Slow-Wave Effect Enhanced Substrate Integrated Waveguide with Multi-Antipodal Blind Via-Holes and Distributed Metal Strips

A slow-wave (SW) effect enhancement method based on substrate integrated waveguide (SIW) is presented, theoretically studied, and experimentally validated. The SW effect is achieved by incorporating multi-antipodal metalized blind via-holes and distributed metal strips longitudinally connecting the bottom of upper posts. This improved SIW-based topology achieves a dramatic cutoff frequency reduction of 55.5% with reference to the conventional SIW with the same lateral size. Meanwhile, the phase velocity is reduced remarkably, realizing a more compact longitudinal dimension. The two effects give rise to a planar size reduction of 80% compared to the conventional SIW, which presents a significant advance in SIW miniaturization technology. A prototype is fabricated for a proof-of-concept, and the measured results are in good agreement with simulations, demonstrating its promising application potential and prospect in the microwave and millimeter-wave components.