Wideband Circularly Polarized Research Articles

A wideband circularly polarized filtering dielectric resonator antenna array based on magneto-electric currents combination

ABSTRACT A circularly polarized (CP) filtering dielectric resonator antenna (DRA) array is proposed based on the magneto-electric currents combination (MECC) method in this paper. The array consists of four rectangular DRAs, four hook-shaped electric dipoles (HSED), and two layers of substrate integrated waveguide (SIW) cavities. The electric current (EC) on the HSED is excited by the slot aperture of the SIW cavity, and the equivalent magnetic current (MC) is simultaneously generated with HSED in the DRA. Based on the surface current regulation, the EC and MC are adjusted to achieve appropriate amplitudes and phases, thereby realizing wideband CP radiation. The filtering function is realized with the high-pass characteristics of the SIW and the effective suppression of the higher-order modes in the resonance cavity. Due to the presence of an air gap between the DRAs and HSED, the higher modes of the DRA are designed for bandwidth enhancement. The prototype of the DRA array has been fabricated and measured, exhibiting a relative bandwidth of 26.1% and an axial ratio bandwidth of 17.77%, with radiation nulls present at either side of the passband. With the advantages of wide bandwidth and high gain, the proposed DRA array can be applied to satellite communications.

A compact broadband circularly polarized monopulse slot array antenna based on gap waveguide technology

ABSTRACT This paper presents a circularly polarized (CP) monopulse slot array antenna based on gap waveguide (GWG) technology. The proposed monopulse antenna is composed of a 4 × 4 array antenna fed by the monopulse comparator network in a compact three-layer structure. To achieve a broad axial ratio (AR) bandwidth of right-handed circular polarization (RHCP) in the sum radiation pattern, a septum polarizer is used in the radiating aperture. Based on this approach, horizontal transition structures are used to excite the radiating array from the WR-28 waveguide to the GWG, which helps to reduce the reflection loss and expand the impedance bandwidth. Experimental results show that the impedance bandwidth is 30.5 GHz to 40 GHz, which is 27.1%. The 3 dB AR bandwidth is 31%. The measured null depth is −40 dB, and the maximum measured gain in the sum pattern is 22 dBi at 34 GHz, while the antenna efficiency is greater than 86%. The advantages of low loss, broad bandwidth, and compact structure make the proposed antenna a competitive candidate for millimeter-wave (mmWave) monopulse direction-finding applications.

Metasurface‐based circularly polarised antenna: Enhanced bandwidth with characteristic mode analysis and symmetric branch design

AbstractA low‐profile circularly polarised (CP) metasurface antenna is proposed, utilising characteristic mode analysis (CMA). The antenna design features a two‐layer laminated substrate, a 4×4 Butterfly‐shaped metasurface, a rectangular slot, an irregular transmission line, and a ground plane. The metasurface is analysed using mode significance (MS), characteristic angle (CA), and characteristic current to determine the resonance bandwidth and CA resonance points, which exhibit a near 90° difference. At the intersection of the two MS modes, their CAs differ by nearly 90°, and their far‐field radiation directions align, indicating the potential for achieving circular polarisation at the desired frequency. The integration of the metasurface with the slot antenna is simulated to validate the CMA findings. Additionally, the CP bandwidth is enhanced by modifying the transmission line branches. Measurement of the fabricated antenna reveals an impedance bandwidth (IBW) of 27.4%, a 3‐dB axial ratio bandwidth (ARBW) of 10.1%, and a peak gain of 6.9 dBic at 4.4 GHz. Compared to the design without branches, IBW and ARBW have increased by 10% and 7.3%, respectively.

A Wideband Circularly Polarized SIW MIMO Antenna Based on Coupled QMSIW and EMSIW Resonators for Sub-6 GHz 5G Applications

A Wideband Circularly Polarized SIW MIMO Antenna Based on Coupled QMSIW and EMSIW Resonators for Sub-6 GHz 5G Applications

Design and Implementation of a Printed Circuit Model for a Wideband Circularly Polarized Bow-Tie Antenna

A crossed bow-tie antenna design for S- and C-Band (2.44–7.62 GHz) with a peak gain of 7.29 dBi is presented to achieve wideband radiation efficiency greater than 90% and circular polarization with a single feed point. The polarization of the antenna is modeled by the input admittance of crossed bow-ties, and the model predictions are validated by experiments. A wideband matching network is designed to be tightly integrated with the antenna and produce a 103% impedance bandwidth. The matching network is decomposed into an equivalent circuit model, and an analysis is presented to demonstrate the principles of the matching network design. A prototype of the optimized antenna design is fabricated and measured to validate the analysis.

Bilateral rectangular shape dielectric resonator antenna coupled with offset microstrip lines for wideband circular polarization

SummaryIn this work, an offset microstrip line coupled bilateral rectangular‐shaped dielectric resonator antenna (RDRA) is designed for broadband circular polarization (CP), which is fabricated and experimentally verified. The vertical microstrip is added in an offset position to generate orthogonal modes and the fundamental modes TEx111 and TEy111. The generation of orthogonal modes designates the antenna structure as a CP antenna with orthogonal modes. Moreover, the location of the microstrip feed arrangement is used to control the polarization state in the proposed work. In the proposed design, the simulated and hand‐measured input impedance bandwidth(|S11| ≤ −10 dB) obtained is 32.6% (3.53–4.9 GHz) and 33.2% (3.56–4.98 GHz), respectively, whereas the simulated and measured axial ratio (AR ≤ 3 dB) shows 16.1% (3.71–4.36 GHz) and 17.03% (3.7–4.39 GHz) of axial ratio bandwidth, respectively. This design shows a consistent radiation pattern and good average gain, with acceptable agreement between simulation and hand‐measured results. The simulated result shows 94% radiation efficiency in the working frequency range.

A substrate-integrated waveguide-based wideband circularly polarized slot antenna using the parasitic square patch array

In this paper, a planar low-profile wideband circularly polarized substrate-integrated waveguide (SIW) based antenna is investigated. The antenna comprises two substrates stacked over each other. The top layer of the antenna is loaded with a 4 × 4 array of parasitic square patches stacked over a spiral slot loaded in the SIW cavity. The spiral slot is utilized for the generation of narrow band circular polarization and to enhance the CP bandwidth, the parasitic patch array is excited through the electromagnetic coupling mechanism without any air gap between them. The antenna is fabricated and tested to validate the simulated results. A wide relative impedance bandwidth of 33% (8.25–11.55 GHz) and the axial ratio bandwidth of 8.55–9.70 GHz (12.60%) is exhibited. The broadside radiation characteristics are achieved with peak gain of 8.05dBic at 9 GHz. The overall size of the antenna structure is 0.8λ0 × 0.8λ0. The proposed antenna is suitable for various satellite applications.

A Wideband Circularly Polarized Antenna Array Loaded With Dual-Layer Metasurface

A Wideband Circularly Polarized Antenna Array Loaded With Dual-Layer Metasurface

Wideband Circularly Polarized Dielectric Resonator Antenna With Wide Overlapped Axial-Ratio and Half-Power Beamwidths

Wideband Circularly Polarized Dielectric Resonator Antenna With Wide Overlapped Axial-Ratio and Half-Power Beamwidths

A compact dielectric resonator antenna with wideband circular polarization characteristics for C and X‐band applications

AbstractA wideband circularly polarized (CP) stacked rectangular dielectric resonator antenna (RDRA) is proposed in this article. The 3 dB axial ratio (AR) and 10 dB impedance bandwidth overlap of more than 66% is obtained. For increased bandwidth, the antenna comprises two dielectric resonators separated by an air gap. The upper dielectric layer is rotated at relative to the lower layer to obtain orthogonal modes for CP Both layers have dielectric constant . The rotation aids excitation of orthogonal modes , and in RDRA. The higher‐order modes generate left‐hand circular polarization at frequencies 6.75, 7.8, and 10.7 GHz, respectively. The upper layer consists of three holes giving a 10 dB impedance bandwidth of 66.7% from 6.52 to 11.02 GHz. The CP gain of 8.7, 6.8, and 6.4 dBi for 6.75, 7.8, and 10.7 GHz, respectively, is measured. The conformal orthogonal feeds enable a 72 3 dB AR bandwidth across the entire frequency band. The radiation efficiency is observed above 89 in the entire band (6.5–11 GHz). This work demonstrates a 66.7 overlap of 10 dB impedance and 3 dB AR bandwidth along with high gain in a single design which is suitable for 5G applications in C‐band as well as other X‐band applications.

The Design and Implementation of a Wide-band Circularly Polarized Conformal Antenna

Background: It gives out the design and verification of single-layer dual-band antenna unit and multi-layer dual-band broadband antenna unit of phased array antenna, and verifies that the multi-layer dual-band broadband antenna unit can meet the design requirements of the receiving frequency band. Objective: It gives out the design and implementation of a wide-band circularly polarized conformal antenna, and presents the characteristics analysis of the antenna. Method: Through related simulation methods, the proposed methods are verified and they can effectively solve the array phase compensation and beam shaping and control in the wide-band circularly polarized conformal antenna. Results: Based on the basic design of the antenna, the active superposition algorithm, phase compensation technology and particle swarm optimization antenna beam shaping technology are both studied. Conclusion: The proposed wide-band circularly polarized conformal antenna can be used in the actual application.

A Wideband Circularly Polarized Dipole Antenna with Compact Size and Low-Pass Filtering Response.

This paper presents a compact wideband circularly polarized cross-dipole antenna with a low-pass filter response. It consists of two pairs of folded cross-dipole arms printed separately on both sides of the top substrate, and the two dipole arms on the same surface are connected by an annular phase-shifting delay line to generate circular polarization. A bent metal square ring and four small metal square rings around the cross-dipoles are employed to introduce new resonant frequencies, effectively extending the impedance and axial-ratio bandwidth. Four square patches printed on the middle substrate are connected to the ground plane by the vertical metal plates in order to reduce the antenna height. Thus, a compact wideband circularly polarized antenna is realized. In addition, a transmission zero can be introduced at the upper frequency stopband by the bent metal square rings, without using extra filter circuits. For verification, the proposed model is implemented and tested. The overall size of the model is 90mm×90mm×33mm (0.37λ0×0.37λ0×0.14λ0; λ0 denotes the center operating frequency). The measured impedance bandwidth and 3 dB axial-ratio (AR) bandwidth are 53.3% and 41%, respectively. An upper-band radiation suppression level greater than 15 dB is realized, indicating a good low-pass filter response.

A Miniaturized Wideband Circularly Polarized Antenna Based on Tightly Coupled Monopole

A Miniaturized Wideband Circularly Polarized Antenna Based on Tightly Coupled Monopole

Conformal Wideband Circularly Polarized H-Plane Horn Antenna Integrated With Quasi-Yagi

Conformal Wideband Circularly Polarized H-Plane Horn Antenna Integrated With Quasi-Yagi

A Wideband Circularly Polarized Antenna With a Nonuniform Metasurface Designed via Multiobjective Bayesian Optimization

A Wideband Circularly Polarized Antenna With a Nonuniform Metasurface Designed via Multiobjective Bayesian Optimization

A Wideband Circularly Polarized Antenna With Metasurface Plane for Biomedical Telemetry

A Wideband Circularly Polarized Antenna With Metasurface Plane for Biomedical Telemetry

Simple Wideband Circularly Polarized Tightly Coupled Dipole Array

Simple Wideband Circularly Polarized Tightly Coupled Dipole Array

Wideband Circularly Polarization and High-Gain of a Slot Patch Array Antenna Realized by a Hybrid Metasurface.

In this paper, a patch array antenna with wideband circular polarization and high gain is proposed by utilizing a hybrid metasurface (MS). A corner-cut slotted patch antenna was chosen as the source due to the possible generation of CP mode. The hybrid MS (HMS), consisting of a receiver MS (RMS) arranged in a 2 × 2 array of squared patches and a linear-to-circular polarization conversion (LCPC) MS surrounding it was then utilized as the superstrate driven by the source. The LCPC MS cell is a squared-corner-cut patch with a 45° oblique slot etched, which has the capability for wideband LCPC. The LCPC unit cell possesses wideband PC capabilities, as demonstrated by the surface current analysis and S-parameter simulations conducted using a Floquet-port setup. The LP EM wave radiated by the source antenna was initially received by the RMS, then converted to a CP wave as it passed through the LCPC MS, and ultimately propagated into space. To further enhance the LCPC properties, an improved HMS (IHMS) was then proposed with four cells cut at the corners, based on the original HMS design. To verify this design, both CMA and E-field were utilized to analyze the three MSs, indicating that the IHMS possessed a wideband LCPC capability compared to the other two MSs. The proposed antenna was then arranged in a 2 × 2 array with sequential rotation to further enhance its properties. As demonstrated by the measurements, the array antenna achieved an S11 bandwidth of 60.5%, a 3 dB AR bandwidth of 2.85 GHz, and a peak gain of 15.1 dBic, all while maintaining a low profile of only 0.09λ0.

Stub Asymmetry-Enabled Self-Phase-Shift Circularly Polarized Antenna under Dual-Mode Resonance

In this article, a novel design approach to wideband dual-mode resonant circularly polarized (CP) antenna is advanced. An analytical design approach with low complexity as supported by a set of closed-form formulas is presented. Thus, the wideband dual-mode CP characteristics can be forward predicted and simply realized by incorporating stub asymmetry-enabled self-phase-shift dipoles and unequal feeding branches. At first, stubs are employed to broaden the impedance bandwidth by simultaneously exciting dual resonant modes. Then, the phase quadrature and equal magnitude conditions for wideband CP can be automatically realized by incorporating unequal Y-shaped microstrip branches and asymmetric slotline stubs. Finally, the coincidence between the simulated and measured results of the fabricated prototype antenna further confirms the feasibility of the design approach. It is shown that the presented antenna can exhibit an impedance bandwidth of 20.1% and a 3 dB axial ratio bandwidth of 16.3% in the boresight direction.

A Simultaneous Study on Wire-Loop, Plate-Loop, and Plate Antennas for Wideband Circular Polarization

We investigate three square-shaped antennas to increase the bandwidth of circular polarization. Each antenna has two adjacent corners excited with the same amplitudes and a phase difference of 90° using a branched feedline vertical to the ground plane. We evaluate the 3 dB axial ratio bandwidth as a function of the loop-arm width using the moment method. It is found that the axial ratio bandwidth reaches 38% for an arm width of 0.04 wavelengths, wider than that of a wire-loop antenna by a factor of three. The simulated results are verified by experimental ones.