| 摘要 |
<p>A radio transmitter for multi-standard mobile communication systems has two stages of frequency up-conversion, the first (304) being a digital process generating a variable IF and the second (316, 318, 320, 326) being an analogue conversion using a fixed frequency local oscillator (318), which alleviates the need for RF filtering after the final stage of power amplification (332).</p> |
