Antenna Model Using Circularly Polarized Elements from Total Gain and Polarization Characteristics

Author(s):  
John N. Spitzmiller
Author(s):  
Anil Badisa ◽  
B T P Madhav ◽  
B Prudhvi Nadh

A compact wearable textile antenna with multiband and circular polarization characteristics is proposed in this work for Wireless Body Area Networks (WBAN). An asymmetrically connected vertical stub as a radiator with the partial ground for quad-band (3.03–3.76[Formula: see text]GHz, 5.48–6.24[Formula: see text]GHz, 7.10–7.40[Formula: see text]GHz, 7.93–8.22[Formula: see text]GHz) operation and horizontal stubs on the radiator with L-slots in the ground is proposed for the triple band (3.16–3.22[Formula: see text]GHz, 7.25–7.36[Formula: see text]GHz and 7.93–8.08[Formula: see text]GHz) circularly polarized radiation. Jeans fabric is used as substrate with dielectric constant [Formula: see text] and loss tangent ([Formula: see text]). The dimensions of the proposed antenna are [Formula: see text][Formula: see text]mm3. Various conductive fabrics are investigated and analyzed as a radiating element. The proposed jeans antenna provides the gain ([Formula: see text] dB) and radiation efficiency ([Formula: see text]%) for all operating bands. The impact of the human body right arm loading on the antenna has been presented in terms of the reflection coefficient ([Formula: see text]) and gain using the CST Microwave studio simulation environment. The proposed antenna provides stable performance under bending conditions and the SAR values that are under acceptable limits ([Formula: see text][Formula: see text]W/kg for 10[Formula: see text]g of tissue). The flexibility, compactness and radiation properties make it suitable as a wearable textile antenna for off-body communication applications.


A design of a circularly polarized planar antenna array of elliptical patches is presented. The designed prototype has been verified experimentally. Elliptical patches produce circular polarization by using a single feed only. A corporate feed network with quarter-wave transformers are used for uniform excitation of all the array elements. Primary advantages of the presented antenna array are structural simplicity, good circular polarization characteristics and no side lobes. Here, the design example is given for 2×2 elliptical patches at 2.8 GHz. Similar procedure can be extended for more number of array elements at the desired frequency of operation to cater the need of communication systems where circular polarization is essential.


2020 ◽  
Vol 9 (1) ◽  
pp. 41-48
Author(s):  
P. M. Paul ◽  
K. Kandasamy ◽  
M. S. Sharawi

A compact multiband circularly polarized slot antenna is proposed here. An F-shaped microstrip feedline is used to excite the square slot antenna loaded with a U-shaped strip and a split ring resonator (SRR) to generate three circularly polarized bands at 1.5 GHz, 2.75 GHz and 3.16 GHz. A meandered slot is used in the feedline and the U-strip to improve the axial ratio bandwidth (ARBW). The meandered feedline excites the slot to produce resonance at 2.5 GHz. This resonance along with that of the F-shaped feed, loaded SRR and U-strip combine to give rise to three circularly polarized bands which can be tuned depending on the feed, SRR and U-strip dimensions. The orientation of the F-shaped feed decides the sense of polarization of the three circularly polarized bands of the proposed antenna. The proposed antenna is fabricated on a substrate of FR4 material with dimensions 50 x 50 x 1.56 mm3. The antenna is prototyped and measured in terms of impedance bandwidth, ARBW, gain and efficiency. The simulated and measured results show reasonably good agreement.


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.


2015 ◽  
Vol 21 (1) ◽  
pp. 59-63
Author(s):  
柳斌 LIU Bin ◽  
杨亦红 YANG Yi-hong ◽  
沈泉涌 SHEN Quan-yong ◽  
徐闽燕 XU Min-yan ◽  
谢子青 XIE Zi-qing ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Nhu Huan Nguyen ◽  
Thi Duyen Bui ◽  
Anh Dung Le ◽  
Anh Duc Pham ◽  
Thanh Tung Nguyen ◽  
...  

A novel wideband circularly polarized antenna array using sequential rotation feeding network is presented in this paper. The proposed antenna array has a relative bandwidth of 38.7% at frequencies from 5.05 GHz to 7.45 GHz with a highest gain of 12 dBi at 6 GHz. A corresponding left-handed metamaterial is designed in order to increase antenna gain without significantly affecting its polarization characteristics. The wideband circularly polarized antenna with 2.4 GHz of bandwidth is a promising solution for wireless communication system such as tracking or wireless energy harvesting from Wi-Fi signal based on IEEE 802.11ac standard or future 5G cellular. A potential application of this antenna as a receiving antenna for RF-DC device to obtain DC power for a wireless sensor node from Wi-Fi signal is shown.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jiawei Yang ◽  
Xi Li ◽  
Lin Yang

A novel planar omnidirectional circularly polarized (CP) antenna is presented. The omnidirectional circular polarization characteristics of the planar antenna are the result of the combined effect of a planar quasi-magnetic dipole (PQMD) and a printed electric dipole (PED) in this paper. The CP radiation pattern of the proposed antenna can be achieved by distributing appropriate current amplitude and phase to both elements, respectively. A power divider is used to adjust the amplitude and phase relationship between two basic components. In order to achieve a planar structure, coplanar waveguide (CPW) feed is adopted to feed the quasi-magnetic dipole for the first time. The overall electrical size of antenna is 1.61λ × 0.38λ. Finally, the correctness of our theoretical analysis is verified by processing and measuring this antenna. Through the analysis of the measurement results, we have obtained the following conclusions: the operating bandwidth of the proposed antenna obtained by measurement is from 5.67 to 5.86 GHz, in which the reflection coefficient is less than −10 dB and the axial ratio is less than 3 dB. Within the available bandwidth, the proposed antenna achieves omnidirectional radiation characteristics with a gain between 0.89 and 2.48 dBic.


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