Power Combiner Integrated with Harmonic Filter

Abstract

Recently, the all-solid-state TV and FM transmitters rated to kW have come to be manufactured. A power combiner and spurious filter are widely used for the output equipments of those transmitters. These output equipments have the defect of large size because both the combiner and the filter employ a quarter wavelength line.
This paper describes the power combiner which has the function of harmonic suppression. As the harmonic filter is integrated with this combiner, the output equipments can be miniaturized.
Good agreement between experimental data and theoretical value is obtained. Furthermore, we made the 4 way combiner for all-solid-state FM 1 kW transmitter. Within 10% bandwidth, output VSWR is less than 1.2, input VSWR is less than 1.1, isolation between input terminals is about 20 dB, insertion loss is 0.25 dB, and harmonics suppression is greater than 30 dB in this combiner.