scholarly journals A SYNCHRONOUS SUB-ARRAY CIRCULARLY POLARIZED MICROSTRIP ANTENNA FOR BISAR ONBOARD UAV

2018 ◽  
Author(s):  
Yohandri

A circularly polarized microstrip antenna for bi-static SAR onboard UAV has been investigated. The both senseof the circular polarization left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) arecan be achieved on experimental and simulation. The 2x2 sub array antenna operated in 1.176 (L-band) withnovel proximity synchronous feed method has been designed, fabricated, and evaluated to show the characteristic of the antenna. The measured result give the axial ratio bandwidth (<3dB) of about 28 MHz (2%), whichconsistent with the simulated result of about 27 MHz (2%). These results satisfy the specification for our BiSARsystem installed onboard UAV.

2021 ◽  
Vol 10 (1) ◽  
pp. 200-207
Author(s):  
Muhammad Fauzan Edy Purnomo ◽  
Vita Kusumasari ◽  
Rusmi Ambarwati ◽  
Sigit Kusmaryanto ◽  
Sholeh Hadi Pramono ◽  
...  

In this paper, we obtain the basic configuration of the left-hand circular polarization (LHCP) array two patches stack triangular truncated microstrip antenna. This construction use the basic corporate feed microstrip-line with modified lossless T-junction power divider on radiating patch for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on airspace with compact, small, and simple configuration. The design of Circular Polarization (CP) is realized by truncating the whole three tips and adjusting the parameters of antenna at the resonant frequency, f=5.2 GHz. The results of characteristic performance and S-parameter for the LHCP array two patches stack antenna at the resonant frequency show successively about 7.24 dBic of gain, 1.99 dB of axial ratio (Ar), and -11.43 dB of S-parameter. Moreover, the impedance bandwidth and the 3 dB-Ar bandwidth of this antenna are around 560 MHz (10.77%) and 50 MHz (0.96%), respectively.


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. 


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bin Zhou ◽  
Junping Geng ◽  
Zhe Li ◽  
Wenzhi Wang ◽  
Xianling Liang ◽  
...  

A dual circularly polarized (CP) omnidirectional antenna based on slot array in coaxial cylinder structure is presented in this paper. It is constructed by perpendicular slot pairs around and along the axis of the coaxial cylinder to realize the omnidirectional CP property, and two ports are assigned in its two sides as left hand circularly polarized (LHCP) port and right hand circularly polarized (RHCP) port, respectively. The proposed antenna achieves a bandwidth of 16.4% ranging from 5.05 to 5.95 GHz with an isolation higher than 15 dB between the two CP ports, and the return loss (RL) is higher than 10 dB within the bandwidth in both of the two ports. From the measured results, the average axial ratio (AR) of the proposed antenna in omnidirectional plane is lower than 1.5 dB.


2021 ◽  
Author(s):  
Stepan Piltyay

The article presents the methodology for designing and optimizing of feed network for a circularly polarized horn antenna. A horn antenna has a metal structure and consists of a waveguide that has a variable cross-section and an open radiating end. Electromagnetic waves in such antenna are excited by a waveguide that is connected to a horn antenna in through the narrow wall. The proposed feed network of the horn antenna consists of a rectangular waveguide with a slot. In order to obtain the excitation of signals with circular polarization at the output, a slot was cut in the waveguide at an angle of 45º. As a result, the network makes it possible to form the signals with right-hand circular polarization and left-hand circular polarization. The presented design of the horn antenna feed network eliminates the need to develop a separate waveguide device of polarization processing. The designed feed network of the circularly polarized horn antenna can be used at an operating frequency of 8.0 GHz. At these frequency the reflection coefficient is less than −19 dB. The proposed horn antenna provides a maximum gain of 21 dB for right-hand circular polarization and a maximum gain of 10 dB for left-hand circular polarization. Cross-polarization isolation is higher than 10 dB. Therefore, the developed feed network of the horn antenna provides narrowband operating mode at the circular polarization with satisfying electromagnetic polarization characteristics and matching at the frequency of 8 GHz. Developed feed network of the horn antenna with circular polarization can be used in radio engineering systems, which carry out polarization processing of signals.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xihong Ye ◽  
Mang He ◽  
Pingyuan Zhou ◽  
Houjun Sun

A compact single-feed circularly polarized microstrip antenna is proposed to achieve symmetric radiation pattern over a wide range of observation angles. In order to reduce the radiation aperture and consequently broaden the circular polarization (CP) and the half power beamwidth (HPBW) of the antenna, a partially etched superstrate and a conducting cavity are employed in the design. Further, reasonable axial ratio (AR) and impedance bandwidths are realized within the compact structure by using a simple series crossed-slot aperture coupled feeding. As a consequence, the overall dimension of the fabricated prototype is 0.32λ0× 0.32λ0× 0.12λ0at the center operating frequency of 1.56 GHz, and a 3.0% overlapped bandwidth of 10 dB return loss (RL) and 3 dB AR is obtained. Within the bandwidth, symmetric CP radiation pattern over almost the entire upper hemisphere is observed and the HPBW is also increased from 60° to 106°.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Tuan-Yung Han

This study proposes a novel 2 × 2 array antenna design with broadband and circularly-polarized (CP) operation. The proposed design uses a simple series-fed network to increase the CP bandwidth without requiring one-by-one adjustment of each array element or a complex feed network. Selecting the appropriate spacing between each array element allows the proposed array antenna to generate CP radiation with a low axial ratio. Experimental results based on a prototype show that this 2 × 2 microstrip array antenna achieves a wide 3 dB axial ratio bandwidth of more than 10%. Simulated data are also provided to confirm the measured results.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5610
Author(s):  
Sachin Kumar ◽  
Gwan Hui Lee ◽  
Dong Hwi Kim ◽  
Hyun Chul Choi ◽  
Kang Wook Kim

A broadband compact-sized planar four-port multiple-input–multiple-output (MIMO) antenna with polarization diversity is presented. The proposed dual circularly polarized (CP) MIMO antenna consists of four G-shaped monopole elements, two of which are left-hand CP and the other two are right-hand CP. A vertical line strip in the G-shaped radiating element acts in balancing the vertical and horizontal electric field components to obtain 90° phase difference between them for circular polarization. Also, an I-shaped strip is incorporated between the ground planes of the G-shaped antenna elements to obtain equal voltage level in the proposed MIMO configuration. The dual circular polarization mechanism of the proposed MIMO/diversity antenna is analysed from the vector current distributions. The impedance bandwidth (S11 ≤ –10 dB) of the MIMO antenna is 105.9% (4–13 GHz) and the 3 dB axial ratio bandwidth (ARBW) is 67.7% (4.2–8.5 GHz), which is suitable for C-band applications. The overall size of the MIMO antenna is 70 × 68 × 1.6 mm3, and the minimum isolation between the resonating elements is 18 dB. The envelope correlation coefficient is less than 0.25, and the peak gain within the resonating band is 6.4 dBi.


2015 ◽  
Vol 8 (6) ◽  
pp. 943-953 ◽  
Author(s):  
Mukesh Kumar Khandelwal ◽  
Binod Kumar Kanaujia ◽  
Santanu Dwari ◽  
Sachin Kumar ◽  
Anil Kumar Gautam

Asymmetric slits loaded irregular shaped microstrip patch antenna with three different ground structures is proposed. All three antennas show triple band characteristics. First antenna with regular ground plane resonates at 1.95, 2.4, and 4.90 GHz with good radiation characteristics and shows right-hand circular polarization at 1.95 GHz. 18.75% of compactness is achieved with triple band characteristics. Further, same patch is used with different defected ground structures. Second antenna resonates at 1.85, 2.4, and 4.85 GHz with suppressed cross-polarization level and antenna shows right-hand circular polarization at 1.85 and 4.85 GHz. Compactness is further improved to the value of 22.91%. The third antenna resonates at 1.95, 2.4, and 4.85 GHz with better gain and radiation characteristics and antenna shows right-hand circular polarization at 1.95 and 2.4 GHz. The small frequency ratio f2/f1 is achieved and the value of f2/f1 is 1.29 and 1.23 for second and third configuration, respectively. Proposed structures show right-hand circularly polarized with suppressed left-hand circularly polarized radiations and suitable for fixed mobile wireless communication applications. All structures are analyzed using Ansoft HFSS v.14 based on finite element method and measured results satisfy the simulated results.


Author(s):  
Muhammad Fauzan Edy Purnomo ◽  
Vita Kusumasari ◽  
Rudy Yuwono ◽  
Rahmadwati Rahmadwati ◽  
Rakhmad Romadhoni ◽  
...  

<span>In this paper, we acquire the configuration of the left-hand circular polarization (LHCP) array four patches stack triangular truncated microstrip antenna. This construction use the basic corporate feed microstrip-line with modified lossless T-junction power divider on radiating patch for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on unmanned aerial vehicle (UAV) with compact, small, and simple configuration. The design of circular polarization (CP) is realized by truncating the whole three tips and adjusting the parameters of antenna at the target frequency, <em>f </em>= 5.2 GHz. The results of characteristic performance and <em>S</em>-parameter for the LHCP array four patches stack antenna at the target frequency show successively about 9.74 dBic of gain, 2.89 dB of axial ratio (<em>Ar</em>), and </span><span>-</span><span>10.91 dB of S-parameter. Moreover, the impedance bandwidth and the 3 dB-<em>Ar</em> bandwidth of this antenna are around 410 MHz (7.89%) and 100 MHz (1.92%), respectively.</span>


Sign in / Sign up

Export Citation Format

Share Document