High power millimetre wave pulse sensor for W-band

A resistive sensor for high power millimetre wave pulse measurement in a frequency range 78-118 GHz (W-band) has been developed. Two sensing elements mounted on a wide wall of a waveguide were employed to measure pulse propagating in the waveguide with 2.4times1.2 mm² window size. A finite difference time domain method was applied to engineer the sensor with optimised frequency response. Two groups of sensors were produced and tested experimentally. Dependence of each sensor´s sensitivity on frequency was measured and reasonable agreement between the measured and calculated values was obtained, once the finite thickness of upper metal contacts of sensing elements and the air gap between them was taken into account during the calculations. Other important characteristics of the sensor, such as voltage standing wave ratio and dependence of the output signal on pulsed power were measured experimentally as well. The sensor was tested up to 2 kW pulse power