Design method about 0.14 THz power divider based on 3 dB directional coupler

A design new method about 0.14 THz power divider based on 3 dB directional coupler was presented. As THz device's dimension is micro -miniature, especially the key structure such as power divider's, it is extraordinary difficult to fabricate by precise machining. Traditional 3 dB directional coupler has 90 electric bridge structure, whose length between coupler slots is only less than 0.5 mm. This size nearly cannot bear the machining stress in processing. By means of analyzing the phase relationship between the direction coupler's branches, it is known that if the length between coupler slots increases only half-wave length's integer-multiple, the phase contrast between branches is still 90. As a result, the bandwidth is sacrificed. Since the dimension of coupling slot increases, this structure makes precise machining easy, and it has a band width about 10% at least yet. Analysis of simulation result provides the verification. The measured insert loss from 0.133 THz to 0.147 THz is less than 1 dB, and the return loss is less than -20 dB.