Enhancing the Power Capabilities of the Stepped Septum Using an Optimized Smooth Sigmoid Profile

Abstract

The typical septum polarizer that has gained popularity in the literature may be unsuitable for high-power applications, due to the sharp corners in the design. In order to address this issue, the fundamentals of the septum operation are fi rst revisited, using a graphical visualization through full-wave analysis. A septum profi led with smooth edges is next presented, with enhanced power-handling capabilities in comparison to the stepped-septum polarizer. In this work, the sigmoid function is introduced to represent the smooth contour of the septum, and to enable diverse confi gurations without any discontinuities. The smooth and stepped profi les are optimized using the Particle Swarm Optimization (PSO) technique. The maximum electric-fi eld intensity around the smooth edges is investigated using a full-wave simulator, HFSS. Our observations show that the maximum electric fi eld is reduced by 40% in comparison to the stepped septum. In Appendix 1, the numerical approach is evaluated by comparing the exact series solution for the half-plane scattering problem with the simulated results in HFSS. In Appendix 2, a septum design with rounded edges is also studied as another possible design to reduce the maximum fi elds.

High-Power Wideband Elliptical-Grooved Over-Mode Circular Waveguide Polarizer

“…The calculated power handling capacity of the polarizer is difference. [6] has the shortest length among the five polarizers, but the power capacity of the metal stepped septum polarizer is lower than that of the truncated waveguide polarizer [8] and the proposed polarizer for the application of tiny-size abrupt structure. The length of the proposed polarizer is more than 11λ shorter than that of the truncated waveguide polarizer [8].…”

“…The existing researches of polarizers mainly focus on the improvement of bandwidth and miniature design. The representative polarizers consist of metal screws [3], metal irises [4], metal stepped septum [5,6], or dielectric-slab [7], which are placed into waveguide to differentiate the phase of the two orthogonally polarized components. These polarizers meet the demands of polarization conversion experiments and applications.…”

“…These polarizers meet the demands of polarization conversion experiments and applications. However, they could not meet the gigawatt-class high-power microwave applications for the tiny-size inserted abrupt structures [3][4][5][6], tending to cause local electric field concentration. Moreover, dielectric-slab polarizer [7] inevitably introduces triple junction, which is prone to result in RF breakdown.…”

Dependence of Irradiated High-Power Electromagnetic Waves on the Failure Threshold Time of Semiconductors Using a Closed Waveguide

“…HPM devices developed in various countries such as the United States, Russia, China, and Japan as well as several countries in Europe can be viewed as being mainly studied for military purposes. However, as described above, intentionally generated electromagnetic waves can cause serious damage to information equipment [10][11][12][13][14][15][16][17][18]. HPEM emulators used to measure the level at which private information devices and systems are upset by high-power transient electromagnetic waves through simulations are more effective than a gigawatt-level electromagnetic wave generator.…”

Development of Broadband LHCP Pyramidal Horn Antenna with Septum Gaussian Profile Polarizer for CP-SAR Sensor Onboard Microsatellite

“…Many methods have been proposed to produce the circularly polarized horn antenna. Some researchers designed stepped septum inside square waveguide as in [2] [3] [4] to achieve wide bandwidth axial ratio, while a different function was used to design septum polarizer to modify stepped septum transition with smooth lines such as Legendre function and Sigmoid function [5] [6]. However, they still have many parameters, and the lines are not easy to fabricate using the FDM 3D printer.…”