Circularly polarized CPW fed MIMO/Diversity antenna for Wi-Fi and WLAN applications

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anubhav Kumar ◽  
Asok De ◽  
Rakesh K. Jain

Abstract In this paper, circular polarized two-element and eight-element CPW fed MIMO/Diversity antenna with defected ground is presented. The dimension of the two-port antenna is 30 mm × 30 mm whereas the edge-to-edge gap between radiating elements is 5.65 mm. The |S11| in dB varies from 4.95 to 5.95 GHz with a gain up to 4.1 dB and efficiency is more than 90%. The isolation of two-element CPW antenna is more than 20 dB with open and diagonal stub in the ground whereas more than 18.7 dB for eight-element antenna without decoupling network. The circular and rectangular stub perturbs the surface current in the ground and is responsible for RHCP and LHCP in two-elements and eight-elements antenna where it covers the complete operating band. The acceptable ECC, TARC, DG, and CCL values of the antenna are determined which represents the diversity characteristics of the antenna. The Wi-Fi/WLAN applications can be fulfilled with the proposed two and eight-element antenna.

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Navneet Sharma ◽  
Anubhav Kumar ◽  
Asok De ◽  
Rakesh K. Jain

Abstract A compact, circularly polarized, CPW-fed antenna is proposed for wearable applications in ISM Band (5.8 GHz). The antenna is based on DGS, where the ground plane is responsible for impedance matching. The 10 dB impedance of the proposed antenna varies from 5.39 GHz to 5.94 GHz. The circular stub introduced in the ground plane mitigates the surface current and enriches the 3 dB axial ratio from 5.73 GHz to 5.92 GHz. Proposed antenna exhibits the LHCP and RHCP pattern of circular polarization, the antenna can effectively work for biomedical and wearable applications. The antenna is analyzed on the skin phantom model and the SAR value obtained is 1.218 W/kg, which is below the maximum permissible level. The proposed antenna is also used for the detection of breast tumors.


Author(s):  
Shilpa U Kharche ◽  
G. Shrikanth Reddy ◽  
Jayanta Mukherjee ◽  
Rajiv Kumar Gupta

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.


2014 ◽  
Vol 697 ◽  
pp. 425-428
Author(s):  
Yan Zhong Yu ◽  
Yun Yan Wang ◽  
Yan Ru Chen

A miniaturized circularly polarized (CP) antenna for ultra-high frequency (UHF) radio-frequency identification (RFID) reader is designed in the present paper. For the aim of miniaturizing antenna, the square radiating patch is opened by four T-shape slots. This can extend the route of surface current, as a result the operating frequency drops and the size reduces. In additional two diagonal corners of the radiation patch are truncated by a square to achieve CP operation. The designed antenna is calculated and optimized by HFSS. The optimized antenna exhibits satisfied performances, and is therefore suitable for UHF RFID reader applications. The designed antenna shows the advantages of small size, simple structure, and low cost.


2014 ◽  
Vol 62 (10) ◽  
pp. 5365-5369 ◽  
Author(s):  
Changjiang Deng ◽  
Yue Li ◽  
Zhijun Zhang ◽  
Zhenghe Feng

2015 ◽  
Vol 9 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Tapan Mandal ◽  
Santanu Das

A coplanar waveguide-fed planar hexagonal monopole ultra-wideband antenna with dual-band rejection characteristics is proposed in this paper. The desired notch frequencies at 3.5 and 5.5 GHz are realized by incorporating mushroom structures. The input impedance and surface current distributions are used for analysis and explanation of the effects of mushroom cells. The prototype and proposed antennas are fabricated and tested. From the measured results, the proposed antenna provides an operating band of 2.81–14.32 GHz for 2 ≤ voltage standing wave ratio (VSWR), while the dual-band stop function is in the frequency bands of 3.3–3.7 GHz and 5.10–5.88 GHz. Moreover, the antenna model also exhibits constant group delay and linear phase in the pass band. The proposed antenna has appreciable gain and efficiency over the whole operating band except the notch bands.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianxiong Li ◽  
Yuchen Jiang ◽  
Xiaoming Zhao

A circularly polarized (CP) wearable antenna based on the FDM (fused deposition modeling) technology is proposed. Conductive fabric is used to realize conductive parts of the patch antenna on the NinjaFlex substrate. The antenna is encapsulated with additional layers of NinjaFlex. Modified patch ensures the CP character at 2.45 GHz. Bending and washing tests are conducted to check the performance stability, and good agreement between simulated and measured results is observed. The experimental results illustrate that the antenna holds 11% 10 dB S11 bandwidth and around 70 MHz 3 dB axial ratio bandwidth. In addition, surface current analysis is also given to understand the operating mechanism of CP wave.


Author(s):  
Prashant Chaudhary ◽  
Ashwani Kumar ◽  
Kamlesh Patel ◽  
Ravi Kumar Arya ◽  
Maifuz Ali ◽  
...  

2021 ◽  
Author(s):  
Xinlei Zhang ◽  
Haining Ye ◽  
Yan Zhao ◽  
Haifeng Zhang

Abstract A tunable linear-to-circular polarization converter (LTCPC) for the terahertz (THz) regime which consists of two conductive layers and a graphene transmissive metasurface layer separated by two dielectric layers is reported in this work. The equivalent surface resistance modeling method is adopted to investigate the peculiar electronic properties of graphene. The simulation results show that when the Fermi energy (Ef) is 1.1 eV, the linearly-polarized wave can be transformed into the circularly-polarized wave in the working band ranging from 0.9498 THz to 1.3827 THz (the relative bandwidth is 37.1%) with axial ratio (AR) less than 3 dB. Moreover, the bandwidth can be regulated to the desired one by varying the Fermi level of graphene metasurface via a bias voltage rather than manually modifying the structure. We have analyzed the mechanism of the polarization conversion, especially, the magnitudes and the phase difference of cross- and co-polarization transmission coefficients, AR curves, and surface current diagrams at y-polarized incidence. Our findings open up promising possibilities towards the realization of graphene controllable devices for polarization modulation, which has advantages of adjustability over traditional devices.


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