Relationship Between IF1, IF2 and RF Central Frequency in USRP-2945/2955

Updated Apr 3, 2020

Reported In

Hardware

  • USRP-2945
  • USRP-2955
  • USRP X310

Issue Details

I want to know the relationship bewteen RF central frequency and the two IF in USRP-2945/2955. For example, the central frequency of my RF signal is 3GHz, then what frequency should IF1 and IF2 be.

Solution

USRP-2945/2955 are using the TwinRX daughterboard. The TwinRX daughterboard for the USRP X Series SDR platform is a two-channel superheterodyne receiver designed for high performance spectrum monitoring and direction finding applications. Because of the feature of superheterodyne frontends, it uses two IF to donconvert an RF signal to baseband signal in each channel as is shown in specification.
 
The LO specification of USRP-2955
 
According to TwinRX IF Board Revision C, it delivers input RF signal to lowband and highband and it use ADF5355 as LO1 and ADF4351 as LO2.

 
 Highband (1.8GHz - 6.0GHz)Lowband (10MHz - 1.8GHz)
IF11.25GHz +/- 40MHz2.345GHz +/- 40MHz
IF21.4GHz2.495GHz