基于半模基片集成波导的柔性带通滤波器

o mitigate performance degradation and enhance the passband characteristics of flexible substrate integrated waveguide (SIW) filters, this paper introduces a rectangular defective ground structure (DGS) etched directly beneath the transmission lines on both sides of the filter. This approach maintains the impedance of the transmission lines while increasing their width, thereby reducing the discontinuity between the transmission lines and the halfmode substrate integrated waveguide(HMSIW) structure. By this method, the impedance matching between the transmission lines and the HMSIW resonant cavity is improved, which decreases the energy loss during electromagnetic wave transmission and enhances the passband performance of the flexible filter. Based on this technique, a flexible bandpass filter with a passband range of 7.75 GHz to 9.35 GHz has been designed. The filter was simulated and tested, and the test results demonstrate superior passband performance and stable operation even under bent conditions.