Abstract: A wideband microwave device for generating even harmonics of an incident microwave signal. A co-planar-type input structure conducts an incident microwave signal with an asymmetrical propagation mode. Two asymmetrical mode outputs of an equiphase divider are applied to respective inputs of two nonlinear circuit structures, whose respective output signals include even harmonics of the incident signal. The two outputs signals are combined in a circuit having an asymmetrical propagation mode output and which may be followed by a filtering circuit helping to isolate the desired even harmonic.