Profile Antenna Research Articles

A Novel Procedure To Hybridize the Folded Transmitarray and Fabry–Perot Cavity With Low Antenna Profile and Flexible Design Frequency

A Novel Procedure To Hybridize the Folded Transmitarray and Fabry–Perot Cavity With Low Antenna Profile and Flexible Design Frequency

Adjustment Method of Main Reflector for a Large Radio Telescope

The performance of the antennas, which plays an important role in millimeter-wave astronomy and space communication, is often limited by their reflector surface accuracy. Microwave holography is a fast and effective technique for measuring the surface profile of reflector antenna. In this paper, the antenna aperture phase profile is obtained by microwave holography to estimate the deviation between the reflector of the Tianma 65 m radio telescope and the ideal paraboloid. The panels of the Tianma 65 m radio telescope is in radial pattern with 14 rings. Each corner of the panel is fixed on the screw of the actuator to move up and down, and the adjacent corners of the four panels share an actuator. We use the method of plane fitting to calculate the adjustment value of every panels corner. But one actuator, which simultaneously controls the common corner of the adjacent panels, will have different adjustment values according to the plane fitting equation based on adjacent panels. In this paper, an adjustment value at the corner of the adjacent panel is obtained by plane fitting and adjustment calculation method with the antenna illumination function as the weight, that is, the optimal adjustment value of 1104 actuators of the Tianma 65 m radio telescope. Through many adjustments and the application of new algorithms, the surface accuracy of the reflector of the Tianma 65 m radio telescope has gradually improved to the current 0.24 mm.

Design of dual circular polarized stacked patch antenna for BeiDou navigation satellite systems

In this article, a design of two-layered, dual circular-polarization (CP) and dual-band path antenna is presented for BeiDou navigation satellite (BDS) system applications. A single 50-Ω Co-axial probe feeding arrangement is employed to achieve dual-band operation and it feeds both the antennas simultaneously. This mode introduces the CP radiation on both upper (RHCP) and lower (LHCP) operation bands. The impedance bandwidth is further widened by accommodating two semi-circular stubs on the top patch. The fabricated and experimentally validated prototype radiates at 1.82 and 3.45 GHz (center frequency). The upper and lower operating band exhibits right and left-handed CP radiations, which constructs dual-band operation. The fabricated prototype has a physical size of πr2 × 0.024 λg with an antenna profile of 2.38 mm (0.024 λg). The experimentally validated upper and lower bands impedance bandwidth with |S11| < −10 dB are 21.1% and 11.1%, respectively. The fabricated prototype is a good candidate to use in BDS applications. [Q2

Circularly Polarized Metamaterial Patch Antenna Circuitry for Modern MIMO Applications

This research is an attempt to highlight that the presented antenna design is proposed for modern wireless communication systems, including 5G networks. The proposed antenna design is structured to realize a reconfigurable antenna terminal to suit smart wireless systems. Therefore, the proposed antenna is structured from twelve-unit cells of metamaterial (MTM) inclusions. For this, effectively, the proposed antenna profile is reduced to 0.21λ0, where λo is the free space wavelength at 2.45GHz, which occupies 40 × 30 mm2 equivalently. This is accomplished by using T-resonator inductors to conduct 3rd iteration Hilbert-shaped MTM inclusions. The proposed antenna is printed on a substrate to cover the frequency bands from 2.6GHz to 4.4GHz. To optimize the antenna performances, a numerical-parametric analysis based on CST MWS commercial software package formulations is invoked for this study. The suggested antenna performance is numerically evaluated for validation using the HFSS software suite. The antenna has great performance while being sufficiently small to be used with integrated electronics.

Characteristic Mode Analysis Based Highly Flexible Antenna For Millimeter Wave Wireless Applications

The millimeter wave spectrum fulfills the demand for higher data rates with low latency. Moreover, futuristic wearable gadgets demand flexible antennas operating at these frequencies, such that they can easily be accommodated. Therefore, the article focuses on designing a compact and highly flexible antenna with the aid of characteristic mode analysis (CMA). A thin polyimide substrate of 0.1 mm thickness is used to maintain flexibility. The overall antenna profile is 0.61λ0×0.61λ0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$0.61{\\lambda }_{0} \ imes 0.61{\\lambda }_{0}$$\\end{document}. The design evolves through four stages, where, in each stage, the solution to the surface current through eigenvalue leads to significant modes. The final stage design generated Mode 2 fundamental mode at 30.5 GHz along with contributing Modes 3 and 5 with a bandwidth range of 28-31.5 GHz. Further, the design is simulated using electromagnetic simulation software, and the prototype is fabricated. The simulated and measured reflection coefficient |S11| > 10 dB in 28.72-32 GHz and 28.9-31.75 GHz. The CMA analyzed, simulated, and measured gain is 4.82 and 5.6 dBi, respectively. The proposed antenna has a stable response for conformal orientations along the x and y-axis. The antenna has resulted in bidirectional radiation in the XZ plane with simulated and measured half-power-beam-width (HPBW) of 58° and 54°. In the YZ plane, it resulted in omnidirectional radiation. The simulated and measured results are in good agreement. The article also performs the link budget analysis. It suggested that the antenna can communicate 100 Mbps of data to a distance of 100 m and 1 Gbps of data up to 70 m. Thus, the proposed antenna structure is suitable for wearable, IoT, and other 5G wireless applications.

2–18 GHz dual‐polarised tightly coupled dipole array with ±75° scanning range

AbstractThe authors proposed an ultrawideband (UWB) dual‐polarised tightly coupled dipole array (TCDA). A split X‐shaped resistive frequency selective surface (FSS) is utilised, which can get more admirable impedance matching. The proposed antenna can achieve active voltage standing wave ratio (VSWR) below 2.9 when scanning up to ±75° and ±60° in the E and H planes from 2 to 18 GHz, respectively. Furthermore, two rectangular patches served as directors are designed, which can provide stronger forward radiation to reduce the loss of resistive FSS for radiation efficiency. As a result, the average radiation efficiency is above 84% and the lowest radiation efficiency is 70%. Moreover, the overall antenna profile is 15 mm (0.1λ at the largest working wavelength). To validate the design method, a 16 × 16 array prototype is fabricated and measured. Good agreement is achieved between the simulations and measurements.

Optimization of Ultra-Wideband bandwidth for the design of microstrip monopole antennas using Defected Ground Structure and star-shaped patche

This paper presents a design of a monopole microstrip antenna developed to support Ultra-wideband (3.1 -10.6 GHz) technology wireless communication systems. An antenna with minimalist dimensions operates on C-Band (wireless LAN) and X-Band (downlink satellite) frequencies. The antenna profile has a star shape patch on the top side and the use of the Defected Ground Structure (DGS) technique on the bottom side on RT DUROID substrate media. The design uses a simulation method using software and measurement tests on antenna prototypes to obtain parameters and antenna performance characteristics. The results of the measurement test, the bandwidth return loss &lt; -10 dB has a difference of 40% (absolute) and 0.7% (Fractional) lower than the simulation when VSWR &lt; 2. The radiation pattern forms an omnidirectional with a maximum directivity (Gain) of 5.18dBi with polarization vertical. Overall, the UWB monopole antenna design results have a low profile, compact, small size, and support mobile communication devices.

Design of a Low Profile Archimedean Spiral Antenna using Compact Defected Ground Structure as a Reflector

In this paper, design and realisation of a low profile Archimedean spiral antenna is presented. The low profile Archimedean spiral antenna is printed on a substrate and backed by a reflector consisting of DGS. The DGS unit cell consists of a parallel combination of meander line inductors and inter-digital capacitors. This, DGS is one of the forms of electromagnetic band gap (EBG) structures providing electromagnetic band gap characteristics. It is used as a reflector with spiral antenna to achieve unidirectional radiation properties and a low profile of antenna. A modified version of uniplanar EBG cell is used as a DGS cell. This cell is used for configuration of the DGS ground plane. This ground plane is evaluated for its electrical characteristics and used as a reflector for the spiral antenna. Archimedean Spiral antenna is designed and simulated in the frequency band of 1-6GHz with DGS as a reflector. The antenna characteristics are studied for physical parameters of the antenna. These parameters are optimized for better electrical characteristics. The performance of the proposed antenna is also compared with conventional metallic (PEC) reflectors. Simulated results of an antenna are validated by measurement. Antenna height reduction of 60% is achieved compared to conventional cavity-backed spiral antennas.

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

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

Low‐profile omnidirectional antenna with broad bandwidth and high gain

AbstractIn this study, a novel low profile wideband omnidirectional antenna is proposed. Horizontal dimension is utilized by introducing annular patches and near‐zero‐index metamaterials, instead of enhancing horizontal gain through increasing the profile of antenna. Measured results illustrate that horizontal gain of this antenna is enhanced to more than 2.5 dBi with 9.81% relative bandwidth (4.97−5.49 GHz) and low profile (0.034λ). Compared with other works, this novel antenna has obvious advantages in electromagnetic characteristics and physical structure, which has great potential in vehicular communications.

A Mixed Decoupling Scheme Based on AMC and ADS for Dual-Polarized Antenna Array

This communication investigates a mixed decoupling scheme for dual-polarized antenna array. The array considered here is a “2-1-2” staggered scheme for base station, with both non-negligible E-plane and H-plane coupling between antenna elements. To suppress the mutual coupling, a novel decoupling scheme is proposed, combining an artificial magnetic conductor (AMC) and an array-antenna decoupling surface (ADS). The decoupling principle of AMC is discussed in detail. The AMC utilized here can not only reduce the antenna profile, but also suppress the E-plane coupling. After adding the ADS, both E-plane and H-plane coupling can be suppressed at the same time, reaching an isolation of better than 22 dB from 3.2 GHz to 3.8 GHz, with an obvious decoupling point in the passband. The realized gain, total efficiency and radiation patterns are also improved after decoupling. In addition, the total profile of the dual-polarized antenna array is only 0.315λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> based on the mixed decoupling scheme.

Low-Profile Broadband Dual-Polarized Dipole Antenna for Base Station Applications

A low-profile broadband dual-polarized antenna is investigated for base station applications. It consists of two orthogonal dipoles, fork-shaped feeding lines, an artificial magnetic conductor (AMC), and parasitic strips. By utilizing the Brillouin dispersion diagram, the AMC is designed as the antenna reflector. It has a wide in-phase reflection bandwidth of 54.7% (1.54–2.70 GHz) and a surface-wave bound range of 0–2.65 GHz. This design effectively reduces the antenna profile by over 50% compared to traditional antennas without an AMC. For demonstration, a prototype is fabricated for 2G/3G/LTE base station applications. Good agreement between the simulations and measurements is observed. The measured −10-dB impedance bandwidth of our antenna is 55.4% (1.58–2.79 GHz), with a stable gain of 9.5 dBi and a high isolation of more than 30 dB across the impedance passband. As a result, this antenna is an excellent candidate for miniaturized base station antenna applications.

Metasurface-Covered Planar Endfire Antenna With Vertical Polarization

A trapped wave-based solution to design compact planar vertically-polarized (VP) endfire antennas is proposed in this paper. By placing a four-element series-fed magnetic dipole array with an inter spacing of half wavelength within a dual-layer metasurface and loading shorting pin arrays at two edges of the metasurface, the VP radiation is realized in a wide impedance band. In addition, the antenna profile can be further reduced by half according to the electric field distribution within the metasurface. Finally, a VP endfire antenna with a reflection bandwidth of 4.3 ~ 5.4 GHz, a peak gain of 9.8 dBi and a low total profile of 0.065λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at the center operation frequency) is designed for the validation. The proposed antenna can be used for some wireless communication systems on or near the ground plane, such as the car roof-mounted terminal for vehicle-to-roadside unit/base station communications.

A proposal on V-shape staircase array antenna with stacked Butler matrix

Massive MIMO is expected to realize a large capacity for wireless communication technology. To reduce the number of devices of the massive MIMO, utilizing a two-dimensional Butler matrix for the feed circuit has been investigated, but complexing its design. We have proposed a Massive MIMO configuration using a stacked Butler matrix and a staircase array antenna to reduce the circuit design cost. This letter proposes a V-shape staircase array antenna with a stacked Butler matrix to reduce antenna profile. Computer simulation clarifies the beam steering range for the proposed antenna.

A beam-steering antenna with low deflecting-loss enabled by a miniaturized flexible lens

A miniaturized flexible lens is proposed for beam control of broadband antenna with low deflection loss. Different from traditional approaches to phase modulation, the three-segment principle presented in this article significantly lowers the maximum necessary phase difference generated by modulated waves, thus reducing the height of the lens and antenna profile. The phase modulation performance of the lens is reconfigured by adjusting the layout of the phase modulation units PMUs according to distribution requirements. Then, a Vivaldi antenna utilizing the miniaturized lens is designed, fabricated, and tested to demonstrate the system’s beam deflecting characteristics. The experimental results demonstrate the capability of the antenna to cover a deflecting range wider than [−20°, 19°] with deflecting loss below 1.4 dB throughout the entire 8–10 GHz working band. Over the operating band, the deflecting gain is greater than 8.7 dBi.

Reconfigurable Folded Transmitarray Antenna With Low-Profile Based on Metasurfaces

A reconfigurable folded transmitarray antenna (RFTA) with fully planar structure is presented in this letter. It consists of an electronically reconfigurable metasurface and a polarization rotating metasurface (PRMS). A pair of PIN diode switches is integrated on the reconfigurable meta-atom to realize the 1-bit transmission phase manipulating, and a patch antenna is integrated on the center of the PRMS to feed the RFTA. Through twice reflecting, polarization rotating, and transmission phase compensation, the spherical wave from the feed is transformed into the scannable pencil-shaped beam. Meanwhile, the antenna profile is reduced to about 1/3 compared to the traditional reconfigurable transmitarray antenna (RTA). The RFTA prototype with 12 × 12 elements is designed, fabricated, and measured. Experimental results show that the gain of 13.4 dBi at 5.8 GHz is obtained and the two-dimensional beam scanning angle covers ±60°. This work significantly reduces the profile of traditional RTA, making it a promising candidate for the wireless communication system with limited space.

Millimeter-Wave Patch Antennas With Ultralow Profile of 20 μm on Flexible Substrate

In applications of flexible communication electronics, the requirement for ultralow profile of antenna is gradually approaching a limit. In order to achieve a higher flexibility, it is necessitated to limit the vertical distance to 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> scale between the integrated antennas and the electrode ground (GND). Such a small Section height results in a severely reduced radiation efficiency and a narrowed bandwidth. In this article, the enhancement of radiation efficiency and bandwidth of a millimeter-wave (mmWave) patch antenna with 20 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> profile height are studied. On the metal GND, by properly opening two (or one) resonant slots with a width of 100 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> , strong resonance coupling between the patch antenna and the slots can be induced, leading to a greatly enhanced radiation efficiency. Meanwhile, the spectra width of TM10 mode of the patch antenna can also be effectively broadened by the mode coupling, giving rise to a greatly improved radiation bandwidth. The physical mechanism and the sensitive factors to maximize bandwidth, antenna gain, and front-to-back ratio are discussed.

A wideband antenna based on self‐packaged suspended coplanar waveguide technology

AbstractIn this article, a wideband antenna is implemented by using a multilayer self‐packaged suspended coplanar waveguide (SCPW). The lower air cavity of the SCPW is not only used for antenna suspending but also as an antenna reflector, while the reflector structure can be expanded by copper coating on the periphery of the multidielectric substrates, which improves the antenna radiation and antenna gain effectively, while the antenna profile is not increased. An extra patch is introduced for generating more resonances, which extends the antenna bandwidth importantly. The proposed antenna is designed to work at 5.42 GHz with a fractional bandwidth of 26.2% (4.71–6.13 GHz), and a maximum gain of 8.4 dBi. The SCPW antenna has been fabricated and measured, and the design has been demonstrated with the advantages of self‐packaging, wideband, favorable gain, and even low profile as well as miniature circuit size.

High Gain Passive UHF RFID Reader Antenna Using Novel FSS for Longer Read Range

Frequency Selective Surface (FSS) is widely used to enhance the gain of antenna & reduces Electromagnetic Interference (EMI). In this work, a novel Frequency Selective Surface (FSS) is designed, analyzed, and fabricated along with passive Radio Frequency Identification (RFID) reader antenna operating at global Ultra-High Frequency (UHF) for wireless RFID applications. The antenna & FSS sheet is fabricated on less costly FR4 substrate with resonant bandwidth of 860–960 MHz. The Fabry–Perot arrangement of FSS sheet with antenna increases the gain & directivity without modifying the antenna profile or increasing radiation patch size. The maximum measured gain is 9.8 dB & 7.2 dB with the Reflection coefficient (S11) of −35 dB & −15 dB at 910 MHz & 950 MHz respectively. The proposed antenna of dimension 40 mm by 40 mm is fabricated & tested for further experimental validation with measured read range longer than 8 m. The novelty in proposed work is integration of FSS with passive UHF RFID technology which can be effectively used in wireless RFID applications for improved read range, higher gain, lower power consumption & better immunity within the resonating band. The proposed antenna effectively isolates out-of-band frequencies from in-band frequencies over a required bandwidth reducing Electromagnetic Interference (EMI) for UHF RFID applications.

Artificial Magnetic Conductor as Planar Antenna for 5G Evolution

A 5G wireless system requests a high-performance compact antenna device. This research work aims to report the characterization and verification of the artificial magnetic conductor (AMC) metamaterial for a high-gain planar antenna. The configuration is formed by a double-side structure on an intrinsic dielectric slab. The 2-D periodic pattern as an impedance surface is mounted on the top surface, whereas at the bottom surface the ground plane with an inductive narrow aperture source is embedded. The characteristic of the resonant transmission is illustrated based on the electromagnetic virtual object of the AMC resonant structure to reveal the unique property of a magnetic material response. The characteristics of the AMC metamaterial and the planar antenna synthesis are investigated and verified by experiment using a low-cost FR4 dielectric material. The directional antenna gain is obviously enhanced by guiding a primary field radiation. The loss effect in a dielectric slab is essentially studied having an influence on antenna radiation. The verification shows a peak of the antenna gain around 9.7 dB at broadside which is improved by 6.2 dB in comparison with the primary aperture antenna without the AMC structure. The thin antenna profile of λ/37.5 is achieved at 10 GHz for 5G evolution. The emission property in an AMC structure herein contributes to the development of a low-profile and high-gain planar antenna for a compact wireless component.