Abstract:

This paper aims at the problem that the frequency offset of the frequency diverse array (FDA) with logarithmically increasing frequency offset (log-FDA) is fixed, the mainlobe's scanning precision is low. Two decoupling optimization methods of log-FDA is proposed. Firstly, the uniform linear array is replaced by the cross subarray architecture with sinusoidal frequency offset. On this basis, we transforme the frequency offset incremental selection problem into the optimization problem of two-dimensional space. In order to realize the beampattern decoupling optimization, we solve the optimal frequency offset increment by improved particle swarm optimization algorithm. Then, the Gray code coding method used in communication is applied to the frequency offset coding of the FDA array. A transmit beampattern decoupling method based on the Gray code frequency offset coding method at the transmitting end is proposed. Finally, simulations verify the effectiveness of the proposed method.

Key words: frequency diverse array(FDA), FDA with logarithmically frequency offset, decoupling, particle swarm optimization, Gray code