The embodiment of the invention relates to a frequency scanning antenna for transceiving radio frequency energy which is used for detecting and monitoring ground-based targets. In one arrangement, the frequency scanning antenna is specifically a structure capable of guiding the radio frequency beam to multiple different angles with respect to the antenna structure. The antenna structure comprises at least two array antennas and a controller for controlling the energy input of two array antennas which are arranged in the antenna structure, so that the antenna structure can use one of the two array antennas to guide the beam to the first angle and use the other array antenna to guide the beam to the second angle different from the first angle. Therefore, two or more array antennas are set in the embodiment of the invention to form antenna structure, and the feeding of each antenna array to the antenna structure is coordinated, so that each scanning area can combine to form an enhanced total scanning area.