《射频系统介绍》PPT课件.ppt

1,Introduction of Radio Frequency Systems,中華大學 通訊系 田慶誠 .tw,中華大學 通訊系,2,Outline,Analog radio communication system Digital wireless communication system Radio Frequency transceiver RF receiver specifications RF transmitter specifications High power RF transmitter,中華大學 通訊系,3,Analog radio communication system,Amplitude modulation Homodyne receiver Heterodyne receiver 外差式接收機 Frequency modulation Super heterodyne receiver 超外差式接收機,中華大學 通訊系,4,Amplitude modulation receiver,Homodyne receiver,1906 Forest 真空管 1906 Fessenden 調幅AM廣播 1912 Armstrong 再生檢波收音機 Wider RF filter bandwidth Bad noise immunity,Demodulation 解調,AM 576 KHz,AF 1002KHz,中華大學 通訊系,5,Amplitude modulation receiver,Heterodyne receiver,Narrow IF filter bandwidth Good noise immunity,Demodulation 解調,AM 1413 kHz,AF 1002KHz,LO 958 kHz,IF 455 kHz,Better Sensitivity,中華大學 通訊系,6,Frequency modulation receiver,Super heterodyne receiver,1918 Armstrong 超外差收音機 1933 Armstrong 調頻FM收音機 Excellent noise immunity Good adjacent channel rejection Bulky IF filter and circuits Higher power dissipation,FM 100 MHz,1st LO 89.3 MHz,2nd LO 10.245 MHz,1st IF 10.7 MHz,Best Sensitivity,2nd IF 455 kHz,Demodulation 解調,中華大學 通訊系,7,Remote controller example,8,9,Remote controller example,FM receiver MC13135,10,中華大學 通訊系,11,Digital wireless communication system,FSK/ASK Wireless modem RFID PSK/QAM (+OFDM) Cellular phone (GSM, GPRS, 3G WCDMA) Digital cordless phone (DECT, PHS) WLAN (802.11a/b/g/n) WPAN (BT, Zigbee, 802.15.3 UWB) WMAN (802.16a WiMAX, 802.16e) DVB-T, DVB-H, DAB GPS,中華大學 通訊系,12,Spectrum of Digital Phones,Frequency Division Duplex, FDD,TDD,中華大學 通訊系,13,WLAN & WPAN Spectrum,Time Division Duplex only,中華大學 通訊系,14,RF Identification System,15,GPS,中華大學 通訊系,16,GPRS,Direct Conversion RFIC,17,Bluetooth,中華大學 通訊系,18,WLAN 802.11 b,Intersil 2001 version,中華大學 通訊系,19,WLAN 802.11 b,Intersil 2003 version,中華大學 通訊系,20,5GHz WLAN 802.11 a,Intersil 2003 version,中華大學 通訊系,21,RF Transceiver,Receiver Double down conversion ( RF down converter + Quadrature demodulator, 數百MHz IF) Low-IF converter (數十MHz數百KHz) Direct conversion (Zero-IF receiver) Transmitter Double up conversion Quasi-direct IQ modulation (Low-IF),中華大學 通訊系,22,WLAN 802.11a RF Transceiver,5.7GHz U-NII Rx/Tx module (FDD mode),Double down conversion,Double up conversion,中華大學 通訊系,23,TD-SCDMA RF Transceiver,MAXIM SiGe BiCMOS,Zero-IF receiver,Quasi-direct IQ modulation,中華大學 通訊系,24,Receiver Specifications,Output Signal-to-Noise Ratio, SNRo (dB) 輸出訊雜比 Noise Figure (dB) 雜訊指數 Sensitivity (dBm) 靈敏度，最低可接收功率 Adjacent channel rejection rate (dBc) Oscillator phase noise level (dBc/Hz) IP1dB, IIP3 (dBm) Dynamic range, Gain controlled range (dB) Relative constellation error (dB),中華大學 通訊系,25,Output Signal-to-Noise Ratio, SNRo (dB),中華大學 通訊系,26,Noise Figure (dB) 雜訊指數,RF Receiver,Base Band Processor MAC,So,No,Si,Ni,SNRi=10log(Si/Ni),SNRo=10log(So/No),NF (dB)= SNRi(dB)-SNRo(dB),NF (dB),中華大學 通訊系,27,Sensitivity (dBm) 靈敏度,Sensitivity(dBm)=Si(min),最低可接收功率 Ni=kToB, standard input noise Si(min)=SNRo(dB)+NF(dB)+kToB(dBm) For 64QAM example: SNRo=20dB, B=20MHz, NF10dB kToB=-174dBm/Hz+10log(20M)dBHz=-101dBm Sensitivity=20dB+10dB-101dBm=-71dBm,中華大學 通訊系,28,WLAN 802.11a Spec.,中華大學 通訊系,29,Blocking Levels,Alternate adjacent channel rejection (dB),Adjacent channel rejection (dB),中華大學 通訊系,30,Channel selection filter,-63dBm-(-85dBm),-47dBm-(-85dBm),中華大學 通訊系,31,Oscillator phase noise level (dBc/Hz),-100dBc/Hz 1MHz offset for WLAN Oscillator,32,OP1dB : Power output at 1dB compression point,OP1dB=13 dBm,1dB,Slope=1,RF2442,IP1dB : Power input at 1dB compression point,IP1dB=-6 dBm,33,Intermodulation Distortion,w2,w1,2w2-w1,2w2,2w1-w2,w2-w1,w2+w1,2w1,Pout (dBm),Freq,IM2,IM3,IM3,IMD(dBc)=POUT(dBm)-IM3(dBm),Pout,34,PIP3,1,3,Fundamental,IM3(dBm),PIP3(dBm) - P1dB(dBm)= 10.63 dB,P1dB,PIN(dBm),10.63dB,When POUT=P1dB, IMD=POUT-IM3= 19.26 dBc,?dBc,中華大學 通訊系,35,Dynamic Range, DR (dB),RF Receiver,Base Band Processor MAC,So= constant,Si(min)= Sensitivity Si(max)=IP1dB,NF (dB),DR(dB)= IP1dB(dBm)-Sensitivity(dBm) = Total gain control range,中華大學 通訊系,36,802.11a Rx Gain control range,Si(min)= Sensitivity=-82dBm Si(max)=IP1dB=-15dBm,DR(dB)= -15dBm-(-82dBm)=67dB,DG=18dB,DG=50dB,中華大學 通訊系,37,Relative constellation error (dB),802.11a,中華大學 通訊系,38,Transmitter Specifications,Transmit spectrum mask,中華大學 通訊系,39,Harmonic distortion,Freq,VIN,Freq,VOUT,w1,w1,2w1,3w1,2nd HMD: Second harmonic distortion (dBc) 20dBc 3rd HMD: Third harmonic distortion (dBc) 20dBc,2nd HMD,3rd HMD,4w1,中華大學 通訊系,40,High power RF transmitter,Determine the OP1dB: QPSK: OP1dB= Output power spec. + 3dB OFDM: OP1dB= Output power spec. + 6dB Fix PA loading impedance Fixed transistor output load line sustain the OP1dB Reduce the distortion and EVM Reduce input nonlinear admittan