Resistive Sensor for High Power Microwave Pulse Measurement of Te01 Mode in Circular Waveguide

Abstract

Abstract-A resistive sensor (RS) devoted for high power microwave pulse measurement in cylindrical waveguide is considered. The modeling results of the interaction of the TE 01 (H 01 ) wave with a semiconductor plate with contacts on sidewalls of the plate placed on a wall of the circular waveguide are presented. A finite-difference time-domain (FDTD) method was employed for the calculation of the electromagnetic field components, reflection coefficient from the semiconductor obstacle, and the average electric field in it. The features of the resonances have been used to engineer the frequency response of the RS. It has been found that such electrophysical parameters of the plate can serve as the prototype of the sensing element (SE) for the circular waveguide RS with flat frequency response.

Modelling of resistive sensor for high power microwave pulse measurement of TE11mode in circular waveguide

“…One contact of it is grounded, while the other one is isolated. The same layout of the SE has been used in our previous papers [3,4] where the RS for TE 01 mode has been analysed. Cross-sectional view of the modelled structure in a cylindrical coordinate system is shown in Fig.…”

“…When E is determined, the dependence of ∆R/R on P can be calculated in a wider dynamical range of the power transmitted through the waveguide in a similar way as in [4]:…”

“…Details about the FDTD application for simulation of a wave propagation within a circular waveguide segment with the SE can be found in [3,4]. To overcome the singularity at r = 0 we have followed a method proposed in [13] that is based on the use of the Cartesian coordinate system in the vicinity of r = 0.…”

“…Like in [4], the main requirements for SE can be formulated as follows: first, it should not cause considerable reflection in the waveguide, so the value of VSWR has been set at <1.2; second, the RS should be able to measure nanosecond-duration HPM pulses; therefore, the DC resistance of the RS should not exceed 50 Ω; finally, the flat frequency response of the RS in the waveguide's frequency band is preferable.…”

“…Having in mind the drawbacks of the measurement of HPM pulses in facilities employing circular waveguides in the output, the RS, in the circular waveguide operating at TE 01 (H 01 ) mode whose losses decrease with increasing frequency, has been developed in our previous paper [4]. However, TE 01 mode propagating in a circular waveguide is not the lowest one [5].…”