摘要 |
A modulator (104) varies the duty cycle of a waveform to amplitude modulate information for transmission. A push-pull amplifier (106) in accordance with the invention, preferably constructed of CMOS devices, receives the waveform with a varying duty cycle in order to drive an antenna (108) such that a wireless transceiver can become excited by the oscillating waveform and receive the amplitude modulated signal and demodulate it to obtain the transmitted information. The power generated by the push-pull power amplifier (106) is simply increased or decreased by varying the voltage of the power supplied to the power amplifier or by varying the number of devices driving the antenna (108) in parallel. |