Matching of active millimetre-wave slot-line antennas

The matching of a radiating, resonant structure to an active millimetre-wave device is investigated. As an active device, an IMPATT diode is considered to be matched to a planar slot-line structure. An analytical IMPATT diode model and an equivalent circuit of the slot line are used to calculate possible oscillation frequencies and large-signal modulation parameters of the diode. In the case of matching the output power is predicted. The results are in satisfactory agreement with experimental data and suggest a diode design with shorted drift regions and reduced diode area for optimum impedance matching.