Wideband Impedance-varying N-way Wilkinson Power Divider/Combiner for RF Power Amplifiers

We propose a compact wideband multi-way power divider/combiner with planar structure for applications to RF power amplifiers (PAs). Uniform transmission lines in the conventional divider are replaced with non-uniform transmission lines (NTLs), which are governed by a truncated Fourier series. An optimization-driven framework is employed in even-mode analysis to obtain the coefficients of the NTLs considering predefined operating bands, whereas three isolation resistors are optimized in the odd-mode analysis to achieve optimal isolation and output port matching over the design bandwidth. For verification purposes, a 4-10 GHz 3-way divider is simulated, and measured. Simulations and measurements are in close proximity and show input/output ports matching of better than -10 dB and transmission of -4.9 +/- 1 dB across the design bandwidth.