The experiments are setup to study the picosecond ultra-short pulses coherent radiation characteristic. The transmitting and receiving antenna employ the tie horn antennas.16 channels electrical pulses with 300 ps duration and jitter less than 50 ps are used. The different frame of 4x1, 4x2, 4x3, 4x4 antenna array radiate the pulses. The receiving antenna measures the electrical field in different distance to the transmitting antennas array. The results show that if the pulses are in coherent condition, the output pulse peak power of antennas array with N elements are N of the single element antenna output.