A low-cost dual-band metasurface-based circularly polarized patch antenna with enhanced gain

A circular polarization (CP) patch antenna is proposed for the first time in this article. The proposed antenna is developed based on a patch antenna combined with one row of diagonal periodic metallic via holes. By optimizing the location of the periodic metallic via holes, two orthogonal waves with 90° phase difference are excited using single feed and a CP patch antenna is obtained. A CP antenna is designed based on the proposed structure and simulated by Ansoft HFSS. The designed CP antenna is fabricated and measured. The measured results present return loss |S11| > 10 dB from 10.4 to 11.6 GHz. The radiation pattern is also measured, and it exhibits good circular polarization property with 3-dB axial ratio (AR) of 1.2 dB and gain of 4.02 dBic. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett1100, 2013; 1097 this 1100 online at wileyonlinelibrary.com. DOI 10.1002/mop.27529

Background/Objectives: To develop Circular Polarized (CP) patch antenna with improved bandwidth and harmonic suppression for RF energy harvesting system. Methods/Statistical analysis: A l /4 resonator is introduced and coupled in proximity to the radiating patch for bandwidth enhancement and high order harmonic suppression. Compared with other dual-resonance patch antennas, the proposed antenna has attractive low-profile property and simple structure. The CP can be achieved by putting arc shape slits at edge of circular patch. The structure, working principle and results we are described. Findings/Applications: The operating bandwidth is from 1.68 GHz to 2.95 GHz (52.91%) with a reflection coefficient less than -10 dB with Axial Ratio bandwidth of 550MHz (2.21 GHz -2.76 GHz) while harmonic suppression over wide frequency range from 1 to 12 GHz is achieved. The experimental and simulated results is good matching except some slight variation. Novelty/Applications: New techniques for both bandwidth enhanced and harmonic suppression and up to 4th higher order harmonics has been suppressed. Proposed structure offers wideband CP Antenna with harmonic suppression. Keywords: RF energy harvesting; microstrip patch antenna; harmonic suppression; circular polarization

A circularly polarized (CP) patch antenna with a new chiral metamaterial structure was proposed. The proposed CP antenna is composed of a conventional linearly polarized patch antenna and a chiral metamaterial (CMM) board. For the CMM unit cell, the geometric parameters of the two pieces of copper films that are patterned on opposite sides of an FR-4 board are quite different. The function that a linear-polarization wave is converted into a circular polarization wave can be realized by the designed structure through simulation verification. When the CMM board is placed in the front of a conventional linear-polarized patch antenna, the antenna polarization mode can be changed to the circular polarized mode. The antenna performances have been investigated numerically and experimentally. Meanwhile, the new CMM structure could be applied to the field of circular-polarized antenna.

This paper presents a few single-substrate multi-metal layer antennas using additively manufactured electronics (AME) solution based on piezoelectric additive fabrication. By vertically stacking metal layers in a 3D printed single substrate, the designed antenna prototype exhibits the advantages of wide bandwidth and ultra-low profile. For proof-of-concept, multi-layer linear polarization (LP) patch antenna elements and 2 × 2 LP antenna arrays are designed, fabricated, and measured. It verifies that the feeding network can be integrated into the same substrate of the antenna array element without increasing the size and profile of the array. Compared with the traditional single-layer LP patch antenna, the proposed LP patch antenna can improve the impedance bandwidth from 5.9% to 10.6% (three layers) and 83% (seven layers), respectively. All these designs can be fabricated in a single substrate with a thickness of 1.5 mm (0.031 λg), which is an ideal solution for the applications where ultra-low profile and wideband patch antenna are expected. Finally, circular polarization (CP) patch antenna elements and 2 × 2 CP antenna arrays are fabricated and measured. Good agreements between the simulated and the measured results verify that wider impedance bandwidth and broader frequency range of under 3-dB axial ratio can be obtained by vertically stacking metal layers. The antennas are designed at sub-6GHz, which have great potentials for 5G consumer mobile electronics.

Miniaturization is one of the prime motives in modern communication systems and can be achieved through size reduction of both components and their packages. Whereas passive components are fairly insensitive to packaging, this is certainly not the case for antennas, as the package is located in the nearfield. The paper focuses on the effects of the casing on the radiation characteristics of a miniaturized patch antenna for circular polarization. Different scenarios involving metallic and dielectric casings with planar dielectric overlays are investigated. A circularly polarized microstrip patch antenna has been designed and investigated with respect to effects introduced by the casing. It is found that a metallic casing severely influences the gain and the axial-ratio bandwidth. It also changes the direction of minimum axial ratio. By placing the patch asymmetrically in the casing, the minimum axial ratio can be improved. A dielectric casing has minimal effect on the radiation properties.

The GPS (Global Positioning System) has come into wide use in Japan. A high performance and low cost, small GPS antenna is required. In this paper, a small circular polarized patch antenna for GPS satellite receivers is investigated. Patch antenna miniaturization can be achieved by adding a slit or slot on the patch element of the antenna. The current path on the patch element increases, and resonant frequency drops by adding the slit. We first investigate the case of a square patch antenna with 4 slits from both sides of the patch. By changing the parameter of the slit structure, an optimum slit parameter for antenna miniaturization is proposed. Then, in order to achieve more miniaturization, a patch antenna with cross-shaped slit is simulated. Parameter optimization is carried out. Finally, the antenna axial ratio is investigated, and an optimum small circular polarized antenna is proposed. A high performance three-dimensional FDTD algorithm using a nonuniform mesh that allows flexible cell size to improve the accuracy of modeling and reduce the computational resources is adopted in this study.

Wideband and high-gain patch antenna with reflective focusing metasurface

The simplicity and intuitive design of traditional circularly polarized (CP) patch antennas, such as the truncated corner patch antenna, has led to their widespread popularity. However, they are limited to a narrowband performance on the order of 0.1%-2% for simultaneously good S11 and axial ratio (AR). We will prove theoretically that this is a direct result of the probe reactance hindering the use of thicker substrates to increase the bandwidth. Furthermore, we propose a novel compensation technique to enhance the bandwidth capabilities of these CP patch antennas. Our method inserts a capacitive element, such as an annular gap or parallel plate, in series with the probe inductance to remove its effect. We demonstrate this technique with simulations and measurements to obtain AR- S11 bandwidth capabilities as high as 12.6%. To the authors' best knowledge, this is the first time that capacitive compensation and thick substrates have been jointly employed to enable broadband CP patch antennas.

A new design based on sequential-rotation arranged polarization conversion metasurfaces (PCMs) is proposed for reducing backscattering and improving radiation performance of circularly polarized (CP) patch antennas. The proposed antenna is composed of a conventional corner-truncated patch antenna loaded with a PCMs. The configuration of the PCMs increases the operating bandwidth and realized gain, as well as reduce radar cross section (RCS). The relative CP bandwidth (both |S11| < −10 dB and AR <3 dB) is improved to 13.65% due to achieving an additional mode by the PCMs. Also, the peak gain is enhanced by 6.6 dB. Moreover, an in-band and out-of-band RCS reduction is achieved compared with the conventional CP patch antenna due to the polarization conversion characteristic of the PCMs. The maximum RCS reduction is 27.5 dB within the band. This design enables an effective strategy for wideband, high-gain, and low-RCS CP patch antennas. A sample operating at C-band was fabricated and measured, demonstrating a satisfactory match between simulation and measurement results, so verifying the proposed idea.

A bandwidth-enhanced, compact, single-feed, low-profile, multilayered, circularly polarized (CP) patch antenna is presented. A corner-truncated patch is introduced as a near-field resonant parasitic element directly beneath a specially engineered radiation patch. Without sacrificing the antenna's low profile and compact size, its presence not only introduces a new pair of orthogonal near-degenerate resonant modes, but also recovers a similar pair from the cross slot of the main patch. With the aid of both circular slots and meander-line slots on these patches, the resulting three pairs of adjacent near-degenerate modes have been successfully combined with the same clockwise polarization to enhance the CP bandwidth by more than a factor of two when compared to the same-height conventional single-layer patch antennas. Measured results are in good agreement with their simulated values and demonstrate that the reported antenna is low-profile: 0.016 λ 0 , achieves a -10-dB impedance bandwidth of ~4.6%, and a 3dB axial-ratio bandwidth of about 2.33% along with realized gains of 4.5 ± 0.15 dBi, throughout that bandwidth. Analyses of the current distributions are used to explain the contributions of the parasitic patch, and further simulation studies validate our design guidelines and show its advantages.

We explore a stacked probe-fed circularly polarized patch antenna to investigate the effects of changing the size of the upper patch and the distance between the upper and the lower patches on antenna polarization and radiation characteristics. Using simulation software Ansys HFSS, we compare return loss and gain values for stacked patch antennas with different shapes and feeding methods and design a stacked patch antenna that can be used for in-band full-duplex systems where the receiver and transmitter elements with orthogonal circular polarization would achieve a high level of self-interference cancellation.

This paper presents the investigation on the effect of two main parameters of a circular polarized patch antenna by using notch technique. The results show that this technique can improve the performance of return loss and gain of the patch antenna. The operating frequency of the proposed antenna is 2.4GHz with 32.66MHz of bandwidth and return loss is -49.63dB. The antenna had been designed and simulated using CST Microwave Studio simulation software. The circular polarization (CP) operation was obtained by implementing double circle slot at 45° orientation on the circular patch antenna. Based on simulation, the antenna gain of 6.36dB with minimum axial ratio (AR) of 1.43dB and 3dB AR bandwidth of 180.54MHz was achieved.

This paper discussed the investigation on the effect of two main parameters of a circular polarized patch antenna by using stub technique. The results show that this technique can improve the performance of return loss and gain result of the patch antenna. The operating frequency of the proposed antenna is 2.4 GHz with 40 MHz of bandwidth and return loss is -40 dB. The antenna had been designed and simulated using CST Microwave Studio simulation software and. The circular polarization (CP) operation was obtained by implementing rectangular slot in the center of the circular patch antenna. Based on simulation, it obtained a gain of 6.22 dB with minimum axial ratio (AR) is 0.829 dB and a 3 dB AR bandwidth of 72.5 MHz.

In this paper, a novel method to enhance axial ratio bandwidth of circularly polarized (CP) patch antenna using artificial magnetic conductor (AMC) structures with LTCC technology at Ka-band is proposed. In order to improve the axial ratio bandwidth, the traditional PEC plane is replaced by an AMC plane. The AMC is composed of periodic square unit cells with truncated opposite corners. The AMC structure and the antenna are simulated using a full-wave solver and the results show a 10 dB return loss bandwidth of 30% and a 3 dB axial ratio bandwidth of 12.7%, and gain is around 7.5 dB within this band, which compared with the traditional corner-cut square circular polarization patch antenna, the axial ratio bandwidth of proposed antenna increased by 9.5%.

Wireless power transfer has become an attractive energy solution to increase the autonomy and supply power to the Micro Aerial Vehicles (MAV) without wired connection. This paper proposes microstrip antennas at 5.8 GHz for microwave wireless power transmission system to a MAV.A single patch antenna is designed for transmitter array with a gain of 5.2dB while a circular polarized patch antenna is designed for rectenna array with a directivity of 6.1dB and an axial ratio of 0.314dB. These antennas are designed, optimized and simulated by using FEKO EM simulation software.