Patent ID: 7346123

Claim:
A quadrature modulator comprising: a local oscillator for oscillating at an oscillation frequency; a frequency conversion block for converting said oscillation frequency to output a converted oscillation frequency; and a quadrature modulation block comprising a frequency divider, a first and second multiplier, and an adder, said frequency divider receiving said converted oscillation frequency and dividing said converted oscillation frequency by a factor of two to output a pair of orthogonal signals having therebetween a phase difference of 90 degrees, said first and second multipliers modulating said pair of orthogonal signals with said baseband signal to output a pair of modulated signals, and said adder adding said modulated signals together to output a carrier signal, wherein said carrier signal has a frequency different from said converted oscillation frequency and any signal frequency generated within said frequency conversion block wherein the oscillation frequency is equal to 4/(2N+1) times the carrier frequency where N is a natural number, wherein the frequency conversion block is adapted to multiply said oscillation frequency by a factor of(2N+1)/2, wherein the first frequency divider divides an output from said frequency conversion block by a factor of two to output a pair of carrier waves having therebetween a phase difference of 90 degrees, wherein the first and second multipliers modulate said carrier waves with a digital baseband signal to output a pair of modulated signals, and wherein the adder adds said modulated signals together to output a digital carrier signal having said carrier frequency, wherein said N is equal to “1”, and wherein said frequency conversion block includes a second frequency divider for dividing said oscillation frequency by a factor of two to generate a divided frequency, and a frequency mixer for mixing outputs from said local oscillator and said frequency divider to generate a first signal having a frequency equal to a sum of said oscillation frequency and said divided frequency.