This thesis improved the structure of traditional envelope elimination and restoration transmitter by replacing the analog components of envelope detector and limiter using digital processing technique of polar transformation. Envelope signal was modulated by delta-sigma modulation, which could suppress the quantization noise and would be good for integrated circuit design. The front end analog circuits of transmitter used high efficiency class-S and class-E power amplifiers to amplify envelope and phase signal separately and finally combined them at the output of class-E power amplifier. The RF transmitters using polar modulation had advantages of high efficiency and linearity when transmitting high PAPR-valued digital modulation signals. For example, when transmitting the QPSK-modulated signal with 900MHz carrier and 1Msps data rate, the transmitter was measured with efficiency as high as 60%, ACPR above 34dB, and EVM less than 6.5%.