●●● ●●●● ●●●●● ●●●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 2Radio transmitter 射频发射机 Radio receiver 射频接收机 2