This preliminary work has introduced the pin-lattice loaded rectangular waveguide that possess filtering capabilities, thus being a potentially important microwave device. As an example, such repeated entering and leaving of passbands and stopbands can find essential use as waveguide elements of interlaced multifunction array antennas. Moreover, the asymptotic technique provides an extremely rapid treatment that allows for much faster design procedures than analyzing other competing metamaterial-loaded waveguides, which may have time-consuming and computationally expensive full-wave simulations as the only recourse for parametric investigations and subsequent designs.