Time-modulated multi-tone antenna array for wireless information and power transfer

This paper aims to design a multi-tone radiator exploiting harmonic radiation characteristic of time-modulated antenna array for wireless information and power transmission (WIPT) and multi-operational WIPT receiver. The time-modulated linear antenna array (TMLAA) radiating simultaneously at modulating and harmonic frequencies separated in multiple switching periods is utilized as a multi-tone radiating system. TMLAA with suitable power in harmonic bands generates multi-tone radiation by employing an optimized switching sequence. The ON and OFF time instants of the TMLAA are optimized to suppress sidelobe level and enhance sideband level. A population-based optimization algorithm, teaching learning based optimization (TLBO), is employed to optimize the ON and OFF instants of the TMLAA to suppress sidelobe level and enhance sideband level. TLBO is utilized for a 16-element TMLAA with minimizing cost function to achieve the above objectives. The 16-element TMLAA with optimized switching radiates multi-tone beams with a minimum of 5 dB peak power difference exploited as WIPT. The purpose of multi-operation is accomplished by utilizing the Wilkinson power divider in the receiver system; its power dividing capability is analyzed using applied wave research (AWR). A voltage doubler type rectifier is modeled for DC generation and is tested using AWR. The DC generating capability is tested for fixed power available at various frequencies, and the fixed desired frequency with various available power levels is tested. The results show that the designed circuitry provides a maximum of 80% power conversion efficiency (PCE).