Abstract: A microwave connector comprises two substrates arranged in orthogonal planes. A first substrate (2) is formed as a microstrip system (8) with a microstrip component (3) connected via a quarter wavelength taper (4) to a parallel transmission line (5). This transmission line terminates in a short circuit (15) to a ground electrode (7) on the back of the microstrip. A second substrate (10) is formed as a slotline system (9) having a slotline (13) between two sheet electrodes (14). In this slotline is a slot (16) of dimensions slightly less than the slotline width and sufficient length to accommodate the microstrip. The microstrip and slotline are electrically unconnected. Energy transfer between microstrip and slotline, or vice versa, takes place by electromagnetic coupling between the transmission line and the edges of the slotline. The slotline may be formed with an additional substrate and slotline electrode in a triplate configuration. Several microstrip components (8.sub.1 to 8.sub.