A novel compact multifunctional coaxial to waveguide power combining transitions for X-band applications

This paper presents the design of novel compact multifunctional coaxial to waveguide power combining transition (PCT) for X-band applications. For the proof of the proposed concept, 2-way PCT operating over the entire X-band (8.2-12.4 GHz) and 4-way PCT operation from 9.5 to 10.8 GHz are designed, developed, and characterised. Two-way PCT achieves a measured return loss better than 14 dB over the operating band, and the measured amplitude imbalance and phase imbalance are within 0.25 dB and 4 degrees, respectively. Four-way PCT achieves a measured return loss better than 15 dB over the operating band, and the measured amplitude imbalance and phase imbalance are within 1 dB and 10 degrees, respectively. Furthermore, a 6-way PCT is also designed, fabricated, and measured to demonstrate the scalability of the proposed concept. The 6-way PCT achieves the measured return loss better than 15 dB from 9.9 to 10.475 GHz, and measured amplitude and phase imbalances are within 0.6 dB and 10 degrees, respectively. The designed power combining transition is proposed to be used in X-band applications like antenna array applications and power combining applications.