The present disclosure relates to a waveguide interface arrangement (1, 1') for electrically connecting a waveguide device (2) to a microwave conductor (3) that runs in a metallization (7, 9) on one main side (6, 8) of a printed circuit board (4), PCB, comprising a PCB dielectric layer (5), a first PCB main side (6) with a first PCB metallization (7) and a first PCB aperture (10) in the first PCB metallization (7), and a second PCB main side (8) with a second PCB metallization (9) and a second PCB aperture (11) in the second PCB metallization (9). The first PCB aperture (10) corresponds to a waveguide aperture (22) and a backshort (15, 15') is attached to the second PCB main side (8), comprising a backshort dielectric layer (16), a first backshort main side (17, 23) with a first backshort metallization (18, 24), and a second backshort main side (19, 19') with a second backshort metallization (20, 20') and a backshort aperture (21, 21') in the second backshort metallization (20, 20'). -The backshort metallizations (18, 24; 20, 20') are electrically connected to each other. -The first backshort metallization (18, 24) covers a main part of the first backshort main side (17, 23). -The second backshort metallization (20, 20') is electrically connected to the second PCB metallization (9). -The backshort aperture (21, 21') is adapted to face the second PCB aperture (11).