IQGain-AN_924AN-924 APPLICATION NOTE One Technology Way P.O. Box 9106 Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 Fax: 781.461.3113 www.analog.com Digital Quadrature Modulator Gain by Ken Gentile The carrier signal is time dependent by definition as indicated by the t term in the arguments of the sine and cosine functions. The Y, I, and Q terms have been assigned t arguments as well, indicating that their values can also be time dependent. The scale factor of is a consequence of using the same number of bits at both the input and output of the adder. Note that the sum of the two N-bit multiplier outputs actually requires N + 1 bits to represent the full range of the summed results. However, the act of constraining the output of the adder to only N bits means that the least significant bit o……