CP Antenna Research Articles

Single-Fed CP Antenna With Abrupt Sense Reversal for GNSS and SATCOM Application

Single-Fed CP Antenna With Abrupt Sense Reversal for GNSS and SATCOM Application

Polarization converter integrated millimeter wave MIMO antenna for dual CP generation

This article provides a novel technique of generating both RHCP and LHCP waves from a CPW fed MIMO antenna over a wide frequency range 24.6–28.2 GHz by integrating it with a metasurface. The metasurface is designed as a broadband reflective cross-polarization converter working from 23–32.6 GHz. The metasurface is placed 1 mm below the MIMO antenna constituting orthogonally placed antenna elements. The impinging electromagnetic waves from the linearly polarized antenna are converted into circularly polarized waves when they get reflected from the metasurface and interfere with the radiated waves from the antenna. In order to decipher the underlying modal behaviours of the metasurface, characteristic mode analysis is utilized. Due to orthogonal orientation of the antennas, oppositely placed antennas exhibit the same type of polarization conversion while adjacently placed antennas exhibit opposite type of polarization conversion. This results in generation of both RHCP and LHCP waves from different elements of the MIMO antenna using the same metasurface at 5 G frequencies registering an axial ratio bandwidth (ARBW) of 15.3%. With a diversity gain (DG) of better than 9.96 and an envelope correlation coefficient (CC) of less than 0.015, the proposed CP antenna exhibits strong MIMO performance. Prototypes of the antenna and the metasurface have been fabricated and measured for validating the simulated results.

A circularly polarized graphene based wideband 1 × 2 array antenna for terahertz spectrum applications

A graphene-based 1 × 2 array antenna with circular polarization for terahertz applications is prescribed in this article. Initially, a novel concept of a folded quarter wave impedance transformer is utilized in the design process of a single element for minimizing the overall antenna size. The opposite corners of the patches have been truncated and structural modifications are performed with the insertion of four flower-shaped slots along with an additional circular slot for achieving a much-improved reflection coefficient and better impedance bandwidth. It also shows a much wider 3 dB axial ratio bandwidth, confirming circular polarization due to the suggested modifications in its geometry. Then, an array antenna has been formed to provide better gain. The configured patches are fed by a magic-T power divider to attain the required impedance matching. The results of the CP antenna array have been analyzed using the HFSS and CST simulators. The propounded 1 × 2 array antenna shows circular polarization with a 3 dB AR bandwidth of 205 GHz (2.345–2.55 THz) and wide spectral coverage of 210 GHz (2.345 − 2.555 THz) along with a maximum gain of 8.65 dB and 99.8 % radiation efficiency with a total size of 53.5 × 102 × 1.56 μm3. It could be utilized for high-speed data transmission, material characterization, terahertz spectroscopy, terahertz imaging, etc. applications.

425 Ghz Highly Compact On-Chip Sequential-Phased CP Antenna With 19% Overlapped Impedance-AR Bandwidth

425 Ghz Highly Compact On-Chip Sequential-Phased CP Antenna With 19% Overlapped Impedance-AR Bandwidth

A new broadband cross-dipole CP antenna with modified square-cavity reflector

ABSTRACTA new broadband cross-dipole CP antenna with modified square-cavity reflector is proposed in this work. The cross-dipole CP antenna is composed of four rotated L-shaped patches, a pair of vacant-quarter feeding loops as sequential-phase feeding network, two modified trapezoid-microstrip lines as impedance tuner, and a square-cavity reflector with four parasitic strips. Different from the traditional vacant-quarter rings, the modified vacant-quarter loops with trapezoid-microstrip lines are utilized to increase the impedance bandwidth (IBW) and provide 90° phase difference. First, the rotated L-shaped patches are used to obtain wide CP operation. Second, a square-cavity reflector is utilized for enhancing the radiation gains. Moreover, four parasitic strips are inserted into the reflector to increase the CP bandwidth. Therefore, multiple CP resonant points could be stimulated simultaneously by fully utilizing these elements, resulting in a wide CP performance. Finally, the proposed cross-dipole CP antenna has a wider −10 dB IBW of 100% (1.0–3.0, 2.0 GHz), broader 3-dB ARBW of 71.2% (1.25–2.65, 1.95 GHz), and a higher radiation gain, which can cover the WiBro (2.3–2.39 GHz) and GPS (L1 1.575 GHz) bands.

Analysis and Optimization of CP Antenna Covered by Thermal Protection System for Broadband Applications

Analysis and Optimization of CP Antenna Covered by Thermal Protection System for Broadband Applications

Design a Dual Polarizations MIMO Antenna Based on Decoupling Elements for 5G Smart-Phones

This paper suggests a compact linear and circular polarization MIMO antenna for sub-6 GHz 5G smartphones. The proposed design can be divided into three parts: Firstly, a linear polarized dipole antenna is presented with dimensions of 1×33.7×32.5mm3 and exhibits an impedance bandwidth (IBW) of 3.24GHz ranging from 3.3GHz to 6.6GHz at S11˂-10dB. The second part includes a circular polarization CPW-Fed antenna with dimensions of 1×23.2×30mm3. The IBW of the CPW antenna is more than 4GHz, starting from 3.9GHz to more than 8GHz at an S11˂-10dB. The 3-dB axial ratio for the CP CPW antenna ranges from 4GHz to 7.38GHz. Finally, a combination of LP and CP antennas is presented to form a dual polarization MIMO system. A MIMO system consists of 5 elements; 4 elements are LP and 1 element is a CP antenna. The size of the MIMO system is 1×82.5×150mm3 printed on an FR-4 substrate. Two impedance bandwidths are found due to the use of two antenna types. The first one (S11, S22, S44, S55) equals 3.44GHz while the second (S33) equals 4.33GHz. HFSS is used for designing and simulating the proposed structures, while CST is used for verifying the results.

Design and Analysis of Circular Polarized Two-Port MIMO Antennas with Various Antenna Element Orientations

This article presents the circularly polarized antenna operating over 28 GHz mm-wave applications. The suggested antenna has compact size, simple geometry, wideband, high gain, and offers circular polarization. Afterward, two-port MIMO antenna are designed to get Left Hand Circular Polarization (LHCP) and Right-Hand Circular Polarization (RHCP). Four different cases are adopted to construct two-port MIMO antenna of suggested antenna. In case 1, both of the elements are placed parallel to each other; in the second case, the element is parallel but the radiating patch of second antenna element are rotated by 180°. In the third case, the second antenna element is placed orthogonally to the first antenna element. In the final case, the antenna is parallel but placed in the opposite end of substrate material. The S-parameters, axial ratio bandwidth (ARBW) gain, and radiation efficiency are studied and compared in all these cases. The two MIMO systems of all cases are designed by using Roger RT/Duroid 6002 with thickness of 0.79 mm. The overall size of two-port MIMO antennas is 20.5 mm × 12 mm × 0.79 mm. The MIMO configuration of the suggested CP antenna offers wideband, low mutual coupling, wide ARBW, high gain, and high radiation efficiency. The hardware prototype of all cases is fabricated to verify the predicated results. Moreover, the comparison of suggested two-port MIMO antenna is also performed with already published work, which show the quality of suggested work in terms of various performance parameters over them.

Beamwidth-Reconfigurable Circularly Polarized Slot Antenna Based on Half-Mode Substrate-Integrated Waveguide

Beamwidth-reconfigurable antennas are useful for the intersatellite link of low earth orbit formation flying and constellation, as they prevent unauthorized satellites from eavesdropping. In this article, a circularly polarized slot array antenna based on a half-mode substrate-integrated waveguide (HMSIW) for the K-band beamwidth reconfiguration is proposed using a new radio frequency (RF) switch structure and a pair of modified −45° and +45° linearly polarized HMSIW slot arrays for the dual operation of a single-pole double-throw (SPDT)/a power divider (PD) and easy integration with other components, respectively. The RF switch structure consists of a T-junction PD, λ/4 lines, and beam lead PIN diodes with current control resistors and without a DC block circuit for low DC power consumption and size reduction. The −45°/+45° linearly polarized HMSIW slot arrays providing linear and circular polarizations (LP and CP, respectively) are operated for CP. The use of a short-circuited termination instead of dissipative termination results in easier integration with other components because the 16 radiating slots consume most of the input power. The dimension of the beamwidth-reconfigurable antenna including the bottom metal layer is 157.2 × 23.3 × 0.254 mm3 (12.5λ0 × 1.86λ0 × 0.0202λ0). The RF switch for the SPDT shows the insertion losses of 1.8–2.3 and 16.7–24.2 dB and an isolation of 20.9–33.4 dB for both outputs within the 10-dB bandwidth. The RF switch for the PD has an insertion loss of 3.9–4.8 dB. The one- and two-antenna operation modes of the CP antenna provide the gains of 9.44 and 6.99 dBic, the axial ratios of 2.24 and 3.47 dB, and the horizontal beamwidths of 35.8° and 78.2°, respectively.

Low-profile high gain circularly polarized CRLH transmission line inspired antenna with artificial magnetic conductor for wearable applications

AbstractIn this work, a compact, wideband, circularly polarized wearable antenna is proposed using asymmetric coplanar strip feeding for wireless health monitor applications in the ISM frequency band. The proposed antenna consists of a composite right/left transmission line (CRLH TL) inspired structure to achieve compactness and a rectangular ring slot is created in the metallic ground to enhance the CP radiation of the antenna. A 5 × 5 artificial magnetic conductor unit cell-based metasurface is designed which is operating at 2.4 GHz as a ground plane for the CRLH-based CP antenna. Implementation of AMC-based metasurface as a ground plane results in enhancement of radiation characteristics of CRLH TL antenna. The proposed antenna has a small footprint of 50 × 50 mm2 with measured impedance bandwidth of 2.3–3.2 GHz. The 3 dB axial ratio bandwidth of the proposed antenna is 2.36–2.78 GHz with peak gain of 5.89 dBi. Simulation and experimental results show that proposed AMC-based antenna is robust in terms of structural deformation. Further, to validate the performance of the antenna for biomedical applications, we have simulated the proposed antenna with human phantom model. The proposed antenna exhibits stable scattering and radiation characteristics with the phantom body environment and due to the inclusion of AMC structure, the proposed design satisfies maximum specific absorption rate value given as per the IEEE standard safety guidelines.

Dual-Band Circularly Polarized Annular Ring Patch Antenna for GPS-Aided GEO-Augmented Navigation Receivers

A compact, single- feed, dual band, circularly polarized annular ring patch antenna coupled to a cross slot is proposed in this letter for GPS-aided GEO-augmented navigation (GAGAN) receivers covering L band, centered at 1176.45 MHz (L5) and 1575.42 MHz (L1) frequencies. The antenna consists of two annular rings configured by two small strips, which is coupled to a cross slot in the ground plane for gain enhancement. Circular polarization in both the bands is produced by introducing perturbations in outer annular ring and two orthogonal strips in the center space of inner annular ring. The proposed CP antenna radiates LHCP in both the desired frequencies. Two shorting pins are introduced near the feed to improve impedance matching. The simulated and measured reflection coefficient, gain, circular polarization, and axial ratio are in accord with each other. The measured 10 dB bandwidth is 2.7% (1168–1200 MHz) for the L5 and 2.5% (1560–1600 MHz) for L1. The AR bandwidth below 3 dB for the designed antenna is 1.5% (1156–1174 MHz) for L5 and 1% (1556–1572 MHz) for L1.

Erratum to “A Novel Compact CP Antenna with Wide Axial Ratio Bandwidth for Worldwide UHF RFID Handheld Reader”

Erratum to “A Novel Compact CP Antenna with Wide Axial Ratio Bandwidth for Worldwide UHF RFID Handheld Reader”

Compact and Low-Profile Linear-/Circular-Polarization Dielectric Resonator Antennas With Extended Bandwidths

The dielectric resonator antenna (DRA) with wide bandwidth, compact size and low profile is considered as an attractive candidate for 5G wireless communications. However, most of the reported DRAs either have bulky volumes or have limited bandwidths. In this paper, a kind of compact and low-profile DRA with extended bandwidth is proposed. By observing the E-field distribution differences between the two target modes and modifying the dielectric characteristics (such as material and dimension) of the designated region where the E-field is very weak for fundamental TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</sub> mode but quite strong for high-order TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">131</sub> mode, the frequency of TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">131</sub> mode can be significantly affected and shifted down to merge with that of TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</sub> mode which is less affected. As a result, extended operating bandwidth can be obtained. This technique also benefits from not having to enlarge the planar size of the high permittivity DR, therefore making the antenna compact enough for 5G beam-scanning and low profile applications. For demonstration, linear- and circular- polarization antenna prototypes were designed and measured. The LP antenna has a −10 dB impedance bandwidth of 17.3% and a peak gain of 7.1 dBi while the CP antenna achieves a 3-dB axial ratio (AR) bandwidth of 12% and a peak gain of 6.6 dBic. Both the antennas have compact volumes of no larger than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.35{\lambda } _{0} \times 0.35{\lambda } _{0} \times 0.11{\lambda } _{0}$ </tex-math></inline-formula> . Based on the LP and CP antenna elements, two <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times5$ </tex-math></inline-formula> antenna arrays with the capability of beam scanning are designed and simulated. Wide scanning angles of ±45° and ±40° can be obtained for the LP and CP arrays, respectively.

CP Antenna with 2 × 4 Hybrid Coupler for Wireless Sensing and Hybrid RF Solar Energy Harvesting.

The main challenge faced by RF energy harvesting systems is to supply relatively small electrical power to wireless sensor devices using microwaves. The solution is to implement a new device in a circularly polarized rectenna with circular polarization sensitivity integrated with a thin-film solar cell. Its dual-feed antennas are connected to a 2 × 4 asymmetric hybrid coupler and a multi-stage voltage doubler rectifier circuit. This configuration has a 2 × 4 asymmetric hybrid coupler used to produce 4 outputs with a 90-degree waveform phase difference. The two ports can independently be connected to the wireless sensor circuit: radiofrequency harvesting of hybrid energy solar and information equipment can be carried out with these two antennas. The Dual-Feed circular patch antenna has a two-port bandwidth of 137 MHz below −15 dB and an axial ratio of less than 3 dB, with a center frequency of 2.4 GHz with directional radiation and a high gain of 8.23 dB. It can be sensitive to arbitrary polarization of the input voltage multiplier waveform to overcome uncertainty in empirical communication environments. A parallel structure is arranged with a thin film solar cell integration from the transmitter with an output voltage of 1.3297 V with a compact composition and RF energy. The importance of adopting a wireless sensor strategy with circular polarization sensitivity and integrated RF solar energy harvesting rather than a single source method makes this research a significant novelty by optimizing the analysis of multiple wireless sensor signal access.

Half cutting dual-band circularly polarized monopole antenna for wireless communications

In this work, a novel half-cutting technique has been implemented on the CP antenna to enhance the axial ratio bandwidth. The projected antenna is designed on 26mm×14.5mm×1.6mm FR4 substrate with relative permittivity 4.4 and loss tangent 0.02. The proposed patch is developed by loading an L – shaped open-ended slot on the monopole element. The half-cutting technique is incorporated on the ground plane flowed by loading circular-shaped slots and stubs. Results have been improved intensely. The achieved two impedance bandwidth (IBW) are 1.80 GHz (3.6 – 5.4 GHz) and 5.3 GHz (5.7 – 11 GHz) at the −10 dB reflection coefficient. Two 3 dB, ARBW of 0.29 GHz (4.38 – 4.67 GHz) and 4.91 GHz (5.79 – 10.70 GHz) are confirmed. The peak gain of 4.77 dBi at 8.46 GHz is achieved. The RHCP and LHCP waves are radiated along the broadside direction under the lower and higher CP modes. It is strongly applied for military and mobile communication (4.4 – 4.5 GHz), 802.11p WLAN (5.850 – 5.925 GHz), WiFi (5.925 – 7.125 GHz) in the united state, in satellite, DL (7.25 – 7.75 GHz) and UL (7.9 – 8.4 GHz) and X – band applications.

Circularly‐polarized cavity‐backed slot antenna array with simplified feeding structure

A class of circularly-polarized cavity-backed slot antenna arrays with simplified feeding structure are proposed. Power dividing network is an essential feeding structure for the design of conventional antenna arrays, which results in complicated antenna structure. A novel feeding technique based on the electric field of cavity modes is introduced to feed the array elements. The slots on the top wall are directly fed by the electric field without additional feeding structure. Crossed slots with different lengths are introduced to achieve the self-phased CP radiation as they produce different perturbation on the two degenerate cavity modes. Therefore, high efficiency and simple antenna structure of the CP slot antenna array are achieved. Then, two CP slot arrays with 3 × 3 and 8 × 8 elements are presented to show the designed feasibility. Finally, the 3 × 3 CP antenna array is fabricated and measured to validate the design concept, which can achieve 12.6 dBic gain, 94% total efficiency, 80% aperture efficiency, and −25 dB cross polarization.

A novel compact dual‐band circular/linear polarization switchable slot annular antenna with filtering network

A novel compact dual-band circular/linear polarization (CP/LP) switchable slot annular antenna with integrated filtering network is proposed in this paper. The feed network is composed of a couple of stepped impedance resonators (SIR) with favorable dual-band filtering characteristic. The SIR structure loaded with T-shape branches can adjust the center frequency more flexibly especially for dual band operating. A PIN diode is welded on the slot antenna to achieve the transform between the linear polarization and the circular polarization of the filtering antenna. The proposed dual-band CP antenna easily achieves 10 dB impedance bandwidth of 140/180 MHz and 3-dB axial-ratio bandwidth approximating 230/210 MHz at 2.6/4.8 GHz.

Roger 3450 Vs RF4 Martials - Based Frequency And Pattern Reconfigurable Rectangular Patch Slot Antennas For RFID Applications

Rectangular Patch Slot Antennas RPSA are getting becoming more likable and popular for practice in wireless implementations such as RFID applications especially in the UHF band thanks to its low-profile structure. This kind of antenna is able to deliver large communication distances but this antenna coverage is very weak which is part of the main drawbacks of these antennas. In this paper, Rectangular Patch Slot Antenna RPSA with different slots has been designed and simulated to be suitable for RFID applications. Circular polarized CP antenna that has been designed to use feed structure with vertical ground encircling a radiating component. The feeding method to feed this antenna is coaxial probe. The paper will concentration on both substrate materials Roger 4350 and FR4 Glass-Epoxy material to model and simulate the designs. The other factor of the design is the patch antenna will cut at the four truncated corners to enhance the antenna gain which will affect considerably the operating frequency. This paper aims to show and find the best feed point area that has an exceptional antenna return loss (S11) and high gain. S11 describe the power reflected from the antenna, which is known as the reflection coefficient S11 must be ≤ -10dB. The design and simulation results of RPSA has been done by high frequency simulation system (HFSS 13.0).

Wideband Circularly Polarized Antenna With Reconfigurable 2-Dimensional Axial Ratio Beamwidth

This paper proposes a wideband circularly polarized antenna with a reconfigurable 2-dimensional axial ratio. For mobile satellite communication, the low profile CP antenna with wide axial ratio scanning and a wide frequency bandwidth is essential. In this paper, we propose the wideband CP antenna with an axial ratio controller. The axial ratio deteriorates when the difference between transverse modes (TM)01 and TM10 gets larger. Therefore, in the proposed antenna, the axial ratio controller is used to compensate for the difference by controlling the amplitude and phase of the received signals. The proposed antenna has three mode states for the 2-dimensional axial ratio region. In a simulation of the wideband CP antenna, the axial ratio was below 3 dB in the 2-dimensional scanning region from -60° to 60° at every azimuth angle in the 20% factional frequency bandwidth. To verify the proposed antenna with the axial ratio controller, the wideband CP antenna is implemented at 5.8 GHz. A low noise amplifier (LNA) and digital phase shifters are employed for the axial ratio controller. The measured axial ratio was below 3 dB in the 2-dimensional scanning region from -60° to 60° at every azimuth angle in the 20% factional frequency bandwidth.

5.8 GHz Circular Polarized Microstrip Feeding Antenna for Solar Panel Application

Circular polarized microstrip antenna have been proposed to establish connection among distributed solar farms. The base station antenna of each solar farm permits more precise on the targeting the radio signal and usually is placed at the open area or at a height place so that the radio waves to be transmitted will not be interrupted. For this paper, circularly polarized microstrip patch antenna (CPMSA) is designs and being reviewed. The patch antenna is based on low-cost, but lossy, and the substrate is made of Rogers RT 5880 (lossy). It consists of a rectangular radiator patch, which is fed by microstrip transmission line. In order to realized circularly polarized antenna, the patch has undergone some design modification to achieve circular rotation. Some technique is proposed to achieve CP antenna. The results indicate that the antenna that uses micro strip feed line technique yields 8.55 dB directive gain, return loss and axial ratio at -24.4 dB and 2.05 dB respectivel. The resonance frequency of 5.8 GHz is being selected since it is suitable used for point to point communication among distributed solar farms that located far from each others.