The system emits a magnetic field pulse that is less than 10 milliseconds in length generated by coils housed in two detection panels spaced 90 cm from each other. System C is a magnetic system with a fundamental operating frequency greater than 5 kHz and less than 50 kHz. The transmission is a CW signal generated by coils housed in two detection panels spaced 90 cm from each other. System D has an operating frequency greater than 100 Hz and less than 1 kHz. There are a separate electronic chassis and two antenna panels, each containing both transmit and receive coils.
Receive coils located in both panels detect the signal reradiated from a tag.
Signal processing circuits trigger an alarm when appropriate. System E has an operating frequency greater than 500 Hz and less than 5 kHz. There are a separate electronic chassis and two antenna panels, each containing both transmit and receive coils. Receive coils located in both panels detect the signal reradiated from a tag. Signal processing circuits trigger an alarm when appropriate.