Analysis of Concrete Inspection Radar Equations to Obtain Radar System Specifications

Concrete structure needs an inspection to prevent structural failures. In concrete inspection activity, ground-penetrating radar (GPR) is one of the tools used to detect the location of steel reinforcement in concrete without the need for invasive action. In this paper, GPR for concrete inspection application is designed using frequency modulated continuous wave (FMCW) and works on ISM bands with a frequency range of 2.4 - 2.5 GHz. Based on radar cross section value and total loss value, a calculation is performed using the radar equation to find the total gain required by the system. The total gain value required by the GPR system with 1-meter detection capability is 11.066 dB and the total gain requirement can be fulfilled using an antenna and low noise amplifier. Meanwhile, the total gain value required by the GPR system with 3-meter detection capability is 165.79 dB. In this research the RX and TX antenna beamwidth specification was calculated. The RX antenna is expected to meet 2.86° - 48.45° beamwidth specifications for 1-meter detection capability and 0.95° - 17.6° beamwidth specifications for 3-meter detection capability. The TX antenna is expected to meet 90° - 126.87° beamwidth specifications for 1-meter and 3-meter GPR detection capability. The GPR FMCW system designed in this paper uses Lime SDR as a transceiver module.