High Efficiency Excitation of Dielectric Rods Using a Magnetic Ring Current

Abstract

We describe a theoretical analysis of the excitation of the fundamental HE surface wave mode on an infinite dielectric rod by a magnetic ring current that is interior to the rod. Earlier work has provided results for an external ring source. Results obtained by us show that for an interior source excitation efficiencies close to 100% are possible for high permittivity dielectrics and launching efficiencies greater than 90% can be achieved over bandwidths greater than 20%. This is a higher efficiency than is possible with an exterior source. Simulation results verifying the theoretical analysis are presented for the practical case of a coaxial waveguide exciting the dielectric rod.Index Terms-Dielectric rod, excitation efficiency, magnetic ring current.

Optimized dielectric rod antennas for terahertz applications

“…1. This current distribution has previously been shown to excite the fundamental HE 11 mode on a dielectric rod with high efficiency [3].…”

“…This length was chosen because it is close to the maximum length achievable with our ablation method of fabrication [5]. The starting diameter of the rod and magnetic ring current radius were selected to maximize the excitation efficiency according to [3].…”

Measurement of mutual coupling between profiled dielectric rod antennas

“…This is an indication only of the likely coupling level. Each dielectric rod is excited by a tuned magnetic ring slot [4]. The measurements were undertaken with a vector network analyzer.…”

“…In this study, the effects of coupling between the dielectric rods have been calculated with the CST software. We have found that highly efficient coupling from a transmission line to a dielectric rod can be achieved with a magnetic current source [4]. This approach is used in the present work in a consideration of rods in an array.…”

Pulse Signals in Open Circular Dielectric Waveguide

“…The waveguide is infinite in both directions along axis z. It is excited by a ring of azimuthal magnetic currents that allows effectively launching the principal FD mode (HE 11 , see Figure 2) in such a structure in a wide frequency band [10]. The time waveform of the excitation currents was chosen to be Gaussian with spatial duration equal to 2/5 of rod radius a.…”