Total efficiency enhancement of X-band compact choke horn antenna with circular polarization and isoflux pattern

2015 ◽  
Vol 9 (1) ◽  
pp. 197-203
Author(s):  
Eric Arnaud ◽  
Luc Duchesne ◽  
Kevin Elis ◽  
Jamil Fouany ◽  
Thierry Monediere ◽  
...  

This paper presents a solution to reduce the feed complexity and to improve the total efficiency of X-band compact choke horn antenna with circular polarization and isoflux pattern. This kind of antenna had been designed before by our laboratory for nanosatellite applications, but it required a 4-way divider with phase shifter which generates the insertion losses and therefore a lower realized gain (RG). Among several feeds, a uniform circular helix antenna has been used here, which produces a satisfying feed without too much damage for the axial ratio (AR) and the isoflux pattern over a 400 MHz radiation bandwidth (8.0–8.4 GHz). Theoretical and experimental results show an AR lower than 5 dB and a RG higher than 0 dB at the limit of coverage, i.e. 65° whatever the azimuth angle (φ).

2017 ◽  
Vol 9 (7) ◽  
pp. 1509-1516 ◽  
Author(s):  
Eric Arnaud ◽  
Cyrille Menudier ◽  
Jamil Fouany ◽  
Thierry Monediere ◽  
Marc Thevenot

This paper presents an original solution to design a compact dual circularly polarized isoflux antenna for nanosatellite applications. This kind of antenna has been previously designed in our laboratory, for a single circular polarization. This antenna is composed of a dual circularly polarized feed and a choke horn antenna. This feed is a cross-shaped slot in the ground plane, which provides coupling between a patch and a ring microstrip line with two ports. It is located at the center of a choke horn antenna. The simulated antenna presents an axial ratio <3 dB and a realized gain close to 0 dB over a 400 MHz bandwidth (8.0–8.4 GHz) at the limit of coverage, i.e. 65° whatever the azimuth angle (φ) and the port. A 20 dB matching for each port and 13 dB isolation characteristics between the two ports have been achieved on this bandwidth. It has been realized and successfully measured.


2015 ◽  
Vol 8 (3) ◽  
pp. 651-659 ◽  
Author(s):  
Eric Arnaud ◽  
Luc Duchesne ◽  
Kevin Elis ◽  
Jamil Fouany ◽  
Thierry Monediere ◽  
...  

This paper presents a tradeoff between isoflux pattern quality and X-band antenna compactness for nanosatellite applications. Having an isoflux radiation and a circular polarization (CP) generally causes a large antenna size which is incompatible for these applications. A new design of an antenna is done with the following maximum antenna dimensions: a diameter of 90 mm and a height of 20 mm above the nanosatellite platform. The isoflux pattern is slightly degraded while a good CP and realized gain are kept. The structure is a compact choke horn. It presents an axial ratio lower than 3 dB and a RG close to 0 dB over a 400 MHz bandwidth (8.0–8.4 GHz). It has been realized and successfully measured.


2021 ◽  
Vol 19 ◽  
pp. 256-261
Author(s):  
Yumi Takizawa ◽  
Atsushi Fukasawa ◽  
Cahya Edi Santosa ◽  
Josaphat Tetuko Sri Sumantyo

This paper presents a plane antenna and array for X-band circular polarization. The novel factors of this development are elliptic resonator antenna and Glass-Epoxy substrates. High efficiency in resonance and radiation of microwave energy is expected by elliptic resonators. Easy process in fabrication is expected by Glass-Epoxy substrate. Elliptic ratios of feed- and reactance-elements are chosen independently each other. The dielectric constant εr and tan δ are 4.6 and 0.010 respectively. Enough bandwidth of axial ratio of circular polarization and directive gain are confirmed to be 15 % of central frequency and 10 dB respectively for antenna array.


2021 ◽  
Author(s):  
SACHIN KUMAR YADAV ◽  
Amanpreet Kaur ◽  
Rajesh Khanna

Abstract A circularly polarized hollow dielectric resonator antenna (CPHDRA) is designed for X-band applications. Rectangular dielectric resonator (RDR) is used as a radiator element, fed by a quarter-wave transformer (QWT) feedline. By performance of the RDR antenna, an air cylindrical rod structure is extracted from RDR to enhance the gain and impedance bandwidth. Two parasitic strips are placed on the top of the RDR to achieve circular polarization with reported ≤ 3-dB axial ratio (AR) bandwidth for X-band applications. In this article, UWB antenna covers range from 2.74 to 10.4GHz by using asymmetrical defective ground structure (DGS). In near field of the dielectric resonator, three different radiating modes namely HE11δ, HE21δ, HE23δ, and HE32δ are at 4.4, 6, 8.8, and 9.9 GHz. For the generation of circular polarization (CP), two orthogonal modes are generated at 8.8 and 9.9 GHz as per XZ and YZ planes. It has reported 23.8 % (8 to 10.1 GHz) of 3-dB AR bandwidth. The simulated and measured impedance bandwidths are 118.46 % and 121.12 % along with a peak gain of 6.55 dB without the use of a metallic reflector. By using a metallic reflector suspended in the bottom side of the substrate with a distance of 13.1mm is reported along with the peak gain of 9.8 dBi.


2017 ◽  
Vol 9 (9) ◽  
pp. 1877-1881 ◽  
Author(s):  
Laaya Sabri ◽  
Nasrin Amiri ◽  
Keyvan Forooraghi

A new single-feed aperture-coupled, X-band microstrip patch antenna array with circular polarization (CP) is designed. CP is achieved using indented microstrip patches fed through the slots on a substrate integrated waveguide. The antenna has the high radiation efficiency more than 90% over the operating frequency. Impedance bandwidth (VSWR < 2) and axial ratio bandwidth (AR < 3 dB) of 11.8, and 10.9% is attained, respectively. Good agreement is achieved between simulated and measured results.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yun Zhou ◽  
Shaojun Fang ◽  
Hongmei Liu ◽  
Shiqiang Fu

A novel polarization-reconfigurable conical helical antenna based on the liquid metal is presented. The antenna is implemented by using truncated structure, variable pitch angle, a matching stub, and a mechanical autorotation device. The experimental results show that a good agreement between simulations and measurements is obtained. The gain of the antenna achieves higher than 8 dBi in the work band (1525–1660.5 MHz), and the 3 dB axial ratio (AR) bandwidth reaches 410 MHz. The polarization mode of the antenna can be switched between right-hand and left-hand circular polarization.


Frequenz ◽  
2020 ◽  
Vol 74 (5-6) ◽  
pp. 191-199
Author(s):  
M. K. Verma ◽  
Binod K. Kanaujia ◽  
J. P. Saini ◽  
Padam S. Saini

AbstractA broadband circularly polarized slotted square patch antenna with horizontal meandered strip (HMS) is presented and studied. The HMS feeding technique provides the good impedance matching and broadside symmetrical radiation patterns. A set of cross asymmetrical slots are etched on the radiating patch to realize the circular polarization. An electrically small stub is added on the edge of the antenna for further improvement in performance. Measured 10-dB impedance bandwidth (IBW) and 3-dB axial ratio bandwidth (ARBW) of the proposed antenna are 32.31 % (3.14–4.35 GHz) and 20.91 % (3.34–4.12 GHz), respectively. The gain of the antenna is varied from 3.5 to 4.86dBi within 3-dB ARBW. Measured results matched well with the simulated results.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thi Kim Thu Nguyen ◽  
Thi Minh Nguyen ◽  
Hong Quang Nguyen ◽  
Thanh Nghia Cao ◽  
Dac Tuyen Le ◽  
...  

AbstractA simple design of a broadband multifunctional polarization converter using an anisotropic metasurface for X-band application is proposed. The proposed polarization converter consists of a periodic array of the two-corner-cut square patch resonators based on the FR-4 substrate that achieves both cross-polarization and linear-to-circular polarization conversions. The simulated results show that the polarization converter displays the linear cross-polarization conversion in the frequency range from 8 to 12 GHz with the polarization conversion efficiency above 90%. The efficiency is kept higher than 80% with wide incident angle up to 45°. Moreover, the proposed design achieves the linear-to-circular polarization conversion at two frequency bands of 7.42–7.6 GHz and 13–13.56 GHz. A prototype of the proposed polarization converter is fabricated and measured, showing a good agreement between the measured and simulated results. The proposed polarization converter exhibits excellent performances such as simple structure, multifunctional property, and large cost-efficient bandwidth and wide incident angle insensitivity in the linear cross polarization conversion, which can be useful for X-band applications. Furthermore, this structure can be extended to design broadband polarization converters in other frequency bands.


Author(s):  
Yiqi Cheng ◽  
Xinhua Wang ◽  
Waheed Ur Rehman ◽  
Tao Sun ◽  
Hasan Shahzad ◽  
...  

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the geometric theory of the applied spatial triangulation function. A three-dimensional model of the cylindrical vane pump was established with the help of MATLAB and Pro/E. The kinematic analysis helped in developing kinematic equations for cylindrical vane pumps and proved the effectiveness of the structural design. The maximum inaccuracy error of the computational fluid dynamics (CFD) model was 5.7% compared with the experimental results, and the CFD results show that the structure of the pump was reasonable. An experimental test bench was developed, and the results were in excellent agreement with the numerical results of CFD. The experimental results show that the cylindrical vane pump satisfied the three-element design of a positive-displacement pump and the trend of changes in efficiency was the same for all types of efficiency under different operating conditions. Furthermore, the volumetric efficiency presented a nonlinear positive correlation with increased rotational velocity, the mechanical efficiency showed a nonlinear negative correlation, and the total efficiency first increased and then decreased. When the rotational velocity was 1.33[Formula: see text] and the discharge pressure was 0.68[Formula: see text], the total efficiency reached its maximum value.


Sign in / Sign up

Export Citation Format

Share Document