scholarly journals Microstrip Feed Trapezoidal Shape Antenna Array with Defected Ground Structure for S Band Applications

Author(s):  
Suganthi Santhanam ◽  
Thiruvalar Selvan Palavesam

In this proposal new trapezoidal patch microstrip feed antenna array with ground defected by square shape is designed for detailed antenna parameter study in terms of return loss, VSWR, gain and radiation pattern for S band applications from 2 to 3 GHz. The bandwidth and radiation properties of four radiating element arranged in 2 x 2 array has been improved by defecting half of the ground by etching square shape opposite to the vertical feed point. 30 x 70 x 1.6 mm dimension structure has been fabricated in FR4 substrate for low cost applications and performance analyzed in three different planes. With comparison of four element array with full ground, the proposed array with defected ground has proved the improvement in behavior with return loss of -34.687 dB and ideally fit with VSWR of 1.038. Parametric study with feed length and substrate thickness has also been performed optimized decision of structure dimension. This study reveals that by reducing the substrate thickness and increasing the feed length, we can improve the performance of loss reduction. The front view has been simulated with full ground and defected ground for comparison and the compared results shows that the loss reduction of -22 dB has been achieved with VSWR value of 1.03 from 2.28 for defected ground structure. The designed structure has been simulated with CST software and the comparison of simulated results has conform that the proposed structure can be used for S band application like airport surveillance radars with wide bandwidth of 120 MHz and gain of 3.52 dBi. Comparison has been made between the proposed antenna array and the antennas available in literature with respect to bandwidth gain, reflection coefficient and defection type for better understanding.

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Fang Xu ◽  
Mu Ju

A triband MIMO antenna used for gsm1800/td-scdma/lte/wi-max/wiLan/wifi has been proposed in this paper. The design with the size of 32 m∗73.6 mm is fabricated on FR4 substrate (thickness is 1.6 mm). This antenna consists of two reversed monopole meandered radiators and defected ground structure which work together to achieve impedance match and enhance isolation for all operating bands. According to the subsequent measured results, the working frequency domains are at gsm1800 (1.71 GHz–1.88 GHz), td-scdma (1.88 GHz–2.025 GHz), lte (2.1–2.35, 2.48–2.51), wi-max (3.5 GHz, 5.5 GHz), wiLan (5.725 GHz–5.8 GHz), and wifi (5.8 GHz–5.88 GHz) approximately. Besides, the measured radiation patterns (gain total) are also well at these working frequency domains and the omnidirectional performance has been achieved for the reversed MIMO antenna array. Furthermore, the realized isolation is more than 15 dB, 24.2 dB, and 22 dB at the first, the second, and the third working frequency band, respectively.


In this paper, a compact microstrip patch has a slot associated with the Defected Ground Structure radiator is presented. Instead of semi-infinite ground plane, the proposed antenna adopts the defected ground plane. The Radiating patch mendacity on the FR-4 substrate which is having dielectric constant of 4.4, thereby provides good bandwidth. This microstrip antenna is designed for wide bandwidth applications in range of 5.5GHz to 7.25GHz. Proposed work introduces a methodology wherein reducing of structure’s increase the bandwidth as well as return loss with defected ground structure (DGS).However since communication systems require small size, broad band and multiband antennas, monopoles have to be ensued for fabricating broad-band and wide-band antennas. In the proposed work investigations are carried out to design a new antenna with broad-band properties. Simulations are carried out via An soft HFSS electromagnetic simulator software- fabricated on FR-4 Substrate and tested with Vector network Analyzer. Measurement and Simulation results obtained prove the applicability of proposed antenna in 5.5GHz to 7.25GHz frequency range with a return loss of -31.3dB and 11.5dB etc. Microstrip feed line technique is used to feed the antenna with 50Ω impedance.


2019 ◽  
Vol 14 (4) ◽  
pp. 448-455 ◽  
Author(s):  
Nanang Ismail ◽  
Teddy Surya Gunawan ◽  
Santi Kartika S ◽  
Teguh Praludi ◽  
Eki A.Z. Hamidi

Radar has been widely used in many fields, such as telecommunication, military applications, and navigation. The filter is one of the most important parts of a radar system, in which it selects the necessary frequency and blocks others. This paper presents a novel yet simple filter design for S-band radar in the frequency range of 2.9 to 3.1 GHz. The center frequency of the filter was designed at 3 GHz with a bandwidth of 200 MHz, insertion loss larger than -3 dB and return loss less than -20 dB. Fifth order microstrip hairpin bandpass filter (BPF) was designed and implemented on Rogers 4350B substrate which has a dielectric relative constant value of (εr)= 3.48 and substrate thickness of (h) =1.524 mm. One element of the square groove was added as Defected Ground Structure (DGS) which can decrease the filter size, reduce harmonization, and increase return loss. Two scenarios were used in the measurement, i.e. with and without enclosed aluminum casing. Results showed that BPF without casing obtained the insertion loss of -1.748 dB at 2.785 GHz and return loss of -21.257 dB in the frequency range between 2.785 to 2.932 GHz. On the other hand, BPF with casing shows a better performance, in which it obtained the insertion loss of -1.643 dB at 2.921 GHz and return loss of -19.529 in the frequency range between 2.820 to 3.021 GHz. Although there is small displacement of frequency and response value between the simulation and implementation, our BPF has the ability to work on S-band radar with a frequency range of 2 to 4 GHz. 


2018 ◽  
Vol 7 (3) ◽  
pp. 56-63 ◽  
Author(s):  
A. Jaiswal ◽  
R. K. Sarin ◽  
B. Raj ◽  
S. Sukhija

In this paper, a novel circular slotted rectangular patch antenna with three triangle shape Defected Ground Structure (DGS) has been proposed. Radiating patch is made by cutting circular slots of radius 3 mm from the three sides and center of the conventional rectangular patch structure and three triangle shape defects are presented on the ground layer. The size of the proposed antenna is 38 X 25 mm2. Optimization is performed and simulation results have been obtained using Empire XCcel 5.51 software. Thus, a miniaturized antenna is designed which has three impedance bandwidths of 0.957 GHz,  0.779 GHz, 0.665 GHz with resonant frequencies at 3.33 GHz, 6.97 GHz and 8.59 GHz and the corresponding return loss at the three resonant frequencies are -40 dB, -43 dB and -38.71 dB respectively. A prototype is also fabricated and tested. Fine agreement between the measured and simulated results has been obtained. It has been observed that introducing three triangle shape defects on the ground plane results in increased bandwidth, less return loss, good radiation pattern and better impedance matching over the required operating bands which can be used for wireless applications and future 5G applications.


2019 ◽  
Vol 11 (08) ◽  
pp. 761-764
Author(s):  
Kaijun Song ◽  
Fei Xia ◽  
Yuxuan Chen ◽  
Yu Zhu ◽  
Jiawei Li ◽  
...  

AbstractA compact wideband out-of-phase power divider (PD) with improved isolation performance is proposed. This divider is formed by connecting an additional stub for isolation to output ports of a traditional Marchand balun with a defected ground structure (DGS) been used. To verify the design, a prototype divider is fabricated and tested. The measured results validate the 53.86% band-width centered at 3.43 GHz with more than 15 dB return loss at all ports, more than 17 dB isolation, respectively.


Author(s):  
Dawit Fitsum ◽  
Dilip Mali ◽  
Mohammed Ismail

<p>This paper presents Dual-Band proximity coupled feed rectangular Microstrip patch antenna with slots on the radiating patch and Defected Ground Structure. Initially a simple proximity coupled feed rectangular Microstrip patch antenna resonating at 2.4 GHz is designed. Etching out a ‘Dumbbell’ shaped defect from the ground plane and ‘T’ shaped slot from the radiating patch of the proximity coupled feed rectangular Microstrip patch antenna, results in a Dual-Band operation, i.e., resonating at 2.4 GHz and 4.5 GHz; with 30.3 % and 18.8% reduction in the overall area of the patch and the ground plane of the reference antenna respectively. The proposed antenna resonates in S-band at frequency of 2.4 GHz with bandwidth of 123.6 MHz and C-band at frequency of 4.5 GHz with bandwidth of 200 MHz, and a very good return loss of -22.1818 dB and -19.0839 dB at resonant frequency of 2.4 GHz and 4.5 GHz respectively is obtained. The proposed antenna is useful for different wireless applications in the S-band and C-band.</p>


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