Parasitic Patch Research Articles

A Wideband Microstrip-to-Waveguide Transition Using E-Plane Probe with Parasitic Patch for W-Band Application

The hollow metal waveguides are attractive components for millimeter-wave circuits owing to low loss. To integrate with the front-end circuit, a transition from microstrip line to waveguide is required. In this article, a microstrip-to-waveguide transition is presented in the W-band by using an E-plane probe with a parasitic patch. The probe is embedded into the waveguide along the center of the broad wall to excite the TE10 mode. A backshort-circuited waveguide with a quarter wavelength is used to obtain sufficient energy coupling and achieve good impedance matching. The additional parasitic patch can introduce a new resonance at a low frequency to enhance the working bandwidth. Hence, the proposed transition achieves wide working bandwidth and low insertion loss. For verification, a back-to-back transition is constructed and measured. The measured results indicate that the proposed transition has a wide working bandwidth covering the entire W-band. The measured reflection coefficient is below −13 dB from 70 to 110 GHz and the average insert loss is 1.1 dB. Attributed to wide working bandwidth and simple structure, the proposed transition is attractive for W-band circuit systems.

A UWB Antipodal Vivaldi antenna with high gain using metasurface and notches

This paper presents a planar ultra–wideband Antipodal Vivaldi Antenna (AVA) working over a super ultra–wideband frequency range of 1.5–55 GHz, found to suffice for various communication standards including that of the 5G mm-Wave communication, microwave imaging, non-destructive testing, defense applications, etc. The proposed antenna, fabricated on a single layer Rogers substrate (RO4003C) having a dielectric constant of 3.38, has a compact dimension of 96 mm × 175 mm × 0.508 mm, i.e., 0. 80 × 0.875 × 0.00254 λ03, where λ0 is the free space wavelength at the lowest frequency of operation. The designed antenna has exponential flaring and a tapered slot edge. Moreover, an elliptical parasitic patch is placed between the flares of the AVA to improve the directive gain. Dielectric lens and metasurface are used to further enhance the gain. The measured return loss, radiation pattern, and gain of the designed AVA are found to be in good agreement with the results obtained from the full-wave electromagnetic simulation.

A low-profile high gain U slotted wide band micro-strip antenna for 5G applications

ABSTRACT This work presents a parasitic wide band compact planar antenna for 5 G mm-wave applications. Besides having high bandwidth (5.22 GHz), the prospective antenna provides an enhanced gain of 5.23dBi which is achieved due to the reflector elements used in the design. The radiating element has a small planar rectangular geometry, with optimised dimensions of 0.342 λ0 × 0.199 λ0 × 0.005 λ0 at 28 GHz frequency of interest and has been designed and fabricated on a substrate of Rogers-RT/Duroid 5800 having a thickness of 0.147λ0 with loss-tangent of 9 × 10−4 and permittivity of 2.2. The proposed antenna operates in the frequency range of 24.71 to 29.93 GHz which falls under the n257 and n258 NR operating band of the FR2 band as defined by ITU for the millimetre wave 5 G spectrum. It is also affirmed in the study that the impedance bandwidth can be tuned by controlling the coupling gap between the radiating and parasitic patches. The measured results of the fabricated prototype of the patch are compared with the simulated results and the two results are in good agreement with each other. The pursuance of the proposed design in terms of gain, efficiency, radiation pattern, and wide bandwidth, qualifies the prototype as a viable option for mm-wave communication.

Wideband Circularly Polarized Microstrip-Slot Antenna with Parasitic Ground Planes

In this study, a new stacked microstrip slot antenna (MSA) with wideband circular polarization (CP) characteristics is proposed. The antenna consists of a square-loop feed configuration, four parasitic square patches, four parasitic vertical planes, and a square ground plane etched with four parasitic square slots. The corner-cut square-loop can excite a stable 270° phase difference by loading an arc-shaped strip into the square-loop. Square-patches, vertical planes, and square slots as parasitic elements are placed together at the side of the square-loop to stimulate two CP resonant points. Simulation and measurement are performed on the designed antenna prototype to demonstrate the design’s rationality. The measured results depict that the measured impedance bandwidth (IBW) for |S11| < −10 dB is 36.4% (4.65 to 6.70 GHz) and the measured axial ratio bandwidth (ARBW) for AR < 3 dB is 25.1% (5.01 to 6.45 GHz). Compared with other reported stacked CP antennas, the proposed antenna has significant advantages in CP bandwidth, which could occupy the wireless local area network ITS (5.8 GHz), (5.725–5.85 GHz), and WIFI (5.85–5.925 GHz) bands.

Bandwidth Enhancement of a Compact Slot Antenna with Frequency Scale Up/down Capability

In this paper, a printed wideband slot antenna is proposed and investigated. The antenna geometry consists of a 45° rotated square slot and a circular parasitic patch situated at its center. In addition, the slot consists of four rectangular notches at every corner. It brings close the resonances of both slot and circular patches and enhances bandwidth. The antenna achieved the measured impedance bandwidth of 111.7% from 2.24 to 7.91 GHz, with almost stable pattern. Furthermore, a comprehensive parametric study has been carried out to prepare a set of guidelines to scale up or down the antenna for a specified impedance bandwidth (111.7%) between different frequency ranges. The frequency scaling feature has been verified by simulating a set of antennas for different frequency bands. The result demonstrates that all antennas under test yield almost equal impedance bandwidth.

Bandwidth Enhancement and Generation of CP of Yagi-Uda-Shape Feed on a Rectangular DRA for 5G Applications.

A wideband circularly polarized rectangular dielectric resonator antenna (DRA) fed by a single feeding mechanism has been studied theoretically and experimentally. The purpose of the study is to determine how adding a parasitic strip next to the flat surface metallic feed would affect various far- and near-field antenna characteristics. Initially, the basic antenna design, i.e., the T-shape feed known as antenna A, produced a 4.81% impedance matching bandwidth (|S11| -10 dB). Due to the narrow and undesirable results of the initial antenna design, antenna-A was updated to the antenna-B design, i.e., Yagi-Uda. The antenna-B produced a decent result (7.89% S11) as compared to antenna-A but still needed the bandwidth widened, for this, a parasitic patch was introduced next to the Yagi-Uda antenna on the rectangular DRA at an optimized location to further improve the results. This arrangement produced circular polarization (CP) waves spanning a broad bandwidth of 28.21% (3.59-3.44 GHz) and a broad impedance |S11| bandwidth of around 29.74% (3.71-3.62 GHz). These findings show that, in addition to producing CP, parasite patches also cause the return loss to rise by a factor of almost three times when compared to results obtained with the Yagi-Uda-shape feed alone. Computer simulation technology was used for the simulation (CST-2017). The planned antenna geometry prototype was fabricated and measured. Performance indicators show that the suggested antenna is a good fit for 5G applications. The simulated outcomes and measurements match up reasonably.

Design and Study of the Performance of Patch Antenna with Double C Slot for MIMO-OFDM Based Communications Systems for Media Technology

Mobile phones, server stacks, and other high-bitrate devices demand greater bandwidth from antennas. More bandwidth means higher bitrates and more data sent. MIMO antennas simultaneously deliver and receive data. MIMO antennas can broadcast data to unreachable places with little noise. Multiple data streams and multipath propagation boost performance and data quality. Many antennas allow MIMO systems to send and receive data at regular intervals. These antennas can perform beamforming and determine a signal's 3-D route. OFDM increases bitrates at the same frequency by multiplexing without guard bands. Multiple orthogonal carrier frequencies increase data in the same bandwidth and avoid carrier distortion. Air gaps, parasitic patches, and substrate modifications are methods to increase bandwidth and beam width for patch antennas. The conventional patch pattern has been modified and refined for maximum success. This article proposes a patch antenna with double C slots. This new design features a large bandwidth, wide beamwidth, and multidirectional transmission pattern. The gain, VSWR, and reflection coefficient of this patch antenna meets the MIMO-OFDM systems with 5G standard. Hence the proposed antenna design is recommended to employ in the MIMO-OFDM system for 5G applications.

Low-profile and wide-band RCS-reduction antenna array based on the metasurface polarization converter.

Antenna elements with a low profile and high front-to-back (FB) ratio mean that no additional reflective cavity is required when forming the array, which greatly helps to simplify and lighten the entire array system. In this paper, we enhance the FB ratio of the antenna to 35 dB while maintaining an ultra-low profile of 0.05 λ0 by attaching the broadband polarization conversion metasurfaces (PCMs) as the parasitic patches to the surface of the radiating patch. Meanwhile, the array formed by the proposed antenna is arranged in a checkerboard form, which makes it have a lower radar cross section (RCS) in the X- and Ku- bands. Even with PCMs loaded, the antenna element maintains a small size of 0.58 λ0 × 0.58 λ0, which ensures the proposed array can achieve the ± 45° beam scanning, making it suitable for the phased array. For verification, we propose a low-sidelobe array composed of the proposed antenna elements, which exhibits a low profile, high FB ratio, and broadband RCS reduction through simulation and measurement.

A wideband circularly polarized monopole antenna with elliptic ring slot patch using characteristic mode analysis

This article presented a wideband circularly polarization (CP) monopole antenna with elliptic ring slot patch using characteristic mode analysis (CMA). By analyzing the characteristic modes of elliptical patch and elliptical ring patch in turn, it is found that the elliptical ring slot patch can meet the phase requirement of CP. Then, the parasitic elliptical ring slot patch is used to broaden the impedance bandwidth and polarization bandwidth of the antenna. The broadband is obtained by the modal significance (MS) analysis, and the CP is realized by analyzing the characteristic current of two modes are orthogonal and the characteristic angle (CA) close to 90°. The proposed antenna was fabricated and measured with the size of 0.59λ0 × 0.59λ0 × 0.02λ0. The measured 3-dB axial ratio (AR) band is from 5.3 to 9.4 GHz (55.8%), and the −10 dB impedance band is from 4.5 to 9.7 GHz (73.2%).

Axial ratio bandwidth enhanced circularly polarized transmitarray antenna with a flat gain response.

In this paper, a novel broadband circularly polarized transmitarray antenna (CPTA) enabled by axial-ratio-improved receiver-transmitter metasurface loaded with parasitic patches is proposed. Split-ring-shaped parasitic patch is utilized to generate an additional resonant mode and significantly broaden the 3-dB axial ratio (AR) bandwidth of proposed receiver/transmitter patches from 6.64% to 15.61%. By cascading the receiver and transmitter with the same polarization and then rotating the cell, Pancharatnam-Berry phase can be exploited for providing a 2π phase shift. As verification, a CPTA prototype integrated with a self-made circularly polarized patch antenna is designed, fabricated, and measured. Experimental results show that the proposed CPTA obtains a 3-dB AR bandwidth of 27.1% from 12.1 to 15.9 GHz and an impedance bandwidth of 20.6% from 12.5 to 15.2 GHz. Additionally, it has a flat gain with a 3-dB gain bandwidth of 18.8% from 12.5 to 15.1 GHz, and a maximum gain of 25.6 dBi at 13.1 GHz is achieved. With the advantages of simple design, wide AR bandwidth, and flat gain performance, the proposed CPTA presents great potential applications in wireless systems.

Design of Inverted Stacked Parasitic Patch Antenna for Communication in White Space TV Band

The proposed work aims to design and develop stacked parasitic microstrip antenna configurations in the TV white-space frequency band, which can work between 470 to 806 MHz for applications like IEEE 802.11. The antenna is designed for both the base station (higher gain) and the user terminal (compact). In this design, two layers are stacked on each other with coaxial feed at the lower circular patch. The two top circular patches are placed in an inverted position and electromagnetically coupled with a lower patch. The substrate used is FR4. The proposed antenna can operate between 499 to 650 MHz frequency band with 5.6dBi gain. The proposed antenna is having an efficiency of 98%. A parametric analysis is done to cater to the requirements of the antenna size, gain, and radiation pattern. The parametric study found that when both top patches are elliptical, the lowest size with the largest gain is achieved.

Design of compact dual‐polarized base station antenna array with high isolation using array decoupled surface and parasitic patch structure

For a compact base station antenna array, the isolation between two co-polarized adjacent elements and two cross-polarized adjacent elements is relatively poor. The introduction of the array decoupled surface (ADS) on the top of the antenna and the introduction of parasitic structures between adjacent elements effectively improve the isolation of the co-polarized and cross-polarized adjacent elements. Array decoupled surface mainly suppresses the mutual coupling between the co-polarized adjacent elements, and the parasitic structure mainly suppresses the mutual coupling between the cross-polarized adjacent elements. Both simulated and measured results show that in the 3.3–3.6 GHz band, the return loss of all ports is better than 10 dB. By introducing the ADS and the parasitic patch structure, the isolation between two co-polarized adjacent elements is improved from about 15 to 21.9 dB, and the isolation between two cross-polarized adjacent elements is improved from about 13 to 22.4 dB. The isolation between two cross-polarized elements in the same unit is greater than 27 dB.

Novel method of Characterization of dispersive properties of heterogeneous head tissue using Microwave sensing and Machine learning Algorithms

A brain tumor is a critical medical condition and early detection is essential for a speedy recovery. Researchers have explored the use of electromagnetic waves in the microwave region for the early detection of brain tumor. However, clinical adoption is not yet realized because of the low resolution of microwave images. This paper provides an innovative approach to improve microwave brain tumor detection intelligently by differentiating normal and malignant tissues using machine learning algorithms. The dataset required for classification is obtained from the antenna measurements. To facilitate the measurement process, an Antipodal Vivaldi antenna with the diamond-shaped parasitic patch (37 mmx21 mm) is designed to operate with a resonance frequency of 3 GHz. The proposed antenna maintains a numerical reflection coefficient (S11) value below -10dB over the entire UWB frequency range. In this paper, Waikato Environment for Knowledge Analysis (WEKA) classification tool with 10 cross-fold validation is used for comparison of various algorithms against the dataset obtained from the proposed antenna.

A Transparent Wideband Dual-Polarized Antenna for Sub-6 GHz Application

In this letter, a novel transparent dual-polarized antenna has been developed for sub-6 GHz application. The proposed antenna composed of transparent conductive mesh and polycarbonates material is of optical transparency. Based on characteristic mode analysis, the proximity-coupling fed driven patch operates in TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> /TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> mode. By stacking the parasitic patch and strips above the driven patch with a cross slot, three resonances are generated. With the T-shaped slots on the parasitic patch, the impedance matching at low frequencies is improved. By etching the slots on the ground and cutting off the corners of the driven patch, good port isolation and stable in-band gain are achieved. The prototype of proposed antenna is fabricated. The measured results show that the proposed antenna exhibits a wide impedance band of 2.76–4.13 GHz with a fractional bandwidth of 39.8%, a good isolation better than 22 dB, a low cross polarization ratio better than 20 dB within the operating band.

Co-Designed Millimeter-Wave and Sub-6 GHz Antenna for 5G Smartphones

This letter proposes a co-designed millimeter-wave (mm-wave) and sub-6 GHz antenna system. The antenna system consists of four 28 GHz mm-wave arrays with reconfigurable radiation patterns and two sub-6 GHz antennas fed with two corner capacitive coupling elements (CCEs). Each corner CCE is formed by the connected ground planes of two mm-wave arrays in the shared-aperture configuration. The two CCEs are separately matched to cover two sub-6 GHz bands. Each mm-wave array consists of an active patch element and two parasitic patch elements loaded with PIN diodes, realizing 90° beam scanning range with two states of the PIN diodes. The measured results of the fabricated prototype show good agreement with the simulated ones. The prototyped mm-wave arrays cover the band 27.5–28.35 GHz, and each achieves 90° beam scanning at 28 GHz, with measured peak realized gain of 7.9 dBi. The CCE ports cover the two sub-6 GHz bands of 0.79–0.96 GHz and 1.7–5 GHz, with measured isolation of above 17 dB and 20 dB, respectively. The mm-wave band isolation is above 26 dB.

Design and Characterization of a Planar Structure Wideband Millimeter-Wave Antenna With Wide Beamwidth for Wearable Off-Body Communication Applications

This letter presents the design of a planar single-layer wideband antenna featuring wide beamwidth has well as high and stable in-band gain. The proposed antenna is a planar monopole fed by a bottom-grounded coplanar waveguide to realize wide beamwidth in both the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">xz</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">yz</i> -planes. Simultaneous optimization of all adjustable antenna parameters, carried out at the full-wave electromagnetic simulation level. The constructive interference of the radiated fields resulting in impedance bandwidth of more than 2 GHz, from 27 to 29 GHz. Along with a stable realized gain (>11 dBi) in the operating frequency band. The proposed antenna maintains a directional radiation pattern in the broadside direction. Merging the radiated modes of the slots and the parasitic patch elements also extends the antenna beamwidth to roughly ±35° with respect to the broadside direction. Following a detailed theoretical analysis, the antenna is validated numerically and experimentally, both in the free space and on a human volunteer chest and arm.

Analysis of Tripleband Single Layer Proximity Fed 2x2 Microstrip Patch Array Antenna

Microstrip patch antennas that are multiband and downsized are required to suit the high demand of modern wireless applications. To meet this need, a one-of-a-kind triple band array antenna has been proposed. The proposed 2x2 microstrip patch array, which comprises of four hexagon-shaped radiating patches are electromagnetically excited by a centrally positioned microstrip feed line in the same plane along with a slotted ground plane, is investigated. CST Microwave Studio, a powerful 3D electromagnetic analysis programme, was used to design and optimize the array antennas. The 2x2 array antenna was constructed on a FR-4 substrate with a dielectric constant of 4.3, a loss tangent of 0.001, and a height of 1.6mm. To optimize energy coupling from the feed line to the radiating patches, the ground plane has an H-shaped groove cut into it. The suggested 2x2 array antenna's multi- frequency behaviour is shown. Three resonant peaks were detected at 1.891GHz, 2.755GHz, and 3.052GHz. The observed bandwidths for these resonances are 234MHz, 69MHz, and 75MHz, respectively, with measured gains of 7.57dBi, 6.73dBi, and 5.76dBi. The goal of this work is to design, build, and test a single layer proximity fed array antenna. Standard proximity fed array antennas contain two substrate layers; however this array antenna has only one. As a consequence, the impedance matching and alignment are better. Simulated and experimental results showed that the this 2x2 array antenna operates in various important commercial bands, such as L and S bands and the array antenna might be beneficial for a wide range of wireless applications. The proposed antenna has good Impedance, S11, and radiation qualities at resonant frequencies. In this work, the 2x2 array antenna with hexagon-shaped radiating patches was successfully created utilizing the single layer proximity fed antenna concept and gap coupled parasitic patches.

Novel implantable antenna with miniaturized footprint size for wideband biomedical telemetry applications

Abstract Medical telemetry applications rely heavily on biomedical implanted antennas. These biomedical implanted devices can enhance and monitor patients’ daily life circumstances. A low-profile, downsized size implanted antenna operating at 915 MHz in the industrial, scientific, and medical (ISM) band is suggested in this research. The antenna is a simple slotted patch supplied by a 50-impedance coaxial probe. The radiator is made up of two slotted parasitic patches with one square-shaped outer radiator are manufactured on a Roger Droid RT5880 substrate with a standard height of 0.254 mm (ε r = 2.2, tanδ = 0.0009). The entire dimension of the given antenna is 11 × 11 × 0.2514 mm with an electrical size of 0.049λ g × 0.049λ g × 0.0011λ g. The antenna spans a bandwidth of 0.82–1.05 GHz when working inside muscle tissues (25.13 percent). The antenna’s calculations and experimental findings are quite similar. The computed specific absorption rate (SAR) values inside muscle of above 1 g mass tissue are 7.25 W/kg, according to the data. The stated SAR values are lower than the limit set by the Federal Communications Commission (FCC). As a result, the proposed small antenna is a strong contender for biological implantable applications.

Compact, broadband, and thin corrugated U-shaped patch-constituted MIMO antennas for airborne UAV applications

AbstractThe major component for the effective functioning of airborne unmanned aerial vehicles (UAVs) is an antenna. The unified integration of an antenna with UAVs without disturbing the other components of UAVs, compact size, thin, and wideband antennas are preferred. Based on these prerequisites, a low-profile and a wideband antenna is presented for autonomous UAVs for C-band applications. The antenna is designed on an extremely thin substrate of size 0.01λ0 without compromising the antenna's broad bandwidth. The antenna structure comprises a corrugated U-shaped patch, a few parasitic patches along with the partial ground. Initially, only a single mode was excited using a U-shaped patch, then further on introducing a few more parasitic patches along with corrugations in a U-shaped patch other modes were also coupled leading to enhancement in the bandwidth of the antenna. The proposed antenna along with a 2 × 2 quad-port multiple input, multiple output (MIMO) antenna is designed and fabricated. The measured results are found to be in good agreement with the simulated results. A broad bandwidth of 74.5% (4.1–9.0 GHz) with 5.02 dBi peak gain at 6.6 GHz is exhibited by the fabricated MIMO antenna. Thus, the designed antenna proves to be an effective candidate for UAV-based C-band applications.

Multi-Resonator Wideband Designs of Semi-Circular Microstrip Antennas

Multi-resonator wideband designs of Semi-Circular microstrip antennas using narrow annular sectoral patches are proposed. The parasitic patches utilize the empty space around the fed patch, thus do not increase the antenna size by a large amount. Amongst various proposed designs, the gap-coupled design of slot-cut semi-circular patches along with narrow sectoral patches yields maximum bandwidth of greater than 900 MHz (>60%) with a peak broadside gain of 7.7 dBi. Against equivalent CMSA, it offers a 20% increase in bandwidth with only a 14.3% increase in the patch area. A resonant length formulation and subsequent design methodology are presented that is useful for re-designing similar antennae in the given frequency range as per specific application.