A high efficiency transmitter with a delta-sigma modulator and a noise cancellation circuit

We propose a new architecture for a transmitter with a delta-sigma modulator and a noise cancellation circuit. A data converter including a deltasigma modulator quantizes the magnitude of the baseband data, which comprises of the in-phase data, I, and the quadrature-phase data, Q. When considering a transmitter with a data converter, a bigb efliciency nonlinear power amplifier can be used, since the envelope of the input signal is quantized to single bit. Quantization noise due to the delta-sigma modulator is canceled by combining an error signal with the same amplitude and opposite phase, without the need for a high Q band-pass filter. Operation of the noise cancellation circuit is verified, and its efficiency is found to be 40%.