Right-hand Circularly Polarized Gain 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 Single-Layer Circularly Polarized Antenna With Improved Gain Based on Quarter-Mode Substrate Integrated Waveguide Cavities Array

In this letter, a single-layer right-hand circularly polarized (RHCP) antenna with low-profile and improved gain based on quarter-mode substrate integrated waveguide (QMSIW) cavities array is proposed and experimentally validated. The proposed antenna consists of a central microstrip patch and four QMSIW cavities with the same dimensions, which are directly cascaded to the central patch. The E-field distribution of the proposed structure is similar to that of a circular SIW cavity working in the high-order TM120 mode. Due to the in-phase equivalent magnetic currents array formed by the fringing electric field of the radiation edges, a high RHCP gain with very low cross polarization in the broadside is achieved. Because of the high-order working mechanism, the antenna can be fed by a coaxial probe directly without any complex power distribution network. Measured RHCP gain of the antenna is up to 10.4 dBi at the center frequency point 5.78 GHz, which is in good agreement with the simulated results.

Design of a wideband right‐handed circularly polarized array of miniaturized mushroom‐shaped antennas for direct broadcast satellite application

AbstractIn this study, a wideband right‐handed circularly polarized (RHCP) array of microstrip patch antennas, for direct broadcast satellite (DBS, 12.2‐12.7 GHz) services have been presented. The single element of the array is a two‐dimensional mushroom‐shaped fractal antenna of resonating frequency 12.49 GHz and an impedance bandwidth of 1.12 GHz. The proposed single element is designed by etching a pair of Minkowski square boxes in one of the two opposite sides of a regular octagon. Furthermore, a thin slot of length equal to one side of the regular octagon is placed in‐between the two Minkowski boxes, which results in the proposed mushroom‐shaped radiating element. The proposed four‐element linear array resonates at 12.47 GHz and gives an impedance bandwidth of 1.04 GHz. The feed network of the array is designed in such a manner to make the array structure very compact. The fabricated single element gives an RHCP gain of 5.25 dBic and its corresponding circular Polarization (CP) bandwidth of 200 MHz. The array gives an RHCP gain of 11.59 dBic and a CP bandwidth of 460 MHz. The measured CP bandwidth of the fabricated array prototype ensures 92% coverage of the entire DBS band with circularly polarized wave, and hence can be used for its related applications.

A High-Temperature Stable Antenna Array for the Satellite Navigation System

This letter presents a high-temperature stable antenna array applied to an adaptive anti-jamming system in satellite navigation. The main features of the antenna are: owing to the titanium alloy and thermal stable ceramic material, the antenna works stably at 400 °C and demonstrates excellent heat-resisting property; no welding is used during the assembly to ensure the reliability of the electric connection under high temperature impact; metal walls are adopted to improve the radiation; the center shorting pillar is designed to reduce the inductance of the feed probe and obtain excellent impedance matching characteristics. During the simulation and experiments, the designed antenna array exhibits excellent performance and proves its suitability for high-temperature application. From 20 °C to 400 °C, the right-hand circular polarization gain is larger than 4 dBi and the operation frequency covers the L1 band of global positioning system and B1 band of BeiDou II.

An Artificially Anisotropic Antenna Substrate for the Generation of Circular Polarization

The purpose of this communication is to present the design of an artificially anisotropic antenna substrate (AAAS) for the generation of circular polarization (CP) for a linearly polarized antenna. The AAAS can be manufactured by assembling thin sheets with certain relative permittivities for the host or environment $\varepsilon _{e}$ and inclusion $\varepsilon _{i}$ materials as a stack. Using two different stacking materials enables the generation of different effective permittivities $\varepsilon _{{{x{'}}}}$ and $\varepsilon _{{{y{'}}}}$ for the wave components propagating in-between an antenna and a ground. The idea is to modify the antenna polarization by exploiting reflections from a ground in a way that CP operation is obtained. By properly designing the AAAS, the radiator shape can be maintained simple. The operation of AAAS is demonstrated for substrates made of homogeneous anisotropic and thin sheets. It is shown that by using sufficient high inclusion permittivity (e.g., $\varepsilon _{i} = 15$ ), the AAAS is observed to even show axial ratio <2 dB with over 25 dBi higher right-hand CP gain than left-hand CP in the main beam of the antenna. A prototype with available low-lossy materials is manufactured and successful correlation with theory and simulation results is observed.

COMPACT COAXIAL PROBE-FED CP SUBSTRATE INTEGRATED WAVEGUIDE CAVITY-BACKED ANTENNA UTILIZING SLOT SPLIT RING

A circularly polarized (CP) substrate integrated waveguide (SIW) cavity-backed slot antenna is proposed. A slot split ring (SSR) etched on the top metal surface of an SIW resonator is employed to generate the right-handed circularly polarized (RHCP) wave. The proposed antenna is excited directly by a coaxial probe with a proper distance from the symmetric axis of the SSR resonator. A prototype of the proposed CP antenna at the center frequency of 10 GHz is manufactured. As a result, the proposed antenna exhibits the advantages of both conventional planar antennas and metallic cavity backed antennas, including simple structure, compact size of 15.8×15.8 mm 2 , light weight, easy fabrication, high gain and wide axial ratio bandwidth. It is proved by experiment that an impedance bandwidth of 10.2% for the reflection coefficient less than −10 dB, an axial ratio (AR) bandwidth of 1.72% for AR less than 3 dB, and a RHCP gain 5.5 dBi have been obtained.

A Cavity-Backed Traveling Wave Antenna for Tri-Band GPS Applications

A cavity-backed tri-band antenna is proposed for the global positioning system (GPS) operating at 1176.45 MHz (L5 band), 1227.60 MHz (L2 band), and 1575.42 MHz (L1 band). The right-hand circular polarization (RHCP) of the proposed antenna is achieved by feeding a cross-type traveling wave antenna at one end and by terminating with a load at the other end. Without using the complicated feed network or the dual-fed structure, the proposed single-feed RHCP antenna gives wide impedance bandwidth ( ${\rm VSWR} ), wide axial ratio ( ${\rm AR} ) bandwidth, and high RHCP gain ( $ > 4 \hbox{dBic}$ ).

Compact Dual-Band Proximity-Fed Circularly Polarized Patch Antenna for BDS Applications

AbstractThis paper presents a compact dual-band proximity-fed circularly polarized (CP) patch antenna for BeiDou Navigation Satellite System (BDS) operation at B1 (1,561 MHz) and B3 (1,268 MHz) bands. The antenna aperture is minimized down to 26.6 mm (λ/9 at the B3 band) in diameter and 12 mm (λ/20 at the B3 band) in thickness using high permittivity dielectric substrate and meandered slots. The antenna design features that the resonant frequency in the higher band could be tuned independently by adjusting the branch length and breadth without affecting the lower band. To achieve right-handed CP (RHCP) radiation property, quadrature phase feeding is employed together with a broadband 0°–90° hybrid utilizing a small surface mount LTCC hybrid coupler chip. Experimental results show that the RHCP gain maintains larger than 1.5 dBic and the axial ratio (AR) stays below 3 dB within the B1 and B3 bands. This antenna design is a promising candidate for small BDS arrays as well as other dual-band BDS applications.

WIDE BEAMWIDTH QUADIFILAR HELIX ANTENNA WITH CROSS DIPOLES

A simple and novel method for increasing the gain at low elevation angle and widening the beamwidth of quadrifllar helix antenna (QHA) is presented. By adding cross dipoles as a re∞ector, the right hand circular polarization (RHCP) gain at 5 - elevation angle (µ = 85 - ) increases by about 1.4dB. Parametric studies are performed to explore the performance improvements. An antenna for CNSS (Compass Navigation Satellite System, 2.492GHz) application is realized based on the studies. The RHCP gain at 5 - elevation angle is about 0.6dB, and 3dB beamwidth is greater than 220 - . 10dB impedance bandwidth is more than 24%, and 3dB axial ratio bandwidth is more than 32%. Measured results are presented to validate the proposed method.

Circularly polarized SIW square ring‐slot antenna for X‐band applications

AbstractIn this letter, a single‐layer circularly polarized substrate integrated waveguide (SIW) square ring‐slot antenna operating in the X‐band is proposed.The circularly polarized wave is generated by a combination of a shortened square ring‐slot etched in the SIW top wall and a shorting via placed between the area bounded by the ring and the SIW bottom wall. Experimental results prove that the antenna with a coax‐to‐SIW transition radiates a right‐hand circularly polarized (RHCP) wave and it achieves the impedance bandwidth of 10.3% for the reflection coefficient less than –10 dB, the axial ratio (AR) bandwidth of 2.6% for AR less than 3 dB, and the RHCP gain 8.0 dBi. The proposed antenna has the advantage of conventional planar structures including low profile, light weight, and easy low cost fabrication. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2590–2594, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27113