A novel adaptive Wi-Fi system with RFID technology

Abstract

A novel adaptive Wireless-Fidelity (Wi-Fi) system is the combination of radio frequency identification (RFID) technology, programmable intelligent microcontroller development board (PIDB) and reconfigurable antenna with beam shape characteristics. The system is capable to sustain a Wi-Fi signal adaptively above its threshold level (-81dBm) within a range up to 100m across three different buildings with variety indoor environments and floors. It is found that the modified ground reflection model has successfully predicted the total path loss of the test-bay buildings which consist of corridors, several floors and windows. The modified propagation model is extremely crucial in determining the projection and height reconfigurable antenna to efficiently cover the scattered measurement points across the three buildings. The need of comparable signal strength is compulsory since the signal strength between 2.4GHz of reconfigurable beam shape antenna and 0.433GHz of RFID tag is different within the same distance. When reconfigurable beam shape antenna radiates with a minimum gain of 4.85dBi, the measured signal strength shows that most of the measurement points are below WiFi's threshold level which is from -69.001dBm to -115.4530dBm. However, the proposed system is able to boost all the signal strength above the threshold level with three different gain of reconfigurable beam shape antenna, 7.2dBi, 9.9dBi and 14.64dBi through the activation of mobile RFID tag at different measurement points at one time. The boosted signal strengths are within the range of -69dBm to -73.056dBm. The capability of the mobile RFID tag in producing certain level of signal strength has been successfully exploited as a wireless stimulator for the system to adaptively activate certain PIN diode switches of reconfigurable beam shape antenna in this finding. The proposed system also has a great potential in realizing a new smart antenna system replacing the conventional switching beam array (SBA) antenna.