Compact quad-band power divider based on quad-mode stub loaded resonator

A compact quad-band equal power divider (PD) based on quad-mode stub loaded resonators (SLRs) and conventional Wilkinson power divider is proposed in this paper. The proposed SLR, analyzed by even/odd mode analysis method, can introduce four narrow passbands and provide more degrees of freedom to tune the resonant frequencies. A prototype of a quad-band equal PD centred at 1.5, 2.5, 3.5 and 5.2 GHz is fabricated. The predicted results on S parameters are compared with the measured ones and good agreement is found.