USRP Reference

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This page provides an index containing technical data for the USRP and various daughterboards

USRP

Specifications (v1)
Rev 4.5
Power 6 V / _ mA
Size (mm) 160 x 160
Weight (g) 130


Power consumption (v1)
State DBSRX+TVRX DBSRX only
Switch ON 770 mA 600 mA
Start 1.60 A 1.37 A
Stop 900 mA 730 mA


The data coming from the USRP1 is ± 32767 as the floating point range. In the USRP2 we use ± 1.0[1].

In comparison, audio source and sink has range ± 1.0

Filtering

If the decimation is a factor of four there are two half-band filters + CIC filter, if it is a multiple of two (i.e. even, but not a factor of four) then there is only one half-band filter + CIC, and if it is an odd number, just a CIC filter[2].

RFX1200

Specifications
Rev 3.0
Frequency 1150 - 1450 MHz
Noise Figure 6-10 dB
TX Power 200 mW (23 dBm)
Antenna TX/RX and RX2
GPIO
Power __ V / __ mA
Size (mm) 142 x 69
Weight (g) 49

The AUX ADC is used to measure received signal level[3]. The AUX DACs are used to set gains on most of the daughterboards[3].

RFX2400

Specifications
Rev
Frequency 2.3 - 2.9 GHz
Noise Figure 6-10 dB
TX Power 50 mW (17 dBm)
Antenna TX/RX and RX2
GPIO
Power __ V / __ mA
Size (mm) 142 x 69
Weight (g) 49

The AUX ADC is used to measure received signal level[3]. The AUX DACs are used to set gains on most of the daughterboards[3].

TVRX

Specifications
Rev
Frequency 50 - 870 MHz
Noise Figure 8-10 dB
Antenna
GPIO
Power __ V / __ mA
Size (mm)
Weight (g) 78
  • Being a TV tuner, TVRX has 75 Ω input. When using 50 Ω cables and antenna, this will result in an SWR of ~ 1.5 (TBC), which is not that bad considering all other deficiencies of a TV tuner.
  • I have measured the sensitivity to be between -123 ... -126 dBm (0.11 and 0.14 µV) using a CW signal, SSB receiver and RF gain set to 71.
  • The TVRX can only receive up to 6 MHz channels (NTSC channel?).
  • Nick Foster on TVRX gain[4]: "The TVRX gain is set via an analog pin and isn't even guaranteed to be monotonic, let alone accurate. It varies with temperature as well. I've tried to compensate for what I can, but the absolute gain really can't be controlled very tightly."

DBSRX

Specifications
Rev 2.2
Frequency 800 - 2400 MHz
Noise Figure 3-5 dB
Antenna only one
GPIO
  • Antenna bias 6V, 500 mA
Power 6 V / __ mA
Size (mm)
Weight (g) 20

This receiver performs surprisingly well. Using the FFT spectrum analyser (avg. α = 0.07) we could detect a -132 dBm CW signal at 2.25 GHz, 250 kHz sampling bandwidth.

Channel Filter

The DBSRX has a programmable channel filter at the output that can be programmed within 1 and 60 MHz.

Python: u.subdev.set_bw(1e6) # set bandwidth to 1 MHz

C++: TBD
Channel filter set to 10 MHz.
Channel filter set to 1 MHz.

LFRX

Specifications
Rev 2.2
Frequency DC - 50 MHz
Antenna RX_A and RX_B
GPIO
Power __ V / __ mA
Size (mm) 69 x 63
Weight (g) 24
  • Input power level: +10 dBm will clip, more than +17dBm could cause damage.
  • With a good and matched antenna, LFRX can receive hamradio traffic without preamp, see http://www.youtube.com/watch?v=BF3VgsKdnUE
  • Subdevice0 is the antenna A, Subdevice1 is the antenna B. You can use both subdevice 0 and 1 at the same time on two different ddc inputs and tune them separately. These subdevices are used as real inputs, and the Q inputs to the ddc are set to zero. The third possibility is to use subdevice2 which treats the antenna A and B as a single complex input (I and Q), and connects them to the I and Q inputs of the DDC input0. When using subdevice2, you cannot use subdevice 0 and 1.[5]
  • Sensitivity of LFRX measure to be between -102 and -97 dBm (1.8 and 3 µV) using a CW signal, SSB receiver and gain set to 20 dB.

LFTX

Specifications
Rev 2.2
Frequency DC - 50 MHz
Antenna TX_A and TX_B
GPIO
DC Power __ V / __ mA
RF Power 3 dBm / 2 mW[6]
Size (mm) 69 x 63
Weight (g) 24

WBX

Specifications
Rev 2
Frequency 50 MHz - 2.2 GHz
Noise Figure 5-6 db[7]
IIP2 40-55 dBm[7]
IIP3 5-10 dBm[7]
TX power 50-100mW up to 1 GHz
30-50 mW above 1 GHz
(adjustable)
Antenna
GPIO
DC Power 6 V / 1.1 A[8]
Size (mm)
Weight (g)

Became available in Jan 2010. Full duplex.


The AUX ADC is used to measure the temperature[3]. The AUX DACs are used to set gains on most of the daughterboards[3].

Receiver Sensitivity in CW

References

  1. Discuss-gnuradio mailing list, 22 Sep 2009
  2. Discuss-gnuradio mailing list, 26 Oct 2009
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Email from Matt Ettus, http://lists.gnu.org/archive/html/discuss-gnuradio/2010-01/msg00321.html
  4. Email Dec 21, 2010 - link TBD
  5. Email from Josh Blum, 21 Feb 2010
  6. Message on discuss-gnuradio dated 25 Aug 2009: http://lists.gnu.org/archive/html/discuss-gnuradio/2009-08/msg00292.html
  7. 7.0 7.1 7.2 WBX Receiver Performance Plots, http://code.ettus.com/redmine/ettus/documents/show/16
  8. According to schematics 540 mA TX and 543 mA RX.