Circularly Polarized Radiation Research Articles

Dual-Linear-to-Circular Polarization Converter Based Polarization-Twisting Metasurface Antenna for Generating Dual Band Dual Circularly Polarized Radiation in Ku-Band

We propose a polarization-twisting metasurface antenna (PTMA) to generate the dual-band dual-circularly polarized (CP) radiation by integrating a dual-linear-to-circular polarization converter (DLCPC) with a linear polarization conversion metasurface (LPCM) in the Ku-band. The DLCPC possesses the functionality of polarization selection and is capable of transforming the linearly polarized (LP) waves into right hand CP (RHCP) waves in low-frequency (LF) and left hand CP (LHCP) waves in high frequency (HF). Based on the DLCPC, the dual-band dual-CP PTMA is designed and fabricated, and then, the measured results indicate that the PTMA is capable of realizing the RHCP radiation in LF and the LHCP radiation in HF. In the meanwhile, the common bandwidths of −1.5 dB gains and 3 dB axial ratios are 12.25–12.95 and 14.00–14.55 GHz, respectively. Our design, by integrating the DLCPC and LPCM to construct the dual-band dual-CP PTMA, should, thus, pave the way for building up more efficient wireless communication systems with the requirement of different CPs as the receiver and the transmitter at downlink and uplink in the Ku-band.

Design of multimode broadband circularly polarized antenna using characteristics mode analysis

In this article, as low-profile fish-shaped monopole antenna is proposed for circular polarization radiation. The modal characteristics of the proposed antenna were analyzed and manipulated using characteristic mode analysis technique. Four characteristic modes with different resonant frequencies and current distributions were chosen as operating modes. In addition, a suitable position excited the desired modes, which achieve broadband circular polarization performance and dual-band performance. Based on the above analysis, a prototype of the proposed antenna was fabricated with dimensions of 60 mm × 60 mm × 1.5 mm to validate simulated results. Measured results show that the 3-dB axial ratio bandwidth (ARBW) of the proposed antenna is 40.7% (4.9–7.4 GHz) and the antenna broadside peak gain is 4.2 dBic within usable bandwidth. In addition, the measured impedance bandwidths of the proposed antenna are 12.2% (2.3–2.6 GHz) and 53.7% (4.5–7.8 GHz). Compared to other designs, the proposed circularly polarized antenna is a promising design operating in WiMAX band and industrial, scientific, and medical bands.

Compact broadband bi‐directional circularly polarized fan‐shaped patch with parasitic annular groove for S ‐band satellite applications

A novel bi-directional circularly polarized (CP) antenna with low profile, real planar configuration and broad axial ratio (AR) bandwidth is presented for S-band satellite relay communication application. The designed antenna consists of four fan-shaped patches, a sequentially rotating feed network and ground plane with annular gaps. Four fan-shaped patches are directly integrated with the feed network on the same FR4 substrate for good impedance matching and compact size. To realize the two-way radiation characteristics and excellent AR bandwidth, one parasitic annular groove on the ground plane is designed. The sequential rotation feeding network can provide good port characteristics within the available bandwidth and good AR. The properties of designed antenna was tested to validate its simulation. The final prototype is 83 × 83 × 0.8 mm3 in size and it can generate a broad impedance bandwidth for voltage standing wave ratio (VSWR) <2 of 36.6% (2.32–3.36 GHz), 3-dB AR bandwidth of 21.3% (2.6–3.22 GHz) and gain over 5.4 dB in the bi-directional direction. The miniaturization, low-cost and good CP radiation for this proposed antenna make it a better candidate for future applications in the field of spacecraft relay communication.

Dual-band high-gain microstrip antenna with a reflective focusing metasurface for linear and circular polarizations

This paper proposes a dual-band high-gain microstrip antenna with a reflective metasurface (MS). The initial designed coaxial-fed laminated microstrip antenna can realize linear polarization (LP) radiation at the lower frequency of 5 GHz and circular polarization (CP) radiation at the higher frequency of 11 GHz, with a relatively low gain of about 5.8 dBi and 5.4 dBic, respectively. To enhance the radiation performance of the microstrip antenna, a reflective focusing MS is proposed, which can focus LP and CP waves at 5 GHz and 11 GHz, respectively. The MS antenna system is constructed by placing the initially designed microstrip antenna on the focal point of the reflective focusing MS, which can achieve the high-gain performance of 13.4 dBi for the LP radiation at 5 GHz, and 18 dBic for the CP radiation at 11 GHz, respectively. The proposed MS and feed antenna were designed and fabricated, and the experimental data were consistent with the simulation results, which verifies the feasibility of the proposed scheme. The proposed reflective focusing MS antenna could provide potential application in the modern wireless communication system.

A compact triple band circular polarized slotted microstrip patch antenna with low frequency ratio

A pentagon shaped triple band circular polarized (CP) slotted microstrip patch antenna with asymmetric single microstrip feed line is designed. The proposed patch antenna is loaded with a pair of asymmetric slits, a pair of symmetric slots and a triangle shape truncation at the right side of the antenna. The antenna is drafted within the size of 0.43λ × 0.43λ and resonates at 2.17, 3.08, and 3.48 GHz with impedance bandwidth (IBW; IS11I < −10 dB) 2.14–2.20, 3.06–3.10, and 3.45–3.51 GHz, respectively. The Axial Ratio Bandwidth (ARBW; AR < 3 dB) is obtained as 2.17–2.40, 3.07–3.10, and 3.48–3.54 GHz at the three resonances which almost cover the IBW. An additional feature of the design is that the CP bands are very closely spaced with frequency ratio of 1.36 between first and second CP resonances and 1.13 between second and third CP resonances. The obtained gain at three resonances is 3.9, 3.79, and 4.81, respectively. The CP radiation patterns are found to be stable with good right hand CP (RHCP) to left hand CP (LHCP) isolation at the boresight direction. This antenna is suitable for S-band applications. The advantage of the proposed design has been highlighted with respect to multiband CP, CP frequency ratio, compactness and RHCP to LHCP isolation. A prototype of the proposed design is fabricated and the measured results are in accord with the simulated results.

Wideband low-RCS circularly polarized antenna with metasurface combining wave diffusion and polarization conversion

A novel and simple low-profile high-gain wideband circularly polarized (CP) slot antenna with low radar cross section (RCS) is presented. The proposed antenna is composed of a traditional linearly polarized (LP) slot antenna and an integrated metasurface-based superstrate. The superstrate consists of a center array with metasurface (MS) unit cells and four surrounding arrays with 4×4 MS unit cells. On the one hand, a wideband and high-gain CP radiation in the frequency band of 5.27-6.18 GHz (a relative bandwidth of 15.9%) is achieved by the polarization conversion property of the MS and four surrounding arrays. On the other hand, a broadband RCS reduction in the frequency band of 4.5-20 GHz (a relative bandwidth of 126.5%) is obtained by the combination of two electromagnetic wave diffusion principles. Inspired by C-band, X-band and Ku-band radar applications, a low-cost stealthy prototype with broadband low RCS and CP radiation is realized.

Reconfigurable leaky wave antenna with low sidelobe based on spoof surface plasmon polariton

A low sidelobe leaky wave antenna (LWA) based on Spoof Surface Plasmon Polariton (SSPP) with switchable right/left-handed circular polarization (CP) and linear polarization (LP) radiation function by controlling the status of two PIN diodes is proposed. Two symmetrical SSPP transmission lines (TLs) are connected through two PIN diodes, and the ON–OFF of diodes constitute three different transmission modes. Two rows of the tapered arranged elliptical patches are loaded periodically around the TL to break the original stable transmission structure for radiation, and suppress the antenna sidelobe levels to less than −10 dB. After experimental verification, the reconfigurable antenna can reach three functionalities: (1) Mode 1: 22°right-handed CP beam scanning from 8.3 to 9.0 GHz; (2) Mode 2: 22°left-handed CP beam scanning from 8.3 to 9.0 GHz; (3) Mode 3: 78°LP beam scanning from 8.3 to 10.3 GHz. In Mode 1 and 2, the axial ratios (ARs) are lower than 3 dB, and the average gain can reach 11.6 dBi, while 13.4 dBi in Mode 3. A leaky wave antenna that can switch the radiation function of linear/circular polarization with favorable performance characteristics, such as wide scanning range, high gain, low sidelobe levels, and high efficiency, makes it an ideal candidate for wireless communication.

A low-profile broadband crossed-dipole antenna with fractal structure and inverted-L plates

A low-profile broadband circularly polarized (CP) crossed-dipole antenna is proposed. In this antenna, the dipole uses a fractal-based structure with multiple similar patches for obtaining broadband CP radiation and impedance matching. The incorporation of the crossed-dipole antenna with four triangular parasitic patches improves both the impedance and axial ratio (AR) bandwidths. Four parasitic coupled inverted-L metal plates are loaded on the ground plane to significantly enhance the AR bandwidth and reduce the antenna profile. The measured results are in agreement with the simulations, which demonstrates that the proposed antenna has a low profile of 0.18 λ0, a − 10 dB impedance bandwidth of 91% (2.78–7.42 GHz), a 3 dB AR bandwidth of 81.5% (2.99–7.1 GHz), and a good right hand circular polarization (RHCP) radiation pattern with an average gain of 7.9 dBi over the whole operating band.

Circularly Polarized High Gain Leaky-Wave Antenna for CubeSat Communication

In this work, a novel planar leaky-wave antenna (LWA) and its array are proposed and presented for CubeSat communication applications. Using the substrate-integrated waveguide (SIW) technology, the proposed LWA is implemented by etching periodic fan-shaped slots on top of an SIW. These novel fan-shaped slots exhibit extraordinary circular polarization (CP) radiation in high efficiency over a wide frequency band. Moreover, by switching the excitation ports, both left-handed (LH) and right-handed (RH) CPs are achieved in a wide beam steering range backward or forward. An SIW LWA prototype has been designed and tested with validate LHCP/RHCP steering beams ranging from –51° to 0° or from 51° to 0° in the elevation when the frequency varies from 27.4 to 37.3 GHz. In the 30% frequency band, the axial ratios (ARs) on the main beams are all less than 3 dB demonstrating the broadband CP characteristic. In this 1-D LWA, the realized gain varies from 12.4 to 17.9 dBi. However, it requires higher gain and a fixed beam but narrow bandwidth (BW) in some applications like CubeSats. Hence, a conformal LWA array is further introduced by combining the CP radiation of two LWAs deployed in two perpendicular surfaces of a one cubic unit (1U) CubeSat. Fed by an elaborated vertical transition, the conformal array is designed at 28 GHz with a high directive sum beam along the diagonal direction, requiring each LWA to radiate at ± 45°. As a result, the total gain is enhanced from 14.4 to 16.6 dBi with an AR of 1.8 dB and a sidelobe level (SLL) of −17.1 dB. The proposed compact planar LWA and its array provide promising CP radiation in terms of ARs, BW, polarization flexibility, impedance matching, efficiency, and gain, which reveals great potential for applications in satellite communication systems that demanding low profile, lightweight, dual CPs, and high directivity.

A Dual Circularly Polarized SIW-Fed Phased Array Antenna With Wide-Angle Beam Scanning Range

We propose a dual circularly polarized (CP) substrate integrated waveguide (SIW) cavity-backed antenna with wide axial ratio (AR) beamwidth, which can generate the right-hand CP (RHCP) or left-hand CP (LHCP) radiation through exciting different ports. Dual CP radiations are accomplished by an SIW directional coupler (DC) in the bottom layer, which provides the desired amplitude and phase conditions for two orthogonal slots. By superposing phase centers of linearly polarized (LP) electric field elements, the proposed antenna achieves a good performance of 3 dB AR beamwidth of 165° in the desired azimuth cut plane. Furthermore, an eight-element dual CP linear phased array with a wide-angle beam scanning ability is comprised by this antenna prototype. Numerical and measured results show that the array antenna can scan its main lobe from – 59° to 58°. In general, the proposed antenna array fed by the SIW structure satisfies the requirement of a multipolarization wireless communication system for low profile, simple structure, and easy integration with planar circuits.

Broadband Dual-Polarized Metal Lens With Theoretically Arbitrarily Variable Focal Diameter Ratio Using 3-D Printing Technology

A wideband dual-polarized metal lens is proposed in this article for millimeter-wave (mm-wave) applications. Compared with the traditional lens, the focal length of the proposed novel metal lens can be of any value in theory; in other words, the focal diameter ratio ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f/D$ </tex-math></inline-formula> ) can be arbitrarily adjusted. The metal 3-D printed technology is used to reduce the fabrication cost. The unit cell of the lens is a square open-ended waveguide. Since the phase velocity of the electromagnetic wave in the metal waveguide is faster than that in the air, the phase compensation can be controlled by adjusting the height of each unit of the lens. It helps to realize the conversion from the quasi-spherical wave of the feed source to the plane wave radiation of the lens. Due to the use of symmetrical elements, the lens can support different dual-polarized radiation (dual-linear polarization and dual-circular polarization). Considering the processing cost and design difficulty, a metal lens with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$9\times $ </tex-math></inline-formula> 9 unit cells was processed to verify our design. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f/D$ </tex-math></inline-formula> is selected as 1. Simulated results for the lens antenna show a peak aperture efficiency (AE) of 43.8% and 38% for linearly polarized (LP) and circularly polarized (CP) radiation, respectively. The antenna shows a stable pattern and wide 3 dB gain bandwidth (26–40 GHz), which covers the entire Ka-band. The measured results of the lens demonstrate a peak gain of 24 dBi and 23 dBic for LP and CP radiation with an aperture of about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.5\,\,\lambda \times 7.5\,\,\lambda $ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> is the free space wavelength at 30 GHz). The proposed lens features a wide gain bandwidth with dual polarization, low cost, and good radiation performance, which is well suited for mm-wave wireless applications.

A Pattern Reconfigurable Circularly Polarized Quadrifilar Helix Antenna Through Phase Control

We have proved in theory and simulation that the circularly polarized (CP) radiation from a resonant quadrifilar helix antenna (QHA) is independent of the phase between two composed bifilar helices, while the CP radiation pattern can be reconfigured by controlling this phase. It is demonstrated that the QHA is capable of generating a wide range of CP radiation patterns, including two cardioid patterns toward both ends, two vertical toroid patterns in two different orientations, and the mixed patterns of cardioid and toroid. A wideband and multilayer feeding network was developed to excite the four basic modes of the proposed QHA through phase control in the experiment. The simulated and measured right-handed circular polarization (RHCP) radiation patterns agree quite well. The proposed QHA was also designed to cover several global navigation satellite system (GNSS) bands. The measured impedance bandwidth is 1.26–1.65 GHz (26.8%) and the 3 dB axial ratio bandwidth is 1.1–1.8 GHz (41.4%) in the endfire mode. It is shown that the proposed QHA can be easily operated in two endfire modes to have an equivalent isotropic pattern for flying objects. When the antenna is operating in the endfire mode, the gain is in the range of 2.1–3.5 dBi, and the radiation efficiency is 70%–85% in the operating band.

A Wideband Low-RCS Circularly Polarized Reconfigurable C-Shaped Antenna Array Based on Liquid Metal

A wideband low radar cross-section (RCS) circularly polarized (CP) reconfigurable patch antenna array based on liquid metal (LM) has been proposed in this article. The array was formed by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4\,{\times }\,4$ </tex-math></inline-formula> CP C-shaped antenna elements fed with a sequential feeding network. The antenna element was designed with a pair of narrow slots, and a microchannel adhered to the top metal layer. The CP reconfiguration depends on the tuning of the slots by moving the LM in the channel. The patch antenna array can obtain good CP radiation and low RCS features without any extra RCS reduction structures other than the array elements. RCS reduction (RCSR) can be realized by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$180^{\circ }\,{\pm }\,37^{\circ }$ </tex-math></inline-formula> reflection phase variations between two different antenna elements under normal incidence for both <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> - and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$y$ </tex-math></inline-formula> -polarizations. The antenna prototype has been fabricated and measured. The measured results show good agreement with simulated results.

Reconfigurable UWB Circularly Polarized Slot Antenna With Three Modes of Operation and Continuous Tuning Rang

In this communication, a tunable circularly polarized (CP) antenna with a reconfigurable integrated feed network is proposed for cognitive radio (CR) applications. The integrated feed network is composed of an ultrawideband (UWB) bandpass filter (BPF), a continuously tunable T-shaped resonator, and an L-shaped microstrip line. The feed network employs three p-i-n diodes to switch between different RF paths, resulting in three modes of operation: an UWB mode (3.5–8.5 GHz), a narrowband bandpass (BP) mode and a narrowband bandstop (BS) mode. The continuous tuning range of the BP/BS narrowband mode is realized by two dc-controlled varactor diodes. The stand-alone antenna attains a −10 dB impedance bandwidth of 92.3% (3.5–9.5 GHz), while it attains an axial ratio (AR) bandwidth of 88.3% (3.1–8 GHz) in its wideband mode. The overlapped bandwidth (matching and AR) of the reconfigurable antenna is 78.2% (3.5–8 GHz). The communicating state covers 80% of the sensing spectrum while maintaining CP radiation. The measured peak realized gain values for the wideband mode range from 2 to 3.2 dBic while the maximum gain for the narrowband mode ranged from 1.95 to 3.1 dBic. The measured results show that the proposed filtenna is suitable for UWB CR systems.

A Planar Bidirectional Circularly Polarized Antenna Using Orthogonal Magnetic Dipoles Without Extra Phase Shift Line

A planar bidirectional circularly polarized (CP) antenna using orthogonal magnetic dipoles (OMDs) without an extra phase shift line is proposed in this work. It consists of a rectangular microstrip magnetic dipole antenna (MMDA) and a loop radiator with two arms directly connected to the open edge of MMDA. The working principle is revealed by the equivalent sources model to provide a clear physical insight at first. The theoretical investigations imply that by controlling the width and the feed locations of the loop antenna on the aperture, the phase and magnitude for CP radiation can be realized in both endfire and backfire directions without introducing an additional phase shift line structure. For demonstration, one antenna prototype is designed and fabricated. The experimental results indicate that an overlapping bandwidth of 5.91% from 2.30 to 2.44 GHz is attained. Compared with the counterpart using OMDs, the proposed antenna exhibits a low design complexity and improved gains of 3.56/1.83 dBic in the endfire/backfire directions.

Low profile and broadband circularly polarized metasurface antenna based on nonuniform array

A broadband low-profile, circularly polarized metasurface antenna with a nonuniform aperture is proposed for L band satellite communications. By optimizing the nonuniform geometry, antenna size is minimized and bandwidth is expanded. Characteristic mode analysis (CMA) clearly reveals the dominant modes and stimulated modes for wideband operation. The feeding structure employs a quadrature phase quarter-power divider to excite a collection of orthogonal modes, generating stable circular polarization (CP) radiation and a phase center. Numerous feeds and crossing slots, in conjunction with the metasurface, produce multiple resonances and minimum axial ratio (AR) locations when excited, resulting in a broad impedance and AR response. The low profile nonuniform metasurface CP antenna achieves a 40% −10 dB impedance bandwidth, a 47% 3 dB AR bandwidth, and a peak gain of 8.7 dBic with a compact dimension of 0.67 × 0.67 × 0.06 λ3.

Toward the Light‐Operated Superconducting Devices: Circularly Polarized Radiation Manipulates the Current‐Carrying States in Superconducting Rings

AbstractThe ability to rapidly control and manipulate superconducting states is one of the great challenges of modern condensed matter physics. Circularly polarized radiation interacting with a superconducting condensate acts as an effective magnetic field that can generate supercurrents and DC magnetic moments through the inverse Faraday effect (IFE). Using the time‐dependent Ginzburg–Landau (TDGL) equation formalism, the current‐carrying states of a small superconducting ring illuminated by such radiation is calculated. Numerical simulations demonstrate the possibility to on‐demand switch between current‐carrying states in the superconductor by controlling the helicity of the electromagnetic field polarization. This result opens the way to all‐optical operation of superconducting devices.

A Low-Profile Broadband Circularly Polarized Metasurface Antenna Aperture Coupled by Shorted Annular-Ring Slot

A low-profile (LP) metasurface antenna is proposed for broadband circularly polarized (CP) operations. The metasurface radiator, formed by a 5 × 5 array of square patches, has a microstrip line fed at its bottom through a shorted annular-ring slot centered on the ground plane. First, the characteristic mode analysis (CMA) methodology is employed to examine the intrinsic modes of the metasurface. Subsequently, a pair of mutually orthogonal modes is selected and excited by the feeding structure with a 90° phase difference to produce CP radiation. For the purpose of verification, a prototype antenna is developed, and the obtained data reveal that the antenna exhibits an impedance bandwidth of 43.9% ranging from 4.8 to 7.5 GHz (S11&lt;−10 dB). The 3-dB axial ratio bandwidth is 22.2% in the range of 5.6–7 GHz, among which a satisfactory left-handed CP radiation is achieved, and the maximum gain in the broadside direction reaches 9.3 dBic at 6.9 GHz.

A Low-Profile Quasi-Loop Magneto-Electric Dipole Antenna Featuring a Wide Bandwidth and Circular Polarization for 5G mmWave Device-to-Device Communication

The deployment of the millimeter (mmWave) frequency spectrum by fifth-generation (5G) device-to-device (D2D) wireless networks is anticipated to meet the growing demands for increased capacity. The antenna is regarded of as an important determinant that guarantees the maximum performance of wireless communication. This paper presents a low-profile magneto-electric (ME) dipole antenna for 5G mmWave D2D communication. A single-element quasi-loop radiator was designed to excite horizontal polarization, and a coaxial probe was used to produce vertical polarization. Subsequently, the structure of the radiator was transformed into a two-element quasi-loop antenna to achieve an omnidirectional radiation pattern with relatively enhanced gain. A coaxially fed T-junction microstrip element was implemented to equally distribute the signal between the two quasi-loop radiators and attain proper impedance matching. Furthermore, a pair of shorting pins was introduced into the two-element design to maintain the circularly polarized (CP) radiation. The finest values of the axial ratio and |S&lt;sub&gt;11&lt;/sub&gt;| were derived by rigorously optimizing all the geometry parameters. Both single-element and two-element quasiloop antennas were fabricated and characterized experimentally on the air substrate. The advantage of avoiding a physical substrate is to realize a wide bandwidth, circumvent dielectric losses, and ascertain the maximum gain. The measured and simulated results agree thoroughly with each other. Stable in-band CP radiation were accomplished, thus confirming an appropriate field vector combination from the coaxial probe and the radiator. The finalized antenna engaged an area of ~7.6λ&lt;sup&gt;2&lt;/sup&gt;&lt;sub&gt;0&lt;/sub&gt; for operation at 23.9–30.0 GHz with an axial ratio &lt;3 dB, radiation efficiency ~80%, and gain &gt;5 dBic.

Dual‐polarized metasurface‐based monopole antenna design using characteristics mode theory for UHF RFID applications

In this research article, a printed dual-polarized metasurface (MTS) inspired printed monopole antenna using characteristics modes theory (CMT) is investigated for UHF RFID applications. A T-shaped monopole with U-shaped asymmetric stubs is designed to generate circular polarization (CP) radiation traits. The grounded MTS layer is constructed with array of unit cells and fixed at air-gap of λo/4 with reference to the monopole radiator (λo is free-space wavelength at CP frequency band, 945 MHz), offering good impedance bandwidth (IBW), stable CP boresight radiation gain, and high radiation efficiency. By using CMT, interpretation of CP characteristics is highlighted, that is, the resonating modes exhibit asymptotic nature at the designated CP band with symptotic nature above and beyond the designated operating bands. Dual-polarized characteristics are observed in both principal planes, due to the effect of grounded MTS loading. The prototype antenna of 0.315λo × 0.315λo is designed and validated. It operates from 836 to 1066 MHz with 24.18% IBW, 5.23% 3-dB axial ratio bandwidth (ARBW) from 905.1 to 950 MHz and attains >6.8 dBic as a CP peak gain with the total efficiency of >83%. Prior to the attainment of good CP attributes in UHF RFID bands, it can be used for RF energy harvesting and wireless power transmission.