A field analysis of a double array microstrip meander-line slow-wave structure is reported in this paper. The potential function U（y

z） and the characteristic admittance of single conductor Yc were calculated with numerical method

and the characteristic dispersion equation and the coupling impedance expression for this structure were derived. The perfor-mance of the microstrip meander-line for different structural parameters were calculated by computer. Two such lines have been used in printed circuit TWTs

experiment results come close to theoretical calculations.