Efficient Design and Experimental Verification of High-Q MPhC BPF for mm-Wave Applications

The metallic photonic crystal (MPhC) structure, consisting of a periodic array of via holes in a low-loss printed circuit board (PCB), has many advantages such as small-size, light-weight and high-Q planar-circuit integration. Accordingly, it has the great potential as a platform to design various electromagnetic wave devices. To efficiently design N-stage direct-coupled MPhC-resonator filter with inductive metal posts, a Step-Tune-Method (STM) is presented to design the filter by successively appending one resonator at a time. The physical dimensions of the added resonator are then extracted from the theoretical frequency characteristics based on the corresponding partitioned coupling matrix. It should be noted that, with the step-tune procedure, the filter can be efficiently designed without the global optimization on all structural parameters. A 5
^th
order direct-coupled-resonator bandpass filter is designed and realized in the K-band.