Circularly Polarized Antenna Array Research Articles

Two‐port circular polarized antenna array for point‐to‐point communication

ABSTRACTA two‐port circular polarization (CP) array antenna is presented in this article. The proposed antenna used two‐port which each port is designed with 2 × 2 array structure and both array consist of four circular radiating elements. The used of 90° triple‐coupled phased shift polarizer at both left and right side of circular‐slotted patches with two‐port generate CP aptitude with high gain performance. Moreover, the presence of slots at center of circular elements produce discontinuity effect to assist change in the E‐field and H‐Field rotation of RF current and force the current to flow in CP. Axial ratio of 1.95 dB confirms the CP capability. Nonetheless, the proposed antenna demonstrates a good characteristic for MIMO's isolation with mutual coupling of −55.0 dB (S12) and −45.1 dB (S21), correlation coefficient of 1.2015e‐4 and diversity gain (Gapp) of 9.9999. The proposed antenna also produced gain as high as 13.23 dB for both port. With those capabilities, the antenna designed is suitable for 5.8 GHz point‐to‐point communication. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2328–2332, 2015

Mutual coupling efficient analysis of rectangle microstrip circular polarization antenna array

Mutual coupling performance of the microstrip circular polarization (CP) antenna array is analyzed in this study. Compared with the single antenna application, in the antenna array, the S11, the radiation pattern, and the axial ratio will all be changed due to the mutual coupling and the axial ratio will be more sensitive. To further prove the concept and performance effect, a model of the microstrip antenna array is developed and analyzed in theory. The simulation and measurement results demonstrate that the relative position of antennas in the array exert different effect on the performances of the antenna. Thus, the study provides some very useful results of the CP antenna array.

Mimo circular polarization array antenna with dual coupled 90° phased shift for point‐to‐point application

ABSTRACTThis article presented a circle‐segmented multiple‐input‐multiple‐output (MIMO) circular polarization (CP) array antenna with dual coupled 90° phased shift for 5.8 GHz Point‐to‐Point application. Convergence of CP capability within MIMO array antenna is successfully realized by two array of four circular‐segmented patch array radiating element that are fed by two RF ports. The MIMO CP array antenna with high gain performance is obtained through the dual coupled 90° phased shift that is connected to each circle‐segmented patch. The dual coupled 90° phased shift ensure the E‐field of circle‐segmented patches function is in 90° phase difference to the initial signals. Similarity between azimuth and elevation plane with axial ratio of 1.9 dB verified the proposed antenna's CP capability. In the mean time, correlation coefficient (ρ) of 1.2015 e − 4, diversity gain (Gapp) of 9.9999, S21 of −45.1 dB show the good isolation quality of the antenna in MIMO structure. The gain of 14.6 dB for each port is also recorded. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:809–814, 2015

Modeling of Efficient Circular Polarized Rectenna Design for Microwave Power Transmission at 2.45GHz

This paper presents a planar rectenna (rectifier + antenna) design at 2.45 GHz ISM band for microwave power transmission for powering devices involving low power consumption, located in unreachable area or needing expensive maintenance costs. The proposed design incorporate a 3×3 circular polarized antenna array with an enhanced directivity of 9.14 dBi and an overall size of 26.18×11.86 cm² modeled by using CST Microwave Studio software, and associated to a microstrip rectifier based on a voltage doubler circuit with HSMS 2822 Schottky diode designed and simulated by using schematic simulation in ADS. A high conversion efficiency of 71% and a DC output voltage of 10V can be reached for a given input power level of 20 dBm with an optimum load of 1500 Ω.

A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array forC-Band Applications

A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in theC-band. The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas. The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization. Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area. A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm2. Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio. Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth.

Improvement on a 2 × 2 Elements High-Gain Circularly Polarized Antenna Array

A novel antipodal Vivaldi antenna with tapering serrated structure at the edges is proposed. Compared with traditional Vivaldi antennas without serrated structure, the gain of the designed antenna is significantly improved in the desired frequency band (4.5–7.5 GHz). In addition, a 2 × 2 Vivaldi antenna array with an orthorhombic structure is designed and fabricated to achieve a circular polarization (CP) characteristic. With this configuration, the 3 dB axial ratio bandwidth of the array reaches about 42% with respect to the center frequency of 6 GHz and a high gain is achieved as well. The novel Vivaldi antenna and CP antenna array both have ultrawide band (UWB) and high-gain characteristics, which may be applied to the field of commercial communication, remote sensing, and so forth.

A novel single feed of circular polarized antenna and open area test site measurements for 2.4 GHz application

ABSTRACTA novel single feed of the truncated edge circular polarized array antenna for 2.4 GHz applications with high gain is analyzed and proposed. The presented circular polarized antenna is comprised of four patches as its radiating elements and fed by a single coaxial connector at the ground layer. Dimension‐wise, the proposed antenna is designed with compact size of 56 × 69 × 1.6 mm3. It is notified that 45° of patches' truncated edge, 45 mm element spacing of Y‐axis, and 39.5 mm element spacing of X‐axis collectively contribute to the circular polarization capability. The prototype of the antenna has a right‐hand circular polarization with an axial ratio of 2.019 in particular of 2.4 GHz. Additionally, the similarity patterns of E‐plane and H‐plane of the antenna prove its circular polarization capability. Further, the proposed antenna seems to have an omnidirectional pattern eventhough using a full ground plane and improved the effective coverage angle. With the measured gain of 5.35 dB and the reflection coefficient of −14.16 dB, the proposed antenna has big potential for Wi‐Fi and biomedical application. The antenna prototype performance is verified, and the experimental result is presented and discussed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1337–1344, 2014

Radiation Efficiency Improvement Method for Multifeed Circular Polarization Antenna Array with Mutual Coupling Effect

In the circular polarization antenna array, the input impedance, axial ratio, and radiation pattern of antenna patch will be changed. Compared with the performances of single antenna, the mutual coupling also led to the low efficiency of all antennas. A novel radiation efficiency elevation method of multifeed circular polarization (CP) antenna array is demonstrated in this paper, in order to solve the problem. To prove the concept of novel method, dual-feed antenna with stubs is developed and fabricated. According to the measured results, each antenna would increase in efficiency by approximate 1dB by applying this novel design method. Therefore, this paper provides dramatically useful results of lessening the negative effect resulting in mutual coupling.

60-GHz Circularly Polarized Antenna Array Made in Low-Cost Fabrication Process

Circularly polarized (CP) antenna operating in the unlicensed 60 GHz frequency range is useful for millimeter-wave radio and radar applications. In this letter, a 2 × 2 right-handed circularly polarized (RHCP) planar array is demonstrated by using four CP antenna elements. A single element has a gain of 7.5 dBiC, while the resulting 2 × 2 array yields a CP gain of 12.5 dBiC. Substrate integrated waveguide (SIW) cavity is used to back each element in order to reduce the mutual coupling between elements and also improve the overall gain. An experimental antenna prototype made through a conventional low-cost printed circuit board (PCB) technique operates in RHCP mode covering the frequency range of interest from 58 to 62 GHz. The antenna is compact, showing a good radiation performance.

Bandwidth- and Gain-Enhanced Circularly Polarized Antenna Array Using Sequential Phase Feed

A technique is developed in this letter to enhance the impedance and axial-ratio (AR) bandwidths as well as broadside gain of a sequential phase (SP) feed 2 × 2 patch array. The proposed antenna is composed of a probe-fed patch, a 2 × 2 corner truncated patch array with a loop, and a slotted metal wall surrounding the feeding structure. The proposed antenna combines the attractive features such as wide impedance and AR bandwidths, low profile, and easiness of design and manufacture. The antenna operating at 5-GHz band is designed and fabricated with overall volume of 1.5 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×1.5 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.06 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> . Measured results show that the antenna array achieves an impedance bandwidth of about 20.8% for |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> |<;-10 dB, a 3-dB AR bandwidth of about 17.6%, a peak gain of 11.5 dBi, and a 3-dB gain bandwidth of 13%, which is completely within the impedance and AR bandwidths.

Wideband Beam-Scanning Circularly Polarized Inclined Slots Using Ridge Gap Waveguide

A wideband circularly polarized (CP) frequency-dependent slot antenna array is designed for beam scanning using the ridge gap waveguide (RGW) technology. The merge between both the printed and the RGW technologies for providing a wideband CP antenna array is newly implemented here. The designed CP antenna has been fabricated, and measurement results are provided and compared to the full-wave analysis. A measured antenna axial ratio (AR) and impedance bandwidths of ~ 21% are achieved from 12.5 to 15.5 GHz. The proposed antenna preserves its CP characteristics of AR below 3 dB while achieving continuous frequency beam scanning from backward to forward directions including broadside radiation that covers +15° to -15° with an average gain of 12.5 dBi.

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.

High-Performance Circularly Polarized Antenna Array Using Metamaterial-Line Based Feed Network

This communication presents a 2 × 2 circularly polarized (CP) antenna array composed of H-shaped patches. The uniqueness of this CP array is its feeding network, where state-of-the-art metamaterial transmission lines (MMLs) are built to obtain the required quadrature phases. Experimental results show that the feed network has excellent power distribution and progressive phases over a wide bandwidth. As a consequence, the MML-based array exhibits excellent performance, viz. 85% impedance bandwidth (SWR ≤ 2), 89% axial-ratio (3-dB) bandwidth, 80% efficiency at a center frequency of 2.5 GHz and 55% pattern bandwidth with a criterion of 8-dBic gain level. The axial-ratio bandwidth is validated with cross-polar discriminations obtained from radiation patterns.

Circularly Polarized Ultra-Wideband Radar System for Vital Signs Monitoring

A robust contactless vital signs monitoring system using circularly polarized ultra-wideband (UWB) radar is presented. The design of the proposed UWB radar system is based on a time-expanded correlation architecture. The circularly polarized antenna array of the radar has an axial ratio bandwidth from 3 to 10 GHz. Use of circular polarization has demonstrated improved accuracy for vital signs monitoring.

Broadband Circularly Polarized Beam-Steering Antenna Array

A wideband circular polarized (CP) switched-beam patch antenna array is presented in this communication. The switched-beam system consists of four two-section branch-line couplers, two wideband 45 phase shifters and 1 × 4 proximity-coupled L-probe feeding CP microstrip patch antenna array. With such an arrangement, the proposed array can obtain a wide axial ratio (AR) bandwidth than that of conventional switched-beam CP antenna array. Measured results showed this array has an impedance bandwidth over a frequency range of 4.04-5.78 GHz (~36%) for |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | <; -10 dB and AR bandwidth from 4.3 to 5.75 GHz (~29%) for AR <; 3dB when the main beam of array is scanned to different four directions.

A Circularly-Polarized Array Antenna Using Linearly-Polarized Sub Grid Arrays for Highly-Integrated 60-GHz Radio

In this communication, we present a new circularly-polarized array antenna using 2×2 linearly-polarized sub grid arrays in a low temperature co-fired ceramic technology for highly-integrated 60-GHz radio. The sub grid arrays are sequentially rotated and excited with a 90°-phase increment to radiate circularly-polarized waves. The feeding network of the array antenna is based on stripline quarter-wave matched T-junctions. The array antenna has a size of 15×15×0.9 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . Simulated and measured results confirm wide impedance, axial ratio, pattern, and gain bandwidths.

Low-Profile Dual Circularly Polarized Antenna Array for Satellite Communications in the X Band

A planar antenna is introduced that works as a portable system for X-band satellite communications. This antenna is low-profile and modular with dimensions of 40 × 40 × 2.5 × cm. It is composed of a square array of 144 printed circuit elements that cover a wide bandwidth (14.7%) for transmission and reception along with dual and interchangeable circular polarization. A radiation efficiency above 50% is achieved by a low-loss stripline feeding network. This printed antenna has a 3 dB beamwidth of 5°, a maximum gain of 26 dBi and an axial ratio under 1.9 dB over the entire frequency band. The complete design of the antenna is shown, and the measurements are compared with simulations to reveal very good agreement.

Experimental Study on Increasing the Received Power of Antenna using Circularly-Polarized Array Antenna

A method to increase the received power of an antenna system by combining polarization, space and frequency diversities is investigated in this paper. The antenna system under investigation consisted of an array of 10 microstrip antenna elements. Each antenna element is a microstrip antena with circular polarization. Two array antennas with circularly polarized elements have been designed for receiving eloctromagnetic energy in 900 MHz and 1800 MHz band. Laboratory measurement has been conducted to study the increase of antenna received power caused by combining space, polarizarion and frequency diversities. Results show that the proposed method is able to increase the received power by 12.9 dB at 900 MHz and by 8.4 dB at 1800 MHz in an indoor environment; and by 15.8 dB at 900 MHz and by 9.5 dB at 1800MHz. This increase is mainly contributed by the use of space diversity, namely the use of array of 10 elements which contributed to increase the received power by 10.3 dB in an indoor environment. The useof circularly-polarized element increased the received power by 2.6 dB. Of the three diversities proposed, frequency diversity was found to have the least significant contribution becase the received power from 1800 MHz band is smaller than the 900 MHz band. DOI: http://dx.doi.org/10.11591/ijece.v2i2.209 Full Text: PDF

A Circularly Polarized Array Composed of Linear Polarized Microstrip Patches Fed by Metamaterial Transmission Line

A novel single-feed circularly polarized antenna array is constructed by a 2 × 2 array of four square linear polarized microstrip patches with orthogonal orientation and phase shift of 90° in between. The sequential rotation and suitable phasing of linear polarized microstrip patches improve the radiation pattern symmetry and input impedance matching of the array antenna. A metamaterial transmission line is designed and applied to feeding the antenna array. The metamaterial transmission line works at its zeroth order resonant mode and there is no phase shift between its four output ports. A circularly polarized antenna array at 5.8 GHz is built and demonstrated, which is fed by the metamaterial transmission line. The antenna array is compact and the whole dimension is about 1.1λ g 2. The antenna gain reaches 9 dBi, and shows a good axial ratio. Experimental results and simulation agree well.

A Novel Design of Wideband Circular Polarization Antenna Array with High Gain Characteristic

A broadband of circularly polarized (CP) patch antenna fed by L-probes has been presented in this paper. In order to improve axial ratio bandwidth, wideband 90° hybrids with two L-probe feeds are used as feeding netwok, and cones act as radiator instead of common circular patch. A total of 6 array elements are used in a 2 × 3 configuration to achieve a maximum gain target of 14 dBi. However, it will enlarge the overall size of the antenna. The feeding network is located on the lower side of the substrate for compacting the size. The measured results agree well with simulations, indicating that the antenna array possesses an impedance (VSWR < 2) bandwidth of 42% and axial ratio (AR < 3 dB) bandwidth of 47.6%. In addition, the 8-dB gain bandwidth and peak gain are 55% and 14 dBi, respectively.