SBAA555 august   2023 AFE8092

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2RF Droop
    1. 2.1 Reasons Behind RF Droop
    2. 2.2 Digital Correction of RF Droop
    3. 2.3 Overview of RF Droop Correction Measurements
    4. 2.4 Enabling the RF Droop Correction
    5. 2.5 Example for Using the RF Droop Correction
    6. 2.6 Frequency Response Before and After Droop Correction and Limitations
  6. 3Summary
  7. 4References

Example for Using the RF Droop Correction

Using the following steps RF droop correction macro can be deployed.

  1. Bring-up the device in the configuration as per requirement.
  2. Send tones and measure the amplitude at the edge of the band (±∆F + FNCO) and at the center of the band (FNCO).
  3. Figure 2-2 demonstrates a plot of amplitude Vs frequency of a channel A transmitter (TXA) which is configures with NCO frequency (FNCO) at 2 GHz and transmitter data rate (Fdata) of 983 MHz.
    GUID-20230612-SS0I-SMRZ-RC0R-8L2WXM61QNW0-low.png Figure 2-2 Amplitude without RF Droop vs Frequency
  4. As mentioned before we need three measurements for amplitude at FNCO and ±∆F + FNCO. Let us take ∆F= Fdata × 0.35 ≈ 340 MHz, hence the values use for function call are determined as follows.
    Variable Value obseved Calculation Final value for C-AFE function call.
    afeInst Single device 0 0
    txChSel TXA 0 for TXA 0
    bandNo Band0 0-Band0 0x0
    ncoNo NCO1 0 for NCO1 0
    deltaFreq 340 MHz ∆F × 216/Fdata Int(22667)
    Amplitude(Ac) at FNCO =2000MHz -9.51 dBm NA NA
    Amplitude(A1) at FNCO + ∆F =2340 MHz -10.122 dBm NA NA
    Amplitude(A2) at FNCO -∆F =1660 MHz -8.933 dbm NA NA
    RHS 0.61 dbm Ac - A1 NA
    LHS -0.577 dbm Ac - A2 NA
    amp1 NA int(10**(RHS/20)*2**15) Int(35151)
    amp2 NA int(10**(LHS/20)*2**15) Int(30661)
  5. Additionally, the function for the previous example can be called by the following command:

    CAFÉ.configureTxRfDroop(0 ,0 ,0 ,0, int (22667), int (35151), int (30661))

  6. The previous procedure must be repeated for every Transmitter channel.