Abstract: In order to achieve good performance of grating-lobe suppression and wide scan±30°angle in 45 octave band for phased array antennas，a design method of wide-band nonequidistant phased array antenna is proposed.Firstly the wide band performance of the non-equidistant array antenna is analyzed theoretically，then the non-equidistant array antenna with 16 microstrip Vivaldi antenna units is simulated，finally the non-equidistant array antenna is processed and measured，and the measurement results are accord with the simulation ones and validats the design method.