| 摘要 |
A radio frequency transmitter circuit including a user input switch for producing an input signal, an oscillator for producing a frequency signal having a first frequency, an antenna connected to the oscillator for broadcasting the frequency signal, a coupling circuit disposed a predetermined distance from the antenna, and a microprocessor for enabling the oscillator and activating the coupling circuit in response to the input signal. When the coupling circuit is activated, a reflected impedance, derived from a change in inductance, is reflected from the coupling circuit upon the antenna thereby shifting the frequency signal to a second frequency. Sequentially activating and deactivating the coupling circuit modulates the frequency signal.
|
