Design and Implementation of New Broadband SIW Directional Coupler

In order to meet the application requirements of broadband system, a novel type of substrate integrated wave guide (SIW) directional coupler based on slot coupling theories is designed. The signal is coupled to the coupling port of SIW through a slot array on the common ground, which consists of vertically arranged transverse and longitudinal slots. The array is a five-element array in the form of positive "T" and inverted "T". Prototype of 3 dB directional couplers is designed, parameters of 5 dB and 7 dB are presented. From the simulated results, it is illustrated that the 3 dB coupler shows approximately 29.9￡￥ fractional bandwidth. The voltage standing wave ratio of the input port is less than 1.42 and the isolation is less than 18 dB in the working frequency band.

TN622+.2