Abstract  
Performance of an amplitude modulator architecture that enables the potential efficiency/cost advantages will be presented. In this presentation, one of the most crucial components, the amplitude modulator, of the envelope elimination and restoration transmitter will be presented and discussed. Over the past decades, many new modulation schemes have been developed to offer higher data rates and better spectral efficiency for the same bandwidth. These modulations format present difficulties for power amplifier because of the statistics of the RF envelope. Conventional class A amplifiers are inefficient for modulations with high crest factors. Some class AB amplifiers including feed forward and pre-distortion methods do improve non-linearity but contribute to efficiency degradation and higher cost. Most recent applications include Doherty amplifiers that improve efficiency by 10% factor. For Doherty amplifier ( an envelope elimination and restoration transmitter) , the overhead circuitry and complexity is similar to feed forward and/or pre-distortion. However, the die size is effectively 6 dB (power rating) smaller than its counterpart, hence the implementation cost is lower. Performance of an amplitude modulator architecture that enables the potential efficiency/cost advantages will be presented. This amplitude modulator delivers 100 watts into 3 ohms in less than 10 nanoseconds. The voltage gain is 10 and provides voltage control from its input to any voltage from 0 to 28 volts. The bandwidth of this amplitude modulator is greater than 50 MHz and its distortion level are better than -50 dBc.