●●● ●●●● ●●●●● 1.Frequency Conversion ●●●0 ●●●●0 ●●●● ●●●● IF oscillator Mixer ● fRF=无o±fF fLo FLo-fL0Lo+亚 Signal Local oscillator Low-side band (LSB)up-side band (USB) Transmitter发射机 up-conversion上变频 Mixer fr十fr fRF fiF=fRF±无o RF oscillator RF-Lo Lo RF Lo+RF Local oscillator 2Lo-RF=IM (image frequency) Receiver接收机 down-conversion下变频 51. Frequency Conversion Transmitter 发射机 up-conversion 上变频 Receiver 接收机 down-conversion 下变频 5