An analysis is presented for multi-strip coupled system consisting of symmetri-cal edge strips and identical middle strips

in which the direct coupled interaction between nearest neighbors plays the leading role. The normal modes of the system are obtained

and the analytic expressions of image impedance and propagation constant for a quarter-wavelength coupled meander line are derived. Numerical results using finite-difference methods are presented for mode impedances in vaccum and filling factors in substrate. The calculation method of microstrip wavelength and impedance with substrate （especially ferrite substrate） is given. The developed theory is used to analyse the impedance-match problem of microstrip meander line ferrite phaser in X-Band

C-Band

and a good agreement with the experimental results is obtained.