Farfields and efficiencies are calculated for an RFID receiving coil in combination with a matching network that has been optimized in CST Design Studio.
The RFID antenna is modelled in CST Microwave Studio as a simple coil. The matching network is a simple lumped network involving two capacitors C1, C2 that have been optimized for a good match at the designed operation frequency of 13.56MHz. Correspondingly, a farfield monitor has been set in CST Microwave Studio at 13.56MHz. An AC, Combine Results task is performed to obtain the farfield of the antenna, considering the effect of the matching network. Radiation and total efficiency of the system are calculated by a postprocessing task. The system total efficiency is improved by almost 20dB, compared to the antenna without matching network.