A Compact 16-Way High-Power Combiner Implemented Via 3-D Metal Printing Technique for Advanced Radio-Frequency Electronics System Applications

In this paper, a size-compact and monolithically integrated millimeter-wave 16-way high-power combiner for advanced radio-frequency (RF) electronics applications is developed featuring a wide operational bandwidth and high isolations between the combiner's adjacent ports. The proposed combiner is operating at the X band and is composed of fifteen 3-dB directional coupler units that are properly configured to achieve the overall structural compactness. The combiner is fast-prototyped as a single part by employing a metallic three-dimensional (3-D) printing technique, which successfully overcomes the difficulty in its monolithic implementation by using conventional subtractive manufacturing techniques. The experimental results demonstrate that the 16-way power combiner achieves an approximately 21% operational bandwidth (8.5-10.5 GHz) at the X band with port isolations of more than 20 dB, an amplitude imbalance of about ±1 dB, a phase deviation of around ±1°, and good return and insertion losses. The excellent RF performance of the combiner makes it a good candidate for applications in multiport high-power electronics systems where highly efficient power transmission and conversion among different ports are required.