GHz WiMAX Research Articles

Nanocomposite Embedded Electric and Magnetic Material Enhancing Antenna Radiation by Linear Relation in Radiators

The main and auxiliary radiating elements are linked by linear mathematical relation and coated with nanocomposite (NC) materials to enhance radiation characteristics. Nanocomposite-based electric material (NE) and nanocomposite-based magnetic material (NM) coated on auxiliary radiating elements to enhance the electromagnetic radiation of the proposed antenna. The radiating elements coated with NE graphene oxide (GO) and NM barium ferrite (BF) have higher electric field and magnetic field distribution respectively. The linear relation of main and auxiliary elements is verified by two substrates FR4, Teflon with correlated results. This proposed NC-coated antenna produces a bandwidth of 4.15 GHz, 4.02 dBi average gain and radiation efficiency of 95.17%, being superior to the antenna without NC coating. Fabricated antenna has 1.56–5.71 GHz bandwidth that includes 2.4/5.2 GHz WLAN, 2.5/3.5 GHz WiMAX, 2.4 GHz ISM, 5G SUB-6 GHz, 5G NR 78 and 2.4/5 GHz Wi-Fi bands.

Compact dual-band dual sense circularly polarized flexible antenna with polarization rotation metasurface for off-body communications

ABSTRACT A dual-band dual circularly polarised flexible antenna, operating at 3.5 GHz for WiMAX and 5.8 GHz for industrial, scientific, and medical (ISM) bands, is proposed for wearable applications. The antenna design integrates a wideband comb-shaped slotted monopole antenna with a polarisation rotation metasurface (PRMF). The PRMF unit cell consists of a nested split square ring in the corner and a square ring in the centre, where the split square rings facilitate polarisation conversion and the centre square ring enhances the axial ratio. The PRMF integration helps achieve dual circular polarisation (CP) radiation, with left-handed CP in the WiMAX band and right-handed CP in the ISM band. The proposed monopole antenna and PRMF are printed on a conformal polyimide substrate, with a total footprint of 48 × 48 mm2 (0.31λo2). The proposed antenna has a 10 dB impedance bandwidth of 24.9% (3.2 to 4.2 GHz) and 18.9% (5.3 to 6.43 GHz), a 3-dB axial ratio bandwidth of 11.1% and 21.4%, and a peak gain of 6.4 and 6.7 dBic in both bands. Numerical and measured results demonstrate that the antenna performs well in the presence of human body and structural deformations. These attributes make the proposed design highly suitable for off-body wearable applications.

Highly compact UWB-MIMO antenna with sharp multi-stop band characteristics

With multi-band rejection characteristics, a new low-profile antenna of size 34 × 34 mm2 is conferred in this article. It consists of quad identical monopole elements (originated orthogonally), contributing ultra-wideband characteristics in the system. The single unit of the proposed design consists of a modified spinning-top shape radiator (MSTSR), excited by a tapered microstrip line feed (TMLF) and semi-circular ground. An excellent bandwidth of 3–12.9 GHz (where S11 < − 10 dB) is obtained at each port. By inserting the structure of four spiral coils, a sharp notch ranging from 7.9 to 8.5 GHz is achieved to filter the X-band satellite communication uplink. In addition, a circular spiral slot in the radiator near the ground plane creates a stop band at 7.35–7.565 GHz band (satellite communication downlink band). Furthermore, symmetrical rectangular trapezoid resonators and inverted symmetrical rectangular trapezoid structures near the feed line are responsible for the elimination of interferences at 5.5 GHz lower WLAN and 3.5 GHz WiMAX respectively. The FR-4 substrate used for the UWB-MIMO design fabrication process and fabricated results are found in good match with the simulated results. Also, the design provides good performance metrics such as total active reflection coefficient, diversity gain, channel capacity loss, isolation, and envelope correlation coefficient.

A dual band CPW-fed MIMO antenna for fifth generation application

This paper presents an innovative integrated dual-band multiple-input multiple-output (MIMO) antenna for the global system for mobile communications band, fed by a coplanar waveguide. The distinctive aspect of this antenna design is its configuration, wherein all the MIMO antenna’s unit cells are placed orthogonal to one another. As a result, there is no need for additional isolation elements to achieve high isolation, simplifying the antenna’s fabrication process. The capability to operate in two frequency bands 3.5 GHz (Wi-Max) and 5.5 GHz (WLAN) is attained by integrating a curved form into the antenna’s radiator elements. Fabricated on an affordable FR-4 dielectric substrate measuring 64 × 64 × 1.6 mm3, the MIMO antenna demonstrates isolation exceeding 18 dB and an envelope correlation coefficient (ECC) of below 0.03. Experimental results from the fabricated four-port dual-band MIMO antenna configuration align with the outcomes of the simulations.

CPW-Fed UWB-MIMO Antenna with Triple-band Notched and High Isolation using Double Y-shaped Decoupling Structure

A ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna using double Y-shaped decoupling structure with high isolation and triple notched-band is presented. The designed antenna composed of two orthogonally placed monopole elements, coplanar ground and double Y-shaped branch. The defected substrate structure is used to achieve miniaturization. By slotting successively C-shaped slot, semi-circular slot and rectangular slot on the radiation patch and the ground, achieved three notched bands at 3.5 GHz WiMAX, 5.25 GHz WLAN, and 7.5 GHz X-band. The proposed antenna can operate in range of 2.56-12 GHz with triple notched bands of 3.31-3.96 GHz, 4.58-5.67 GHz and 6.57-8.16 GHz. Considering all the results, it can be concluded that the antenna presented has a great performance in terms of good radiation, high isolation (&gt;24 dB), a low level ECC (&lt;0.01) and a high DG level (&gt;9.99), which proves the presented antenna has good prospect in UWB-MIMO systems.

Metamaterial-based Octagonal Ring Penta-band Antenna for Sub-6 GHz 5G, WLAN, and WiMAX Wireless Applications

Metamaterial-based Octagonal Ring Penta-band Antenna for Sub-6 GHz 5G, WLAN, and WiMAX Wireless Applications

A reconfigurable wideband MIMO antenna combines RF energy harvesting

SummaryThis article introduces a novel and groundbreaking approach combining multiple‐input‐multiple‐output (MIMO) technology with radio frequency (RF) energy harvesting. The proposed antenna consists of two semi‐circular monopole antenna components, optimized with dimensions of 89 × 51.02 × 1.6 mm3, that share a common ground plane to achieve MIMO characteristics. A series of split‐ring resonators on the ground plane significantly enhances the isolation between the two radiating components. Band‐notched features are performed in the 3.5 GHz WiMAX and 5.5 GHz WLAN bands through modified C‐shaped slots in the radiating patch and two rectangular split‐ring resonators serving as parasitic devices near the feed line. The reconfiguration of band‐notching is made possible by controlling the modes of the embedded PIN diodes. The two antenna elements maintain mutual coupling below −18 dB from 1.5–13 GHz, achieving an impressive 158.62% impedance bandwidth. The antenna's efficiency and gain experience significant drop, indicating effective interference suppression at the center frequencies of the notch bands, and its performance in MIMO systems is assessed through parameters including envelope correlation coefficient, port isolation, radiation patterns, efficiency, gain, and diversity gain. The simulated properties of the designed antenna closely align with the measured outcomes, demonstrating its reliability and consistency. Moreover, the article evaluates the antenna's potential for RF energy harvesting, achieving a maximum harvested energy of 4.88 V. This proposed antenna can be used in multiple applications, like wideband, band‐notching MIMO, and RF energy harvesting. This proposed antenna is an efficient, reconfigurable wideband MIMO antenna with novel RF energy harvesting capability.

A Metamaterial Inspired Multiband Conformal Bandpass Filter with Improved Quality Factor for Sub-6 GHz Wireless Communication Applications

This paper deals with the design, simulation, and practical modeling of metamaterial-based multiband conformal bandpass filter (BPF) for various wireless communication applications with improved quality factors. The novel metamaterial in the form of a split ring resonator is loaded on the ground plane face of the proposed BPF. The overall dimension of the designed BPF is only [Formula: see text]. The proposed BPF is tuned initially for quality factor enhancement based on the thickness of the substrate, physical parameters of the f transmission line, ground plane, externally loaded elements, and the gap in the metamaterial loading. The suggested filter operates at triple band covering the frequency bands from 1.4 to 2.2, 3.6 to 3.9, and 4.8 to 5.9[Formula: see text]GHz, which are suitable for sub-6[Formula: see text]GHz 5G and other wireless applications. The insertion loss is observed as 1[Formula: see text]dB, which is suitable for the proposed BPF. The conformal behavior of the filter is judged through bending deformation analysis at various bending positions like (15[Formula: see text], 30[Formula: see text], 45[Formula: see text], 60[Formula: see text], and 90[Formula: see text]). The proposed BPF retains triple pass band characteristics at various bending deformations, which makes it suitable to be used in curved structures or flexible circuitry. The theory of equivalent circuits and quality factor [Formula: see text] of the designed BPF is discussed in this paper. The results are analyzed experimentally through ANRITSU-MS2037C combinational analyzer. The proposed BPF is suitable for sub-6 GHz 5G, WLAN, and Wi-Max applications.

Dual nanocomposite materials that enhance the radiation characteristics of flexible circular antenna

A novel dual nanocomposite filled circular shaped flexible slot antenna is introduced for WLAN/WiMAX/5G/Wi-Fi applications. The circular radiating patch is given two slots that are filled with nanocomposite materials PANI/CCo and PDMS/AgNW, which enhances antenna radiation properties in both lower and upper band independently. The antenna is fabricated deploying a coplanar waveguide (CPW) fed system that encompasses a patch featuring a circular shape and CPW ground combined with a circular ring shape. The dual band is formed by introducing a narrow rectangular slot on the circular radiating patch and is designed for a mid-frequency 3.85 GHz, of two resonance frequencies. Different bending radii are used to evaluate antenna flexibility, and findings are in good match for a flat antenna. With good radiating qualities over the whole dual band, the suggested fabricated antenna covers the 2.4/5.2/5.8 GHz WLAN, 2.5/5.5 GHz WiMAX, 2.3/2.6 GHz 5G, 2.4/4.9/5.2/5.5/5.8 GHz Wi-Fi, and 5G SUB 6 GHz bands.

Triple‐band circularly polarized conformal antenna for vehicular communication applications

AbstractVehicular communication presents a compact wideband implantable antenna for the best wireless transmission of information. The key role of the antenna is handled by the thickness of the substrate present in that antenna. Also, the shape of the antenna causes the performance characteristics. Now, vehicle‐to‐vehicle communication is the interesting task for designers to create successful and organized vehicular communication systems. This article presents a triple‐band circularly polarized conformal antenna for vehicular communication. An antenna is introduced as a triple‐band circular polarized conformal antenna and preserved a suitable mount on the vehicle surface for greater gain to provide well‐maintained operational performance characteristics. For getting circular polarization, circular cuttings are provided in the design of the proposed antenna. The radiation gives a fixed direction by providing 0.3 mm thickness. Here, use a circularly polarized antenna to rectify the signal absorption due to the contact material used in the antenna. A polyamide material is used as a substrate to get a probable successful link and improve the flexibility of the antenna. The triple‐band circularly polarized antenna is designed to operate in vehicular communication bands such as 2.4 GHz Wi‐Fi, 3.5 GHz WiMAX, and 5.9 GHz dedicated short range communication. The antenna is designed to resonate in a triple band to improve the antenna parameters like frequency response characteristics, gain, return loss, voltage standing wave ratio, left hand circularly polarization, right hand circularly polarization, axial ratio, fidelity factor, directivity, radiated power, and input impedance. Under the operating frequency bands of 2.4, 3.4, and 5.9 GHz, the efficiency of the proposed antenna is 98.48%, 97.31%, and 97.90%, respectively. The triple‐band circularly polarized conformal antenna is implemented in the high‐frequency structure simulator platform. The proposed tri‐band antenna is applicable in vehicular communication systems and healthcare for efficient wireless transmission.

Compact UWB Monopole Antenna with Tunable Dual Band Notched Characteristics for WiMAX and WLAN Applications

The present work shows a planar compact ultra-wideband (UWB) monopole antenna with controllable dualband-notch frequencies at 3.3 GHz for WiMAX and 5 GHz for WLAN. In the proposed antenna, the lower notchband (at a frequency of 3.3 GHz) is made by cutting a thin horizontal strip on top of the radiating patch. The uppernotch band (at a frequency of 5 GHz) is made by putting two narrow parasitic strips in the shape of an “I” oneither side of the radiating patch. The incorporation of three varactor diodes between the radiating patch and three metallic strips provides the flexibility of adjusting the notch frequencies. The notch band tunability between 3.15 GHz and 3.69 GHz and between 4.93 GHz and 5.59 GHz, respectively, is achieved by changing the bias voltageof the varactor diode between 0 V and 30 V. The gain and efficiency characteristics of the designed antenna alsoexhibit band rejection at the respective notch frequencies. The design principle is validated by fabricating andmeasuring a prototype of the proposed dual-band, notched UWB antenna. For three different bias voltages of thevaractor, the simulated and experimental findings are in reasonable agreement. The proposed works demonstratebetter-notch characteristics as compared with other reported works over the UWB range

Design of High Selectivity Compact Dual-Band Bandpass Filter With Seven Transmission-Zeros for GPS and WiMAX Applications

A miniaturized Y-shaped dual-band bandpass filter with multiple transmission zeros/poles is presented in this work. The proposed filter configuration comprises series coupled lines, shunt cascaded coupled line and parallel open stubs, and stepped impedance resonators. Analysis of the proposed filter is executed using a circuit simulator, and the magnitude and bandwidth variations have been studied. Equations for transmission zero frequencies have been derived and verified based on lossless transmission line theory and even-odd mode analysis to validate the proposed filter configuration. A prototype operating at 1.38 GHz (GPS) and 3.4 GHz (Wi-Max) applications is fabricated and experimented. The final prototype occupies a compact area of 0.33λg × 0.20λg, where λg is the guided wavelength at the first band (1.38GHz). The experimental results show that the roll-off rate for the first and second passbands is 212.5 and 188 dB/GHz, respectively, indicating high selectivity. The insertion loss is better than 20 dB indicating good isolation between the two passbands.

Design and Analysis of CPW Fed Antenna with Triangular Separated Stub for Wireless Applications

One of the most active areas of research in the field of communication systems today is wireless technology, and a study of communication systems would be lacking without a grasp of how antennas work and are constructed. We offer a straightforward and small printed ultra-wideband antenna with dual-band notched properties. A redesigned ground plane and a rectangular patch make up the proposed antenna. The lossy FR4 substrate is etched with the rectangular patch. The rectangular patch that a U-shaped slot has embedded in it is parasitized by a circular ring strip. A rectangular slit, two inverted-L slits, and a slit are imbedded into the ground plane. The antenna structure uses some bandwidth improvement and bandnotched techniques to widen the bandwidth and create notches. With dual-notched bands of 3.30-4.20 and 5.10-5.85 GHz, the proposed antenna covers the 3.3/3.7 GHz WiMAX, 3.7/4.2 GHz C-band, and 5.2/5.8 GHz wireless local area network systems. This is demonstrated by the simulated and measured results, which indicate that the proposed antenna offers a very wider bandwidth ranging from 3.04 to 17.30 GHz, defined by the return loss less than 10 dB.

On-Body Low-Profile Compact AMC-Integrated Wideband Antenna for Body Area Network Applications

This communication presents a wideband and a low-profile flexible wearable antenna intended to operate at a 2.45 GHz WBAN band. The suggested antenna comprises a CPW-fed monopole antenna backed by an artificial magnetic conductor (AMC) to act as a reflector. The latest AMC-integrated design uses R03003 as a dielectric substrate. The suggested design features an impedance bandwidth of 71.03% (1.87–3.93 GHz) with a gain value of 3.62 dBi and has a compact footprint of 40 × 40 mm2. The incorporation of wideband AMC with a monopole antenna leads to bandwidth enhancement and covers the 3.5 GHz WiMAX band. Simulation and experimental studies provide evidence that in the case of structural deformities and human body loading, the suggested AMC-integrated antenna is stable and shows superior efficiency relative to the traditional monopole antenna. Furthermore, numerical analysis demonstrates that the amount of radiation AMC-integrated antenna decreases tremendously in terms of specific absorption rate for various bodily attachment scenarios. Three body templates with various compositions and forms were used to study the effects of the antenna on bodily attachment. Extensive experiments on human body phantoms and bodily attachment are also conducted and the results are presented. The suggested AMC-integrated design thus confirms a promising contender for portable wearable wireless applications.

Electromagnetic Band Gap Based Via-less Jeans Patch Antenna for 5.5GHz WiMAX Application

Wearable electronics have gained opportunities in recent years, and the last decade has been evidence of this growth in Wireless Body Area Networks (WBAN). They meet the criteria for personalizing healthcare, communication, patient monitoring, tracking, and rescue operations. The main challenge for the WBAN is to handle the radiator's coupling with the human body. An artificially generated Electromagnetic Band Gap (EBG) structure was designed and used in this work to improve the performance of a microstrip patch antenna. A jeans-based microstrip patch antenna with an EBG surface demonstrated to enhance the performance for 5.5 GHz WiMAX application. The use of an EBG surface increases return loss by 20%, with a reasonable bandwidth of 0.528 GHz (5.271 GHz to 5.749 GHz) at the resonance frequency of 5.5 GHz. The EBG surface improved the Voltage Standing Wave Ratio (VSWR) by 60%. A three-layered human body tissue model is also used for on-body measurements to determine the performance of an EBG-based antenna. The presence of human tissues generally reduces performance and shifts the resonance, but the shifting in this work with the simplified EBG structure and adequate gain and VSWR is only 2.6 percent.

CPW Fractal Antenna with Third Iteration of Pentagonal Sierpinski Gasket Island for 3.5 GHz WiMAX and 5.2 GHz WLAN Applications

Nowadays, the compact and multiband antennas are typically required for personal communication devices in the continuously developing wireless communication industry. The fractal antenna with the third iteration of the pentagonal Sierpinski gasket island for WiMAX and WLAN applications is presented in this work. It starts with the fundamental design of the square patch (Antenna A1) and pentagonal patch (Antenna A2). This simulation work is done using CST Microwave Studio simulation studio by applying the concept of the zero, first, second and third fractal iteration. Then, it goes on to use the fractal geometry concept of the Sierpinski gasket island structure with three designs step. The designs consist of the first iteration (Antenna B1), second iteration (Antenna B2) and third iteration (Antenna B3) of fractal geometry. The simulation work of Antenna B3 is compared with the fabrication work of the same design. After that, the measurement of the Antenna B3 is done in laboratory with - 29.55 dB at 3.41 GHz and - 20.40 dB at 5.28 GHz for its operating frequencies with bandwidth of 3.52 GHz and 5.48 GHz, respectively. At targeting 3.5 GHz WiMAX, 5.2 GHz WLAN application and 7.24 GHz of Antenna B3, the antenna shows the – 17.78 dB, - 29.63 dB and – 22.73 dB, respectively, and this value is feasible for WiMAX and WLAN operation.

Antennas for Licensed Shared Access in 5G Communications with LTE Mid- and High-Band Coverage.

Two novel antennas are presented for mobile devices to enable them to access both licensed shared access (LSA) bands (1452-1492 and 2300-2400 MHz) and all the long-term evolution (LTE) mid (1427-2690 MHz) and high (3400-3800 MHz) bands, together with the GSM1800, GSM1900, UMTS, and 3.3 GHz WiMAX bands. These antennas do not require any passive or active lumped elements for input impedance matching. One of them is a dual-band antenna and the other is a wideband antenna. Both antennas have high efficiency in all the LSA bands, as well as the mid- and high-LTE bands, and nearly omnidirectional radiation patterns in the mid band. In the high band, the radiation patterns of the wideband antenna are less directional than those of the dual-band antenna. The wideband antenna was fabricated and tested and the measurements demonstrated that it had good wideband performance in a wide frequency range from 1.37 to 4 GHz, covering all the above-mentioned bands.

A Frequency Reconfigurable Fractal UWB Antenna Using Ground Stub and PIN

A hexagonal shaped repeated loop structure with reconfigurable ground stub technique is proposed for ultra-wideband (UWB) application. Effects of repeated loops in the fractal structure and position of reconfigurable ground stub are optimized for ultra-wideband characteristics with better performance of the antenna. Two PIN diodes are used in the ground stub to achieve reconfigurability. The proposed fractal antenna is designed with FR4 substrate with an overall dimension of 40×44×1.6 mm3. The design shows frequency reconfiguration from Ultra-wideband characteristics to multiband for different possible switching conditions. The entire design is carried out in CST 2018 environment and the simulated results show that the proposed design is suitable for sub 6GHz wireless LAN, Bluetooth, WiMAX and other wireless applications.

A compact triple bands C shaped multiband monopole antenna for WLAN and WiMAX application

Antennas play a crucial role in communication as they serve as both transmitters and receivers. They are capable of supporting numerous applications and demanding higher bandwidth among which monopole antennas have emerged as a superior alternative to traditional antennas. A novel coplanar waveguide (CPW)-fed triple-band monopole antenna is proposed for WLAN and WiMAX applications. The antenna features a compact and simple Cshaped strip structure, allowing for easy fabrication. The prototype exhibits triple operating bands covering the required bandwidths of 2.4/5.2/5.8 GHz WLAN and 3.5/5.5 GHz WiMAX standards. Good radiation performance and antenna gain are achieved across the three frequency ranges. Another compact monopole multiband antenna is designed, consisting of five rectangular patches forming a C-shaped structure. It operates at frequencies covering WiMAX, WLAN, short-range radar, and wireless data transmission applications. The antenna demonstrates significant bandwidth to accommodate the respective frequency ranges required for these applications. The antenna design is simulated using HFSS v13 software.

Design of three multibranch microstrip antennas compatible with WiMAX/WiFi/4G/5G NR for coal mine applications

AbstractIn this letter, three microstrip antennas are designed and fabricated for coal mine applications, each of which can be compatible with WiMAX, WiFi, 4G, and 5G NR bands. The first one is the Pentagon antenna, which is realized by optimizing the sizes and positions of five branches. The second one is designed by adding a passive inverted L‐shaped branch on the top of a trident antenna. And the third one is designed by loading an inverted L‐shaped structure in the ground of the trident antenna. The simulated and measured results showed that each of the three proposed antennas can cover the frequency bands of 2.51–2.68, 3.40–3.60, and 4.80–4.90 GHz for commercial 5G NR of coal mines, 1.88–2.66 GHz for China Mobile/Unicom/Telecom full‐band of 4G, 2.40–2.484 GHz for WiFi, and 2.50–2.69 GHz for WiMAX. Good agreements between the simulated and measured results confirm the practical feasibility of the proposed multiband antennas.