Excitation of the microstrip higher order leaky modes by aperture-coupling method

A simple method for exciting the microstrip higher order leaky modes is demonstrated in the paper. Properly arranging narrow slots on the ground plane where the vertical electric fields are small can excite these higher order modes. The experiments of excitation of the second and the third higher order leaky modes are carried out to verify the practicability. It is suitable to develop new microwave device and radiation source, such as applications in multi-beam antenna design.