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

3 130-MHz Digital Repeater System Overview

In this example, the AFE74xx is evaluated as a direct RF-sampling, single-chip 4T4R wideband repeater. The AFE74xx as a repeater supports signal bandwidths from 130 MHz to 1.2 GHz. The bandwidth of operation for the experiments conducted in this application report is 130 MHz. The goal for all wireless communication systems is to effectively distribute signals to and from users while providing optimum coverage. Such goals have driven the demand for systems to operate at higher data rates. Although not yet permanently decided, 5G is supposed to support peak data rates in the Gbps range and average user data rates of up to 100 Mbps. To achieve these data rates, wide signal bandwidths of 500 MHz, 1 GHz, and even up to 2 GHz are required. The demand for wide-band RF repeaters capable of operating with such high bandwidths is sure to increase in order to achieve optimum coverage for wireless systems. In general, RF repeaters are located throughout cells where RF signal-path obstructions exist between users and base stations. A few different repeater types follow:

  • Analog: performs analog processing on received signal
  • Digital: performs digital processing on received signal
  • On-frequency: retransmits frequency on the same frequency that it was received
  • Off-frequency: retransmits frequency on frequency other than the received signal

Typical repeater systems configurations are 4T4R made up of four 1T1R or two 2T2R subsystems. This application report showcases the AFE74xx as an integrated, single-chip, 4T4R, digital wideband repeater.