“…1(a) Since the coordinate along longitudinal axis of the upper waveguide isx 0 = a 1 /2, the waveguide mode becomes evanescent, i.e., the slot does not excite propagating waves, and the microwave power concentrates in the region limited by the slot. Earlier, a similar junction mode was considered based on mathematical modeling [7]. It was shown that at x 0 = a/2, the maximum power transfer from the lower to the upper waveguide can be achieved when the distance z 0 (measured along axis z as shown in Fig.…”