Patent ID: 7020190

Claim:
A frequency translator, comprising: a phase accumulator; a CORDIC phase rotator coupled to the phase accumulator comprising N stages, each stage having an inphase (I) input, a quadrature (Q) input and a phase angle (θ) input, each stage (k) further comprising a first adder to compute a quantity I±2 −k Q, a second adder to compute a quantity Q±2 −k I and a third adder to compute θ±φ k , where φ k is an angle rotation of stage k, where each stage outputs the sum generated by each adder to be used as inputs to a succeeding stage, and wherein the N th stage outputs an inphase component and a quadrature component from its first and second adders respectively that correspond to an input vector rotated by a desired phase angle; a stochastic rounding apparatus that reduces error due to truncation of a result of higher precision arithmetic, said stochastic rounding apparatus including a third adder that adds a multi-bit random number with the truncated least significant bits of an output of said CORDIC phase rotator, wherein said stochastic rounding apparatus adds a carry bit produced by said third adder to the most significant bits of said output of said CORDIC phase rotator, and a dithering apparatus that eliminates harmonics caused by digital to analog converter non-linearity, including a fourth adder that adds a 1-bit random number with an output of said stochastic rounding apparatus, wherein an output of said fourth adder is provided to a digital to analog converter.