SLAA871 January   2019 AFE7422 , AFE7444

 

  1.   AFE74xx as a single-chip wideband repeater using loopback mode
    1.     Trademarks
    2. 1 Introduction
    3. 2 Repeater Mode (RX-TX Loopback With SerDes Bypassed)
      1. 2.1 Overview of the AFE74xx Repeater Mode
      2. 2.2 Configuration of the AFE74xx as a Repeater
      3. 2.3 Programming the Repeater Mode
        1. 2.3.1 Hardware Setup
        2. 2.3.2 Software Setup and GUI Configuration
    4. 3 130-MHz Digital Repeater System Overview
      1. 3.1 Key System Specifications
    5. 4 System Overview
      1. 4.1 Block Diagram
      2. 4.2 Design Considerations
      3. 4.3 Highlighted Products
        1. 4.3.1 LMK04828
      4. 4.4 System Design Theory
    6. 5 Hardware and Testing
      1. 5.1 Measured Latency and Gain
        1. 5.1.1 Hardware
        2. 5.1.2 Test Setup and Results
      2. 5.2 Measured Linearity Performance
        1. 5.2.1 Hardware and Test Setup
        2. 5.2.2 Test Results
      3. 5.3 Measured Selectivity (Out-of-Band Jammer)
        1. 5.3.1 Hardware and Test Setup
        2. 5.3.2 Test Results
    7. 6 Terminology

5.2.1 Hardware and Test Setup

The DAC38RF82 is an RF DAC that generates the signal of the ACPR performance measurements. When measuring ACPR degradation, the RF DAC outputs a clean 20-MHz long-term evolution (LTE) signal centered at 1907 MHz. The output signal of the DAC first passes through a band-pass filter before being connected to the input of the repeater.

Figure 15 shows the test setup for ACPR degradation. The ACPR of the LTE waveform is measured directly at the output of the DAC and also at the output of the repeater using the spectrum analyzer. The comparative difference in ACPR is the degradation of the LTE waveform due to the repeater.

slaa871-test-setup-for-acpr-degradation.gifFigure 15. Test Setup for ACPR Degradation