●●● ●●●● ●●●●● ●●●0 Microwave and RF Design of ●●●●0 ●●●0 ●●●● ●● Wireless Systems Chapter 7 Mixers Dr.Xian Qi Lin 1
Chapter 7 Microwave and RF Design of Wireless Systems Dr. Xian Qi Lin Mixers 1
●●● ●●●● ●●●●● ●●●0 ●●●●0 Antenna ●●●● IF Bandpass Power ●●●● ●● Data Modulator filter Mixer filter ampiifier in Local Radio transmitter oscillator 射频发射机 Antenna Low Bandpass noise F IF filter amplifier Mixer filter amplifier Demedulator Data out Local Radio receiver oscillator 射频接收机 2
Radio transmitter 射频发射机 Radio receiver 射频接收机 2
●●● ●●●● ●●●● ●●●● ●●●● ●●●● A mixer is a three-port device,that uses a nonlinearor time-varying element to achieve frequency conversion. Filter must be used to select the desired frequency. 7.1 Mixer characteristics §7.2 Diode mixers §7.3 FET mixers 3
A mixer is a three-port device, that uses a nonlinear or time-varying element to achieve frequency conversion. Filter must be used to select the desired frequency. §7.1 Mixer characteristics §7.2 Diode mixers §7.3 FET mixers 3
●●● ●●●● ●●●● ●●●0 ●●●●0 ●●●● 7.1 Mixer Characteristics ●●● ● ● 1.Frequency Conversion缬率变换 2.Image Frequency 7镜频 3.Conversion Loss 变频损耗 4.Noise Figure噪声系数 5.Isolation隔离 4
§7.1 Mixer Characteristics 1. Frequency Conversion 频率变换 2. Image Frequency 镜频 3.Conversion Loss 变频损耗 4. Noise Figure 噪声系数 5. Isolation 隔离 4
●●● ●●●● ●●●●● 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 5
1. Frequency Conversion Transmitter 发射机 up-conversion 上变频 Receiver 接收机 down-conversion 下变频 5