Backfire/endfire radiation performance of quadrifilar helical antennas

Propagation and radiation characteristics of dielectric‐loaded axial‐mode helical antenna

“…Further, many types of helical antennas have been investigated by many researchers and are reported in the literature including modified helical antenna [2], quadrifilar helical antennas [3], internally matched helical beam antenna [4], bifilar helical antenna [5], spherical helical antenna [6], rnultifilar helical antennas [7], cavity backed helical antennas [8], aperture-coupled helix antenna [9], conical helical antenna [10], helical antennas with nonuniform helix diameter [11], sleevecage and sleeve-helical antennas [12], double-helix antenna [13], quasi-taper helical antenna [14], etc.…”

“…In the modulation-based configurations, it is a large challenge to achieve high frequency sources. Some methods based on four-wave mixing effects between the modulating sidebands in semiconductor optical amplifiers [3] and highly nonlinear fibers [4] were proposed recently and try to triple the frequency of the generated microwave.…”

Printed wire antennas for wireless communications

“…When the helical antenna works in normal mode, the radiation pattern is broadside [25]. When it works in axial mode, the radiation pattern is endfire [13]. As mentioned in Chapter 1, the non-resonant axial-mode helical antenna with a travelling current distribution can radiate circularly polarized wave over a broad range of frequency with fairly high gain.…”

“…Some resonant antennas, such as microstrip antennas, can radiate the circular polarized wave by adding the perturbation elements such as a slit or stub in the diagonal line of a squared patch [11]. Moreover, some non-resonant antennas, including spiral antennas [7], [12], axial mode helical antennas [13], and loop antennas [14], [15] can also radiate circular-polarized wave with extended frequency bandwidth. This project will mainly focus itself on the development of a new class of non-resonant printed wire antennas with circular polarization.…”