. The measured results reveal it realizes a wideband impedance bandwidth of 42.0% (2.78–4.26 GHz) and a high port isolation of 35 dB. Also, the length of its harmonic suppression is measured from 4.56 to 7 GHz, while the depth reaches more than 20 dB. In addition, the measured gain and radiation efficiency curves in the operating band are relatively stable and both are at a high average value (8.2 dBi, 85%).

A low‐power‐consumption massive MIMO scheme based on multibeam antenna array

AbstractIn this paper, a low‐power‐consumption massive multiple‐input and multiple‐output (MIMO) scheme with an integrated multibeam antenna array is proposed for the green fifth‐generation (5G) communication base stations. The referenced antenna array includes 8 × 16 dual‐polarized antennas with Butler matrix networks, leading to low radiofrequency (RF) complexity and low consumption. The measured results demonstrate that the antenna array achieves four beam clusters with a 45° coverage in elevated plane, with gain of 15.4 dBi at 3.6 GHz. Based on this, the generated beam clusters and corresponding RF chains can be switched independently according to the real‐time user scenario. It is analyzed that the consumption for both RF chains and computation can be reduced with a similar channel capacity compared with the conventional phased array. With the merits of low complexity and low consumption, the proposed massive MIMO scheme exhibits promising usage for green 5G base station applications.

Electronically Steerable Parasitic Patches for Dual-Polarization Reconfigurable Antenna Using Varactors

This paper presents a dual-polarized reconfigurable antenna loading electronically steerable parasitic patches. The proposed dual-polarized antenna is surrounded by four parasitic patches each of which is mounted by two varactor diodes on the ground. By tuning the varactors, continuous two-dimensional beam-steering can be achieved for each of the polarization. A prototype of the proposed antenna is fabricated and measured. Excellent agreement between the simulated and measured results is observed. It is observed that the maximum beam-scanning angles in E-plane and H-plane are greater than ±25∘, which is suitable for 5G base station applications.

A Low-Profile Triple-Band Shared-Aperture Antenna Array for 5G Base Station Applications

In this article, a triple-band shared-aperture dual-polarized antenna array is proposed for fifth generation (5G) base station applications. The shared-aperture antenna array consists of an antenna operating in the low-band (LB) 0.69–0.96 GHz, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times $ </tex-math></inline-formula> 2 antenna array operating in the middle-band (MB) 1.8–2.7 GHz, and a <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 $ </tex-math></inline-formula> 4 antenna array operating in the high-band (HB) 3.3–3.8 GHz. A wideband bandstop frequency selective surface (FSS) is introduced to eliminate the influence of the LB antenna on the MB/HB antenna array. The MB antenna is co-designed with the wideband bandpass FSS, such that it does not affect the radiation performance of the HB antenna array. Therefore, the LB antenna, MB antenna array, and HB antenna array are successfully integrated within a compact volume of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.69\lambda _{L} \times 0.69\lambda _{L} \times 0.177\lambda _{L}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{L}$ </tex-math></inline-formula> is the free-space wavelength at 0.69 GHz). Measured results demonstrate that the proposed low-profile shared-aperture antenna array offers stable radiation patterns and an average gain of 6.5, 7.6, and 8.2 dBi in the LB, MB, and HB, respectively. Owing to the wide bandwidth, low-profile height, shared-aperture, and compact size, the proposed antenna array is promising for 5G massive MIMO applications.

Substrate Integrated Waveguide Antenna at Millimeter Wave for 5G Application

This paper presents a dual-band slot antenna using substrate integrated waveguide (SIW) technology at 26 and 28 GHz. High loss is one of the main challenges faced by 5G base station network due to the severe path loss at high frequency. Hence, high gain antennas are required for 5G base station applications to overcome path loss issue. Hence, this work designs a high gain SIW antenna based on slot technology to excite dual-bands with high gain capability. The antenna is designed with two slots shaped to resonate at two different frequencies: 26 and 28 GHz. The antenna is analyzed using CST software and fabricated on Roger RT5880 substrate with permittivity of 2.2 and lost tangent of 0.0009 with thickness of 0.508 mm. The design operates at 26 and 28 GHz with measured reflection coefficients less than -10 dB. Measured high gains of 8 and 8.02 dB are obtained at 26 and 28 GHz, respectively. Overall, the antenna showed good performance that would benefit the fifth-generation applications.

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.

Dual-Broadband Dual-Polarized Shared-Aperture Magnetoelectric Dipole Antenna for 5G Applications

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.

Locating Pareto optimal designs of antenna through parallel multiobjective evolutionary algorithm

Population-based multiobjective metaheuristics are potential in microwave component designs because all electric properties could be optimized simultaneously to find several tradeoff designs in a single run. However, they often suffer extremely-expensive computational time caused by too many full-time objective function evaluations. In this paper, firstly, an efficient parallel implementation of MOEA/D (multiobjective evolutionary algorithm based on decomposition) is proposed to reduce the overall computational time. Secondly, optimization speed, approximation performance to the entire Pareto front, and algorithm robustness of the proposed parallel MOEA/D are investigated through extensive standard test instances. Then, a complete design procedure based on the proposed optimization algorithm is presented to locate multiple Pareto optimal designs of antenna. Finally, a compact broadband dual-polarized antenna operating at 3.3-5.0 GHz is designed for 5G base station applications. Comparisons are made to verify the great performance of the proposed method.

A Broadband Dual-polarized Antenna for 2G/3G/4G/5G Base Station Applications

A Broadband Dual-polarized Antenna for 2G/3G/4G/5G Base Station Applications

Compact Dual-Polarized Base Station Antenna Array Using Laser Direct Structuring Technique

In this letter, a compact ±45° polarized base station antenna array fabricated using laser direct structuring (LDS) technique is presented. The proposed antenna array operates in fifth-generation (5G) NR band 41 (2496–2690 MHz). The simple antenna elements of the array consist of a modified patch radiator fed by Y -shaped probes realized by injection molding, which are amenable to efficient mass production. An antenna unit (AU) is investigated to meet the specification requirements in practical base-station applications. A prototype of the AU was manufactured and measured, and the results showed that it is able to fulfill the design requirements within the operating band. These features also show that this LDS-based antenna array would be a promising solution for 5G base station applications.

Dual-Band Dual-Polarized Base Station Antenna With a Notch Band for 2/3/4/5G Communication Systems

This letter proposes a new design of a dual-band dual-polarized base station antenna with a notch band for second-generation (2G), 3G, 4G, and the sub-6 GHz 5G systems. The antenna is composed of a four-leaf loop radiator, two-layer parasitic annular disk and a pair of crossed Y-shaped baluns. By introducing mouse-ear shaped arm to the edge of each radiator, a dual-band operating characteristic and a notch band from 2.9–3.2 GHz are realized. The annular disks and gradient strips are beneficial for bandwidth enhancement. The measured results show that the proposed antenna offers two broad bands with the fractional bandwidth of 55.8% (1.55–2.75 GHz), and 14% (3.3–3.8 GHz) for voltage standing -wave ratio (VSWR) 30 dB. This design achieves stable gain of 7.1 ± 0.5 dB and half power beam width of 68 ± 5° during the working bands. These attractive features make the antenna an ideal candidate for 2G, 3G, 4G, and the sub-6 GHz 5G base station applications.

Broadband Dual-Polarized Loop Cross-Dipole Antenna for 5G Base Station Applications

A broadband dual-polarized base station antenna is proposed in this paper. The antenna consists of loop cross-dipoles, Y-shaped coupling feeding lines, and a metal box reflector. An equivalent circuit model including a signal flow diagram is established to analyze the mechanism of the proposed antenna in detail. Moreover, the Y-shaped coupling feeding lines are introduced to control the coupling with the antenna to achieve broadband and good impedance matching. The prototype of the antenna is fabricated and measured. The measured results show that the antenna with simple structures can operate at the band of 3.2–5.22 GHz (48%) with high port-to-port isolation (35 dB) and stable gain (9 ± 1 dBi). The measured results show good agreement with simulated results, especially in cross-polarization discrimination ratio (&gt;27 dB) and the half power beam width (61° ± 3° at the E-plane, 68° ± 3° at the H-plane). In summary, the proposed antenna could be a good candidate for 5G sub-6 GHz base station applications.

Triband Dual-Polarized Shared-Aperture Antenna for 2G/3G/4G/5G Base Station Applications

This article presents a novel triband dual-polarized shared-aperture antenna with frequency-selective function for sub-6 GHz base station applications. The proposed antenna is composed of a dual-polarized square loop antenna with two parasitic loops for 2G/3G/4G (1710-2690 MHz) and a differentially fed dual-polarized planar antenna for 5G (3300-3600 and 4800-5000 MHz) base station applications. These two antennas are placed coaxially but different altitudes for saving the installation space. In order to achieve good individual performance for these two antennas in the same aperture without interference or blocking, the lower band (LB) antenna is designed as a frequency-selective surface (FSS) for the nether mid/upper bands (M/UBs) antenna. The measured results show that the proposed antenna achieves a high port isolation (>20 dB) between LB and M/UBs and a -10-dB impedance bandwidth of 50.4% (1.60-2.70 GHz), 14.9% (3.28-3.80 GHz), and 8.6% (4.75-5.18 GHz). To further validate the design concept, an antenna array composed of four LB elements and eight M/UBs elements with the corresponding spacing is fabricated and measured, which demonstrates the application of the triband shared-aperture antenna in array form.

Ultrawideband Low-Profile and Miniaturized Spoof Plasmonic Vivaldi Antenna for Base Station

Stable radiation pattern, high gain, and miniaturization are necessary for the ultra-wideband antennas in the 2G/3G/4G/5G base station applications. Here, an ultrawideband and miniaturized spoof plasmonic antipodal Vivaldi antenna (AVA) is proposed, which is composed of the AVA and the loaded periodic grooves. The designed operating frequency band is from 1.8 GHz to 6 GHz, and the average gain is 7.24 dBi. Furthermore, the measured results show that the radiation patterns of the plasmonic AVA are stable. The measured results are in good agreement with the simulation results.

Design and characterization of a compact single-layer multibeam array antennausing an 8×8 Butler matrix for 5G base station applications

A multibeam array antenna employing a Butler matrix is a promising solution for fifth generation (5G) base stations. Due to inaccurate phase differences between output ports in the Butler matrix, the radiation characteristics could show incorrect main beam directions. In addition, the literature has also reported the issue of high amplitude imbalance in the Butler matrix. This paper presents a single-layer multibeam array antenna fed by an 8×8 Butler matrix operating at 28 GHz for 5G base station applications-a more cost-effective solution for large-scale production. The Butler matrix consists of twelve quadrature hybrids, sixteen crossovers, and eight phase shifters. This circuit was integrated with eight antenna elements at the output ports of the Butler matrix. The proposed multibeam array antenna was fabricated using a low dielectric constant and a low loss tangent substrate. The dimensions of the multibeam array antenna were 88×106×0.254 mm3 . The Butler matrix achieved low insertion losses and low phase error with average values of 2.5 dB and less than ±10 ° at 28 GHz, respectively. The measured return losses were less than -10 dB at 28 GHz. The measured radiation patterns were obtained and eight main beams were pointed at ±6 ° , ±18 ° , ±30 ° , and ±44 ° with measured gains between 9 dBi and 14 dBi.

Multiple Beam Synthesis of Passively Cooled 5G Planar Arrays Using Convex Optimization

An extended-feature, system-driven convex algorithm for the synthesis of uniform-amplitude, irregular planar phased arrays with simultaneous multi-beam optimization for mm-wave 5G base station applications in multi-user scenarios is presented. The inter-user interferences are suppressed by minimizing the maximum sidelobe level (SLL) for a beam scanned freely inside a given sector. The aperture size is restricted to the size of the heatsink baseplate dimensions. A minimum guaranteed inter-element spacing in the final layout is pre-defined, which prevents element overlapping, eases the thermal problem and helps reduce the effects of high mutual coupling (MC). The algorithm performance is tested via the synthesis of a 64-element integrated array with at least half a wavelength inter-element spacing. The optimized array results show that, compared to their regular counterparts, significant reduction in the SLLs is achieved for a beam scanned inside the defined sector, while keeping the maximum temperature of the array at a reliable level. The effect of MC on the results is also investigated via full-wave simulations and it is explained how embedded element patterns can potentially be included in the optimization. Superior capabilities of the proposed method are illustrated by comparing the algorithm output to those reported in the state-of-the-art literature.

Supply- and Load-Modulated Balanced Amplifier for Efficient Broadband 5G Base Stations

This paper presents a broadband efficient power amplifier (PA) targeting sub-6-GHz 5G base station applications. Due to the demanding requirements in both peak-to-average power ratio (PAPR) and bandwidth in 5G systems, we employ a combination of both load and supply modulation for efficiency enhancement. Active matching, implemented using an RF-input load-modulated balanced amplifier (LMBA) architecture, enables efficient octave-bandwidth operation. Supply modulation, which is carrier frequency agnostic, is then used to further extend the back-off efficiency. This paper focuses on a study of supply modulation strategies for the load-modulated PA using an efficient GaN eight-level discrete supply modulator. To overcome the bandwidth limitations associated with discrete-level switching, a commutation rate reduction (CRR) filter is applied in digital baseband and its effects are analyzed theoretically and experimentally. The supply-modulated LMBA is characterized across 1.8–3.8 GHz with 100-MHz, 10-dB PAPR signals. An output power of 34 dBm with average composite (total) PAE ranging from 22.4% to 43.9% across the band is demonstrated, with an ACLR of about −50 dBc after digital predistortion.