A wireless communication apparatus may include: an oscillator including 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. The phase locking circuit may be configured to generate a control signal to lock an oscillation frequency of the oscillator based on an oscillation signal generated by the oscillator, and provide the generated control signal to the variable capacitor.