Simplified design technique for high performance microstrip multi-section couplers

A new design technique has been developed which improves the design of microstrip multi-section coupler by a simplified version of the non-uniform coupler method. The design is further improved by the use of the "saw-tooth" odd and even mode equalisation technique. The measured results demonstrate an improved performance over the multi-section coupler in terms of coupling performance and bandwidth, whilst the size and the fabrication tolerance are better than the nonuniform line coupler.