| 摘要 |
A transmitter 108 converts a complex baseband signal 140 having I and Q quadrature signal components 141 and 142 for transmission by an antenna 114. An intermediate frequency based complex-to-real up-converter 130 uses subsampling to convert the complex baseband signal 140 into a real digital signal 144 having digital signal representations 174. An intermediate frequency based bandpass filtering digital-to-analog converter 132 uses Delta-Sigma, bandpass techniques to convert the real digital signal 144 into a first analog signal 146 having analog signal representations 182. A post-conversion bandpass filter 134 isolates and boosts the signal-to-noise ratio of a selected analog signal representation 186 to output a second analog signal 148 having a post-filtered selected analog signal representation 192. A tracking bandpass filter 136 further bandpasses and up-converts the second analog signal 148 to output a transmittable signal 150 having a tracking-filtered selected analog signal representation 196.
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