Simulation of a four-arm spiral antenna for GPS result shows that considering the coaxial impedance matching connected coaxially to the helical antenna
can reduce the antenna geometries complexity.
A normal-mode helical antenna
(NMHA) has been studied for more than half a century, and the operation principles are well known by a simple equivalent model, proposed by Kraus and Wheeler, based on the assumption that the each turn is the superposition of electric and magnetic dipoles [1,2].
A quadrifilar helical antenna
with parasitic loop," IEEE Antennas Propag.
Capsalis, "Theoretical approach of the interaction between a human model and a mobile handset helical antenna
using numerical methods," Progress In Electromagnetics Research, Vol.
The helical antenna
is tuned to the lower frequency (900 MHz) band.
One approach to smaller antennas is the Contrawound Toroidal Helical Antenna
(CTHA) consisting of two or more helices wrapped around a toroidal core.
Before using Mathcad, SkyCross depended on manipulating lab built models for one particular class of antennas, the Quadrifilar Helical Antenna
A helical antenna
element has been selected and its optimization parameter is the number of turns of the helix in a fixed height and radius .
Substituting pitch of helical antenna
([rho] = l/2) equal to dipole length and taking its product with radianlength (l = [lambda]/2[pi]) will produce the CP if the CP conditions are fulfilled by equating it to the area of loop antenna of radius a.
As the name implies, QFHAs are primarily based on helical antennas
, A single helical antenna
is capable of operation in two primary modes: normal and axial.
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The helical antenna
attached onto the handset was the radiation source, and electromagnetic absorption upon the head was measured.