A 330-GHz Radial Power Division/Combination Network Based on Circularly Polarized TE11 Mode

Abstract

To compensate for severe mode interference and machining difficulties above the W-band of the traditional radial power combining scheme, a radial power division/combination network based on circularly polarized (CP) TE11 mode is designed. Firstly, the amplitude and phase distribution of the branches of a radial power divider under the excitation of CP mode are analyzed. The amplitudes of each branch are approximately equal, and the phase increases/decreases with equal differences. Therefore, a radial power divider with 16 branches based on a septum circular polarizer (SCP) is designed. An orthogonal cascade structure (OCS) and a parallel cascade structure (PCS) are proposed, and it is concluded that to obtain higher transmission efficiency, OCS and PCS should be used respectively when the phase or amplitude difference of SCP is worse. Finally, the power divider and a microstrip probe transition structure are cascaded back-to-back by using OCS, and the power division/combination network is obtained. Simulation results show that at 310-360 GHz, the amplitude difference of the branches of the power divider is less than ±0.35 dB; the combining efficiency of the power division/combination network is greater than 90%. This network has the advantages of single-mode operation, simple structure, and high combining efficiency. In addition, this article provides a feasible solution to the problem of depolarization loss caused by the cascade of SCPs.