Circularly Polarized Microstrip Antenna Research Articles

A design of ring-shaped dual-band/multi-band circularly polarized microstrip antenna based on slots mutual coupling

A new approach for designing a single-feed circular microstrip antenna with dual-band/multi-band circularly polarized (CP) radiation are demonstrated and studied experimentally. It is presented that by embedding pairs of asymmetrical ring-shaped arc slots to the boundary of both circular patch and the ground plane the impedance bandwidth of the antenna increases. This can be achieved by making use of both mutual coupling between the resonances of the ring-shaped arc slots and the fundamental resonances of the circular antenna. Also, by extending the ring-shaped arc slots out with narrow slots, the circular microstrip patch antenna can perform dual-band/multi-band CP radiation. Further details of the proposed CP microstrip antenna designs are described, and typical experimental results are presented and discussed.

A NEW OMNIDIRECTIONAL CIRCULAR POLARIZATION MICROSTIP ANTENNA

The configuration of a new circularly polarized microstrip antenna with omnidirectional radiation pattern for GPS-L1 application is proposed in this paper. The designed antenna has a back- to-back rectangular-patch structure, and two patches are fed by coaxial cable connected with a Wilkinson power divider. The horizontal omnidirectional radiation pattern was achieved by both simulation and measurement. Axial ratio in the peak gain plane was around 3 dB ranging from 1.5 dB to 3.6 dB. The variation of RHCP gain in the horizontal omnidirectional circular polarization plane was smaller than ±1 dBic. And peak RHCP gain of the designed antenna was about 2.3 dBic.

Design of the Circularly Polarized Microstrip Antenna as Radio Frequency Identification Tag for 2.4 GHz of Frequency

Design of the Circularly Polarized Microstrip Antenna as Radio Frequency Identification Tag for 2.4 GHz of Frequency

DESIGN AND SIMULATION BASED STUDIES OF A DUAL-BAND CIRCULARLY-POLARIZED SQUARE MICROSTRIP ANTENNA

A dual-band circularly-polarized microstrip antenna is proposed, and the antenna for GPS is designed. The radiation characteristics of the dual-band circular polarization are achieved by installing one pair of L-shaped slits at all edges of the square patch. The impedance matching in the dual band is tuned by an L-probe feed. The proposed antenna is effective and useful in the design for dual-band circularly-polarized operation.

Ground‐embedded dual‐slot perturbation for switchable circularly polarized microstrip antenna

ABSTRACTThis article reports a new ground‐embedded dual‐slot perturbation for a reconfigurable circularly polarized microstrip antenna. The perturbation consists of the small inner and the large outer slots with two PIN diodes in one diagonal corner for generating and alternating right‐/left‐handed circular polarization, respectively. The measured results of the implemented antenna which used the ground‐embedded dual slot show an agreement with the simulation and successfully demonstrate circularly‐polarized radiations with good controllability. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2537–2539, 2014

Performance Comparison of Differential Evolution, Particle Swarm Optimization and Genetic Algorithm in the Design of Circularly Polarized Microstrip Antennas

Performance evaluation of evolutionary optimization techniques is done with respect to the design of circularly polarized microstrip antennas. The optimization techniques include conventional differential evolution, particle swarm optimization and genetic algorithm along with their advanced schemes. The optimization is done for impedance matching over a predefined frequency range, circular polarization, and high gain at a center frequency. The control parameters of all the algorithms are tuned using meta-level particle swarm optimization algorithm. Three cases are considered with three conventional feeding techniques, namely probe feed, transmission line feed, and the cross-aperture coupled feed. A fuzzified cost function is developed for optimization to ensure proper outcome from each optimization algorithm. The antenna parameters obtained from the algorithm producing best results are fabricated and their performances measured.

Comparative Analysis of a Circularly Polarized Microstrip Antenna with a Cross-Slot using Single and Double Substrate

This paper compares the different parameters for differently configured single substrate circular patch and double substrate square patch microstrip antenna. The proposed antenna 1 is fed by proximity coupled feed whereas the proposed antenna 2 is single fed to excite the antenna. Copper clad substrate is used in this design. The circular polarization is achieved by the proposed antennas without 90° hybrid coupler. The proposed antennas are applicable for L and S band applications (1.26GHz and 2.56/2.65 GHz respectively). The gain of both of the antenna are approximately same. This comparison will provide the technique for miniaturization using single substrate.

Calibration of Mutual Coupling Effect for Adaptive Arrays Composed of Circularly Polarized Microstrip Antennas

In this article, a new mutual coupling calibration method, the element pattern reconstruction method, is proposed and utilized to calibrate the mutual coupling effect of circularly polarized microstrip arrays. Previous work has verified that the new calibration method is suitable for arrays composed of not only wire elements but also linearly polarized microstrip elements. The mutual coupling calibration of circularly polarized microstrip arrays employing the new method is presented in this work. For a well-designed circularly polarized microstrip array, the calibration matrix for the main polarization component can be used to calibrate the received signals with high accuracy. The numerical results verify the effectiveness of the new calibration method for the circularly polarized microstrip arrays.

Stacked dual-band circularly polarized microstrip antenna with small frequency ratio

A single feed dual-band circularly polarized stacked microstrip patch antenna with a small frequency ratio is presented. The lower patch is having a pair of peripheral cuts in the circular patch with cross slot loaded at the center and truncated corner square ring is used as the parasitic patch. The frequency ratio of dual-band achieved is 1.05. The 3-dB axial ratio bandwidth is 1.4% for the upper band and 1.1% for the lower band. Proposed structure is fabricated on the FR-4 epoxy substrate and fed by SMA connector. The measured results are in good agreement with the simulated. The antenna shows stable radiation characteristics for both the operating bands. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1933–1937, 2014

Compact Wide-Beam Circularly-Polarized Microstrip Antenna With a Parasitic Ring for CNSS Application

A compact single-feed circularly-polarized (CP) wide beam microstrip antenna is proposed for CNSS application. The antenna is designed with a double-layer structure, comprising a circular patch with two rectangular stubs along the diameter direction and a parasitic ring right above it. The resonance frequency and the CP characteristics are mainly controlled by the circular patch and the rectangular stubs, respectively. The vertical HPBW (half power beam width) could be widened by the parasitic ring. Experimental results show that the measured vertical HPBW is approximately 140° and the measured out-of-roundness for the horizontal radiation pattern is only 1.1 dB. Besides, it could maintain good low-profile characteristics.

Compact circularly polarized microstrip antenna for GPS applications

ABSTRACTA compact design of circularly polarized microstrip antennas is described. The antenna has a square‐ring radiating patch, and it is excited by a feeding network consisting of a quadrature coupler with dual lumped capacitors and an impedance‐matching circuit. The feeding network has a considerably smaller size than a traditional 90° hybrid, and therefore, it is placed at the inner slot of the square‐ring patch. By tuning the capacitance value of the lumped capacitors, the antenna can generate good circular polarization radiation. An antenna prototype designed for global positioning system applications is implemented. From the measured results, the 10 dB‐return‐loss bandwidth and 3 dB‐axial‐ratio bandwidth of the prototype are 3% and 1%, respectively. Simulation results obtained by HFSS are also provided to validate the experiment. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1293–1296, 2014

Single‐feed cross‐slot loaded compact circularly polarized microstrip antenna for indoor WLAN applications

ABSTRACTA novel single‐feed circularly polarized microstrip antenna with compact size is proposed for indoor wireless local area network (WLAN) applications. The antenna structure consists of eight slits which are introduced at the boundary and the corners in the radiating square patch with a cross‐slot at the center. The proposed antenna shows a compactness of 42% compared with the conventional circularly polarized antenna design at indoor WLAN frequency band. It is found that the resonance frequency of the proposed structure is highly depending on length and width of cross‐slot and corner slit for entire band of circular polarization. The 3 dB axial ratio bandwidth of the proposed antenna is 1.9%. Proposed structure is fabricated on the FR‐4 epoxy substrate and fed by a single coaxial probe. Measured results show a good agreement with the simulated results. Antenna shows stable radiation characteristics for the entire operating band. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1313–1317, 2014

Circularly Polarized Arrowhead-Shape Slotted Microstrip Antenna

A novel single-feed arrowhead-shape slotted microstrip antenna for circular polarization (CP) is proposed. To achieve CP radiation and antenna size reduction, an arrowhead-shaped slot is embedded in the first quadrant along the diagonal axes of a square patch. Thus, the structure is asymmetric, and good-quality CP performance can be achieved by adjusting the size of the slot. The antenna is simulated and practically fabricated. Measured results confirm the validity of this design and show a good agreement with simulated results. The antenna generates CP radiation at 911 MHz with an overall size of 87 × 87 × 4.572 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The fabricated antenna shows an impedance bandwidth of 35.0 MHz (888.0-923.0 MHz) with 8.0 MHz (908.0-916.0 MHz) 3-dB axial-ratio bandwidth (ARBW).

Frequency-Reconfigurable Microstrip Patch Antennas With Circular Polarization

A simple design of circularly-polarized (CP) microstrip antennas with frequency agility is described. The reconfigurable antenna is composed of a square radiating patch, four varactor diodes, and two lumped capacitors. With a coaxial probe, two orthogonal resonant modes of the square patch antenna are simultaneously excited. When the equivalent capacitance values of the varactors are increased, the resonant frequencies of the two modes are decreased, and at the same time the lumped capacitors with a specific value are introduced to produce a difference between the two resonant frequencies so that a CP operating frequency can be generated and tuned. For the proposed design, only one dc voltage is required to vary the CP operating frequency, and experimental results indicate that the CP frequency can be switched between 1.97 GHz and 2.53 GHz; in addition, good CP performances can be obtained at each CP operating frequency.

ANN Synthesis Model of Single-Feed Corner-Truncated Circularly Polarized Microstrip Antenna with an Air Gap for Wideband Applications

A computer-aided design model based on the artificial neural network (ANN) is proposed to directly obtain patch physical dimensions of the single-feed corner-truncated circularly polarized microstrip antenna (CPMA) with an air gap for wideband applications. To take account of the effect of the air gap, an equivalent relative permittivity is introduced and adopted to calculate the resonant frequency andQ-factor of square microstrip antennas for obtaining the training data sets. ANN architectures using multilayered perceptrons (MLPs) and radial basis function networks (RBFNs) are compared. Also, six learning algorithms are used to train the MLPs for comparison. It is found that MLPs trained with the Levenberg-Marquardt (LM) algorithm are better than RBFNs for the synthesis of the CPMA. An accurate model is achieved by using an MLP with three hidden layers. The model is validated by the electromagnetic simulation and measurements. It is enormously useful to antenna engineers for facilitating the design of the single-feed CPMA with an air gap.

Broadband Circularly Polarized Microstrip Antenna with Coplanar Parasitic Ring Slot Patch for L-Band Satellite System Application

A novel capacitive-coupled probe-fed circularly polarized (CP) microstrip antenna with coplanar parasitic ring slot patch has been proposed for the International Maritime Satellite (INMARSAT) and the Global Positioning System (GPS) applications. The key feature of the design is employing capacitive-coupled four-probe feeds to increase impedance bandwidth and adopting coplanar parasitic ring slot patch to enhance CP bandwidth. The feed network is compact and neat using only T-junction power dividers and phase shifters with shunted short-circuited microstrip stubs for lightning protection. The characteristics of the proposed antenna have been studied by simulation and experiment. The final antenna can produce a ${ S}_{11} 14 dB impedance bandwidth of nearly 27%, a 3-dB axial-ratio bandwidth of nearly 16%, and a gain of higher than 8 dB in the whole maritime satellite communication work band.

移动通信中的双向圆极化微带天线的设计

移动通信中的双向圆极化微带天线的设计

Omnidirectional Dual-Band Dual Circularly Polarized Microstrip Antenna Using ${\rm TM}_{01}$ and ${\rm TM}_{02}$ Modes

An omnidirectional dual-band dual circularly polarized (CP) antenna with wide beam radiation patterns using 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">02</sub> modes is investigated. The proposed antenna is composed of a circular patch with eight curved slots and a disk-loaded coaxial probe. The horizontal and vertical polarizations are obtained by the currents flowing on the patch and on the coaxial probe, respectively. Omnidirectional CP fields can be achieved at both resonant modes when the two orthogonally polarizations are equal in amplitude and different in phase by 90°. With a low profile of 0.017 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , the proposed antenna exhibits a wide beamwidth of 100° in the elevation plane at both modes. The measured axial ratios (ARs) at the two resonant modes in the azimuth plane are 1.71 and 2.82 dB, respectively. The measured left-hand CP (LHCP) and right-hand CP (RHCP) gains in the azimuth plane are 0.1 dBic at the lower center frequency and -1.1 dBic at the upper center frequency, respectively. These measured results are congruent with the simulated data. In addition, the methods to broaden the bandwidth of the proposed antenna are given and discussed in details.

Improved Wheeler Cap Method Based on an Equivalent High-Order Circuit Model

The conventional Wheeler cap method usually produces accurate radiation efficiency of small antennas when the antennas under test (AUTs) operate as a simple series or a parallel RLC resonance circuit. However, this method often gives unreliable radiation efficiency if the AUT has a complicated operating principle such as circular polarization (CP), multiple resonances, or broad-band properties. In this paper, we propose an improved Wheeler cap method based on the equivalent high-order circuit model including transformers to provide accurate radiation efficiency, although the AUT does not operate as a simple resonance circuit. For building equivalent high-order circuit models, a method for estimating the initial values of a genetic algorithm (GA) is also proposed, which effectively reduces the searching space and improves the convergence of the optimization. To verify the proposed method, we measure the radiation efficiency of a CP microstrip antenna, a UHF RFID tag antenna, and a triple-resonance microstrip antenna.

Circularly Polarized Proximity-Fed Microstrip Array Antenna for Micro Satellite

Design of circular polarization microstrip antenna array was developed to support micro-satellite technology. Circular polarization antenna array used for data transmission applications operating in the S band frequencies from the satellite to the ground station . In this study of the patch array using proximity coupling techniques in this study to obtain high gain and wide of bandwidth. The structure of the antenna array design consists of four identical square patch elements and to use the concept of corporate transmission line fed power divider network uses three transformers quarter-lambda T-junction. Bandwidth impedance matching for resonance between two patches is ¾ l antenna system for center frequency of 2.25 GHz. The antenna is designed using the method of moments through simulation with microwave office software applications. The results of simulations and measurements obtained antenna parameters, such as: bandwidth of return loss <-10 dB above 100 MHz resonant frequency shifted to 1.75%, VSWR (1 to 2), the bandwidth of axial ratio <3 dB is 1.6% (narrowband) and the maximum directivity (gain) is 9.128 dB. Overall study results showed good performance antenna array with circular polarization properties, high gain and operates in the S band frequency micro satellite system.