Proposed Antenna Structure Research Articles

A Low-Profile Circularly Polarized Millimeter-Wave Broadband Antenna Analyzed with a Link Budget for IoT Applications in an Indoor Scenario.

Broadband antennas with a low-profile generating circular polarization are always in demand for handheld/ portable devices as CP antennas counter multipath and misalignment issues. Therefore, a compact millimeter-wave antenna is proposed in this article. The proposed antenna structure comprises two circular rings and a circular patch at the center. This structure is further embedded with four equilateral triangles at a 90° orientation. The current entering the radiator is divided into left and right circular directions. The equilateral triangles provide the return path for current at the differential phase of ±90°, generating circular polarization. Structural development and analysis were initially performed through the characteristic mode theory. It showed that Modes 1 to 4 generated good impedance matching from 20 to 30 GHz and Modes 1 to 5, from 30 to 40 GHz. It also demonstrated the summation of orthogonal modes leading to circular polarization. The antenna-measured reflection coefficient |S11| > 10 dB was 19 GHz (23-42 GHz), and the axial ratio at -3 dB was 4.2 GHz (36-40.2 GHz). The antenna gain ranged from 4 to 6.2 dBi. The proposed antenna was tested for link margin estimation for IoT indoor conditions with line-of-sight (LOS) and non-line-of-sight (NLOS) conditions. The communication reliability with co- and cross-polarization was also studied under these conditions, and the results proved to be satisfactory.

Design of a Stacked Dual-Patch Antenna with 3D Printed Thick Quasi-Air Substrates and a Cavity Wall for Wideband Applications

In this paper, we propose a stacked dual-patch antenna with 3D printed thick quasi-air substrates and a cavity wall for wideband applications. To achieve the theoretical maximum bandwidth of the patch antenna, the quality factor of the system needs to be minimized. To achieve this, the area of the conductive radiator should be enlarged, while the permittivity of the substrate within the patch must be reduced close to 1. To realize a patch antenna with this maximum bandwidth, the stacked dual-patch configuration is employed to obtain an extended conductive radiator area. In addition, square-pipe resin frames manufactured using a 3D printing method are applied to the proposed antenna to implement a quasi-air substrate structure that has a low permittivity value close to 1. The proposed stacked dual-patch antenna with a quasi-air substrate has a broad bandwidth of 20.7%. The results demonstrate that by using the proposed antenna structure, broadband characteristics close to the fundamental bandwidth limit of the patch antenna can be achieved.

Design and Implementation of Novel H-Shaped Self-Diplexing SIW Rectangular Cavity-Backed Antenna with Harmonic Suppression for Terrestrial Communications

A novel and low profile, planar, rectangular cavity-backed self-diplexing substrate integrated waveguide (SIW) antenna with H-shaped slot for dual-band wireless services was designed and demonstrated. The proposed antenna structure radiates from H-shaped slot, which is etched on top of the SIW rectangular cavity, and is excited by two separate 50 Ω microstrip feed lines. The H-shaped slot is a combination of two vertical slots and one horizontal slot; because of that the presented antenna radiates at two distinct frequency bands around 8.95 GHz and 10 GHz, simultaneously. The design methodology results show that the H-shaped slot is significantly more effective than various other slots in the proposed geometry to suppress the unwanted harmonics, attaining good impedance matching and bandwidths and achieving better isolation between these two ports. Hence, the complete design mechanism helped to achieve self-diplexing characteristics. Furthermore, a self-diplexing H-shaped SIW rectangular cavity-backed antenna was fabricated and characterized for the complete demonstration purpose and found good covenants between the simulated one. Measured results show that the presented designed has impedance bandwidths for the lower and upper frequency bands of around 2.0% (8.89–9.03 GHz) and 3.1% (10.01–10.32 GHz), respectively, and obtained maximum measured gain of 5.11 dBi and 5.41 dBi at 8.95 GHz and 10.15 GHz, respectively. The proposed self-diplexing SIW rectangular cavity-backed structure shows that front-to-back ratios (FTBRs) are more than 21 dB, and on the other side, it provides good isolation between the two ports, which is more than 20 dB.

Design and performance analysis of an L-shaped radiator and defected ground antenna for enhancing wireless connectivity in brain implants

Brain implantable wireless microsystems has potential to treat neurological diseases and maintain the quality of life. Highly efficient miniaturized antenna is the fundamental part of BID (brain implantable device) for reliable signaling of data through dissipative intracranial material. In this paper, a patch antenna with L-shaped defected ground is demonstrated. L-shaped radiator contributed to achieve the resonance at 2.45 GHz industrial scientific and medical (ISM) band. Antenna size is reduced to 10 × 10 × 0.25 mm3. The proposed L-shaped ground plane geometry is contributing in improving the radiation performance. |S11| value shifts from 15 dB to 30 dB after modifying the ground plane. Proposed structure attained the gain of −14 dBi when located between the Dura and CSF layers at the depth of 12 mm in human brain model. Full wave simulated antenna prototype is fabricated and measured for performance verification. Impedance bandwidth of 270 MHz and broadside radiation pattern (for transferring maximum electromagnetic energy away from tissue) are maintained by the proposed antenna. Brain tissue safety is ensured by specific absorption rate which is 0.709 W/kg and in compliance with the safety limits of 1.6 W/kg for 1-g averaged tissue. Proposed antenna structure is the promising candidate for medical implant technology.

Design, fabrication, and measurement of a miniaturized MIMO antenna applicable for 5G communication

Abstract The design of low-profile Multiple-Input-Multiple-Output (MIMO) antennas for various 5G applications is a topic of huge interest in academia, research, and telecommunication sector. In this aspect, a compact and low-profile 5G MIMO antenna has been designed and analyzed for various 5G applications, specifically for the 24 GHz bands (24.25–24.45 GHz and 25.05–25.25 GHz) and local multipoint distribution system band (27.5–28.35 GHz) of the 5G spectrum. The proposed antenna structure is 20 × 20 × 1 mm3 in dimension. Two spade-shaped radiators composed of Copper (annealed) material are placed orthogonally to improve isolation and maintain signal diversity. Rogers RT 5880 is used as the material for substrate. The antenna exhibits a wide bandwidth of 21.5–28.5 GHz. The mutual isolation |S21| has been maintained ≤29 dB due to the insertion of a T-shaped parasitic strip in between the radiating elements. Novelty in design and superiority in performance has been observed when compared with related antenna categories.

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.

High Gain Metamaterial Implemented Antenna Design with Circular Polarization for mm-Wave 5G and 6G Sub-THz Communication

A high-gain metamaterial-enabled circularly polarized antenna has been proposed. Two patch structures patch A and patch B have been designed by using different shape slots. After slot etching on the patch, two different metamaterial techniques were used. Circular metamaterial (MTM) was implemented for Patch A, while rectangular MTM was used for Patch B. The implementation of MTM resulted in increased antenna gain, as well as improvements in impedance bandwidth RL and AR. So, in the proposed article two antenna structures ANT-A and ANT-B, are presented. The maximum gain achieved for ANT-A is 34.759dBi, covering the frequency bands (28.997-202.113) GHz, and (205.884-336.693) while in the case of ANT-B, it is 36.3155dBi, covering the frequency bands (29.178-330.490) GHz, and (334.936-336.702) GHz. The proposed antenna structure is a useful design for mm-wave 5G and 6G Sub-THz communications.

Design of Miniaturized Printed Spiral Monopole Antenna

This paper introduces the design, simulation and implementation of miniaturized printed monopole antenna for medical application. FR-4 substrate dielectric constant 4.3, and thickness 0.8 mm have been used. The proposed antenna operates in Medical Implant Communication System (MICS) band. It has a spiral shape with an overall dimension of (9x9x0.8) mm3. The proposed antenna was simulated and evaluated using the CST microwave studio package. The simulation results show that the designed antenna operates at a frequency of 401.3MHz with a return loss of (-10.904 dB) and bandwidth (3.9 MHz). The proposed antenna structure was fabricated and experimentally tested. Results of simulation and implementation show that the proposed antenna possesses a miniaturized dimensions and acceptable performances, enabling their use in medical applications

A novel slotted dumbbell-shaped dielectric resonator antenna with enhanced bandwidth for C-band and 5G sub-6 GHz applications

Abstract This manuscript presents a novel aperture-coupled fed slotted dumbbell-shaped (SDS) dielectric resonator antenna (DRA) with enhanced bandwidth for 5G sub-6 GHz, short-range wireless communications, and C-band applications. The DRA is excited by HEM11δ mode. The proposed SDS-DRA is designed by assembling the four frustums of conical DRAs with the base and apex of one on top of another. The measured operating frequency of SDS-DRA is from 3.5 GHz to 9.6 GHz (impedance bandwidth of 93.1 %). The SDS-DRA shows a peak gain of 9.7 dBi in the operational frequency range, with an average peak gain of 6.02 dBi. The antenna’s average radiation efficiency is found to be 84.6 %. The proposed SDS-DRA produces omnidirectional-like radiation patterns with significantly low cross-polarization in the broadside direction. The size (l × w × h) of the proposed SDS-DRA is 1.55λ g × 1.55λ g × 0.67λ g where, λ g is the guided wavelength in mm at 3.5 GHz for effective permittivity (ϵ eff ), 7.1. To validate the simulation results, the proposed antenna structure is built, and its performance is measured. The findings of simulation and measurement results are found to be quite congruent.

Compact dual band 4-port MIMO antenna for 5G-sub 6 GHz/N38/N41/N90 and WLAN frequency bands

In this investigation, a dual-band 4 port MIMO antenna is designed, fabricated and measured. The MIMO design consists of perturbed hexagonal patch along its periphery on the top of the substrate and the connected ground plane on the bottom. The MIMO design has an overall dimension of 50 × 50 × 0.8 mm3. The proposed antenna structure demonstrates the dual frequency band of 2.47–3.38 GHz and 4.94–7.24 GHz, respectively covering the 5G sub-6 GHz/WLAN/HiperLAN band applications. Moreover, the radiation efficiency, gain and far-field patterns are also presented across both the operating bands. The antenna diversity parameters which include ECC, DG, MEG, CCL and TARC are studied and found excellent for the MIMO antenna implementation. The channel loss of the proposed 4 × 4 MIMO antenna is calculated and found 21.54 b/s/Hz at SNR of 20 dB. The proposed design is modeled in CST Microwave Studio and the results are compared with the fabricated prototype antenna for the practical implementations.

Synthesis of a Multiband Microstrip Patch Antenna for 5G Wireless Communications

This paper presents a multiband microstrip patch antenna for future 5G Millimeter Wave (mm-wave) wireless technologies. The synthesized antenna is designed to be based on the genetic algorithm (GA) optimization tool in the high frequency simulation software (HFSS). The optimized dimensions of the engineered antenna are 24 × 24 × 0.203 mm3, comprising of a ground plane. The antenna design simulated results have been implemented via (HFSS) and microwave studio (CST) tools. The proposed antenna structure is engineered using Rogers RT-Duroid 4003 substrate as a dielectric medium. The Conformist rectangular and circular patches are modified to get multiband operation in the mm-wave band 25–32 besides 40–60 GHz frequency ranges. The input reflection coefficient (S11\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathrm{S}}_{11}$$\\end{document}) simulation results were compared with the measurements to check the validity of the design. The fabricated antenna radiation efficiency and gain values are also measured over the desired bandwidths. The measured gain and radiation efficiency values reached up to 9.75 dBi, 0.85%, and 10.75 dBi, 0.84%, for both bandwidths, respectively.

Analysis and Design of Dual-Polarized Millimeter-Wave Filtering Magneto-Electric Dipole Antenna

A wideband dual-polarized millimeter-wave filtering magneto-electric dipole (ME-dipole) antenna design is proposed based on a transmission line model with multiple open-circuited loads. Based on the transmission line theory, the input impedance of a quarter-wavelength open-circuited transmission line is zero. Thus, a transmission line terminated with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> open-circuited loads has <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> transmission zeros. Inspired by this conclusion, the proposed antenna structure is developed which consists of three parts: the microtrip feedlines, the ME-dipole radiator and a printed branch structure. The former three parts can be regarded as three open-circuited loads of an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> -stub-loaded transmission line model while the last part is utilized for bandwidth improvement. By optimizing the length parameters of these three parts, three antenna radiation nulls can be generated as predicted. For verification, a dual-polarized antenna is implemented. Measurement results show that the proposed antenna has an operation bandwidth of 42.1% and an average realized gain of 7.5 dBi. In addition, it has three controllable radiation nulls and a better than 16 dB out-of-band suppression level. Above features make the proposed antenna a good candidate for 5G millimeter-wave (mm-wave) applications.

Pattern-Reconfigurable Flexible Textile Antenna Using RF-Switch Integrated Circuits

A pattern-reconfigurable flexible textile antenna covering the 2.45 GHz Industrial, Scientific and Medical (ISM) band is presented. The design utilizes RF-switch Integrated Circuits (ICs) packaged into reconfiguration modules as switchable vias to change between the omnidirectional and broadside radiation modes of a center-shorted patch. Analytical models to calculate the resonance frequency of each mode are developed to give more physical insights into the mode resonance and assist the design optimization. An antenna prototype is experimentally characterized to further validate the concept and analysis of the proposed antenna structure. The stable performance under on-body environment and various bending test conditions demonstrates the antenna operation in wearable scenarios.

Breast Cancer Detection by Terahertz UWB Microstrip Patch Antenna Loaded with 6X6 SRR Array

This paper presents cancer tumor detection in the breast phantom and cancer tissue detection in the excised breast tissue phantom by the ultra-wideband terahertz microstrip patch antenna. The proposed antenna structure consists of a silicon dioxide substrate with a dielectric constant of 3.9 and a thickness of 200 µm, a radiating gold patch of length 560 µm, width 700 µm, and thickness 36 µm which is on top of the substrate, and an array of 6 × 6 gold Split Ring Resonator at the ground plane. Each SRR is separated by 28.75 µm. An array of SRR at the antenna's ground plane enhances bandwidth, efficiency, gain, directivity and reduces back radiation. The antenna operates in the frequency range of 0.1-3 THz, with a gain of 19.22 dBi and an efficiency of 98.74%. The antenna setup with the breast phantom and excised breast tissue phantom in between have been designed and analyzed in the CST microwave studio 2019 version. Tumor in the breast phantom and the cancerous tissue in the breast tissue phantom can be detected by placing the phantoms between the two identical antennas. The difference in the dielectrics of the breast and the tumor layers can determine the difference between healthy and malignant tissue. A typical breast phantom model that replicates a real-human breast and a specific excised tissue that replicates the actual breast tissue with and without cancer tissue in terms of dielectric and optical properties has been employed in this study to detect the tumor and cancerous tissue.

High-gain printed monopole antenna with dual-band characteristics using FSS-loading and top-hat structure

In this paper, a printed monopole antenna with high-gain and dual-band characteristics for applications in wireless local area networks and the internet of things sensor networks is presented. The proposed antenna consists of a rectangular patch with multiple matching stubs surrounded to improve the impedance bandwidth of the antenna. The antenna incorporates a cross-plate structure which is seated at the base of the monopole antenna. The cross-plate consist of metallic plates aligned perpendicularly which enhances the radiations from the edges of the planar monopole to maintain uniform omnidirectional radiation patterns within the antenna’s operating band. Furthermore, a layer of frequency selective surface (FSS) unit cells and a top-hat structure is added to the antenna design. The FSS layer consist of three unit cells printed at the back side of the antenna. The top-hat structure is placed on top of the monopole antenna and comprises of three planar metallic structures arranged in a hat-like configuration. The coupling of both the FSS layer and the top-hat structure presents a large aperture to increase the directivity of the monopole antenna. Thus, the proposed antenna structure realizes a high gain without compromising the omnidirectional radiation patterns within the antenna’s operating band. A prototype of the proposed antenna is fabricated where good agreement is achieved between the measured and full-wave simulation results. The antenna achieves an impedance bandwidth |S11| < − 10 dB and VSWR ≤ 2 for the L and S band at 1.6–2.1 GHz and 2.4–2.85 GHz, respectively. Furthermore, a radiation efficiency of 94.2% and 89.7% is realized at 1.7 and 2.5 GHz, respectively. The proposed antenna attains a measured average gain of 5.2 dBi and 6.1 dBi at the L and S band, respectively.

Circularly Polarized Dual-Frequency MIMO Antenna With Cosecant-Squared Radiation Pattern for Ku-Band Applications

In this paper, the realization of a circularly polarized multiple-input, multiple-output (MIMO) array antenna with a cosecant squared pattern, is presented. The proposed antenna structure consists of microstrip patches with rectangular slots etched from the top. The desired radiation pattern is generated using amplitude tapering obtained by modifying patch widths and slot lengths, based upon the amplitude coefficients of the Woodward-Lawson method for pattern synthesis. A MIMO arrangement with circular polarization is formed by connecting two such arrays excited by two ports. A <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> -shaped slot is used to minimize the mutual coupling. Using two shorting pins, the isolation is enhanced and kept above 30 dB. This arrangement offers a small size (52 mm ×24 mm × 0.8 mm), wide bandwidth, and high gain antenna operating at 13.2 and 16.6 GHz. The antenna operates in a wide bandwidth, from 12.6 GHz to 14.25 GHz, and from 16 to 17.61 GHz, with admirable directional characteristics. The achieved gain is 16.9 dB and 16.6 dB with a cosecant pattern and low side lobe level. The analysis of the, VSWR, gain, axial ratio, group delay, efficiency, and MIMO performance metrics are also investigated, both in simulation and in experiment.

Compact hybrid EBG microstrip antenna for wearable applications

Abstract A novel strip line fed, circularly polarized (CP), annular slotted dual band antenna using hybrid electromagnetic band gap (EBG) structure for Global Positioning System (GPS) has been herein designed, analyzed, and investigated for wearable applications. Adjusting the radii of the annular slots on the radiating patch excellent circular polarized (CP) radiation and impedance matching is achieved. The design demonstrates Kapton based flexible, robust, and low-profile solution with permittivity of 3.4 to meet the requirements of wearable applications. Due to the high losses of the animal body, the electromagnetic band gap (EBG) structure is used to reduce back radiation and the effect of frequency detuning. The proposed antenna structure also enhances the front-to-back ratio (FBR) by 10 dB. This antenna with dimensions 0.56λ 0 × 0.4913λ 0 × 0.002λ 0 analyzed using a flexible Kapton substrate. Optimized hybrid EBG structure provides an excellent Specific Absorption Rate (SAR) along with all other antenna parameters, within acceptable for GPS-based wearable applications at 1.13 GHz and 1.157 GHz frequency band. Therefore the proposed antenna is a suitable candidate for GPS-based tracking and wireless body area network (WBAN) applications. The proposed antenna was also tested upon fabrication and the measured results agree with simulated results.

Polarization-insensitive planar patch antenna with large embedded serial capacitance for on-metal tag design

A polarization-insensitive planar patch antenna, which has a large embedded serial capacitance, is proposed for constructing a metal mountable tag by using merely a single radiator. The proposed antenna structure itself contains two flaps of patches, which are very closely overlapped, for generating a large capacitive reactance for reducing the resonant frequency of the tag. It has been found that the surface currents in the overlapped region are in the reverse direction as the large capacitance is virtually placed in series. This feature has been tactfully employed for producing a pair of orthogonal currents for designing the polarization-insensitive tag antenna and it can generate orthogonal fields in a unique way, making it readable from almost all directions at all points above the metal surface. For analyzing the impedance properties, an equivalent circuit was also constructed. This tag antenna is compact, and it can be read from ~ 15 m with 4W EIRP. Furthermore, the tag resonant frequency is shown to be unaffected much by its backing material. The proposed tag antenna is polarization-insensitve as it can be accessible from almost all directions on the metal.

Simultaneous detection of molecules with the surface-enhanced infrared absorption sensor platform based on disk antennas with double spacer

Biomolecule detection has become important in many applications such as medical diagnosis, forensic analysis, basic biological studies, and food quality assessment. In particular, the Mid-infrared range offers an important opportunity for biomolecular sensing as it covers the molecular vibrational spectra of vital biochemicals such as Deoxyribonucleic acid, Ribonucleic Acid, and proteins. In this study, a double band absorbing plasmonic nanoantenna array with two gold disk resonators is proposed. The biosensing ability of this structure was investigated using the protein-goat anti-mouse immunoglobulin G model and Polymethyl methacrylate film. The basic structural bonds of protein monolayer, namely Amide-I, Amide-II, and Amide-III showed vibrational signatures at 6010 nm (∼1664 cm−1), 6496 nm (∼1539 cm−1), and 6989 nm (∼1431 cm−1) wavelengths, respectively. In addition, the spectral response of the proposed antenna structure was investigated using a Polymethyl methacrylate film by detecting the C=O and the C-H bonds. The strong dipole moment at C=O showed a strong absorption deep at 5782 nm (∼1730 cm−1) while the C-H bond has shown a relatively low absorption deep at 3350 nm (∼2985 cm−1) and 3395 nm (∼2946 cm−1). Our findings indicate that the double spacer disk configuration detects the spectral signature of the protein monolayer and Polymethyl methacrylate film in each band, simultaneously. The dual-band can be tuned independently by carefully engineering the radii of the double disks without making an effect on the other band. The proposed structure can be used as a characterization tool for identifying unknown complex molecules by simply detecting their spectral fingerprints in each mode of the dual-band, independently. Also, this design strategy can be insight to multi-mode SEIRA platforms, where more complex chemical molecules are needed to be detected or identified in biology, chemistry, and defense areas.

Conformal strip fed circularly polarized defected dielectric resonator antenna (CPDDRA) for 6G applications

In this paper, a broadband circularly polarized (CP) dielectric resonator antenna (DRA) is proposed for terahertz (THz) applications. It consists of a silicon-based defected rectangular dielectric resonator (DR), excited by an asymmetric conformal strip feeding and a defective metallic ground plane. Multiple orthogonal modes are excited using a defective dielectric resonator antenna (DRA) and asymmetric conformal metallic strip to generate circular polarization. The proposed antenna has a fractional bandwidth of 89.5% (2.87–7.52 THz) and an axial ratio bandwidth of 79.2% (2.73–6.31 THz). The proposed antenna provides RHCP radiation pattern in the +z-direction and LHCP in the −z-direction. A peak gain of 6 dB is achieved at 6.9 THz with a compact antenna dimension of 50 × 40 μm2. An equivalent circuit with lumped elements is also presented for the proposed antenna in this paper. The simulated results of the proposed structure are in good agreement with those of equivalent circuit model. The proposed antenna structure fulfils all the requirements of a 6G antenna by operating over a wide terahertz frequency spectrum with circular polarization characteristics, an average peak gain, stable radiation patterns and compact dimensions.