Dual Circularly Polarized Patch Antenna Research Articles

Dual circularly polarized Fabry-Perot antenna with metamaterial-based corner reflector for high gain and high aperture efficiency

Based on the ray-tracing model, a new method of achieving a high gain and high aperture efficiency Fabry-Perot antenna with metamaterial-based corner reflector is proposed. The proposed Fabry-Perot antenna is composed of a dual circularly polarized patch antenna feed and the metamaterial-based corner reflector. The metamaterial-based corner reflector consists of four phase correction metasurfaces and a partially reflective surface. First, theory and analysis of the Fabry-Perot antenna with metamaterial-based corner reflector are presented. Then, the performances of the dual circularly polarized antenna feed, the traditional Fabry-Perot antenna, and the Fabry-Perot antenna with metamaterial-based corner reflector are compared among each other and analyzed. Finally, the proposed Fabry-Perot antenna is fabricated and measured. The measured left-hand circular polarization (LHCP) gain and the measured right-hand circular polarization (RHCP) gain of the proposed Fabry-Perot antenna are 21.4 dBi and 21.3 dBi, respectively. Comparing with the antenna feed, the LHCP gain and RHCP gain of the proposed Fabry-Perot antenna are enhanced by 16.4 dB and 16.3 dB, respectively. Compared with the traditional Fabry-Perot antenna, the metamaterial-based corner reflector acts as both a reflection surface and a phase correction surface. It manipulates the propagation direction and phase of electromagnetic wave. The proposed Fabry-Perot antenna with high gain, high aperture efficiency and low sidelobe at 2.8 GHz paves the way for developing the solar radio telescope and conducting the observation.

A Low-profile and Low-cost Dual Circularly Polarized Patch Antenna

A Low-profile and Low-cost Dual Circularly Polarized Patch Antenna

Dual Circularly Polarized Patch Antenna with Improved Interport Isolation for S-Band Satellite Communication

This paper presents a bi-port, single-layered (planar), dual circularly polarized (CP) patch antenna with improved interport isolation for S-band satellite telemetry and telecommand applications. The dual-port, planar antenna is based on a square-shaped radiator with trimmed corner to achieve CP characteristics (RHCP and LHCP) for excitations from respective ports. However, the RF isolation between the two ports is very low due to strong power leakage from transmit (Tx) to transmit (Rx) port. The externally employed tunable self-interference cancellation (SIC) circuit achieves high isolation between orthogonal ports while axial ratio (AR) is ≤3 dB for both right and left handed circular polarization modes. The employed single-tap SIC circuit/loop attains the high interport isolation through signal inversion mechanism. The proposed antenna design achieves ≥72 dB peak interport isolation in addition to ≥30 dB and 15 dB port to port isolation over the isolation or SIC bandwidths of 15 MHz and 90 MHz (−10 dB bandwidth for both ports), respectively. The port to port isolation performance is improved without significant degradation in antenna radiation characteristics. The validation model of the presented planar antenna based on single element characterizes much better measured interport isolation performance compared to those dual CP printed antennas reported earlier as endorsed through detailed comparison

Frequency-Ratio Reduction of a Low-Profile Dual-Band Dual-Circularly Polarized Patch Antenna Under Triple Resonance

A novel design concept to reduce the frequency ratio of a dual-band dual-circularly polarized (CP) microstrip patch antenna (MPA) is presented by using its reshaped 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> , and TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> modes. First, the far-zone radiated fields of the traditional MPA are theoretically investigated. It demonstrates that the normal |E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">θ</sub> | and |E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">φ</sub> | fields at xoz plane are orthogonally generated under its TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> modes, respectively. Unfortunately, its TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> mode radiates the nonbroadside |Eθ| fields at xoz plane. Then, an open-ended stub is loaded around the edge of the radiator, aiming to reshape the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> mode as the broadside radiation. After that, the patch width is decreased with the loading of two shorting pins. The main target is to move the TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> mode resonating between TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> modes. Finally, the proposed antenna is fabricated and tested. The results illustrate that its left-hand CP and right-hand CP radiation patterns are satisfactorily acquired at around 2.134 and 2.223 GHz, respectively, thus gaining a small frequency ratio of around 1.04. Meanwhile, the antenna holds the low-profile (0.02 free-space wavelength), small-backlobe, single-layer, singlefed, and single-radiator properties.

A Dual Circularly Polarized Patch Antenna With High Isolation for MIMO WLAN Applications

A dual circularly polarized (CP) stacked patch antenna for Multiple-Input Multiple-Output (MIMO) WLAN applications (2.4-2.485 GHz) is presented, which exploits a square ring slot feeding technique. The antenna occupies an overall area of 96 mm x 96 mm x 39 mm, when also including the metal reflector. The 7-dBic gain antenna prototype presents an axial ratio lower than 2.5 dB as well as a port isolation higher than 25 dB. An envelope correlation coefficient (ECC) lower than 0.02 is also achieved among the two ports, thanks to the polarization orthogonality. Moreover, the stacked patch has been duplicated and used in a two-antenna system for a 4 x 4 MIMO WLAN which fits an overall volume of 157 mm x 96 mm x 39 mm. Antenna performance in terms of S-Parameters, gain, axial ratio, ECC and channel capacity are compared and discussed, together with the effect of the inter-element distance.

A Linearly Polarized Patch Antenna With a Continuously Reconfigurable Polarization Plane

A linearly polarized (LP) wave with an arbitrary polarization plane is generated by combining left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) waves radiated from a dual-circularly polarized patch antenna. The polarization plane of the LP wave is continuously controlled by changing the phase difference between the LHCP and RHCP waves by using variable phase shifters composed of a quadrature hybrid and varactor diodes. Experimental results show that the polarization plane rotates continuously from −95° to 107° with a cross-polarization discrimination kept better than 22 dB in the boresight direction at 5.2 GHz.

X-Band Dual Circularly Polarized Patch Antenna With High Gain for Small Satellites

This paper presents an X-band circularly polarized patch antenna with a simulated high gain of 12.5 dBi and a simulated side-lobe-level of below −20 dB, within the bandwidth of 5.2%. This single element antenna achieves high gain by exploiting the mode superposition of TM11 + TM13 (excited by a circle of vias loading the cavity) and TM12 + TM14 (excited by the cavity itself) radiated from the two apertures, respectively. A simple feeding network, consisting of a quadrature hybrid and a couple of 90° bent branches, is used in the design to excite RHCP or LHCP mode in the antenna cavity. A capacitive disk feeding is implemented so that the antenna can be matched to the feeding network, and the super-positioned fields inside the cavity are not disturbed by the feeding pins. This approach makes the design of a dual-sense circularly polarized antenna with high gain easier since the array configuration is not needed. High gain, in combination with a dual-sense circular polarization, makes the proposed antenna particularly attractive for space applications involving small satellites. With the proposed design, it is possible to employ only one antenna rather than two (RHCP and LHCP), thus saving space on the aircraft, which is clearly a limited resource.

3-D Printed Inhomogeneous Substrate and Superstrate for Application in Dual-Band and Dual-CP Stacked Patch Antenna

This paper presents the extensive study on the effects of inhomogeneous substrate and superstrate for the exploration of dual-band and dual-circularly polarized patch antenna. As well known to all, the technology for circularly polarized (CP) patch antenna has been often restrictedly achieved by altering the shape of patch conductor surface by a few standard manufacturing processes. Benefited from the 3-D printing technology, it is demonstrated here that CP waves can be alternatively generated via an intact metal patch mounted on low-profile inhomogeneous substrate. As for the inhomogeneous superstrate, low profile is insufficient to make it become a polarizer. As such, a dual-band and dual-CP stacked patch antenna is proposed, where the lower patch and its superstrate exactly serve as the ground and substrate of the upper one. Different impacts of low-profile inhomogeneous substrate and superstrate on polarization are utilized to ensure the isolation of left- and right-hand circular polarizations. Besides, due to the usage of intact patches, two operating bands are independently formed and can be easily located in proximity to each other. A prototype operating at 2.75 and 3.2 GHz is then fabricated and measured. Measured results are found in reasonably a good agreement with the simulated ones.

A Compact Broadband Dual-Polarized Patch Antenna for Satellite Communication/Navigation Applications

In this letter, a compact and robust dual circularly polarized patch antenna for combined Globalstar/GPS application has been presented. The designed patch antenna is accomplished with size of 40 × 40 × 6 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> over the frequency bandwidth of 1570-1650 MHz, which is 0.21λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.21λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.03λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ( λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at the lowest frequency of the operating bandwidth). Instead of air substrate, high-permittivity substrate is adopted for the size reduction. The bandwidth reduction due to the inclusion of the high-permittivity substrate is compensated by introducing a parasitic patch. In addition, a 90 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> hybrid is utilized for achieving dual circular polarization. The designed antenna is validated by the measurement, presenting a 5% fractional bandwidth (1570-1650 MHz) for both VSWR <; 2, axial ratio less than 3 dB, and port isolation less than -6 dB.

All Polarization Receiving Rectenna With Harmonic Rejection Property for Wireless Power Transmission

In this paper, a high conversion efficiency rectenna for wireless power transmission at 2.45 GHz is proposed. The rectenna is fabricated on a low-cost FR-4 substrate. The proposed design contains a dual circularly polarized patch antenna in which a high-order harmonic rejection property is embedded, and a pair of rectifying circuits without harmonic rejection filters. The dimension for the proposed rectenna design is 100×100×3.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The proposed rectenna collects waves in all polarization senses simultaneously with a suitable air gap width, chosen to maximize antenna gain, and provide high isolation between the rectifying circuits. The rectifying circuits are fed by the wave power of orthogonally polarized waves. The conversion efficiency is improved by blocking the second and the third harmonic noise from reemission without suffering loss from filters: the second harmonic noise is rejected with a T-shape slot, while the third is rejected by a U-shape resonator. The measured conversion efficiency of the proposed rectenna reaches 82.3% when the inputs of the rectifying circuits are fed at 22 dBm, surpassing the majority of existing rectenna designs in the current literature. The functionality of reception at all polarizations is also verified, distinguishing our design from other proposals.

Dual Circularly-Polarized Patch Antenna Using Even and Odd Feed-Line Modes

This communication proposes a new patch antenna with dual circularly polarized capability at 2.575 GHz. The design exploits the even and odd modes in a coplanar waveguide transmission line and enables simultaneous right- and left-handed circular polarization, with two individual excitation ports. A patch antenna is fed by multimode transmission line and the advantages and disadvantages are discussed. A prototyped antenna realized up to 20 dB isolation between ports with S21 <; -10 dB bandwidth of 87 MHz. Realized gains for the two modes of operation are 5.77 and 7.23 dBic. The proposed structure is compact and easy to manufacture.