Time-Domain Electromagnetic Sputtering Effect of Slot Array at Resonant Frequency

Objects with low radar cross section (RCS) are difficult to identify using the frequency-domain methods. However, in the time domain, the field amplitude of the scattering waveform from low RCS objects might be very large in the beginning, and becomes smaller when the interaction reaches a stable state. This effect is called the time-domain electromagnetic sputtering effect (simply called sputtering effect). Study of the sputtering effect of low-RCS objects might be helpful in developing new methods for low RCS object detection, especially for the objects covered with periodic structures. This communication is focused on the sputtering effect of the slot array with low in-band RCS at the resonant frequency. The backward scattering properties from the slot array are studied both in time domain and frequency domain, and the array is fabricated and measured. Meanwhile, an equivalent circuit method is also introduced for explaining the sputtering effect.