Near field focusing properties of finite wire array under sinusoidal pulse excitation

In this paper near field focusing by a finite wire array composed of resonant wire elements executing time reversal is studied for the first time for the case of non-monochromatic sinusoidal pulse excitation. It has been shown that subwavelength focusing with characteristic resolution ~ lambda_r/4 at the distance ~ lambda_r/5 from the array is achievable with a very short array. We show that the resolution is limited by the narrowband resonance of antenna and is superior to the case of monochromatic excitation only in respect of producing smaller side lobe response not focal spot size.