USRP-2945 Block Diagram

Signals received by the USRP-2945 are amplified, downconverted, filtered, digitized, and decimated before being passed to the host computer.


usrp-2945 block diagram


usrp-2945 block diagram pt2


usrp-2945 block diagram pt 3

The following list describes the path of the individual blocks:

  • Depending on the frequency of interest, the input signal is first amplified by a high-band (HB) or low-band (LB) pre-amplifier.
  • The input attenuator attenuates the signal.
  • Another pre-amplifier (pre-amplifier 2) amplifies the signal further.
  • The filter bank filters the signal depending on the incoming frequency of interest.
  • The HB or LB attenuator attenuates and amplifies the signal.
  • The phase-locked loop (PLL) controls the voltage-controlled oscillator (VCO) so that the device clocks and local oscillators (LO) can be frequency-locked to a reference signal.
  • The first mixer downconverts the signals to the Intermediate Frequency (IF) 1 frequency using either the internal IF1 LOs of either RX1 or RX2, or the LO IN 0 IF1 connector.
  • Either the HB IF1 amplifier and the 1.25 GHz SAW filter, or the LB IF1 amplifier and the 2.345 GHz SAW filter amplifies and filters the IF 1 signal.
  • The IF1 amplifier amplifies the signal.
  • The signal is mixed with either the internal IF2 LOs of either RX1 or RX2, or the LO IN 0 IF2 connector.
  • The IF2 amplifier amplifies the signal.
  • The IF2 amplifier band-pass filters the signal for 80 MHz of bandwidth at IF2 (150 MHz) .
  • The analog-to-digital converter (ADC) digitizes the IF2 signal.
  • The digital downconverter (DDC) frequency-shifts, filters, and decimates the signal to in-phase/quadrature data (I/Q) at a rate you specify.
  • The downconverted samples are transported to the host computer over a standard PCIe connection.