The main objective of this paper is to develop a portable, advanced and high operating frequency GPR prototype system, which will be able to provide an increased sensitivity and resolution in terms of defects detectability at a penetration depth range up to 40-50 cm in concrete. For this purpose, the theoretical assessment of multiple GPR antenna-frequency approaches was initially performed using electromagnetic wave simulation tools for the propagation of radar waves within concrete, aiming to predict the required antenna frequency and characteristics that are most effective in detecting internal concrete elements and defects of interest found in realistic structures. Form the modeling results obtained, which are described in this paper, a portable, advanced, single-channel GPR system was developed, which uses a highfrequency shielded dipole antenna in monostatic arrangement and operates at a central operating frequency of 2600 MHz. Finally, the evaluation of the performance of the developed GPR technology was carried out under laboratory conditions, where concrete samples of varying dimensions and with different embedded structural features of known characteristics were tested. The validation results produced from this study indicated the high potential and efficiency of the developed GPR device to accurately detect internal concrete features with superior resolution and with sufficient penetration for concrete to be adequately resolved in depths up to 40 cm.