射頻系統(tǒng)介紹ppt課件(參考版)
2025-02-24 16:04本頁面
【正文】 Du p lexerAn t en n aSw it chRx F requ en cySynt h esizer5 . 445 5 . 545 GHzT x F requ en cySynt h esizer5 . 500 5 . 550 GHzBaseb an dBaseb an dIQIQ225 MHzVCO280 MHzVCOVG AL NA Mixer IF AMP .PAMixer IF AMP .T x 5 . 725 5 . 775 GHzRx 5 . 775 5 . 825 GHzI / Q Dem o d u lat o rI / Q M o d u lat o rSi(min)= Sensitivity=82dBm Si(max)=IP1dB=15dBm DR(dB)= 15dBm(82dBm)=67dB DG=18dB DG=50dB 中華大學(xué) 通訊系 37 Relative constellation error (dB) Data rate (Mbits/s) Relative constellation error (dB) 6 5 9 8 12 10 18 13 24 16 36 19 48 22 54 25 中華大學(xué) 通訊系 38 Transmitter Specifications ? Transmit spectrum mask 中華大學(xué) 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(xué) 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 admittance 中華大學(xué) 通訊系 41 AM to AM and AM to PM Conversion I Q BER will increase due to magnitude and phase migrations of the IQ constellation when amplifier’s gain is pressed. AM/PM AM/PM AM/AM AM/AM 中華大學(xué) 通訊系 42 Spectrum regrowth frequency Lower Adjacent Channel Upper Adjacent Channel Carrier Channel Caused by IM3 AM/AM AM/PM 。Du p lexerAn t en n aSw it chRx F requ en cySynt h esizer5 . 445 5 . 545 GHzT x F requ en cySynt h esizer5 . 500 5 . 550 GHzBaseb an dBaseb an dIQIQ225 MHzVCO28
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1