Complex Impedance-Transforming Based And Compact Arbitrary Phase-Difference Based Coupler

The thesis presents three multi function couplers which could be used widely in the RF circuits and systems. The first coupler is the complex impedance-transforming one that features complex impedance matching intrinsically, leading to the reduction of the circuits size and loss. The second coupler is the compact arbitrary phase-difference one that features the combination of the phase shifter and the coupler, in which analysis is conducted on the tradeoff between bandwidth and miniaturized degree. The third coupler is the dual-band high-directivity coupler based on Substrate Integrated Coaxial Line(SICL), with low crosstalk and shielded structure. The design procedures and equations to the couplers are demonstrated. According the design method, three kinds of planar couplers are implemented. The matching between the theory and experiment results verifies the proposed three coupler.