Abstract: In this paper, a full-aperture linear tightly coupled active phased array antenna system with ultra-wide bandwidth and wide angle scanning performance is described. The design procedure and implementation method of the full-port feeding tightly coupled ultra-wideband wide angle scanning array without dumb element are studied. Two mirror symmetry dipole elements are fed by a Wilkinson power divider simultaneously. Extended dipole elements are utilized at the edge of array to eliminate the truncation effect and effectively reduce the active voltage standing wave ratio (VSWR) at low frequencies. Vertical metal walls are utilized at the other edge of array to replace the dummy elements. Meanwhile, vertical metal walls can also support the wide angle impedance matching (WAIM) layer. Finally, the full-aperture antenna array is realized. In order to meet the requirements of large instantaneous bandwidth and wide angle scanning performance, the radio frequency link of the T/R component uses a phase shifter plus a frequency-insensitive time delay device, so as to improve the beam pointing spatial dispersion and waveform time dispersion performance of large instantaneous bandwidth while large angle scanning. The ultra-wideband wide angle scanning array aperture, cooler plate, T/R components, beam control and power board and rear cover are integrated in high-density stack-type. A 1 × 10 full-aperture ultra-wideband active phased array is fabricated. The measurement results show that the array antenna can work across 4 octaves, the scanning range is greater than or equal to ±45°, and the instantaneous operating bandwidth can cover the full frequency band of the active phased array antenna system, which is of great significance for realizing integrated multi-function software defined satellite evolution in orbit, reducing cost and improving flexibility.