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°, 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°, 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°, respectively. The designed power combining transition is proposed to be used in X-band applications like antenna array applications and power combining applications.