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Resistive sensors for WRD250 and WRD750 double ridged waveguides are developed. Using the developed sensors, short high power microwave (HPM) pulses covering frequency ranges 2.6–7.8 and 7.5–18 GHz can be measured directly. The novelty of the proposed sensors is not only the measurement of a few ns duration HPM pulses but also the expansion of frequency bandwidth to WRD750 waveguide frequencies. The flat frequency response of the sensors is sacrificed to measure short HPM pulses, but a wide operating frequency band is still maintained. The response time of developed sensors was estimated using the time-domain reflectometry method, and by comparing the shapes of short HPM pulses registered by the sensor and microwave probe connected to the wide bandwidth oscilloscope. The measurement results show that the sensors demonstrate quite good general characteristics with a short response time of 1.05 and 0.7 ns for WRD250 and WRD750 sensors, respectively. The times of response are promising when using these sensors for measuring short monochromatic HPM pulses, the duration of which is around 5 ns. [ABSTRACT FROM AUTHOR]

Finite-difference time-domain (FDTD) method is frequently used for calculation of transmission and reflection characteristics of periodic structures. We propose a hybrid FDTD technique for evaluation of the transmittance and reflectance spectra of periodic structures that significantly reduces the usage of computer memory and time of the calculation. In the considered case, calculation time and memory occupation were reduced up to 30% and 20%, respectively, compared to the standard FDTD procedure. Calculated results fit well in the experimentally measured data. [ABSTRACT FROM PUBLISHER]

Two types of resistive sensors with flat frequency response for WRD840 and WRD250 double-ridged waveguides were developed. The first type of sensors is optimized for microwave power measurements inside the waveguide. The second type of sensors is connected to the particular horn antenna and optimized for microwave pulse power density (or electric field strength) measurements in free space. The flat frequency response of the sensors was designed by changing the parameters of the sensing element. Proposed sensors can measure high-power microwave pulses covering frequency ranges 0.84–2.0 GHz and 2.6–7.8 GHz. [ABSTRACT FROM PUBLISHER]

Thin metal coatings on glass are widely used in modern windows to improve their thermal properties. However, while there are some available papers on the properties of microwave propagation through commercial metallized windows glass below 6 GHz there seems to be a lack of papers regarding metallized multiglazed windows at higher frequencies. Such data are of the great importance when designing modern microwave communication systems working in urban environments. In this paper, the shielding effectiveness (SE) of modern energy-saving glasses and windows were investigated at microwave frequencies from 1 to 20 GHz. Wide measurement range together with proposed fast calculation procedure based on the matrix multiplication method, allowed us to elucidate the reasons responsible for the extremes in dependencies of SE on frequency. It was also shown that by comparing measured and calculated results, the conductivity of the thin metallic layer used in modern energy-saving windows can be determined. During the study, we found that attenuation of microwave radiation passing through modern windows can be as high as 60 dB. [ABSTRACT FROM AUTHOR]

Discusses the use of resistive sensors based on the electron heating effect in semiconductors, for microwave pulse-power measurement in the waveguide. Proposal of substitution procedure of replacing a microwave electric field; Development of diaphragm-type resistive sensor.