Wireless communication apparatus and method

1. A wireless communication apparatus, comprising:

an oscillator comprising

a coil assembly exposed to an outside of the wireless communication apparatus,

a variable capacitor, and

a negative resistor; and

a phase locking circuit connected to the coil assembly and the negative resistor, and configured to:

generate a control signal to lock an oscillation frequency of the oscillator based on an oscillation signal generated by the oscillator;

provide the generated control signal to the variable capacitor; and

restore, in response to the oscillation frequency of the oscillator being changed by a change in capacitance of the coil assembly, the changed oscillation frequency of the oscillator to a target frequency by controlling the variable capacitor.

2. The wireless communication apparatus of claim 1 , wherein the oscillator is configured to oscillate at the oscillation frequency, and the oscillation frequency is determined based on the variable capacitor and a coil included in the coil assembly.

3. The wireless communication apparatus of claim 1 , wherein the phase locking circuit is further configured to compensate for a variation in the oscillation frequency by controlling a capacitance of the variable capacitor in response to a change in impedance of the wireless communication apparatus.

4. The wireless communication apparatus of claim 1 , further comprising:

a controller configured to detect a capacitance of the variable capacitor, and determine that at least a portion of the coil assembly is in contact with an external object, in response to the capacitance of the variable capacitor being less than a threshold capacitance.

5. The wireless communication apparatus of claim 4 , wherein the controller is further configured to generate biometric data indicating a biosignal, based on a change in the capacitance of the variable capacitor, after the at least a portion of the coil assembly contacts the external object.

6. The wireless communication apparatus of claim 5 , wherein the controller is further configured to detect a voltage applied to the coil assembly and generate biometric data based on the detected voltage.

7. The wireless communication apparatus of claim 1 , further comprising:

a receiver configured to process an external signal received through the coil assembly; and

a transmitter configured to generate a data signal to be transmitted to the outside of the wireless communication apparatus through the coil assembly.

8. The wireless communication apparatus of claim 1 , further comprising:

a transmitter configured to generate a data signal to be transmitted to the outside of the wireless communication apparatus through the coil assembly, by controlling the variable capacitor of the oscillator to have a capacitance corresponding to a frequency indicated by a modulation signal in which data is frequency-modulated, based on the modulation signal.

9. The wireless communication apparatus of claim 1 , wherein the wireless communication apparatus is configured to control phases of powers respectively provided to a plurality of coils included in the coil assembly by switching connections between the negative resistor and the plurality of coils.

10. The wireless communication apparatus of claim 1 , further comprising:

a receiver configured to detect an envelope of a signal in response to the signal being received from the outside of the wireless communication apparatus through the coil assembly, and restore a data signal from the detected envelope.

11. A wireless communication method, comprising:

generating, by a phase locking circuit connected to a coil assembly and a negative resistor of an oscillator, a control signal based on an oscillation signal generated by the oscillator;

locking, by the phase locking circuit, an oscillation frequency of the oscillator by providing the generated control signal to a variable capacitor of the oscillator; and

restoring, in response to the oscillation frequency of the oscillator being changed by a change in capacitance of the coil assembly, the changed oscillation frequency of the oscillator to a target frequency by controlling the variable capacitor.

12. The wireless communication method of claim 11 , further comprising controlling, by the phase locking circuit, a capacitance of the variable capacitor to compensate for a variation in the oscillation frequency.

13. The wireless communication method of claim 11 , further comprising determining, by a controller, whether the coil assembly is in contact with an external object, based on a comparison of a capacitance of the variable capacitor to a threshold capacitance.

14. The wireless communication method of claim 13 , further comprising generating, by the controller, biometric data indicating a biosignal, based on a change in the capacitance of the variable capacitor, after determining that the coil assembly is in contact with the external object.