Experimental and simulated transmission coefficients for the bulk mode and nontrivial edge mode with and without defects. (a) Schematic illustration of the test configurations. The input port is fixed at column 2 (yellow star). (b,c) Transmission spectra experimentally probed as the output port is connected to columns 3, 6, 9, and 12 in the same row with the input port for the edge-to-edge case (row 14) and bulk-to-bulk case (row 11), respectively. (d) The average transmission (25-28 MHz, yellow region) for the edge-edge case and bulk-bulk case when port 2 is swept from columns 3-14 in the same row. The propagation loss of the edge mode is substantially lower than the bulk mode. (e) Numerically simulated transmission spectra for the edge mode propagating from column 2 to column 8 at the bottom row, and when different capacitors in the upper row (row 13) are connected to ground at both ends. (f) Numerically simulated transmission spectra for the bulk mode propagating from column 2 to column 8 at row 11 and when different capacitors in the upper row (row 10) are connected to ground at both ends.