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.