| 摘要 |
<p>A quadrature modulator (210) and demodulator (310) which provide the requisite level of performance while minimizing power consumption. In the quadrature modulator (210), the I and Q signals are provided to two pairs of mixers. Each mixer in a pair of mixers modulates an I or Q signal with the respective inphase or quadrature IF sinusoid. The I and Q modulated signals from each pair of mixers are summed. The signals from the summers are provided to a third pair of mixer and modulated with the respective inphase and quadrature RF sinusoids. The signals from the third pair of mixers are summed and provided as the modulated signal. Using this quadrature modulator (210) topology, the amplitude balance and phase error of the modulated signal are made insensitive to the amplitude imbalance and/or phase error of the quadrature splitters used to generate the IF and RF sinusoids. Furthermore, since the first two pairs of mixers and the two subsequent summers are operated at IF frequency, the performance requirements (e.g., bandwidth and linearity) of these components can be ensured while utilizing less power. The inventive concept can be further adopted for use in a quadrature demodulator (310).</p> |
