Sub-wavelength Array With Embedded Chirped Delay Lines Based on Time Reversal Technique

In this communication, a new approach for sub-wavelength array design based on time reversal technique is proposed. Three chirped delay line with different group delay slopes are embedded into a sub-wavelength array as independent feeding lines. With the pre-distortions provided by the chirped delay line, when time reversal technique is used, the novel sub-wavelength array has far-field super-resolution focusing property. Different from evanescent-to-propagating spectrum conversion mechanism, the new approach can improve the radiation efficiency of the sub-wavelength array because no micro-scatterers in the near field of the array elements are required.