SBAA682 April   2025 AFE7728D , AFE7768D , AFE7769D

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Acronyms Used in This Document
  5. 2Distributive Antenna System
  6. 3Repeater System
  7. 4Goals of DAS and Repeater Design
  8. 5RF Repeater System Without FPGA/ASIC
  9.   10
  10. 6Overcoming Bandpass Filter Effects From Cable Dispersions and Multi-Path
  11. 7Summary

The benefits of the internal RX DDC to TX DUC direct loop back includes the following:

  • Reduction of overall repeater system power consumption: the system designer does not need to include the FPGA and the JESD204 power consumption into the system. The designer can also reduce the size of the power supply circuitry as needed.
  • Reduction of overall system cost: with the removal of the FPGA and downsizing of the PCB size and power supply circuit power capacity, the designer can further reduce the overall cost.

Moreover, the system designers can have additional flexibilities in the design. They can configure the AFE7769D RX DDC to TX DUC loopback with the following capabilities:

  • Flexibility to enable which signal chain has the loopback path feature: For example, the user can enable RX1 to TX1 and RX2 to TX2 with DDC to DUC loopback, while maintaining traditional JESD204 interface with the FPGA for RX3 to TX3 and RX4 to TX4.
  • Flexibility to enable internal signal mux feature to allow RX channels to loop back to certain TX channels: for example, the user has ability to route RX1 to TX2 and RX2 to TX1, if the PCB layout requires such flexibility.