CPW-fed Circularly Polarized Slot Antenna with Small Gap and Stick-shaped Shorted Strip for UHF FRID Readers

Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 181-188
Author(s):  
Chien-Yuan Pan ◽  
Chum-Chieh Su ◽  
Wei-Lin Yang

Abstract A new circularly polarized (CP) slot antenna with a small gap and a stick-shaped shorted strip is presented. The proposed antenna has a sufficient bandwidth for ultrahigh frequency (UHF) radio-frequency identification (RFID) reader applications. The antenna structure consists of a rectangular slot with a small gap, a stick-shaped shorted strip and a 50 Ω coplanar waveguide (CPW) feedline with an asymmetrical ground plane. By using the stick -shaped shorted strip to disturb magnetic current distribution on the slot, the CP radiation can be generated. The measured results demonstrate that the proposed antenna can reach a 10 dB return loss impedance bandwidth of 14.1 % (894–1030 MHz) and a 3 dB axial ratio (AR) bandwidth of 6.4 % (910–970 MHz). The whole antenna size is 80 × 80 × 1.6 mm3.

2021 ◽  
Vol 36 (5) ◽  
pp. 589-595
Author(s):  
Canjie Chen ◽  
Quanyuan Feng

A novel compact printed broadband circularly polarized slot antenna is proposed in this paper. The antenna consists of an inverted L-shaped coplanar waveguide feed structure and a square ground plate loaded with three rectangular slots. The antenna achieves good impedance matching and circular polarization characteristics by adjusting the size of the L-shaped band and the rectangular slot. The simulation results show that the antenna has a 10-dB impedance bandwidth of 1360 MHz (690-2050 MHz) and a 3 dB axial ratio (AR) bandwidth of 490 MHz (770-1260 MHz). Additionally, the maximum gain reached 4.02 dBi. The antenna proposed in this paper can be applied to UHF RFID and GPS frequency bands.


2021 ◽  
Vol 17 (1) ◽  
pp. 1-11
Author(s):  
Vijay Sharma ◽  
Tejpal Jhajharia

Abstract The article proposes design investigation and experimental results of a coplanar waveguide (CPW) fed square slot antenna that gives wideband circular polarization. This circular polarization characteristic is achieved by embedding a square shape stub to left bottom corner and an L-shaped strip to the right upper corner of the slot. A high impedance bandwidth of 87.8 % (3.6–9.0 GHz), a wide axial ratio bandwidth of 73.05 % (4.2–9.0 GHz) and wide 3-dB axial ratio beamwidth of 90° in the entire frequency range of interest are achieved with this antenna structure. To improve the 3-dB axial ratio bandwidth, three slots (two horizontal and one vertical) are scratched at the exterior periphery of the ground plane. These perturbation assemblies are accountable to excite orthogonal modes and help increase an axial ratio bandwidth. The designed antenna displays the constant and steady radiation patterns in the complete frequency range of concern. The overall dimension of the presented compact antenna is 0.24λ × 0.24λ × 0.01λ.


2020 ◽  
Vol 12 (5) ◽  
pp. 431-436
Author(s):  
Kapil Saraswat ◽  
Trivesh Kumar ◽  
A. R. Harish

AbstractIn this paper, a wideband circularly polarized corrugated G-shaped grounded ring slot antenna is presented. The proposed antenna structure is excited using a coplanar waveguide-fed monopole antenna, which is placed inside a corrugated G-shaped grounded ring. Due to the asymmetry in the ground plane, two orthogonal modes, having equal magnitude and out of phase by 90° are excited, resulting in circular polarization (CP). The generation of the CP in the proposed antenna structure is explained using thin dipole current element approximation. A prototype of the proposed antenna is fabricated and tested. The measured results exhibit a 3 dB axial ratio bandwidth of 37.6% (2.22–3.25 GHz), and reflection coefficient bandwidth (|S11| ≤ −10 dB) of 47.91% (2.13–3.47 GHz). Additionally, the design guidelines are also presented for G-shaped grounded ring slot antennas.


Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 651-655 ◽  
Author(s):  
Yilin Liu ◽  
Kama Huang

Abstract A novel design of a coplanar waveguide (CPW) feed antenna array with circular polarization (CP) and a high front-to-back ratio is described. The proposed CP array is achieved by using a compact CPW–slotline transition network etched in the ground plane. The measured results show that this kind of feeding method can improve the impedance bandwidth, as well as the axial ratio bandwidth of the CP antenna array and provide adequate gain. The proposed array can achieve a 6.08% impedance bandwidth and a 4.10% CP bandwidth. Details of the antenna design and experimental results are presented and discussed.


A wideband coplanar waveguide (CPW) antenna with circular polarization characteristics using modified ground slot is studied in this work. Proposed design incorporates a hexagonal slot instead of rectangular slot, accounting for enhanced impedance matching. This ground slot is energized by a 50Ω feed line, resulting in excitation of two orthogonal phase quadrature modes (even-odd modes). Thus, fulfilling the essential criteria required for realizing circular polarization. A narrow horizontal slit (lg) is embedded in the ground plane at immediate left of feed line, accounting for wideband characteristics. 10dB impedance bandwidth of proposed antenna extends from 2.65- 5.60 GHz, while 3dB axial ratio bandwidth extends from 3.90- 5.80 GHz. Hence, overlapping bandwidth of proposed antenna extends from 3.90 - 5.60 GHz. RHCP characteristics with monopole radiation pattern makes proposed antenna useful for WLAN, radio navigation and radiolocation applications.


Author(s):  
Amrita Gorai ◽  
Bappadittya Roy ◽  
G. K. Mahanti

A compact circularly polarized CPW-fed slot antenna is proposed here. The antenna consists of a pentagonal patch within an asymmetrical slot with a single coplanar waveguide feed. The proposed antenna is excited with CPW feed mechanism and investigated experimentally. The structure is fabricated on FR4 epoxy substrate with a permittivity of 4.4. The impedance bandwidth of 10[Formula: see text]GHz (4[Formula: see text]GHz to 14[Formula: see text]GHz) and the axial ratio bandwidth of 1.2[Formula: see text]GHz with the corresponding fractional bandwidth of 113%. The simulation results fulfil the bandwidth requirements of IEEE 802.11a (5.15–5.35[Formula: see text]GHz/5.47–5.725[Formula: see text]GHz) for wireless applications. In terms of bandwidth, compactness and circular polarization comparable results between simulated and measured results clearly show the validity of the proposed structure.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Rongling Jian ◽  
Yueyun Chen ◽  
Taohua Chen

In this paper, a novel wideband circularly polarized (CP) millimeter wave (mmWave) microstrip antenna is presented. The proposed antenna consists of a central patch and a microstrip line radiator. The CP radiation is achieved by loading a rectangular slot on the ground plane. To improve the 3-dB axial ratio bandwidth (ARBW), two symmetric parasitic rectangular patches paralleled to a central patch and a slit positioned to the right of the central patch are loaded. To verify this design, the proposed antenna is fabricated with a small antenna of 2.88 × 3.32 × 0.508 mm3. The measured impedance bandwidth (IMBW) for S11<−10 dB of the proposed antenna is 35.97% (22.8 to 33.8 GHz). Meanwhile, the simulation result shows that the 3-dB ARBW is 15.19% (28.77 to 33.5 GHz) within impedance bandwidth, and the peak gain is from 5.08 to 5.22 dBic within 3-dB ARBW. The proposed antenna is suitable for CP applications in the Ka-band.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dalia M. Elsheakh ◽  
Magdy F. Iskander

This paper describes the design and development of a triband with circularly polarized quasi-Yagi antenna for ka-band and short range wireless communications applications. The proposed antenna consists of an integrated balun-fed printed dipole, parasitic folded dipole and a short strip, and a modified ground plane. The antenna structure, together with the parasitic elements, is designed to achieve circular polarization and triband operating at resonant frequencies of 13.5 GHz, 30 GHz, and 60 GHz. Antenna design was first simulated using HFSS ver.14, and the obtained results were compared with experimental measurements on a prototype developed on a single printed circuit board. Achieved characteristics include −10 dB impedance bandwidth at the desired bands, circular polarization axial ratioAR<3 dB, front to back ratio of 6 dB, gain value of about 4 dBi, and average radiation efficiency of 60%. The paper includes comparison between simulation and experimental results.


2018 ◽  
Vol 11 (2) ◽  
pp. 182-189 ◽  
Author(s):  
Shilpee Patil ◽  
Anil Kumar Singh ◽  
Binod Kumar Kanaujia ◽  
R. L. Yadava

AbstractThis paper presents a compact microstrip antenna using FR-4 substrate for dual band circularly polarized operation using a modified square ring slot in the ground plane with microstrip line feed. Simulation of the impedance characteristic and radiation characteristic for the proposed antenna is carried out using commercially available HFSS software. The simulated data validate measured results and shows good agreement. Proposed antenna shows an impedance bandwidth (return loss >10 dB) of 50.88% at 5.9 GHz of center frequency and 29.92% at 12.8 GHz of center frequency for lower and upper band, respectively. The 3 dB axial ratio bandwidth for lower and upper band is 26.4 and 3.0%, respectively and measured peak gain for the lower and upper band is found as 3.2 and 3.4 dBic, respectively. The proposed antenna can be suitable for wireless communication in C and Ku bands.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Biao Li ◽  
Yang Ding ◽  
Ying-Zeng Yin

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.


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