Investigation of circular polarization technique in Q-slot antenna

2019 ◽  
Vol 12 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Amer T. Abed ◽  
Mandeep S. J. Singh ◽  
Aqeel M. Jawad
Keyword(s):  
Circular Polarization ◽  
Electric Fields ◽  
Surface Current ◽  
Axial Ratio ◽  
Slot Antenna ◽  
Strip Line ◽  
Resonant Frequencies ◽  
Left Hand ◽  
Low Profile ◽  
A New Technique

AbstractThis paper describes and analyzes a new technique used in Q-slot antenna to generate circular polarization (CP). The CP characteristics were investigated carefully by studying the surface current distribution, the phase difference between the left hand circular polarization (LHCP) and right hand circular polarization (RHCP) at some resonant frequencies, and the measured values of the axial ratio bandwidth (ARBW). Normal arms (E1 and E2) were cut in the upper elliptical feeding strip line to form an open-mouth structure. The arms E1 and E2 were made equal in length and set perpendicular to each other to have normal electric fields, leading to the generation of CP radiation. A formula was modified for the dual resonant frequencies f1, f2 of the modes TM010 and TM001. The measured values of the ARBW indicated that the antenna has a wide ARBW of 4.8–5.93 GHz, which is approximately 52% of the 3rd operating band of 4.7–6.8 GHz. The wide ARBW in a small size indicated that the design of the Q-slot antenna overcame the limits of designing antennas with wide ARBW in small size and low profile. A formula for normalized field was driven according to the complementary of the Q-slot antenna.

A novel single-feed reconfigurable antenna for polarization and frequency diversity

2016 ◽  
Vol 9 (5) ◽  
pp. 1155-1161 ◽  
Author(s):  
Ailar Sedghara ◽  
Zahra Atlasbaf
Keyword(s):  
Circular Polarization ◽  
Simple Structure ◽  
Dual Band ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Frequency Diversity ◽  
Resonant Frequencies ◽  
Frequency Bands ◽  
Left Hand ◽  
Microstrip Feed

A novel dual-band single-feed reconfigurable annular-ring slot antenna with polarization diversity is proposed. This antenna has the ability to switch frequency bands and polarization at the same time whereas applying a simple structure. It consists of two concentric circular slots and two tuning stubs on one side of the substrate and a 50 Ω microstrip feed line and two stubs on the other side. The proposed antenna can be switched between two resonant frequencies, 2.4 GHz (WLAN) and 3.5 GHz (Wimax). Furthermore, it can be switched between linear polarization (LP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP) at the first frequency band, LHCP and RHCP at the second band. All these capabilities are achieved by applying only five PIN diodes on both sides of the substrate. Simulation and experimental results indicate that the proposed antenna demonstrates a good impedance bandwidth at the two frequency bands and satisfactory radiation pattern in five different states.

scholarly journals Single-Arm Archimedean Spiral Antenna with Broadband Circular Polarization

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qingyuan Fang ◽  
Mengzhe Jin ◽  
Weidong Liu
Keyword(s):  
Circular Polarization ◽  
Surface Current ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Strip Line ◽  
Spiral Antenna ◽  
Archimedean Spiral ◽  
Low Frequencies ◽  
Current Path ◽  
Measurement Results

In this paper, a single-arm Archimedean spiral (SAAS) antenna with broadband circular polarization is investigated. Unlike traditional single-arm Archimedean spiral antenna, the antenna arm consists of a hybrid meandered strip line and a smooth arc strip line. Especially at low frequencies, the meandered strip line significantly improves the circular polarization performance by extending the antenna surface current path. The effects of the meandered strip line on the radiation pattern and axial ratio (AR) are studied in detail. To obtain unidirectional radiation, a metallic cavity is added below the SAAS antenna. The measurement results show that the voltage standing wave ratio (VSWR) is less than 2 from 0.88 GHz to 8.82 GHz, which indicates a wide impedance bandwidth of 1 : 10 is realized. A wide AR bandwidth of 1 : 5 is available, that the measured AR is less than 3 dB from 1.6 GHz to 8 GHz.

scholarly journals A Low-Profile Wideband Linear-to-Circular Polarization Conversion Slot Antenna Using Metasurface

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1164 ◽  
Author(s):  
Jian Dong ◽  
Chang Ding ◽  
Jinjun Mo
Keyword(s):  
Circular Polarization ◽  
Satellite Communication ◽  
Axial Ratio ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Polarization Conversion ◽  
Compact Structure ◽  
Low Profile ◽  
Unit Cells ◽  
Linearly Polarized

A new low-profile wideband linear-to-circular polarization conversion microstrip slot antenna based on a metasurface for C-band satellite communication applications is proposed in this paper. The metasurface basically consists of four unit cells with parasitic square cross gaps arranged in a 2 × 2 layout. By loading the metasurface on the microstrip slot antenna, linearly polarized (LP) waves from the source antenna are converted into circularly polarized (CP) waves. Then, by etching three more parasitic square cross gaps in the middle of the metasurface, enhanced impedance bandwidth and axial ratio bandwidth (ARBW) are achieved. Furthermore, an equivalent circuit and a phase analysis are presented to explain how a wide ARBW is realized by the metasurface. A final model with an overall size of 36 × 36 × 3.5 mm3 (approximately 0.65λ0 × 0.65λ0 × 0.06λ0 at 5.5 GHz) was designed and fabricated. The measured S11 bandwidth and 3 dB ARBW were 39.25% from 4.28 GHz to 6.37 GHz and 17.77% from 5.18 GHz to 6.19 GHz, respectively. As a result, the proposed antenna shows great potential for satellite communication applications due to its low profile and compact structure, wide impedance bandwidth, and wide axial ratio bandwidth.

Development and Miniaturized of Circularly Polarization Diversity at Cavity Backed SIW Antenna for X-Band Application

Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 317-320
Author(s):  
Saeid Karamzadeh ◽  
Vahid Rafiei ◽  
Hasan Saygin
Keyword(s):  
Schottky Diodes ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Polarization Diversity ◽  
Circularly Polarized ◽  
Left Hand ◽  
Low Profile ◽  
X Band ◽  
Coaxial Feed ◽  
Good Agreement

Abstract In this work circularly polarization diversity has been achieved by utilizing two Schottky diodes on low profile cavity-backed substrate integrated waveguide (CBSIW). In comparison with other studies in the literature, the size of antenna has been reduced to 0.54λg × 0.76λg by helping a 50-Ohm coaxial feed line. The impedance bandwidth, axial ratio bandwidth and antenna gain are improved to 10.02 %, 5.2 % and 7.68dBi, respectively. In addition, the proposed antenna can generate either a left-hand circularly polarized (LHCP) or a right-hand circularly polarized (RHCP) radiation. The developed antenna was fabricated and tested and the achieved results were in good agreement with the simulated one.

Polarization Reconfigurable Dual-Band Rectangular Slot Antenna

Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 339-351
Author(s):  
Rohit Kumar Saini
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Dual Band ◽  
Slot Antenna ◽  
Pin Diodes ◽  
Rectangular Slot ◽  
Left Hand ◽  
Right Hand ◽  
Lower Band ◽  
The Senses

Abstract A novel dual-band rectangular slot antenna is presented for dual-sense reconfigurable polarization. A W-shaped microstrip feedline and two rectangular parasitic patches are used to obtain dual-band circular polarization. Further, the feedline is modified so that the senses of polarization at the two bands are opposite. By introducing PIN-diodes in the feed lines, polarization can be switched among left-hand circular polarization (LHCP), right-hand circular polarization (RHCP), and linear polarization (LP). A prototype dual-band dual-sense antenna with f01 = 1.9 GHz and f02 = 3.45 GHz is fabricated in a 1.6 mm thick FR4 substrate. The measured circular polarized bandwidths are more than 7.6 % for the lower band and 5 % for the upper band.

A CPW-fed uniplanar dual-band tri-polarization diversity antenna based on PIN diode for the wireless communication

2017 ◽  
Vol 9 (8) ◽  
pp. 1695-1703
Author(s):  
Haixiong Li ◽  
Yunlong Gong ◽  
Jiakai Zhang ◽  
Jun Ding ◽  
Chenjiang Guo
Keyword(s):  
Wireless Communication ◽  
Circular Polarization ◽  
Coplanar Waveguide ◽  
Axial Ratio ◽  
Dual Band ◽  
Slot Antenna ◽  
Reconfigurable Antenna ◽  
Pin Diode ◽  
Left Handed ◽  
The Right

In this paper, a coplanar waveguide (CPW)-fed dual-band uniplanar tri-polarization reconfigurable antenna based on the PIN diode switch is proposed. The proposed antenna can be reconfigured between the linear polarization (LP) and the circular polarization (CP) mode, including both the right-handed circular polarization and left-handed circular polarization simultaneously within the dual operating bands. The central frequencies of the bands are 2.63 and 4.42 GHz, respectively, and the overlapped operating bandwidth is 17.8 and 3.40%. The proposed reconfigurable antenna is a closed-slot antenna fed by the CPW transmission line and the reconfigurable mechanism is to regulate the T-shaped driven stub through switching the PIN diodes on and off. The scattering parameters, axial ratio, radiation pattern, gain, and the radiation efficiency of the proposed antenna are all investigated in the following. The optimized antenna has been fabricated to experimental test, the simulated and the measured results agree well with each other. The lower frequency band of the proposed antenna covers the 2.40 GHz WLAN specification and the upper band can be used for the 5 G communication (4.40–4.50 GHz); therefore it is suitable to be applied in the mobile wireless communication.

A printed wide-beamwidth circularly polarized antenna via two pairs of radiating slots placed in a square contour

2016 ◽  
Vol 9 (3) ◽  
pp. 649-656 ◽  
Author(s):  
Neng-Wu Liu ◽  
Lei Zhu ◽  
Wai-Wa Choi
Keyword(s):  
Ground Plane ◽  
Large Angle ◽  
Axial Ratio ◽  
Dielectric Substrate ◽  
Slot Antenna ◽  
Radiation Patterns ◽  
Circularly Polarized ◽  
Low Profile ◽  
Orthogonal Pairs ◽  
Good Agreement

A low-profile circularly polarized (CP) slot antenna to achieve a wide axial-ratio (AR) beamwidth is proposed in this paper. The radiating patch consists of two orthogonal pairs of parallel slots etched symmetrically onto a ground plane. Firstly, our theoretical study demonstrates that the CP radiation can be satisfactorily achieved at the broadside, when the vertical and horizontal paired-slots are excited in the same amplitude with 90° phase difference. Secondly, the principle of CP radiation of the proposed antenna on an infinite ground plane is described. Through analyzing the spacing between two parallel slots, the |Eθ| and |Eφ| radiation patterns can be made approximately identical with each other over a large angle range. As such, the slot antenna achieves a wide AR beamwidth. After that, the 3 dB AR beamwidth with respect to the size of a finite ground plane is investigated to constitute a practical CP antenna on a finite ground plane. In final, the proposed CP antenna with a 1–4 probe-to-microstrip feeding network is designed and fabricated on a finite ground plane of a dielectric substrate. Measured results are shown to be in good agreement with the simulated ones about the gain, reflection coefficient, AR bandwidth, and radiation patterns. Most importantly, a wide 3 dB AR beamwidth of 126° and low-profile property with the height of 0.036λ0 are achieved.

scholarly journals A Novel Dual-Band Circularly Polarized Rectangular Slot Antenna

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Biao Li ◽  
Yang Ding ◽  
Ying-Zeng Yin
Keyword(s):  
Return Loss ◽  
Coplanar Waveguide ◽  
Surface Current ◽  
Axial Ratio ◽  
Dual Band ◽  
Slot Antenna ◽  
Surface Current Density ◽  
Circularly Polarized ◽  
Rectangular Slot ◽  
Metal Frame

A coplanar waveguide fed dual-band circularly polarized rectangular slot antenna is presented. The proposed antenna consists of a rectangular metal frame acting as a ground and an S-shaped monopole as a radiator. The spatial distribution of the surface current density is employed to demonstrate that the circular polarization is generated by the S-shaped monopole which controls the path of the surface currents. An antenna prototype, having overall dimension 37 × 37 × 1 mm3, has been fabricated on FR4 substrate with dielectric constant 4.4. The proposed antenna achieves 10 dB return loss bandwidths and 3 dB axial ratio (AR) in the frequency bands 2.39–2.81 GHz and 5.42–5.92 GHz, respectively. Both these characteristics are suitable for WLAN and WiMAX applications.

A Polarization Reconfigurable Slot Antenna with a Novel Switchable Feeding Network

Frequenz ◽  
2017 ◽  
Vol 72 (1-2) ◽  
Author(s):  
Peng Xie ◽  
Guang Ming Wang
Keyword(s):  
Circular Polarization ◽  
Microstrip Line ◽  
Slot Antenna ◽  
Transition Structure ◽  
Detailed Design ◽  
Left Hand ◽  
Design Considerations ◽  
Right Hand ◽  
5 Ghz

AbstractA polarization reconfigurable slot antenna is proposed in this paper. The antenna consists of a microstrip line-to-slotline transition structure, two radiation slots and a switchable feeding network. The feeding network is a gradually changed ring slot with six switching diodes on it. By controlling the diodes states, the antenna can generate y-direction polarization, z-direction polarization, left-hand circular polarization and right-hand circular polarization. Detailed design considerations of the proposed antenna, simulated and measured results are presented and discussed. Measured results agree well with simulated. The results proved that the antenna can realize polarization reconfiguration effectively at 5 GHz.

scholarly journals Dual Circularly Polarized Planar Four-Port MIMO Antenna with Wide Axial-Ratio Bandwidth

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5610
Author(s):  
Sachin Kumar ◽  
Gwan Hui Lee ◽  
Dong Hwi Kim ◽  
Hyun Chul Choi ◽  
Kang Wook Kim
Keyword(s):  
Circular Polarization ◽  
Multiple Input Multiple Output ◽  
Vector Current ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Circularly Polarized ◽  
Mimo Antenna ◽  
Left Hand ◽  
Input Multiple Output ◽  
Polarization Mechanism

A broadband compact-sized planar four-port multiple-input–multiple-output (MIMO) antenna with polarization diversity is presented. The proposed dual circularly polarized (CP) MIMO antenna consists of four G-shaped monopole elements, two of which are left-hand CP and the other two are right-hand CP. A vertical line strip in the G-shaped radiating element acts in balancing the vertical and horizontal electric field components to obtain 90° phase difference between them for circular polarization. Also, an I-shaped strip is incorporated between the ground planes of the G-shaped antenna elements to obtain equal voltage level in the proposed MIMO configuration. The dual circular polarization mechanism of the proposed MIMO/diversity antenna is analysed from the vector current distributions. The impedance bandwidth (S11 ≤ –10 dB) of the MIMO antenna is 105.9% (4–13 GHz) and the 3 dB axial ratio bandwidth (ARBW) is 67.7% (4.2–8.5 GHz), which is suitable for C-band applications. The overall size of the MIMO antenna is 70 × 68 × 1.6 mm3, and the minimum isolation between the resonating elements is 18 dB. The envelope correlation coefficient is less than 0.25, and the peak gain within the resonating band is 6.4 dBi.

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