A direct digital RF amplitude modulator

In English This paper describes a direct digital RF amplitude modulator, which uses a 10-bit linear interpolation current steering digital to analog converter (DAC) and a Gilbert cell mixer to generate an RF amplitude modulated signal directly. The linear interpolation increases the attenuation of the DAC's image components. The low pass filter (LPF) is eliminated, and the RF transmitter structure can be simplified. This modulator is suitable for realizing the system-on-chip design. The chip has been fabricated in a 0.35μm, 3.3V digital CMOS process.