R. Alladi, P. V. Naidu, R. P, S. R. Kotha, S. Charan, and S. Harish, “Low profile microstrip fed printed antenna for portable RF energy harvesting system”, IJET, vol. 7, no. 2, pp. 828–831, May 2018, doi: 10.14419/ijet.v7i2.12435.