A numerical control attenuator based method of power agility in signal generators

Power agility is a crucial technology in modern signal generators, which guarantees the performance of frequency agility in a large number of military issues. In this paper a novel method of power agility based on numerical control attenuator is proposed. Also the traditional power control methods based on ALC system are reviewed, and the shortcoming is analysed. Then the detailed design process of the proposed method is elaborated. In this method a special circuit is designed to replace CPU which was used to transfer control command in order to shorten the operation time remarkably. This circuit contains three parts, such as bus controller, data transmission bus and command decoder. The flexibility and validity of the proposed method are analysed concisely and also tested by an actual experiment. The experiment results show that the power agility time can be shortened in 55ns at a carrier frequency of 1GHz based on a 16dB attenuator. This method has been adopted by some types of commercial signal generators.