Reduction of Beam Squinting and Cross-Polarized Fields in a Wideband CP Element
TL;DR: In this article, the fringing characteristics as well as modal fields of a suspended substrate circular patch are restricted to achieve wide circularly polarized (CP) bandwidth in a simple probe-fed microstrip antenna.
Abstract: Achieving wide circularly polarized (CP) bandwidth in a simple probe-fed microstrip antenna is essential for many practical applications. Existing knowledge guides exploring a thick substrate-based patch design. However, it suffers from two major inherent issues: squinting of beam and high cross-polarized (XP) radiation. No solution is available so far. This letter successfully addresses both issues by imposing restriction on the fringing characteristics as well as modal fields of a suspended substrate circular patch. Engineered ground plane bearing different strategic defects has been explored leading to about 50% correction in beam squinting with reference to antenna boresight and 2–8 dB reduction in a peak XP level. Realistic design, physical insight, and the experimental validation ensure its huge potential for practical applications.
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TL;DR: In this article , a triple-mode operation by capacitive slot loading is proposed for bandwidth enhancement of single-fed circularly polarized (CP) patch antennas, where three orthogonal LP modes are used for CP bandwidth enhancement, where the middle mode is shared by two cross-polarized modes with the same polarization.
Abstract: A method of triple-mode operation by capacitive slot loading is proposed for bandwidth enhancement of single-fed circularly polarized (CP) patch antennas. Instead of using even-numbered linearly polarized (LP) modes with quadrature phase, three orthogonal LP modes are used for CP bandwidth enhancement, where the middle mode is shared by two cross-polarized modes with the same polarization. The advantages include reduced constraints, lower complexity, and a higher degree of freedom for antenna design. Guided by the method, a U-slot antenna and an E-shaped antenna are proposed and designed with characteristic mode analysis (CMA). Both antennas work with a TM 10 -like mode and a TM 01 -like mode. Differently, the U-slot antenna works with an additional slot mode and the E-shaped antenna works with an additional TM 11 -like mode. The operating modes are manipulated by the slot loadings for creating phase difference. As a result, wideband CP radiation is achieved with a single feeding. CMA-based empirical formulas are derived for fast design. The proposed method and antennas are experimentally validated. Both antennas measure a bandwidth exceeding 21% for 10 dB return loss and 3 dB axial-ratio (AR), a significant improvement compared with conventional corner-truncated U-slot patch antennas of similar thickness or volume.
24 citations
TL;DR: In this article, a single-fed circularly polarized dielectric resonator antenna (CP-DRA) without beam squint is presented, which consists of an S-shaped D resonator with a metalized edge and two rectangular RDR blocks.
Abstract: A new single-fed circularly polarized dielectric resonator antenna (CP-DRA) without beam squint is presented. The DRA comprises an S-shaped dielectric resonator (SDR) with a metalized edge and two rectangular dielectric resonators (RDRs) blocks. Horizontal extension section is applied as an extension of the SDR, and a vertical-section is placed in parallel to the metallic edge. A vertical coaxial probe is used to excite the SDR and the vertical RDR blocks through an S-shaped metal element and a small rectangular metal strip. The two added RDRs that form an L-shaped DR improve the radiation characteristics and compensate for the beam squint errors. A wideband CP performance is achieved due to the excitation of several orthogonal modes such as [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text]. The experimental results demonstrate an impedance bandwidth of approximately [Formula: see text] (3.71-7.45 GHz) and a 3-dB axial-ratio (AR) bandwidth of about [Formula: see text] (3.72-6.53 GHz) with a stable broadside beam achieving a measured peak gain of about [Formula: see text]. Furthermore, a 100% correction in beam squint value from [Formula: see text] to [Formula: see text] with respect to the antenna boresight is achieved.
9 citations
DOI•
26 Mar 2023
TL;DR: In this article , the authors presented a novel circular polarization (CP) antenna loading with a parasitic ring metal strip, which was designed for global positioning system (GPS) L1 band applications.
Abstract: The paper presents a novel circular polarization(CP) antenna loading with a parasitic ring metal strip, which is designed for global positioning system (GPS) L1 band applications. The antenna consists of a defected ground plane with four arc-slots and a circular slot, a dielectric substrate, a parasitic ring metal strip, and a radiating patch (RP) with a arc-slot. By rotating the parasitic ring metal strip to opening slot on the RP, the antenna can be transformed from left-handed circular polarization (LHCP) to right-handed circular polarization (RHCP). The size of the antenna can be reduced by using slots on the ground. The simulation and optimization results show that impedance bandwidth of the L/RHCP antenna is over 100 MHz, and the axial ratio bandwidth is over 20 MHz.
TL;DR: In this article , a dual-band metasurface-based microstrip patch antenna with both linear and circular polarization (CP) for multiband communication is reported, which consists of a combination of metasuran and metamaterial inspired structures that are demonstrated as an effective technique to correct the beam squint problem and reduce the cross-polarized radiation.
Abstract: A compact, dual‐band metasurface‐based microstrip patch antenna with both linear and circular polarization (CP) for multiband communication is reported in this work. The ingredients in the antenna design consist of a combination of metasurface and metamaterial inspired structures that are demonstrated as an effective technique to correct the beam squint problem and reduce the cross‐polarized radiation, usually experienced by thick substrate‐based broadband CP antennas. A fractal boundary metasurface is introduced to achieve CP over a small frequency band. Eight Electric‐LC resonators are symmetrically placed in the same plane of the radiating patch to widen the CP bandwidth, correct the beam squint, reduce the cross‐polarized radiation, and realize a subwavelength resonance of λ0/5.15 order. The measured impedance bandwidths (|S11| < −10 dB) of the proposed antenna are 7.8% (3.7–4.0 GHz) and 27.58% (5.05–6.65 GHz) in the lower and upper‐frequency band, respectively. The measured 3‐dB axial ratio bandwidth (ARBW) is 24.8% (5070–6510 MHz) at 5.8 GHz. The fabricated prototype has an overall size of 55 × 55 × 4.08 mm (0.696λ0 × 0.696λ0 × 0.051λ0 at 3.8 GHz or 1.063λ0 × 1.063λ0 × 0.078λ0 at 5.8 GHz) with a realized peak gain of 4 dBi in the lower band and 7.1 dBic in the upper band. The measured results are consistent with the simulation results.
References
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Book•
01 Jan 1989
TL;DR: Analysis and design of circular microstrip elements micro Strip patch antennas circular polarization and bandwidth electromagnetically coupled dipoles multilayer configurations large bandwidth hybrid flat dipoles and arrays numerical analysis of microstrip patch antennas segmentation and desegmentation methods for microstrip antenna design transmission line model.
Abstract: Analysis and design of circular microstrip elements microstrip patch antennas circular polarization and bandwidth electromagnetically coupled dipoles multilayer configurations large bandwidth hybrid flat dipoles and arrays numerical analysis of microstrip patch antennas segmentation and desegmentation methods for microstrip antenna design transmission line model of microstrip antennas design and technology of low cost printed antennas analysis and design considerations of printed array antennas circularly polarized array antennas microstrip antenna feeds advances in substrate technology special measurement techniques for printed antennas CAD of microstrip and triplate systems resonant microstrip antenna elements and arrays applications of microstrip antennas monolithic conical conformal microstrip tracking antenna extensions and variations of the microstrip antenna concept.
1,501 citations
TL;DR: In this article, two variations of a novel feeding technique for a wideband circularly polarized aperture-coupled microstrip antenna are described, and experimental results are shown for each antenna, and results for the two designs are compared.
Abstract: Two variations of a novel feeding technique for a wideband circularly polarized aperture-coupled microstrip antenna are described. Prototype designs for wideband linearly polarized elements are first presented, and then used for circularly polarized designs. Techniques used for design of the feed network are detailed, for both series feed and parallel feed versions. Experimental results are shown for each antenna, and results for the two designs are compared. The impedance and axial ratio bandwidths for these antennas are among the best yet achieved for microstrip antenna elements. Several design variations are also discussed. >
376 citations
"Reduction of Beam Squinting and Cro..." refers background in this paper
...A variety of techniques have been explored so far, which include the use of an L-shaped probe [3], [4], multipoint feed networks [5]–[6], EM-coupled patches [7]–[10], metasurface and metamaterials [11]–[13], engineered ground and substrates [14], [15], parasitic elements [16], etc....
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TL;DR: In this article, a defected ground structure (DGS) pattern is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna, which is simple and easy to etch on a commercial microstrip substrate.
Abstract: A defected ground structure (DGS) is proposed to reduce the cross-polarized (XP) radiation of a microstrip patch antenna. The proposed DGS pattern is simple and easy to etch on a commercial microstrip substrate. This will only reduce the XP radiation field without affecting the dominant mode input impedance and co-polarized radiation patterns of a conventional antenna. The new concept has been examined and verified experimentally for a particular DGS pattern employing a circular patch as the radiator. Both simulation and experimental results are presented.
275 citations
"Reduction of Beam Squinting and Cro..." refers background in this paper
...Defected ground structures (DGSs) were primarily explored for linearly polarized (LP) patch and arrays [21]–[28] to reduce their cross-polarized radiations and mutual coupling issue....
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08 Nov 2010
TL;DR: In this article, Chen et al. present a survey of the state-of-the-art in the field of reconfigurable antenna design and their application in WSNs and wearable antenna networks.
Abstract: Preface. List of Contributors. Acknowledgments. 1 Numerical Analysis Techniques (Ramesh Garg). 1.1 Introduction. 1.2 Standard (Yee s) FDTD Method. 1.3 Numerical Dispersion of FDTD Algorithms and Hybrid Schemes. 1.4 Stability of Algorithms. 1.5 Absorbing Boundary Conditions. 1.6 LOD-FDTD Algorithm. 1.7 Robustness of Printed Patch Antennas. 1.8 Thin Dielectric Approximation. 1.9 Modeling of PEC and PMC for Irregular Geometries. References. 2 Computer Aided Design of Microstrip Antennas (Debatosh Guha and Jawad Y. Siddiqui). 2.1 Introduction. 2.2 Microstrip Patch as Cavity Resonator. 2.3 Resonant Frequency of Circular Microstrip Patch (CMP). 2.4 Resonant Frequency of Rectangular Microstrip Patch (RMP) with Variable Air Gap. 2.5 Resonant Frequency of an Equilateral Triangular Microstrip Patch (ETMP) with Variable Air Gap. 2.6 Input Impedance of a Microstrip Patch. 2.7 Feed Reactance of a Probe-Fed Microstrip Patch. 2.8 Radiation Characteristics. 2.9 Radiation Efficiency. 2.10 Bandwidth. 2.11 Conclusion. References. 3 Generalized Scattering Matrix Approach for Multilayer Patch Arrays (Arun K. Bhattacharyya). 3.1 Introduction. 3.2 Outline of the GSM Approach. 3.3 Mutual Coupling Formulation. 3.4 Finite Array: Active Impedance and Radiation Patterns. 3.5 Numerical Example. 3.6 Conclusions. 3.7 References. 4 Optimization Techniques for Planner Antennas (Rabindra K. Mishra). 4.1 Introduction. 4.2 Basic Optimization Concepts. 4.3 Real Coded Genetic Algorithm (RCGA). 4.4 Neurospectral Design of Rectangular Patch Antenna. 4.5 Inset-fed Patch Antenna Design Using Particle Swarm Optimization. 4.6 Conclusion. References. 5 Microstrip Reflectarray Antennas (Jafar Shaker and Reza Chaharmir). 5.1 Introduction. 5.2 General Review of Reflectarrays: Mathematical Formulation and General Trends. 5.3 Comparison of Reflectarray and Conventional Parabolic Reflector. 5.4 Cell Elements and Specific Applications: A General Survey. 5.5 Wideband Techniques for Reflectarrays. 5.6 Development of Novel Loop-Based Cell Elements. 5.7 Conclusion. References. 6 Reconfigurable Microstrip Antennas (Jennifer T. Bernhard). 6.1 Introduction. 6.2 Substrate Modification for Reconfigurability. 6.3 Conductor Modification for Reconfigurability. 6.4 Enabling Reconfigurability: Considerations for Reconfiguration Mechanisms. 6.5 Future Trends in Reconfigurable Microstrip Antenna Research and Development. References. 7 Wearable Antennas for Body Area Networks (Peter S. Hall and Yang Hao). 7.1 Introduction. 7.2 Sources on the Human Body. 7.3 Narrowband Antennas. 7.4 Fabric Antennas. 7.5 Ultra Wideband Antennas. 7.6 Multiple Antenna Systems. 7.7 Conclusion. References. 8 Printed Antennas for Wireless Communications (Satish K. Sharma and Lotfollah Shafai). 8.1 Introduction. 8.2 Broadband Microstrip Patch Antennas. 8.3 Patch Antennas for Multiband Wireless Communications. 8.4 Enhanced Gain Patch Antennas. 8.5 Wideband Compact Patch Antennas. 8.6 Microstrip Slot Antennas. 8.7 Microstrip Planar Monopole Antenna. References. 9 UHF Passive RFID Tag Antennas (Daniel Deavours and Daniel Dobkin). 9.1 Introduction. 9.2 Application Requirements. 9.3 Approaches. 9.4 Fabrication. 9.5 Conclusion. References. 10 Printed UWB Antennas (Zhi Ning Chen, Xianming Qing and Shie Ping See). 10.1 Introduction. 10.2 Swan Antenna with Reduced Ground Plane Effect. 10.3 Slim UWB Antenna. 10.4 Diversity Antenna. 10.5 Printed Slot UWB Antenna and Band-Notched Solutions. References. 11 Metamaterial Antennas and Radiative Systems (Christophe Caloz). 11.1 Introduction. 11.2 Fundamentals of Metamaterials. 11.3 Leaky-Wave Antennas. 11.4 Resonant Antennas. 11.5 Exotic Radiative Systems. References. 12 Defected Ground Structure for Microstrip Antennas (Debatosh Guha, Sujoy Biswas, and Yahia M. M. Antar). 12.1 Introduction. 12.2 Fundamentals of DGS. 12.3 DGS for controlling Microstrip Antenna Feeds and Front-End Characteristics. 12.4 DGS to Control/Improve Radiation Properties of Microstrip Patch Antennas. 12.5 DGS for Reduced Mutual Coupling between Microstrip Array Elements and Associated Improvements. 12.6 Conclusion. Appendix: A Brief DGS Chronology. References. 13 Printed Leaky Wave Antennas (Samir F. Mahmoud and Yahia M. M. Antar). 13.1 Introduction. 13.2 The Leaky Wave as a Complex Plane Wave. 13.3 Radiation Pattern of a Leaky Wave. 13.4 Examples of Leaky Mode Supporting Structures. 13.5 The Excitation Problem. 13.6 Two-Dimensional Leaky Waves. 13.7 Further Advances on a Class of Periodic Leaky Wave Antennas. References. Appendix I Preliminary Ideas: PTFE-Based Microwave Lamiantes and Making Prototypes. Appendix II Preliminary Ideas: Microwave Connectors for Printed Circuits and Antennas. Index.
260 citations
"Reduction of Beam Squinting and Cro..." refers background in this paper
...Along with several advantages, microstrip technology suffers from some inherent shortcomings, limited matching bandwidth (S11 < −10 dB) [1], [2] being one of them....
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TL;DR: In this paper, a two-probe feed was used to overcome the radiation pattern distortion, high crosspolarization and low efficiency due both to higher-order modes and surface-wave generation.
Abstract: In thick microstrip patches, probe inductance prevents matching of the patch impedance to the input connector. The probe inductance can be tuned out with a capacitive gap. To maintain simplified construction the gap is here etched on the patch surface. Bandwidths equal to or greater than that theoretically predicted are realised. Use of a single probe-compensated feed results in radiation pattern distortion, high crosspolarisation and low efficiency due both to higher-order modes and surface-wave generation. Two-probe feeding is used here to overcome these problems and to give a wide-band antenna with good radiation pattern control and high efficiency.
216 citations
"Reduction of Beam Squinting and Cro..." refers methods in this paper
...A few thick or suspended substrate based designs used a probe-fed E-shaped patch [17], circular patch with a linear slot [18], and on-patch probe compensation [19]....
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