Specific dielectric constant calibration method for an electromagnetic prober
An electromagnetic prober comprising a transmission antenna, a reception antenna, a reception signal processing section for generating an analytic signal on the basis of a detection signal of the reception antenna, and an analytic processing section for performing a predefined analytic process on the basis of the analytic signal, wherein the analytic processing section divides the analytic signal into a plurality of time-based ranges and performs a predefined computation on average cycle periods in the respective time-based ranges of the analytic signal to calculate average dielectric constants in depth ranges of the medium corresponding to the respective time-based ranges.
1. Specific dielectric constant calibration method for an electromagnetic prober, which comprises a transmission antenna for radiating electromagnetic radiation, a reception antenna for receiving echoes of the radiated electromagnetic radiation, a reception unit for generating a reception signal on the basis of a detection signal of the reception antenna and a signal processing section for processing the reception signal to output an analytic signal, the signal processing section having a cycle adjusting section for converting the reception signal into an analytic signal having a different signal cycle period through frequency conversion, the cycle adjusting section having setting means for setting a frequency conversion constant, the method comprising the step of:
adjusting the setting means so that the cycle period of the analytic signal when the electromagnetic radiation is radiated from the transmission antenna in the air is matched with a reference period predetermined according to a reference specific dielectric constant.
2. Specific dielectric constant calibration method for an electromagnetic prober as set forth in claim 1 , the signal processing section generating and outputting the analytic signal having the predefined relationship between the cycle period and the specific dielectric constant on the basis of the reception signal having cycle periods varying according to specific dielectric constants in the medium.
3. Specific dielectric constant calibration method for an electromagnetic prober as set forth in claim 1 , the method further comprising the steps of:
radiating electromagnetic radiation from the transmission antenna toward a reference dielectric material having a predefined specific dielectric constant and a predefined calibration distance,
adjusting the setting means so that a time lag between an echo reflected on the surface of the reference dielectric material and an echo reflected at the calibration distance in the analytic signal is matched with a time required for the electromagnetic radiation to travel the calibration distance in the reference dielectric material, and
then determining the cycle period of the analytic signal obtained by the in-air radiation from the transmission antenna as the reference period.