Design of parallel coupled-line directional couplers

This paper explained the work theory and the process of design about the parallel coupled line directional coupler.According to the main characters of coupled stripline and coupled microstrip.It design the coupled parallel strip-line directional couplers and coupled parallel microstrip directional couplers that the frequency is 2.5 GHz.According to the technique performance,the type and structure of directional coupler are confirmed.Using the ADS software environment the circuit model of coupled parallel line directional couplers is designed.The S-parameter of directional couplers can be simulated and optimized in order to gain the expected demand.It can be seen that in the bandwidth,the coupled performance of coupled stripline dxirctional couplers is superior to the coupled microstrip directional couplers.