Increasing the impedance bandwidth of a microstrip antenna by using under coupling technique

Author(s):  
B. Lee ◽  
G.C. Kang ◽  
H.Y. Lee ◽  
J.C. Lee ◽  
N.Y. Kim ◽  
...  
Frequenz ◽  
2020 ◽  
Vol 74 (1-2) ◽  
pp. 41-51
Author(s):  
Alka Verma ◽  
Anil Kumar Singh ◽  
Neelam Srivastava ◽  
Binod Kumar Kanaujia

AbstractIn this article, a new structure comprising of a novel compact slot loaded polarization dependent Electromagnetic Band Gap structure (SLPDEBG), which enhances the performance of circularly polarized rotated square patch antenna by placing SLPDEBG unit cells around it, has been designed. The proposed antenna, having dimensions 0.640 λo x 0.640 λ x 0.0128 λo (λo stands for the free space wavelength at 2.39 GHz), shows that the measured impedance bandwidth and AR bandwidth is 120 MHz and 50 MHz, respectively, with a peak gain of 3.52 dB. Some prominent features of the proposed structure are: front to back ratio of 64, 3 db, beamwidth of 92° at xz-plane and 74° at yz-plane. This prototype antenna finds its application in wireless communication of ISM band. Good performance of the proposed antenna is verified by the close agreement between the simulated and measured results.


2016 ◽  
Vol 78 (5-9) ◽  
Author(s):  
Muhammad Fauzan Edy Purnomo ◽  
Hadi Suyono ◽  
Panca Mudjirahardjo ◽  
Rini Nur Hasanah

The circularly polarized (CP) microstrip antennas, both of singly- and doubly-fed types, possess inherent limitation in gain, impedance and axial-ratio bandwidths. These limitations are caused mainly by the natural resonance of the patch antenna which has a high unloaded Q-factor and the frequency-dependent excitation of two degenerative modes (TM01 and TM10) when using a single feed. Many applications which require circular polarization, large bandwidth, and good performance, especially in the field of wireless communication, are still difficult to be designed by using antenna software. Some consideration to take will include the application target and design specification, the materials to be used, and the method to choose (formula, numerical analysis, etc). This paper explains and analyzes the singly-fed microstrip antenna with circular polarization and large bandwidth. This singly-fed type of microstrip antenna provides certain advantage of requiring no external circular polarizer, e.g. the 900 hybrid, as it only needs to apply some perturbation or modification to a patch radiator with a standard geometry. The design of CP and large-bandwidth microstrip antenna is done gradually, by firstly truncating one tip, then truncating the whole three tips, and finally modifying it into a pentagonal patch structure and adding an air-gap to obtain larger bandwidths of impedance, gain and axial ratio. The last one antenna structure results in a novelty because it is a rare design of antenna which includes all types of bandwidth (impedance, gain, and axial ratio) being simultaneously larger than the origin antenna. The resulted characteristic performance of the 1-tip (one-tip) antenna shows respectively 1.9% of impedance bandwidth, 3.1% of gain bandwidth, and 0.45% of axial-ratio bandwidth. For the 3-tip (three-tip) step, the resulted bandwidths of respectively impedance, gain, and axial ratio are 1.7%, 3.3% and 0.5%. The pentagonal structure resulted in the bandwith values of 15.67%, 52.16% and 4.11% respectively for impedance, gain, and axial ratio. 


Author(s):  
Murari Shaw ◽  
Niranjan Mandal ◽  
Malay Gangopadhyay

Abstract In this paper, a stacked microstrip patch antenna with polarization reconfigurable property has been proposed for worldwide interoperability for microwave access (WiMAX) application. The proposed antenna has two substrate layers: upper and lower layers with two radiating patches connected with the coaxial probe. Without the upper layer the lower square-shaped substrate layer having regular hexagonal radiating patch with probe fed acts as a linear polarized antenna with impedance bandwidth for (S11 ≤ −10 dB) is 370 MHz 10.56% (3.32–3.69 GHz) cover WiMAX (3.4–3.69 GHz) application band. The hexagonal radiating patch is perturbed with an optimum rectangular slot to enhance the impedance bandwidth of the antenna. The lower substrate layer having hexagonal patch with the same probe position is stacked with the upper square-shaped substrate layer with same sized square patch and the upper patch soldered with the coaxial probe. The overall stacked antenna generates a circularly polarized band when the opposite corner of the top square radiating patch of the upper layer is truncated with optimum size. In order to generate another circularly polarized band and to improve the input impedance matching of the stacked antenna, the top radiating patch is perturbed with two slots and a slit. The stacked circularly polarized antenna generates impedance bandwidth of 12.75% (3.23–3.67 GHz) for (S11 ≤ −10 dB) with two circularly polarized bands (3.34–3.37 GHz) and (3.66–3.70 GHz) as per (axial ratio ≤ 3 dB) for WiMAX application. Therefore, the proposed antenna can be used as linearly polarized or dual band circularly polarized according to requirement.


2016 ◽  
Vol 9 (5) ◽  
pp. 1179-1184 ◽  
Author(s):  
Kalyan Mondal ◽  
Partha Pratim Sarkar

In this work, microstrip antenna with W- and V-shaped radiating patches have been proposed. Here square- and circular-shaped modified ground planes have been designed by poly tetra fluoro ethylene (PTFE) substrate with dielectric constant 2.4. Broadband with high gain is obtained by optimum selection of radiating patch with modified ground plane. The ground planes are modified by loading a U-shaped slot. The simulated and measured results are compared. Considering −10 dB impedance bandwidth maximum frequency band of 6.97 GHz (3.04–10.01 GHz) with percentage bandwidth of 106.8% is achieved. The proposed antenna exhibits maximum peak gain of 5.1 dBi. The simulation and measurement have been done by Ansoft designer software and vector network analyzer.


2016 ◽  
Vol 9 (4) ◽  
pp. 843-850 ◽  
Author(s):  
Dinesh Kumar Singh ◽  
Binod Kumar Kanaujia ◽  
Santanu Dwari ◽  
Ganga Prasad Pandey ◽  
Sandeep Kumar

The design and measurement of reconfigurable circularly polarized capacitive fed microstrip antenna are presented. Small isosceles right angle triangular sections are removed from diagonally opposite corners for the generation of circular polarization (CP) of axial ratio bandwidth of 11.1%. Horizontal slits of different lengths are inserted at the edges of the truncated patch to provide the dual-band CP and by switching PIN diodes across the slits ON and OFF, reconfigurable circularly polarized antenna is realized. The antenna shows dual-band behavior with reconfigurable CP. In order to enhance the operation bandwidth of the antenna, an inclined slot was embedded on the patch along with PIN diodes across the horizontal slits. This proposed antenna gave an impedance bandwidth of 66.61% (ON state) ranging from 4.42 to 8.80 GHz and 68.42% (OFF state) ranging from 4.12 to 8.91 GHz and exhibits dual-frequency CP with PIN diode in OFF state and single-frequency CP with PIN diode in ON state with good axial ratio bandwidth. The axial ratio bandwidth of 4.42, 2.35, and 2.72% is obtained from the antenna. The antenna has a similar radiation pattern in all the three different CP bands and almost constant gain within the bands of CP operation.


2013 ◽  
Vol 427-429 ◽  
pp. 648-651
Author(s):  
Xiao Feng Xiong ◽  
Wei Dong Chen

A novel broad band and wide beam microstrip helical antenna is proposed based on the modification of traditional helical antennas. Through selecting the appropriate operating mode between the axial mode and the normal mode, this new antenna can broad both the beamwidth and the bandwidth. To improve the gain of the antenna, An antenna array with 1*16 elements is designed and fabricated. Meanwhile, cavity-loaded feeding network is utilized for probe station measurement. The simulated impedance and radiation pattern are studied. The proposed antenna shows a wide impedance bandwidth from 7.6GHz to 9.6GHz for |S11|<-10dB, with wide 3dB beamwidth of E-plane about 1200, respectively.


1998 ◽  
Vol 44 (1-2) ◽  
pp. 49-60 ◽  
Author(s):  
D N Khanra ◽  
S K Chowdhury ◽  
A K Mallick

2021 ◽  
Vol 2070 (1) ◽  
pp. 012110
Author(s):  
S. Imaculate Rosaline

Abstract This paper describes the design of a compact dual band microstrip antenna based on metamaterial inspired split ring radiating element and a complementary spilt ring resonator (CSRR). The antenna has a very compact dimension of 20×20×0.8 mm3. It covers the 2.5/5.2/5.8 GHz frequencies, pertaining to IEEE 802.11 b/g/a standards suitable for WLAN applications with a -10dB impedance bandwidth of 250 MHz and 860 MHz. The CSRR creates a negative permittivity region, thus providing miniaturization of the antenna and the introduction of additional split gaps in the radiating element creates a positive permeability within the desirable frequency range, yielding better impedance matching. The negative properties of those structures are verified using S-parameter retrieval method. A prototype of the proposed antenna is fabricated and the measured results are fairly in good agreement with the simulation results. Dipole like radiation patterns are observed at both the operating frequencies. The measured peak gains are 0.58 dBi, 1.27 dBi and 2.10 dBi at 2.5, 5.2 and 5.8 GHz respectively.


2019 ◽  
Vol 11 (2) ◽  
pp. 165-175 ◽  
Author(s):  
Wafaa Mohammed Hashim ◽  
Asst. prof. Dr. Adheed Hasan Sallomi

a staircase patch microstrip antenna with slots is proposed to cover the 2G/3G/4G cellular mobile base station bands, when the antenna is excited with a transmission line, creates several modes these modes are composite to obtain a large bandwidth. The proposed antenna operates in the band from 0.86 GHz to 4.78 GHz with an impedance bandwidth of 138%. The use of staircase patch antenna is to achieve more attractive performance such as wider bandwidth, better impedance matching and better radiation. Inserting different slots to the patch of the antenna to enhance the gain and return loss. The gain is obtained ranging from 2.18 dBi to 5.3 dBi. Good radiation efficiencies ranging from 70% to 97% is achieved.


2018 ◽  
Vol 7 (3) ◽  
pp. 87-92 ◽  
Author(s):  
P. Khanna ◽  
A. Sharma ◽  
A. K. Singh ◽  
A. Kumar

A CPW – Fed octagonal ring shaped antenna for wideband operation is presented. The radiating patch of proposed octagonal ring antenna consists of symmetrical slot in place of conventional annular ring microstrip antenna. The ground plane consists of two rectangular slots, while the radiator and the ground plane are on same plane that utilizes the space available around the radiator. The proposed antenna is simulated through Ansoft’s High Frequency Structure Simulator (HFSS). Measured result shows balanced agreement with the simulated results. The prototype is taken with dimensions 47 mm × 47 mm × 1.6 mm that achieves good return loss, constant group delay and good radiation patterns over the entire operating bandwidth of 2.0 to 9.5 GHz (7.5 GHz). The proposed antenna achieves high impedance bandwidth of 130%. Thus, the proposed antenna is applicable for S and C band applications.


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