Abstract-A 2 × 2 quasi-Yagi antenna array fed by a novel orthogonal T junction is presented. The orthogonal T junction is constructed with a traditional microstrip T junction, two planar microstrip to CPW transitions and two orthogonal microstrip to CPW transitions. The orthogonal T junction can be integrated with the quasi-Yagi array element directly. A 2 × 2 prototype operated from 7.6 GHz to 12 GHz is fabricated and measured.

We describe a novel optoelectronic technique to generate and detect THz electromagnetic waves by using large-aperture planar photoconducting antennas and antenna arrays. This appoach is an effective method of producing directional and steerable sub-millimeter wave pulses.