A Simple Low Loss Partially-Filled 16-way Radial Power Combiner

摘要

A new N-way partially-filled radial combiner design is proposed. The design integrates the advantages of printed circuit board (PCB) technology and those of air cavities into a single reactive power combiner. Minimal transmission losses are achieved using an air cavity, and the PCB allows flexibility with regard to port terminations. Importantly, simple and accurate PCB etching is exploited to achieve a wide-band central port match, without resorting to the typical high accuracy machining of the central feed pin. A 16-way prototype was manufactured and tested. When symmetrically excited, the measured input reflection coefficient is less than -15 dB over 20 % fractional bandwidth at 4 GHz. Peripheral port signal amplitude and phase imbalances are within ± 0.3 dB and 2.5 degrees, respectively. The prototype incurs less than 0.45± dB transmission loss, yielding a combining efficiency better than 90% in the operating band. Additionally, the cavity housing as tested was made without the use of CNC machines.