.225 Ghz Waveguide Power Combiner With Corrugated Horn Radiation Characteristics

Power combining techniques and corrugated horns have important applications in millimeter-wave and THz frequency band. So a rectangular waveguide power combiner and corrugated horns with center frequency of 225 GHz are studied in this paper by using theory analysis and simulation.Main works are as follows:(1) A rectangular waveguide power combiner has been designed. Distribution of the electric field and the efficiency of the combiner are investigated by numerical calculation and simulation. The results of numerical calculation show that magnitude of the combining peak electric field is decreased as the phase difference of the two input waves is increased. The position of the combining peak electric field is far away from the input port with the increase of thickness between the two input waveguide. The results of simulation are in agreement with those of the numerical calculation. The results of simulation show that the efficiency of the combiner is upper than 90 percent with phase difference of the two input waves less than 35 degree and the bandwidth is 10GHz.(2) Single-mode and over-mode corrugated horns have been studied. The mode transmission coefficient is obtained by using conservation of complex power technique and generalized scattering matrix, and then we obtain the antenna far-field radiation pattern by using circular caliber far-filed radiation formula. For single-mode corrugated horn with hyperbolic surface profile, in the conditions of fixed input and aperture radius, the greater open angle of horn, the lower edge level of E plane main-lobe, it means that the far-field radiation pattern is better. In the range of 5 10λc≤P≤λc, the longer period P ,the wider the width of E plane main-lobe, the lower edge level of E plane main-lobe. Otherwise, there are little impacts on radiation pattern of H plane with the variation of the parameters. For over-mode corrugated horn, linear and hyperbolic surface profile of the corrugated horn are studied. The results of numerical calculation show that the far-field radiation of former is better than the latter.