摘要 |
An apparatus for deactivating a resonant circuit without physically contacting the resonant circuit. The EAS system includes a numerically controlled oscillator for generating an alternating electric signal, the frequency of the alternating electric signal varying in accordance with a numerical frequency control signal; a clock having a substantially fixed frequency connected to the numerically controlled oscillator; and a transmitting antenna connected to the numerically controlled oscillator for establishing an electromagnetic field within a deactivation zone. The frequency of the alternating electric signal is restricted to being an integer multiple of an integer sub-multiple of the clock frequency. |