On the power handling of a high power combiner for industrial, scientific, and medical applications

Authors: ARASH AHMADI

Abstract: In this paper a 2-way broadband power combiner that can handle up to 1 kW output power is designed and fabricated. The combiner covers the frequency range of 30 to 500 MHz, which is intended for industrial, scientific, and medical (ISM) applications. The power handling of the power combiner depends on the power handling of the components that constitute the combiner. The combiner is composed of some coaxial transmission lines and a transmission line transformer. The ferrite cores, which are used to suppress the common mode current, are one of the major limiting factors, regarding the power handling of the combiner. The power combiner is implemented with some binuclear and some stacked toroids of material 61, which is extensively used for common mode current suppression in this frequency range. As real ferrites have complex permeability, some of the input power dissipates as heat in the ferrite cores. The power dissipation due to the equivalent parallel resistance of each ferrite core is calculated. The proper operation of the high power combiner is verified by simulation of the temperature rise in the ferrite cores due to heat dissipation.

Keywords: Power combiner, broadband, transmission line transformer, ferrite core, power handling

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