Multilayered circularly polarized microstrip antenna integrated with defected ground structure for wide impedance and axial ratio bandwidth

2016 ◽  
Vol 30 (17) ◽  
pp. 2256-2267 ◽  
Author(s):  
Pravin R. Prajapati
2015 ◽  
Vol 9 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Amanpreet Kaur ◽  
Rajesh Khanna ◽  
Machavaram Kartikeyan

In this paper, a three layered stacked circularly polarized rectangular dual band microstrip antenna with a defected ground structure (DGS) and a feed network with stub (showing dual wideband characteristic) is designed, fabricated, and tested for WLAN, Zig bee, Wi-Max, and IMT band applications. The proposed antenna is fabricated on an FR4 substrate with dielectric constant (εr) of 4.4; tanδ of 0.0024 and a height of 1.57 mm.The antenna has a surface area of 4.8 × 4.1 cm2and a total height of 5.1 mm. The designed antenna covers two wireless bands from 2.39 to 2.64GHz and 3.39–3.76 GHZ with impedance bandwidths (VSWR < 2) of 250 MHz (9% bandwidth centered at 2.515 GHz) and 370 MHz (10% bandwidth centered at 3.57 GHz), respectively. This antenna is capable of covering IEEE 802.11b/g/n standards of WLAN from 2.4 to 2.485 GHz, bluetooth applications from 2.4 to 2.483 GHz, ZigBee applications from 2.4 to 2.485 GHz, IEEE 802.16/ Wi-MaX applications from 3.4 to 3.69 GHz and international mobile telecommunications (IMT) band from 3.4 to 3.6 GHz. As the antenna is circularly polarized, the misalignment of the receiver with transmitter does not affect the performance of the system. The antenna designing was done using CST MWS V'10 and the prototype of the designed antenna was tested for the validation of S11(dB) and gain results against the simulated ones experimentally. The proposed antenna shows a gain of 4.08 dBi at 2.5 GHz and a gain of 5.024 dBi at 3.51 GHz.


2015 ◽  
Vol 8 (7) ◽  
pp. 1101-1109 ◽  
Author(s):  
Pravin R. Prajapati ◽  
Amalendu Patnaik ◽  
M. V. Kartikeyan

A novel asymmetric “+” shaped fractal slotted circularly polarized microstrip antenna with a Yagi–Uda structure is proposed. Four asymmetric plus shape slots are embedded symmetrically in the center of all four quadrants of a square patch. To suppress undesirable higher modes, dumbbell-shaped defected ground structure (DGS) is introduced at the ground layer of the antenna. We introduce a method to compensate the reduction in gain occurring due to the presence of DGS, without changing in the overall size of the antenna. A 3 dB axial ratio bandwidth of 4 MHz at center frequency of 862 MHz, 10 dB impedance bandwidth of 13.20 MHz and a gain of 4.25 dB is achieved with the proposed antenna. A laboratory prototype of the proposed antenna is made to cross-verify the simulation results. Very good agreements between the two are obtained. The proposed antenna may prove useful for International Mobile Telecommunication application for designing high-gain arrays.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Guo Liu ◽  
Liang Xu ◽  
Yi Wang

A novel high-performance circularly polarized (CP) antenna is proposed in this paper. Two separate antennas featuring the global positioning system (GPS) dual-band operation (1.575 GHz and 1.227 GHz for L1 band and L2 band, resp.) are integrated with good isolation. To enhance the gain at low angle, a new structure of patch and two parasitic metal elements are introduced. With the optimized design, good axial ratio and near-hemispherical radiation pattern are obtained.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Pravin Ratilal Prajapati

An application of defected ground structure (DGS) to reduce out-of-band harmonics has been presented. A compact, proximity feed fractal slotted microstrip antenna for wireless local area network (WLAN) applications has been designed. The proposed 3rd iteration reduces antenna size by 43% as compared to rectangular conventional antenna and by introducing H shape DGS, the size of an antenna is further reduced by 3%. The DGS introduces stop band characteristics and suppresses higher harmonics, which are out of the band generated by 1st, 2nd, and 3rd iterations. H shape DGS is etched below the 50 Ω feed line and transmission coefficient parameters (S21) are obtained by CST Microwave Studio software. The values of equivalent L and C model have been extracted using a trial version of the diplexer filter design software. The stop band characteristic of the equivalent LC model also has been simulated by the Advance Digital System software, which gives almost the same response as compared to the simulation of CST Microwave Studio V. 12. The proposed antenna operates from 2.4 GHz to 2.49 GHz, which covers WLAN band and has a gain of 4.46 dB at 2.45 GHz resonance frequency.


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