A design mapping formula of asymmetrical multi-element coupled line directional couplers

This paper presents a design mapping formula, which is the relation between performance specification and design parameters, for asymmetrical multi-section coupled transmission line directional coupler. The presented mapping function can provide convenience in its use and accurate design parameters for a given design specification. Simulations and experiments on designed three-, five-, and seven-element coupled line directional couplers with 16 dB/spl plusmn/0.2 dB coupling show the validity of the presented design mapping formula.