Abstract: An analysis is made of the evaluation of the millimeter-wave(MMW) power density(PD) in the area of the biological sample in the vicinity of MMW irradiators used in experiments on MMW biological effects. An idea is presented to calculate the MMW PD in the area of the biological sample using the electric field measured in the scanning plane based on the plane wave expansion technique. A method to calculate the MMW electric field via open-ended waveguide measurement is also given. With the application of the sampling theorem and the Fast Fourier Transform(FFT), two groups of numerical forms of the algorithm equations suitable for two kinds of FFT subroutines are derived. Finally, the measurement algorithm is fully tested by the measurement and calculation carrier out for an MMW irradiator.

Key words: millimeter wave, irradiator, power density, plane wave expansion, electric field measurement