S11 Bandwidth Research Articles

Design and development of 4 × 4 MIMO antennas for smart 5G devices

The 5G technology will revolutionize the world more than 3G or 4G. 5G means a world where not only people but all the things are also connected. Thus, a new version of wireless technology gives us a lot of advantages which include a boost in speed, reduce reluctance, and provides a more reliable connection for a wide range of users. In this paper, the design of 5G Multiple Inputs and Multiple Outputs (MIMO) antenna structure is proposed. Also, an inset feeding technique is being used. MIMO is the means for improving the capacity of the radio link. It provides higher data rates and reliability which also operates at millimeter-wave (mm-wave) frequency. The patch antenna is designed to resonate at a 29 GHz frequency. The FR4 epoxy, a dielectric substrate is used in the proposed design which has a dielectric constant (er) of 4.4 and thickness (h) of the substrate is 1.6 mm. In this work, Ansys HFSS software is used to design and simulate the MIMO antenna system. At a desired frequency of 29 GHz, the multiple antennas are resonated with better S11, low VSWR, higher performance, and high bandwidth.

Broadband 120 GHz L-Probe Differential Feed Dual-Polarized Patch Antenna With Soft Surface

This article presents a broadband 120 GHz L-probe differential feed dual-polarized patch antenna with a soft surface. The impedance bandwidth is widened with additional resonance points by applying an L-probe feeding topology. Using differential feeding and soft surface, the overall radiation performance including the radiation pattern, cross-polarization, and isolation is improved for a wide bandwidth covering the targeted band, and the analysis of each structure is described in this article. The measured S11 bandwidth, peak gain, 3 dB gain bandwidth, and isolation are 28.3%, 9.8 dBi, 26.4%, and 28.5 dB, respectively. The proposed dual-polarized antenna reveals the widest S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> bandwidth, with a 3 dB gain when compared with the previously reported millimeter and sub-THz dual-polarized antennas. Moreover, to the best of the authors’ knowledge, the proposed dual-polarized antenna is demonstrated at the highest frequency compared with the previously reported dual-polarized antennas.

Low‐profile circularly polarized metasurface antenna with tailored reflection phase

A low-profile metasurface antenna with circularly polarized radiation and tailored anisotropic reflection is proposed in this letter. The metasurface antenna composed of excitation structure (microstrip line with coupling slot) and a metasurface layer. The metasurface functions for two goals, generating circularly polarized wave for radiation and tailoring reflection phase for scattering, respectively. The overall structure of the metasurface antenna is compact with a dimension of 0.67λ × 0.67λ × 0.05λ at 5 GHz. Numerical and measured results confirm that the metasurface antenna exhibits 11.1% −10 dB S11 bandwidth from 4.68 to 5.23 GHz, 10.8% 3 dB axial ratio bandwidth from 4.782 to 5.37 GHz and a maximum gain of 6.83 dBic. Besides, the metasurface antenna achieves anti-phase reflection under orthogonal polarized incident waves at around 5 GHz. To demonstrate a potential application, 16 identical metasurface antennas are put in a 4 × 4 array. The metasurface antenna array achieves directive circularly polarized radiation with a maximum gain of 15 dBic. On the other hand, when under normal illumination, the scattering field of metasurface antenna array is redistributed due to phase cancelation, so that the backward radar cross section of the array is significantly reduced, which is applicable for military platform.

RETRACTED ARTICLE: A Novel Eye-Shaped Monopole Antenna for Dual Band and Wideband Communication Applications

This paper presents a compact dual-band monopole antenna printed on the low-cost FR4 substrate for multi wireless communication applications. The novel antenna consists of an eye-shaped patch and a semi-circular shaped slot on the half elliptical ground plane. The combination of the eye-shaped patch and a semi-circular shaped slot on the ground is used to expand the total length of the current path. This expansion improved the return loss and broadened the bandwidth of the two bands for the desired antenna. The antenna’s measurement results include multi-band frequencies such as S, C, X, Ku, K and Ka-band which covers the bandwidth requirements of WiMAX, WLAN, satellite TV, and other applications at the lower and upper-frequency band. The dimension of the antenna is (26 × 20 × 1.6) mm3 at the minimum frequency of 3.15 GHz. The proposed configuration operates at 3.55 and 19.95 GHz with a bandwidth of about 28.17% (3.15–4.15 GHz), and 147.37% (5.25–34.65 GHz), respectively for the simulation part. The measured bandwidth (− 10 dB) for S11 in the lower and upper band is about 49.71% (2.688–4.506 GHz) and 152.01% (4.933–35.861 GHz) at a center frequency of 3.657, and 20.346 GHz, respectively. The proposed antenna has a suitable radiation characteristic of 97% and 91% and a good gain of 2.97 dBi and 6.71 dBi, at the lower and upper operating band. The Vector Network Analyzer (VNA) Rhode & Schwarz ZVA40 device has been used to measure the results of the antenna and both of the software ANSYS-electromagnetic suite and CST microwave studio is used to simulate the results of the design.

Design of a Dual-Polarized Omnidirectional Dielectric Resonator Antenna for Capsule Endoscopy System

In this paper, a new dual-polarized (DP) omnidirectional hemisphere dielectric resonator antenna (DRA) for wireless capsule endoscope system (WCE) is proposed. The antenna was excited in its omnidirectional TM018 and TE018 modes to radiate DP wave by a feeding probe and arc microstrip line, respectively. Omnidirectional DP wave can be obtained when the TM018 and TE018 mode are equal in amplitude and phase. The TM018 mode that is equivalent to electric dipole can be obtained by probe feeding. The TE018 mode is excited by four arc microstrip lines feeding. They provide a pair of equivalent magnetic dipoles that are orthogonal to TM018 mode. The DP omnidirectional DRA be fabricated without the need of feed network than circularly polarized. The WCE and the human body equivalent tissue model are adopted in simulation. Water is equivalent to gastric juice during measurement. Communication links between the proposed capsule antenna and the external receiving antenna are measured to demonstrate the advantages the DP brings when capsule antenna is placed in different orientations. The capsule endoscope system with different antennas is placed in water to measure receiving power. The measurement shows that the fabricated antenna exhibits a wide impedance bandwidth for S11 <; -10 dB (2.4-2.48 GHz). The radiation efficiency of the antenna is between 15-18%, and the peak gain is between -13.5 and -15dBi.

A Novel Eye-shaped Monopole Antenna for Wideband and 5G Applications

ABSTRACT This paper presents a compact dual-band monopole antenna printed on the low-cost FR4 substrate for multi wireless communication applications. The novel antenna consists of an eye-shaped patch and a semicircular shaped slot on the half elliptical ground plane. The antenna’s measurement results include multiband frequencies such as S, C, X, Ku, K, and Ka-band, which covers the bandwidth requirements of WiMAX, WLAN, satellite TV, and 5G applications at the lower and upper-frequency band. The dimension of the antenna is (26 × 20 × 1.6) mm3 at the minimum frequency of 3.15 GHz. The proposed configuration operates at 3.55 and 19.95 GHz with a bandwidth of about 28.17% (3.15–4.15 GHz) and 147.37% (5.25–34.65 GHz), respectively, for the simulation part. The measured bandwidth (−10 dB) for S11 in the lower and upper band is about 49.71% (2.688–4.506 GHz) and 152.01% (4.933–35.861 GHz) at a centre frequency of 3.657 and 20.346 GHz, respectively. The proposed antenna has a stability of the radiation characteristics, suitable gain, and good impedance across the operating bandwidth of the dual-band antenna.

Highly efficient artificial magnetic conductor enabled CPW fed compact antenna for BAN wearable applications

Abstract In this paper a coplanar waveguide feed (CPW) monopole antenna backed with artificial magnetic conductor (AMC) structure for efficient radiation has been presented for off-body wearable applications. A split ring resonator (SRR) having thiner and longer lines to produce higher inductance and six splits with smaller gaps for high capacitance have been placed underneath CPW fed monopole to achieve resonance mode at a lower frequency. Higher values of inductance and capacitance produce resonant modes at relatively lower frequencies resulting in highly miniaturized antenna. The desired −10dB S11 bandwidth has been optimized firstly, by tuning/optimizing flow of surface currents with the help of several slots/slits and later by realizing AMC reflector with the help of full ground backed foam. The proposed antenna covers 2.45 GHz industrial, scientific and medical (ISM) band body area network (BAN) application and posses good front to back ratio (FBR) and thereby low and acceptable values of specific absorption rate (SAR). The proposed antenna has been designed and simulated using Ansys high frequency structured simulator and tested using vector network analyzer and anechoic chamber. The simulated and measured results well agree with each other.

Generation of plane spiral orbital angular momentum using circular double-slot Vivaldi antenna array

A novel and feasible solution to generate plane spiral orbital angular momentum (PSOAM) vortex beam is proposed in this paper. The general principle of generating PSOAM in circular antenna array (CAA) is deduced, and verified by the simulation of the dipole CAA. Four double-slot Vivaldi antenna elements connect sequentially and are inserted into a CAA, which makes the proposed antenna easily fabricated and fully miniaturized. Both simulated and measured results show that it can generate PSOAM with l = 3 (l is the mode number of vortex wave) at 5 GHz. The vortex phase of l = 3 is observed, the measured peak gain is 5.7 dB. The VSWR remains below 2 from 4 to 6 GHz, which shows the impedance bandwidth of S11 < −10 dB is more than 40%.

High Refractive Index Metamaterial Superstrate for Microstrip Patch Antenna Performance Improvement

We propose a high refractive index metamaterial （HRIM）that is formed by symmetrically etching square metal patches on both sides of a dielectric plate. By reducing the gap of adjacent patches and the thickness of dielectric plate, the proposed metamaterial can suppress the diamagnetic response and enhance the capacitance coupling, so that the refractive index of the metamaterial is higher than 10 in wideband from 4 GHz to 8 GHz. Attributing to the property of high refractive index, the metamaterial can effectively improve the performance of a microstrip antenna when it is loaded as a superstrate. The measured results reveal that the impedance bandwidth of S11< -10 dB is 690 MHz (12.4%) and the maximum gain reaches to 13 dB at 5.6 GHz. The 1 dB and 3 dB gain bandwidth are 380 MHz (6.7%) and 590 MHz (10.3%), respectively. The antenna has a subwavelength profile of 0.19λ ( λ _0 is the free space wavelength of the antenna central frequency). Furthermore, the profile can be further reduced to 0.15λ when the radiation patch of the antenna is surrounded by metasurface.

Project and Analysis of Quasi-Periodic PBG for Microstrip Antenna

Abstract In this work the influence of quasi-periodic distributions of air holes with 6, 12 and 6-fold modified symmetries, applied to the substrate of a rectangular microstrip patch antenna are analyzed. To validate the study, parameters such as S11 parameter, bandwidth, total gain, radiation pattern and electric field were investigated through computational simulations. The results obtained for all the PBG structures were compared to each other and to a reference antenna without PBG. In addition, we analyzed the resonating modes of each structure and it was observed improvements in bandwidth and gain for all modified structures when compared with the reference antenna, as well as reduction of the dielectric constant that is also recalculated. Some prototypes were built to compare the computational results to the measured results. It was verified that the measured and simulated results of return loss are in agreement and the antenna with 6-fold modified symmetry presented better performance than the others analyzed PBG structures.

A Linear-to-Circular Polarization Conversion Metasurface Based Wideband Aperture Coupled Antenna

This paper proposes an aperture-coupled antenna with an ultrathin, single-layer metasurface for linear-to-circular (LP–CP) polarization conversion. The unit cell of the metasurface consists of a hexagonal ring surrounded by a square ring printed on both sides of a dielectric substrate for wideband LP-CP conversion. A patch antenna excited by an H-shaped slot aperture uses a 5 × 5 array of the metasurface as a superstrate. Simulated and measured radiation patterns of the proposed antenna are in good agreement. Measured S11 and axial ratio bandwidth of the proposed antenna are 21.5% and 19.23% respectively. Boresight radiation gain is around 10 dBic over 9.5 GHz to 11.5 GHz.

A Low-Profile Wideband Linear-To-Circular Polarization Conversion Slot Antenna Using Metasurface.

A new low-profile wideband linear-to-circular polarization conversion microstrip slot antenna based on a metasurface for C-band satellite communication applications is proposed in this paper. The metasurface basically consists of four unit cells with parasitic square cross gaps arranged in a 2 × 2 layout. By loading the metasurface on the microstrip slot antenna, linearly polarized (LP) waves from the source antenna are converted into circularly polarized (CP) waves. Then, by etching three more parasitic square cross gaps in the middle of the metasurface, enhanced impedance bandwidth and axial ratio bandwidth (ARBW) are achieved. Furthermore, an equivalent circuit and a phase analysis are presented to explain how a wide ARBW is realized by the metasurface. A final model with an overall size of 36 × 36 × 3.5 mm3 (approximately 0.65λ0 × 0.65λ0 × 0.06λ0 at 5.5 GHz) was designed and fabricated. The measured S11 bandwidth and 3 dB ARBW were 39.25% from 4.28 GHz to 6.37 GHz and 17.77% from 5.18 GHz to 6.19 GHz, respectively. As a result, the proposed antenna shows great potential for satellite communication applications due to its low profile and compact structure, wide impedance bandwidth, and wide axial ratio bandwidth.

25GHz 40GHz Circularly Phase Array Microstrip Patch Antenna for Millimeter Wave Communication

Millimeter wave technology will enable to provide high data rate. It is also expected to provide continuous good quality, low latency video. For high-resolution video, wireless communication will require huge bandwidth. The present 4G spectrum will be unable to meet the demand of each mobile user. To solve bandwidth shortage millimeter wave technology is consider. In this paper present a circularly phase array designed. It is operating in the 25GHz to 40GHz. To enhance bandwidth the array used edge couple parasitic patch arrangement which provides dual resonance. The array is designed in circular phase array with the rotational feeding line. The designed used polyflon CuFlon(tm) low dielectric constant, Ɛr = 2.1 and tangential loss, δ = 0.00045 with height h = 1.6mm. The designed achieved 8.41dB gain. The array achieved good return loss, S11 bandwidth i.e. -11.83dB ≤ S11 ≤ -37.8dB (25GHz to 40GHz) and voltage standing wave ratio, VSWR ≤ 1.7 (25GHz to 40GHz).

420-GHz terahertz SIW slot antenna with quartz superstrates in silicon technology

To meet the needs of terahertz imaging and communication, a 420-GHz on-chip antenna (OCA) with high gain and high radiation efficiency is designed using a standard 55 nm CMOS technology. In the proposed OCA structure, the substrate integrated waveguide (SIW) antenna forms a back cavity to suppress the surface waves and separate the radiation aperture from the low-resistivity substrate. To increase the efficiency of OCA, a single-layer quartz superstrate is proposed. An analytical model to calculate the radiation efficiency is presented, and a detailed design approach is described. The proposed antenna is simulated using Ansoft HFSS. The simulated antenna has a maximum gain of 4.9 dBi and a radiation efficiency of 76.27%. The bandwidth of S11 below −10 dB is 44 GHz. The OCA has good performance and can be widely used in terahertz imaging and communication.

A Low-Profile Decoupling Slot-Strip Array for 2 × 2 Microstrip Antenna

Two-dimensional antennas provide additional variables that can be used to control and shape the pattern, and widely used in engineering applications include tracking radar, communications, direction finding and many others. However, the reduced mutual coupling becomes more complex due to the mode and strength of the mutual coupling field between sani adjacent elements are different. In this paper, a low-profile decoupling slot-strip array (DSSA) for 2 × 2 microstrip antenna is proposed. The DSSA consists of a slot array etched on the ground plane and a strip array printed on the radiation patches plane. The band-stop effect of the slot array decreases the mutual coupling of both H-plane and D-plane. Meanwhile, the coupling current generated by the induced current on strip array can cancel the coupling current generated by excited current, which can significantly improve the E-plane isolation Additionally, the scattering parameters of other three types of antenna which have the different relative positions of feeding ports are also discussed. To verify the proposed viewpoint, a 2 × 2 antenna with the DSSA is modeled and manufactured. The experimental results demonstrate that a considerable mutual coupling reduction of 33.2 dB for H-plane, 28.5 dB for E-plane, and 24.1 dB for D-plane is achieved while 10 dB bandwidth for S11 remains almost unchanged. Fortunately, the experimental results are in good agreement with the simulation results, which confirms that the DSSA has an excellent promising application in two-dimensional antenna.

Wideband Waveguide-to-Microstrip Transition for mm-Wave Applications

Introduction. Increased data rate in modern communication systems can be achieved by raising the operational frequency to millimeter wave range where wide transmission bands are available. In millimeter wave communication systems, the passive components of the antenna feeding system, which are based on hollow metal waveguides, and active elements of the radiofrequency circuit, which have an interface constructed on planar printed circuit boards (PCB) are interconnected using waveguide-to-microstrip transition.Aim. To design and investigate a high-performance wideband and low loss waveguide-to-microstrip transition dedicated to the 60 GHz frequency range applications that can provide effective transmission of signals between the active components of the radiofrequency circuit and the passive components of the antenna feeding systemMaterials and methods. Full-wave electromagnetic simulations in the CST Microwave Studio software were used to estimate the impact of the substrate material and metal foil on the characteristics of printed structures and to calculate the waveguide-to-microstrip transition characteristics. The results were confirmed via experimental investigation of fabricated wideband transition samples using a vector network analyzer Results. The probe-type transition consist of a PCB fixed between a standard WR-15 waveguide and a back-short with a simple structure and the same cross-section. The proposed transition also includes two through-holes on the PCB in the center of the transition area on either side of the probe. A significant part of the lossy PCB dielectric is removed from that area, thus providing wideband and low-loss performance of the transition without any additional matching elements. The design of the transition was adapted for implementation on the PCBs made of two popular dielectric materials RO4350B and RT/Duroid 5880. The results of full-wave simulation and experimental investigation of the designed waveguide to microstrip transition are presented. The transmission bandwidth for reflection coefficient S11 &lt; –10 dB is in excess of 50…70 GHz. The measured insertion loss for a single transition is 0.4 and 0.7 dB relatively for transitions based on RO4350B and RT/Duroid 5880.Conclusion. The proposed method of insertion loss reduction in the waveguide-to-microstrip transition provides effective operation due to reduction of the dielectric substrate portion in the transition region for various high-frequency PCB materials. The designed waveguide-to -microstrip transition can be considered as an effective solution for interconnection between the waveguide and microstrip elements of the various millimeter-wave devices dedicated for the 60 GHz frequency range applications.

Compact Wideband Circularly Polarized Antenna with Symmetric Parasitic Rectangular Patches for Ka-Band Applications

In this paper, a novel wideband circularly polarized (CP) millimeter wave (mmWave) microstrip antenna is presented. The proposed antenna consists of a central patch and a microstrip line radiator. The CP radiation is achieved by loading a rectangular slot on the ground plane. To improve the 3-dB axial ratio bandwidth (ARBW), two symmetric parasitic rectangular patches paralleled to a central patch and a slit positioned to the right of the central patch are loaded. To verify this design, the proposed antenna is fabricated with a small antenna of 2.88 × 3.32 × 0.508 mm3. The measured impedance bandwidth (IMBW) for S11&lt;−10 dB of the proposed antenna is 35.97% (22.8 to 33.8 GHz). Meanwhile, the simulation result shows that the 3-dB ARBW is 15.19% (28.77 to 33.5 GHz) within impedance bandwidth, and the peak gain is from 5.08 to 5.22 dBic within 3-dB ARBW. The proposed antenna is suitable for CP applications in the Ka-band.

Circularly Polarized Wearable Antenna Based on NinjaFlex-Embedded Conductive Fabric

A circularly polarized (CP) wearable antenna based on the FDM (fused deposition modeling) technology is proposed. Conductive fabric is used to realize conductive parts of the patch antenna on the NinjaFlex substrate. The antenna is encapsulated with additional layers of NinjaFlex. Modified patch ensures the CP character at 2.45 GHz. Bending and washing tests are conducted to check the performance stability, and good agreement between simulated and measured results is observed. The experimental results illustrate that the antenna holds 11% 10 dB S11 bandwidth and around 70 MHz 3 dB axial ratio bandwidth. In addition, surface current analysis is also given to understand the operating mechanism of CP wave.

Coplanar waveguide‐fed electrically small dual‐polarized short‐ended zeroth‐order resonating antenna using Ω‐shaped capacitor and single‐split ring resonator for GPS/WiMAX/WLAN/C‐band applications

This work explains the design and analysis of a triple-band electrically small (ka = 0.56 < 1) zeroth-order resonating (ZOR) antenna with wideband circular polarization (CP) characteristics. The antenna compactness is obtained due to ZOR frequency of composite right/left-handed (CRLH) transmission line (TL) and wideband CP radiation are achieved due to the introduction of single-split ring resonator and asymmetric coplanar waveguide fed ground plane. The proposed antenna obtains an overall electrical size including the ground plane of 0.124 λ0 × 0.131 λ0 × 0.005 λ0 at 1.58 GHz and physical dimension of 23.7 × 25 × 1 mm3 are achieved. The antenna provides a size reduction of 44.95% compared to a conventional monopole antenna. The novelty behind the ohm-shaped capacitor is the generation of extra miniaturization with better antenna compactness. The antenna provides dual-polarized radiation pattern with linear polarization radiation at 1.58 and 3.54 GHz, wideband CP radiation at 5.8 GHz. The antenna measured results shows good impedance bandwidth of 5%, 6.21%, and 57.5% for the three bands centered at 1.58, 3.54, and 5.8 GHz with a wider axial ratio bandwidth (ARBW) of 25.47% is obtained in the third band. The antenna provides a higher level of compactness, wider ARBW, good radiation efficiency, and wider S11 bandwidth. Hence, the proposed antenna is suitable for use in GPS L1 band (1.565-1.585 GHz), WiMAX 3.5 GHz (3.4-3.8 GHz) GHz, WLAN 5.2/5.8 GHz (5.15-5.825 GHz), and C-band (4-8 GHz) wireless application systems.

Ultra‐wideband antenna for wearable Internet of Things devices and wireless body area network applications

AbstractThis paper presents a compact and planar ultra‐wideband (UWB) antenna, designed and characterized for the wearable Internet of Things (IoT) devices and wireless body area network (WBAN) applications. Two different substrates, ie, FR4 (h = 1.6 mm) and denim textile substrate (h = 1 mm), are used in the process of design and fabrication of the proposed antenna. The dimensions of the proposed antenna are 31 mm × 42 mm for FR4 substrate and 70 mm × 56 mm for denim textile substrate. The antenna structure consists of a rectangular radiating patch with two symmetrical staircase‐shaped slits. A reduced ground plane technique is used for the purpose of improving impedance bandwidth, which is further enhanced by the insertion of a small notch in the reduced ground plane which has improved the overall impedance matching characteristics of the proposed UWB antenna. The measured impedance bandwidth for S11 &lt; −10 dB and gain of the FR4 and denim textile substrate UWB antennas are 7.71 GHz/5.12 dBi and 7.95 GHz/3.57 dBi, respectively. The ADS momentum simulator is used for antenna simulations, and the simulated and measured results are generally found in good agreements.