Loaded bifilar helical antenna with small radius and large pitch angle

1991 ◽  
Vol 27 (17) ◽  
pp. 1568 ◽  
Author(s):  
H. Nakano ◽  
H. Mimaki ◽  
J. Yamauchi
2008 ◽  
Vol 44 (19) ◽  
pp. 1103 ◽  
Author(s):  
F. Yang ◽  
P. Zhang ◽  
C.-J. Guo ◽  
J.-D. Xu

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Shiqiang Fu ◽  
Yuan Cao ◽  
Yue Zhou ◽  
Shaojun Fang

A new low-profile variable pitch angle cylindrical helical antenna employing a copper strip as impedance transformer is proposed in this paper. Under the circumstance of a limited antenna height, the circular polarization performance of the antenna has been enhanced by changing the pitch angle and the input impedance matching has been improved by adjusting the copper strip match stub. The design method of the proposed antenna is given. The optimal antenna structure for INMARSAT application has been fabricated and measured. The measured results show that in the whole maritime satellite communication work band the VSWR is less than 1.2, its antenna gain is higher than 9 dBi, and the axial ratio is lower than 2.5 dB. The experimental results have a good agreement with the simulations. The proposed antenna is compact and easy tuning. It provides a promising antenna element for maritime satellite communication applications.


2006 ◽  
Vol 49 (1) ◽  
pp. 17-19
Author(s):  
Ze-Hai Wu ◽  
Edward K. N. Yung

1978 ◽  
Vol 31 (1) ◽  
pp. 71
Author(s):  
KR Soni

Earlier work on the radiation fields of a travelling-wave helical antenna in a compressible electron plasma has been extended to evolve expressions for the electromagnetic mode component R. and the electroacoustic or plasma mode component Rp of its radiation resistance. These expressions, - which are general in nature but involve complicated integrals, cover the special cases of multiturn loops, circular arcs and linear antennas. Analytical expressions for R. are then derived for the particular example of a helical antenna of small pitch angle with a fractional or integral number of turns. It is found that R. increases with pitch angle for some values of plasma frequency.


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.


2014 ◽  
Vol 134 (8) ◽  
pp. 1096-1103 ◽  
Author(s):  
Sho Tsujimoto ◽  
Ségolène Dessort ◽  
Naoyuki Hara ◽  
Keiji Konishi

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