Compact substrate integrated waveguide Wilkinson power dividers

Two half-mode SIW Wilkinson power dividers are investigated in this paper. The presented compact half-mode SIW power dividers benefit from the excellent shielded transmission characteristics of the SIW in the power splitting branch, unlike the previously published HMSIW Wilkinson power divider. Two structures with waveguide and microstrip line feeds were simulated. The simulations of the half-mode power divider with microstrip launchers demonstrate similar results to those achieved with the all-waveguide half-mode SIW structure. A prototype was fabricated to investigate the half-mode power divider with microstrip feed lines. Measurement results demonstrate improved isolation characteristics in comparison with the previously published literature on all SIW “Y” branch power dividers. A passband of 4.2GHz, or 40% bandwidth centered at 10.5GHz, was measured. The measured input return loss was less than 10dB, and the measured isolation was greater than 10dB over the entire operating bandwidth. The maximum isolation was found to be over 40dB at 12.4GHz.