A two-dimensional sparse array topology based on the quadrate spatial arrangement is presented. Under the precondition that effective aperture is uniformly distributed, the proposed array reduces the antenna coupling effectively. The proposed array topology is applied to a radar system with 35.5 GHz carrier frequency and 5 GHz bandwidth. This system contains 64 transmit antennas and 64 receive antennas, so it can generate an efficient three-dimensional reconstructed image by means of electric scanning. The simulation results of the point spread function indicate that the system achieves a high spatial resolution, which is 6 mm in lateral direction and 3 cm in range direction. The high-resolution imaging result of a distributed target shows the outstanding performance of the proposed array topology experimentally.