Oversized microstrip line as differential guided-wave structure

An oversized microstrip line as a differential guided-wave structure is proposed. For most guided-wave structures such as microstrip line and waveguide, the signal transmission will be in the form of fundamental mode propagation, where higher-order mode propagations should be avoided. In this reported work, the first higher-order propagation mode (TE10) of a microstrip line is excited. Its guide-wave characteristic was simulated and measured. The oversized microstrip line supporting TE10 propagation mode is proposed for the microwave and millimetre-wave differential circuit and system designs.