Fig. 7: Experimental results of fabricated A1-mode LWR filters.

a SEM images of the fabricated LWR filters. b A zoom-in view of region A in the filter with traditional IDTs. c A zoom-in view of region A in the filter with checker-shaped IDTs. d The measured S21 responses of the LWR filter with traditional IDTs. e The measured S21 responses of the LWR filter with checker-shaped IDTs