就先进射频发送器而言,直接转换I/Q调制是一种很有吸引力的解决方案,它以较低的成本实现了复杂调制。直接I/Q调制器可以产生任意相位、频率和幅度的波形。在典型应用中,I/Q调制器产生一个单边带输出信号。理想调制器在I混频器和Q混频器本机振荡器之间有完美的90°相移,而且没有其它不想要的相位或增益减损,其输出将仅包含所需要的边带信号。实际上,非理想性是由其它相位误差源引起的,如基带I/Q延迟不匹配和DAC歪斜失真。 In terms of advanced RF transmitters, direct conversion I / Q modulation is an attractive solution that enables complex modulation at a lower cost. Direct I / Q modulator can generate arbitrary phase, frequency and amplitude of the waveform. In a typical application, the I / Q modulator produces a single-sideband output signal. The ideal modulator has a perfect 90 ° phase shift between the I mixer and the Q mixer’s local oscillator, and no other unwanted phase or gain impairments, the output will only contain the required sideband signal. In fact, the nonidealities are caused by other phase error sources, such as baseband I / Q delay mismatch and DAC skew.