Patent ID: 8917958

Claim:
An electrical waveguide transmission device that accepts a differential electrical input signal and conveys the input signal to a Mach-Zehnder optical modulator having a series push-pull traveling wave electrode with first and second Mach-Zehnder signal electrodes having a characteristic impedance; said device comprising: a first input signal conductor and a second input signal conductor accepting a differential electrical input signal; at least one input ground conductor interposed between the first and second signal input conductors, forming a first waveguide between the first input signal conductor and a ground conductor having a first characteristic impedance, and forming a second waveguide between the second input signal conductor and a ground conductor having a second characteristic impedance; a first output signal conductor; and a second output signal conductor without a ground conductor interposed between the first and second output signal conductors; said first and second output signal conductors forming a third waveguide having a third characteristic impedance that is the sum of the first and second characteristic impedances, and is also substantially equal to the characteristic impedance of the Mach-Zehnder traveling wave electrode.