scholarly journals Impedance Matching of Axial Mode Helical Antennas

2021 ◽  
Vol 20 ◽  
pp. 66-69
Author(s):  
Hossein Mardani ◽  
Neil Buchanan ◽  
Robert Cahill ◽  
Vincent Fusco
Keyword(s):  
Input Impedance ◽  
Impedance Matching ◽  
Ground Plane ◽  
Center Frequency ◽  
Design Parameters ◽  
Axial Mode ◽  
Impedance Characteristics ◽  
Measurement Results ◽  
Line Theory ◽  
Helical Antennas

In this paper, we study the input impedance characteristics of axial mode helical antennas to find an effective way for matching it to 50 Ω. The study is done on the important matching parameters such as like wire diameter and helix to the ground plane gap. It is intended that these parameters control the matching without detrimentally affecting the radiation pattern. Using transmission line theory, a simple broadband technique is proposed, which is applicable for perfect matching of antennas with similar design parameters. We provide design curves to help to choose the proper dimensions of the matching section based on the antenna’s unmatched input impedance. Finally, using the proposed technique, a 4-turn axial mode helix is designed at 2.5 GHz center frequency and the measurement results of the manufactured antenna will be included. This parametric study gives a good insight into the input impedance characteristics of axial mode helical antennas and the proposed impedance matching approach provides a simple, useful method for matching these types of antennas.

On the current distribution and input impedance of bent dipoles having a finite thickness

1972 ◽  
Vol 15 (9) ◽  
pp. 1069-1075 ◽  
Author(s):  
V. S. Varyvdin ◽  
F. I. Kolomoitsev ◽  
V. V. Ovsyanikov
Keyword(s):  
Current Distribution ◽  
Input Impedance ◽  
Finite Thickness

scholarly journals Design of a Compact UWB Antenna with Triple Band-Notched Characteristics

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Wang ◽  
Yan Zhang
Keyword(s):  
Input Impedance ◽  
Impedance Matching ◽  
Ground Plane ◽  
Surface Current ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Uwb Antenna ◽  
Notch Band ◽  
Parametric Studies ◽  
Triple Band

A new compact ultra-wideband (UWB) antenna with triband-notched characteristics is presented. The structure of the proposed antenna is simple and symmetric. A modified ground is introduced to obtain a wide impedance bandwidth of 2.9–13.4 GHz withS11<-10 dB. By inserting two arc-shaped slots in the radiation patch, two sharp bands of 3.3–3.7 GHz and 5.15–5.35 GHz are notched. The notch band of 7.25–7.75 GHz is achieved by etching a U-shaped slot in the ground plane. The notched bands can be controlled, respectively, while the characteristics of the proposed UWB antenna almost keep completely unchanged at the unnotched frequencies. Equivalent circuit models, surface current distributions, and input impedance are applied to analyze the principle of the proposed UWB antenna. Parametric studies are given. Simulated and measured results show that the proposed antenna has good impedance matching, stable radiation patterns, and constant gain.

scholarly journals Design of Compact Tri-Band Fractal Antenna for RFID Readers

2017 ◽  
Vol 7 (4) ◽  
pp. 2036 ◽  
Author(s):  
Mohamed Ihamji ◽  
Elhassane Abdelmounim ◽  
Hamid Bennis ◽  
Mostafa Hefnawi ◽  
Mohamed Latrach
Keyword(s):  
Radio Frequency ◽  
Radiation Pattern ◽  
Radio Frequency Identification ◽  
Input Impedance ◽  
Microstrip Antenna ◽  
Ground Plane ◽  
Physical Parameters ◽  
Fractal Antenna ◽  
Frequency Identification ◽  
Rectangular Microstrip Antenna

In this paper, a multiband and miniature rectangular microstrip antenna is designed and analyzed for Radio Frequency Identification (RFID) reader applications. The miniaturization is achieved using fractal technique and the physical parameters of the structure as well as its ground plane are optimized using CST Microwave Studio. The total area of the final structure is 71.6 x 94 mm<sup>2</sup>. The results show that the proposed antenna has good matching input impedance with a stable radiation pattern at 915 MHz, 2.45 GHz, and 5.8 GHz.

scholarly journals Impact of Graphene Thickness on EM Modelling of Antenna

2020 ◽  
Vol 1009 ◽  
pp. 75-80
Author(s):  
Sasmita Dash ◽  
Christos Liaskos ◽  
Ian F. Akyildiz ◽  
Andreas Pitsillides
Keyword(s):  
Graphene Sheet ◽  
Input Impedance ◽  
Finite Thickness ◽  
Three Dimensional ◽  
Slab Thickness ◽  
Two Dimensional ◽  
Thin Slab ◽  
Full Wave ◽  
Electromagnetic Modelling ◽  
The Impact

This paper presents illustrative electromagnetic modelling and simulation of graphene antenna using a two-dimensional graphene sheet of zero thickness and a three-dimensional graphene slab of finite thickness. The properties of the antenna are analyzed in terms of the S11 parameter, input impedance, VSWR, radiation pattern, and frequency reconfiguration using the full-wave electromagnetic simulator. Furthermore, this work numerically studies the modelling of graphene antenna using a three-dimensional graphene thin slab and the impact of graphene slab thickness on the performance of graphene antenna.

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