Difference between revisions of "TwinRX"

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(→‎USRP Compatibility: fix USRP compatibility and master clock rate)
 
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Line 1: Line 1:
 
== Device Overview ==
 
== Device Overview ==
−
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. The receiver is tunable from 10 MHz - 6 GHz and has 80 MHz of instantaneous bandwidth per channel, providing the versatility nessary to analyze a variety of signals in multiple bands of interest. Each channel has an independent RF signal chain with preampilifiers, preselectors, and two mixer stages for superior selectivity. Users can tune the two channels independently to simultaneously montior uplink and downlink communication with a combined bandwidth of 160 MHz. The ability to share the LO between channels across multiple daughterboards enables the phase-aligned operation required to implement scalable multi-channel phased-arrays. The receiver is capable of fast frequency hopping to detect frequency agile emitters. Configurable RF attenuation and preamplication allow users to optimize dynamic range in favor of noise figure for faint signals, or IP3 for stronger signals. UHD automatically configures the RF signal path for optimized performance in the pre-defined use cases, and provides the flexibility to adjust settings manually. Support for RFNoC on the X Series motherboard enables deterministic FPGA-accelerated computations for real-time spectrum analysis.  
+
 
 +
The TwinRX daughterboard for the USRP X300 and X310 SDR platform is a two-channel superheterodyne receiver designed for high performance spectrum monitoring and direction finding applications. The receiver is tunable from 10 MHz - 6 GHz and has 80 MHz of instantaneous bandwidth per channel, providing the versatility necessary to analyze a variety of signals in multiple bands of interest. Each channel has an independent RF signal chain with preampilifiers, preselectors, and two mixer stages for superior selectivity. Users can tune the two channels independently to simultaneously monitor uplink and downlink communication with a combined bandwidth of 160 MHz. The ability to share the LO between channels across multiple daughterboards enables the phase-aligned operation required to implement scalable multi-channel phased-arrays. The receiver is capable of fast frequency hopping to detect frequency agile emitters. Configurable RF attenuation and preamplication allow users to optimize dynamic range in favor of noise figure for faint signals, or IP3 for stronger signals. UHD automatically configures the RF signal path for optimized performance in the pre-defined use cases, and provides the flexibility to adjust settings manually. Support for RFNoC on the X Series motherboard enables deterministic FPGA-accelerated computations for real-time spectrum analysis. The TwinRX daughterboard is supported by the USRP Hardware Driver™ (UHD) software API for seamless integration into existing applications.
 +
 
 +
[[File:TwinRX BlockDiagram.png|1000px|center]]
  
 
== Key Features==
 
== Key Features==
Line 10: Line 13:
 
* RF shielding
 
* RF shielding
 
* Independent RF signal channels with optional LO sharing
 
* Independent RF signal channels with optional LO sharing
−
 
+
|[[File:TwinRX large.png|250px|center]]
 
|}
 
|}
  
Line 16: Line 19:
 
===Features===
 
===Features===
 
* 2 superheterodyne frontends (2 receive)
 
* 2 superheterodyne frontends (2 receive)
 +
* 80 MHz per channel
 +
* Independent tuning
 +
* LO Sharing Capability
 +
* Coherent and phase-aligned operation
 +
* Preselection Filters
 +
* RF Shielding
  
 
===Antennas===
 
===Antennas===
Line 21: Line 30:
  
 
===Gains===
 
===Gains===
−
* Receive Gains Range: 0-95dB
+
* Receive Gains Range: 0-93dB
  
 
===Bandwidths===
 
===Bandwidths===
Line 31: Line 40:
 
===Ports===
 
===Ports===
 
The TwinRX has six MMCX RF connectors on it.
 
The TwinRX has six MMCX RF connectors on it.
 +
 +
{|
 +
|style="vertical-align:top"|
  
 
{|class="wikitable"
 
{|class="wikitable"
−
!Connector
+
 
−
!Description
+
! Connector
−
!Damage Threshold/Max Output
+
! Description
 +
! Min
 +
! Nominal
 +
! Damage
 
|-
 
|-
  
 
| J1
 
| J1
 
| LO2 Export
 
| LO2 Export
−
| 0 dBm output
+
| 0 dBm
 +
| 3 dBm
 +
| NA (Output)
 
|-
 
|-
  
 
| J2
 
| J2
 
| LO2 Input
 
| LO2 Input
−
| +20dBm input
+
| 0 dBm
 +
| 2 dBm
 +
| 20dBm
 
|-
 
|-
  
 
| J3
 
| J3
 
| LO1 Export
 
| LO1 Export
−
| +5 dBm output
+
| -12 dBm
 +
| 5 dBm
 +
| NA (Output)
 
|-
 
|-
  
 
| J4
 
| J4
 
| LO1 Input
 
| LO1 Input
−
| +10dBm input
+
| -10 dBm
 +
| -5 dBm
 +
| 10dBm
 
|-
 
|-
  
 
| J5
 
| J5
−
| Antenna 1 connector (RX1)
+
| Antenna 1 connector RX 1
−
| +10 dBm input
+
|
 +
|
 +
| 10 dBm
 
|-
 
|-
 +
  
 
| J6
 
| J6
−
| Antenna 2 connector (RX2)
+
| Antenna 2 connector RX 2
−
| +10 dBm input
+
|
 +
|
 +
| 10 dBm
 
|-
 
|-
 +
 +
 
|}
 
|}
  
 
===Preselector Filters===
 
===Preselector Filters===
 +
{|
 +
|style="vertical-align:top"|
 +
 
{|class="wikitable"
 
{|class="wikitable"
 
!Band
 
!Band
Line 107: Line 140:
 
|-
 
|-
  
 +
|}
 +
 +
|style="vertical-align:top"|[[File:TwinRX Normalized Preselector Response.png|650px|center]]
 
|}
 
|}
 
* Each preselector filter has a ±40 MHz band overlap.
 
* Each preselector filter has a ±40 MHz band overlap.
−
 
  
 
==RF Specifications==
 
==RF Specifications==
−
'''Freq Range'''
+
===Freq Range===
 
* 10MHz - 6GHz
 
* 10MHz - 6GHz
  
−
'''Noise Figure'''
+
===Noise Figure===
−
* Final Numbers Needed
+
{| class="wikitable" style="width:60%"
 +
!Frequency
 +
!Preamp Enabled
 +
|-
 +
 
 +
| 10 MHz - 3 GHz
 +
| < 5
 +
|-
 +
 
 +
| 3 GHz - 5 GHz
 +
| < 4
 +
|-
 +
 
 +
| 5 GHz - 6 GHz
 +
| < 8
 +
|-
 +
 
 +
|}
 +
 
 +
===RX Third Order Intercept (dBm)===
 +
{| class="wikitable" style="width:60%"
 +
 
 +
!Frequency
 +
!Full Scale = -45 dBm
 +
!Full Scale = -30 dBm
 +
!Full Scale = -20 dBm
 +
|-
 +
 
 +
| 10 MHz - 1.8 GHz
 +
| -8
 +
| -2
 +
| 16
 +
|-
 +
 
 +
| 1.8 GHz - 3 GHz
 +
| -10
 +
| -1
 +
| 14
 +
|-
 +
 
 +
| 3 GHz - 6 GHz
 +
| -13
 +
| -1
 +
| 12
 +
|-
 +
 
 +
|}
 +
 
 +
 
 +
===Phase Noise (dBc/Hz)===
 +
{| class="wikitable" style="width:60%"
 +
!Frequency Offset
 +
! 0.9 GHz
 +
! 2.4 GHz
 +
! 5.8 GHz
 +
|-
 +
 
 +
| 10 kHz
 +
| -88
 +
| -86
 +
| -82
 +
|-
 +
 
 +
 
 +
| 100 kHz
 +
| -105
 +
| -107
 +
| -103
 +
|-
 +
 
 +
 
 +
| 1 MHz
 +
| -124
 +
| -127
 +
| -127
 +
|-
 +
 
 +
|}
  
−
'''RX IIP3 (Max)'''
+
===Input/Output Impedance===
−
* Final Numbers Needed
+
* All RF Ports are matched to 50 Ohm with -10dB or better return loss generally. Detailed test is pending.
  
−
'''RX IQ Imbalance'''
+
===Input Power Levels===
−
* Final Numbers Needed
+
* The maximum input power for the TwinRX is +10 dBm.
  
 
==Hardware Specifications==
 
==Hardware Specifications==
Line 139: Line 251:
 
* 10% to 90% non-condensing
 
* 10% to 90% non-condensing
  
−
==USRP Compatibility==
+
== USRP Compatibility ==
−
* X Series only
+
 
 +
* X300 and X310 USRP only
 +
 
 +
* <code>master_clock_rate</code> of 200e6 only. The TwinRX daughterboard does not operate with the master clock rate of 184.32e6; operation with this master clock rate will result in UHD errors such as the following:
 +
 
 +
<pre>
 +
[ERROR] [DBMGR] The daughterboard manager encountered a recoverable error in init.
 +
Loading the "unknown" daughterboard implementations to continue.
 +
The daughterboard cannot operate until this error is resolved.
 +
ValueError: TwinRX clock rate 92160000.000000 is not a multiple of the pfd freq 12500000.000000.
 +
</pre>
 +
 
 +
==Phase Synchronization==
 +
The TwinRX daughterboard is capable of phase-synchronous operation, and is recommended for phase-coherent applications. Please note that the TwinRX is receive-only. The SBX and UBX daughterboards are also recommended for phase-coherent applications, and are capable of both transmit and receive operations.
  
 
==Schematics==
 
==Schematics==
−
[http://files.ettus.com/schematics/twinrx/twinrx.pdf TwinRX Schematics] '''*Needed'''
+
The TwinRX daughterboard is composed of two PCBs, the Intermediate Frequency (IF) board and the RF board. There are two functionally identical revisions of TwinRX at the moment. Please check the back of your TwinRX to see which you have. The schematics for TwinRX revision B should answer most possible questions. If you have any further questions please email [mailto:support@ettus.com support@ettus.com].
  
−
==Mechanical Information==
+
TwinRX Revision A  - (159685A-01)
−
===Drawings===
+
* IF Board Revision B - (158671B-01L)
−
* [[Media:cu ettus TwinRX cca.pdf| PDF Format]] <span style="background:#FF0000">'''*Needed'''</span>
+
* RF Board Revision C - (156263C-01L)
 +
 
 +
TwinRX Revision B  - (159685B-01)
 +
* IF Board Revision C - (158671C-01L)
 +
* RF Board Revision D - (156263D-01L)
 +
 
 +
[[File:TwinRX IF Board Rev C.pdf]]
 +
 
 +
[[File:TwinRX RF Board Rev D.pdf]]
  
 
==RF Connectors==
 
==RF Connectors==
 +
{|
 +
|style="vertical-align:top"|
 
The antenna ports are MMCX connectors with 50 ohm input impedance. By default Antenna 1 (RX1) is routed to Channel 1 and Antenna 2 (RX2) to Channel 2. This routing can be changed to swap the antennas or to share a single antenna to both channels. The damage threshold for the antenna inputs is 10 dBm. In practice the available gain makes much lower input powers recommended for achieving the best dynamic range and noise figure.
 
The antenna ports are MMCX connectors with 50 ohm input impedance. By default Antenna 1 (RX1) is routed to Channel 1 and Antenna 2 (RX2) to Channel 2. This routing can be changed to swap the antennas or to share a single antenna to both channels. The damage threshold for the antenna inputs is 10 dBm. In practice the available gain makes much lower input powers recommended for achieving the best dynamic range and noise figure.
 +
|[[File:TwinRX 80 Inputs.jpg|250px|center]]
 +
|}
  
 
==Local Oscillator Connectors==
 
==Local Oscillator Connectors==
 +
Note: LO sharing cables are not required for a single TwinRX setup. LO sharing cables are only required with two TwinRX daughterboards in a single USRP X300/X310.
 +
 +
{|
 +
|style="vertical-align:top"|
 +
 +
 +
{|
 +
|style="vertical-align:top"|
 +
 
{|class="wikitable"
 
{|class="wikitable"
  
Line 165: Line 311:
 
| LO2 Export
 
| LO2 Export
 
| 0 dBm
 
| 0 dBm
−
| 0 dBm
+
| 3 dBm
 
| NA (Output)
 
| NA (Output)
 
|-
 
|-
Line 172: Line 318:
 
| LO2 Input
 
| LO2 Input
 
| 0 dBm
 
| 0 dBm
−
| +20dBm
+
| 2 dBm
 +
| 20dBm
 
|-
 
|-
  
Line 178: Line 325:
 
| LO1 Export
 
| LO1 Export
 
| -12 dBm
 
| -12 dBm
−
| +5 dBm
+
| 5 dBm
 
| NA (Output)
 
| NA (Output)
 
|-
 
|-
Line 186: Line 333:
 
| -10 dBm
 
| -10 dBm
 
| -5 dBm
 
| -5 dBm
−
| +10dBm
+
| 10dBm
 
|-
 
|-
 +
 +
| J5
 +
| Antenna 1 connector RX 1
 +
|
 +
|
 +
| 10 dBm
 +
|-
 +
 +
 +
| J6
 +
| Antenna 2 connector RX 2
 +
|
 +
|
 +
| 10 dBm
 +
|-
 +
  
 
|}
 
|}
 +
 +
| style="padding-left: 30px" | [[File:TwinRX 80 LOs.jpg|250px|center]]
 +
|}
 +
 +
===LO Sharing with Neighbour TwinRXs===
 +
{|class="wikitable"
 +
!TwinRX (A Slot)
 +
!TwinRX (B Slot)
 +
|-
 +
|J1 LO2 Export
 +
|J2 LO2 Input
 +
|-
 +
|J2 LO2 Input
 +
|J1 LO2 Export
 +
|-
 +
|J3 LO1 Export
 +
|J4 LO1 Input
 +
|-
 +
|J4 LO1 Input
 +
|J3 LO1 Export
 +
|-
 +
 +
|}
 +
 +
==Software API==
 +
 +
===New Multi USRP Functions===
 +
The advanced functionalities of the TwinRX will be exposed through new functions implemented in [http://files.ettus.com/manual/classuhd_1_1usrp_1_1multi__usrp.html Multi-USRP].
 +
 +
===Antenna Mapping===
 +
The two channels of the TwinRX can be independently configured to use either of the two antenna ports, '''RX1''' and '''RX2''' using the standard antenna selection function in <code>multi_usrp</code>.
 +
 +
    virtual void set_rx_antenna(const std::string &ant, size_t chan = 0) = 0;
 +
 +
Select the RX antenna on the frontend.
 +
* '''ant''' the antenna name
 +
* '''chan''' the channel index 0 to N-1
 +
 +
 +
===Local Oscillator Control and Routing===
 +
The TwinRX has two channels, '''CH1''' and '''CH2''' and each channel has two local oscillators, '''LO1''' and '''LO2'''. The local oscillators for a channel can be sourced from that channel's '''internal''' synthesizers, the '''companion''' channel's synthesizers, or '''external''' inputs. The value <code>multi_usrp::ALL_LOS</code> can be used to specify that the command be run on both synthesizers for a channel. The defaults are to operate on
 +
 +
    virtual std::vector<std::string> get_rx_lo_names(size_t chan = 0) = 0;
 +
 +
Get a list of possible LO stage names
 +
* '''chan''' the channel index 0 to N-1
 +
* Returns a vector of strings for possible LO names
 +
 +
 +
    virtual void set_rx_lo_source(const std::string &src, const std::string &name = ALL_LOS, size_t chan = 0) = 0;
 +
 +
Set the LO source for the usrp device. For USRPs that support selectable LOs, this function allows switching between them. Supported options for source: internal, external, companion.
 +
* '''src''' a string representing the LO source
 +
* '''name''' the name of the LO stage to update
 +
* '''chan''' the channel index 0 to N-1
 +
 +
 +
    virtual const std::string get_rx_lo_source(const std::string &name = ALL_LOS, size_t chan = 0) = 0;
 +
 +
Get the currently set LO source.
 +
* '''name''' the name of the LO stage to query
 +
* '''chan''' the channel index 0 to N-1
 +
* Returns the configured LO source
 +
 +
 +
    virtual std::vector<std::string> get_rx_lo_sources(const std::string &name = ALL_LOS, size_t chan = 0) = 0;
 +
 +
Get a list of possible LO sources.
 +
* '''name''' the name of the LO stage to query
 +
* '''chan''' the channel index 0 to N-1
 +
* Returns a vector of strings for possible settings
 +
 +
 +
    virtual double set_rx_lo_freq(double freq, const std::string &name, size_t chan = 0) = 0;
 +
 +
Set the RX LO frequency.
 +
* '''freq''' the frequency to set the LO to
 +
* '''name''' the name of the LO stage to update
 +
* '''chan''' the channel index 0 to N-1
 +
* Returns a coerced LO frequency
 +
 +
 +
    virtual double get_rx_lo_freq(const std::string &name, size_t chan = 0) = 0;
 +
 +
Get the current RX LO frequency.
 +
* '''name''' the name of the LO stage to query
 +
* '''chan''' the channel index 0 to N-1
 +
* Returns the configured LO frequency
 +
 +
 +
    virtual freq_range_t get_rx_lo_freq_range(const std::string &name, size_t chan = 0) = 0;
 +
 +
Get the LO frequency range of the RX LO.
 +
* '''name''' the name of the LO stage to query
 +
* '''chan''' the channel index 0 to N-1
 +
* Returns a frequency range object
 +
 +
 +
===Exporting Local Oscillators===
 +
 +
    virtual void set_rx_lo_export_enabled(bool enabled, const std::string &name = ALL_LOS, size_t chan = 0) = 0;
 +
 +
Set whether the LO used by the usrp device is exported For USRPs that support exportable LOs, this function configures if the LO used by chan is exported or not.
 +
* '''enabled''' if true then export the LO
 +
* '''name''' the name of the LO stage to update
 +
* '''chan''' the channel index 0 to N-1 for the source channel
 +
 +
 +
    virtual bool get_rx_lo_export_enabled(const std::string &name = ALL_LOS, size_t chan = 0) = 0;
 +
 +
Returns true if the currently selected LO is being exported.
 +
* '''name''' the name of the LO stage to query
 +
* '''chan''' the channel index 0 to N-1
 +
 +
==Drawings==
 +
* [[File:cu usrp twinrx cca.pdf]]
  
 
==Certifications==
 
==Certifications==
Line 195: Line 474:
 
As of December 1st, 2010 all Ettus Research products are RoHS compliant unless otherwise noted. More information can be found at [http://ettus.com/legal/rohs-information http://ettus.com/legal/rohs-information]
 
As of December 1st, 2010 all Ettus Research products are RoHS compliant unless otherwise noted. More information can be found at [http://ettus.com/legal/rohs-information http://ettus.com/legal/rohs-information]
  
−
==Certificate of Volatility==
+
===China RoHS===
−
* [[Media:volatility TwinRX r1 1.pdf]] <span style="background:#FF0000">'''*Needed'''</span>
+
'''Management Methods for Controlling Pollution Caused by Electronic Information Products Regulation'''
  
−
==RF Performance Data==
+
'''Chinese Customers'''
−
* [http://files.ettus.com/performance_data/twinrx/TwinRX-without-UHD-corrections.pdf TwinRX without UHD Corrections] '''* NEEDED'''
+
 
 +
National Instruments is in compliance with the Chinese policy on the Restriction of Hazardous Substances (RoHS) used in Electronic Information Products. For more information about the National Instruments China RoHS compliance, visit [http://www.ni.com/environment/rohs_china ni.com/environment/rohs_china].
 +
 
 +
==Certificate of Volatility==
 +
[https://www.ni.com/pdf/manuals/377337a.pdf TwinRX Letter of Volatility]
  
 
==Downloads==
 
==Downloads==

Latest revision as of 11:02, 25 January 2023

Device Overview

The TwinRX daughterboard for the USRP X300 and X310 SDR platform is a two-channel superheterodyne receiver designed for high performance spectrum monitoring and direction finding applications. The receiver is tunable from 10 MHz - 6 GHz and has 80 MHz of instantaneous bandwidth per channel, providing the versatility necessary to analyze a variety of signals in multiple bands of interest. Each channel has an independent RF signal chain with preampilifiers, preselectors, and two mixer stages for superior selectivity. Users can tune the two channels independently to simultaneously monitor uplink and downlink communication with a combined bandwidth of 160 MHz. The ability to share the LO between channels across multiple daughterboards enables the phase-aligned operation required to implement scalable multi-channel phased-arrays. The receiver is capable of fast frequency hopping to detect frequency agile emitters. Configurable RF attenuation and preamplication allow users to optimize dynamic range in favor of noise figure for faint signals, or IP3 for stronger signals. UHD automatically configures the RF signal path for optimized performance in the pre-defined use cases, and provides the flexibility to adjust settings manually. Support for RFNoC on the X Series motherboard enables deterministic FPGA-accelerated computations for real-time spectrum analysis. The TwinRX daughterboard is supported by the USRP Hardware Driver™ (UHD) software API for seamless integration into existing applications.

TwinRX BlockDiagram.png

Key Features

  • Two-Channel Superheterodyne Receiver
  • Frequency Range: 10 MHz - 6 GHz
  • Bandwidth: 80 MHz per channel ( 160 MHz total )
  • RF shielding
  • Independent RF signal channels with optional LO sharing
TwinRX large.png

Daughterboard Specifications

Features

  • 2 superheterodyne frontends (2 receive)
  • 80 MHz per channel
  • Independent tuning
  • LO Sharing Capability
  • Coherent and phase-aligned operation
  • Preselection Filters
  • RF Shielding

Antennas

Receive: RX1 or RX2

Gains

  • Receive Gains Range: 0-93dB

Bandwidths

  • TwinRX: 80 MHz per channel ( 160 MHz total )

Sensors

  • lo_locked: boolean for LO lock state

Ports

The TwinRX has six MMCX RF connectors on it.

Connector Description Min Nominal Damage
J1 LO2 Export 0 dBm 3 dBm NA (Output)
J2 LO2 Input 0 dBm 2 dBm 20dBm
J3 LO1 Export -12 dBm 5 dBm NA (Output)
J4 LO1 Input -10 dBm -5 dBm 10dBm
J5 Antenna 1 connector RX 1 10 dBm
J6 Antenna 2 connector RX 2 10 dBm

Preselector Filters

Band Range
LB1 10 - 500 MHz
LB2 500 - 800 MHz
LB3 800 - 1.2 GHz
LB4 1.2 - 1.8 GHz
HB1 1.8 - 3.0 GHz
HB2 3.0 - 4.1 GHz
HB3 4.1 - 5.1 GHz
HB4 5.1 - 6.0 GHz
TwinRX Normalized Preselector Response.png
  • Each preselector filter has a ±40 MHz band overlap.

RF Specifications

Freq Range

  • 10MHz - 6GHz

Noise Figure

Frequency Preamp Enabled
10 MHz - 3 GHz < 5
3 GHz - 5 GHz < 4
5 GHz - 6 GHz < 8

RX Third Order Intercept (dBm)

Frequency Full Scale = -45 dBm Full Scale = -30 dBm Full Scale = -20 dBm
10 MHz - 1.8 GHz -8 -2 16
1.8 GHz - 3 GHz -10 -1 14
3 GHz - 6 GHz -13 -1 12


Phase Noise (dBc/Hz)

Frequency Offset 0.9 GHz 2.4 GHz 5.8 GHz
10 kHz -88 -86 -82
100 kHz -105 -107 -103
1 MHz -124 -127 -127

Input/Output Impedance

  • All RF Ports are matched to 50 Ohm with -10dB or better return loss generally. Detailed test is pending.

Input Power Levels

  • The maximum input power for the TwinRX is +10 dBm.

Hardware Specifications

  • Ettus Research recommends to always use the latest stable version of UHD. Minimum UHD version is 3.10.0.0

TwinRX

  • Current Hardware Revision: 2
  • Minimum version of UHD required: 3.10.0.0
  • Minimum version of GNU Radio required: 3.7.10

Environmental Specifications

Operating Temperature Range

  • 0-40 °C

Operating Humidity Range

  • 10% to 90% non-condensing

USRP Compatibility

  • X300 and X310 USRP only
  • master_clock_rate of 200e6 only. The TwinRX daughterboard does not operate with the master clock rate of 184.32e6; operation with this master clock rate will result in UHD errors such as the following:
[ERROR] [DBMGR] The daughterboard manager encountered a recoverable error in init.
Loading the "unknown" daughterboard implementations to continue.
The daughterboard cannot operate until this error is resolved.
ValueError: TwinRX clock rate 92160000.000000 is not a multiple of the pfd freq 12500000.000000.

Phase Synchronization

The TwinRX daughterboard is capable of phase-synchronous operation, and is recommended for phase-coherent applications. Please note that the TwinRX is receive-only. The SBX and UBX daughterboards are also recommended for phase-coherent applications, and are capable of both transmit and receive operations.

Schematics

The TwinRX daughterboard is composed of two PCBs, the Intermediate Frequency (IF) board and the RF board. There are two functionally identical revisions of TwinRX at the moment. Please check the back of your TwinRX to see which you have. The schematics for TwinRX revision B should answer most possible questions. If you have any further questions please email support@ettus.com.

TwinRX Revision A - (159685A-01)

  • IF Board Revision B - (158671B-01L)
  • RF Board Revision C - (156263C-01L)

TwinRX Revision B - (159685B-01)

  • IF Board Revision C - (158671C-01L)
  • RF Board Revision D - (156263D-01L)

File:TwinRX IF Board Rev C.pdf

File:TwinRX RF Board Rev D.pdf

RF Connectors

The antenna ports are MMCX connectors with 50 ohm input impedance. By default Antenna 1 (RX1) is routed to Channel 1 and Antenna 2 (RX2) to Channel 2. This routing can be changed to swap the antennas or to share a single antenna to both channels. The damage threshold for the antenna inputs is 10 dBm. In practice the available gain makes much lower input powers recommended for achieving the best dynamic range and noise figure.

TwinRX 80 Inputs.jpg

Local Oscillator Connectors

Note: LO sharing cables are not required for a single TwinRX setup. LO sharing cables are only required with two TwinRX daughterboards in a single USRP X300/X310.


Connector Description Min Nominal Damage
J1 LO2 Export 0 dBm 3 dBm NA (Output)
J2 LO2 Input 0 dBm 2 dBm 20dBm
J3 LO1 Export -12 dBm 5 dBm NA (Output)
J4 LO1 Input -10 dBm -5 dBm 10dBm
J5 Antenna 1 connector RX 1 10 dBm
J6 Antenna 2 connector RX 2 10 dBm
TwinRX 80 LOs.jpg

LO Sharing with Neighbour TwinRXs

TwinRX (A Slot) TwinRX (B Slot)
J1 LO2 Export J2 LO2 Input
J2 LO2 Input J1 LO2 Export
J3 LO1 Export J4 LO1 Input
J4 LO1 Input J3 LO1 Export

Software API

New Multi USRP Functions

The advanced functionalities of the TwinRX will be exposed through new functions implemented in Multi-USRP.

Antenna Mapping

The two channels of the TwinRX can be independently configured to use either of the two antenna ports, RX1 and RX2 using the standard antenna selection function in multi_usrp. 

   virtual void set_rx_antenna(const std::string &ant, size_t chan = 0) = 0;

Select the RX antenna on the frontend.

  • ant the antenna name
  • chan the channel index 0 to N-1


Local Oscillator Control and Routing

The TwinRX has two channels, CH1 and CH2 and each channel has two local oscillators, LO1 and LO2. The local oscillators for a channel can be sourced from that channel's internal synthesizers, the companion channel's synthesizers, or external inputs. The value multi_usrp::ALL_LOS can be used to specify that the command be run on both synthesizers for a channel. The defaults are to operate on 

   virtual std::vector<std::string> get_rx_lo_names(size_t chan = 0) = 0;

Get a list of possible LO stage names

  • chan the channel index 0 to N-1
  • Returns a vector of strings for possible LO names


   virtual void set_rx_lo_source(const std::string &src, const std::string &name = ALL_LOS, size_t chan = 0) = 0;

Set the LO source for the usrp device. For USRPs that support selectable LOs, this function allows switching between them. Supported options for source: internal, external, companion.

  • src a string representing the LO source
  • name the name of the LO stage to update
  • chan the channel index 0 to N-1


   virtual const std::string get_rx_lo_source(const std::string &name = ALL_LOS, size_t chan = 0) = 0;

Get the currently set LO source.

  • name the name of the LO stage to query
  • chan the channel index 0 to N-1
  • Returns the configured LO source


   virtual std::vector<std::string> get_rx_lo_sources(const std::string &name = ALL_LOS, size_t chan = 0) = 0;

Get a list of possible LO sources.

  • name the name of the LO stage to query
  • chan the channel index 0 to N-1
  • Returns a vector of strings for possible settings


   virtual double set_rx_lo_freq(double freq, const std::string &name, size_t chan = 0) = 0;

Set the RX LO frequency.

  • freq the frequency to set the LO to
  • name the name of the LO stage to update
  • chan the channel index 0 to N-1
  • Returns a coerced LO frequency


   virtual double get_rx_lo_freq(const std::string &name, size_t chan = 0) = 0;

Get the current RX LO frequency.

  • name the name of the LO stage to query
  • chan the channel index 0 to N-1
  • Returns the configured LO frequency


   virtual freq_range_t get_rx_lo_freq_range(const std::string &name, size_t chan = 0) = 0;

Get the LO frequency range of the RX LO.

  • name the name of the LO stage to query
  • chan the channel index 0 to N-1
  • Returns a frequency range object


Exporting Local Oscillators

   virtual void set_rx_lo_export_enabled(bool enabled, const std::string &name = ALL_LOS, size_t chan = 0) = 0;

Set whether the LO used by the usrp device is exported For USRPs that support exportable LOs, this function configures if the LO used by chan is exported or not.

  • enabled if true then export the LO
  • name the name of the LO stage to update
  • chan the channel index 0 to N-1 for the source channel


   virtual bool get_rx_lo_export_enabled(const std::string &name = ALL_LOS, size_t chan = 0) = 0;

Returns true if the currently selected LO is being exported.

  • name the name of the LO stage to query
  • chan the channel index 0 to N-1

Drawings

Certifications

RoHS

As of December 1st, 2010 all Ettus Research products are RoHS compliant unless otherwise noted. More information can be found at http://ettus.com/legal/rohs-information

China RoHS

Management Methods for Controlling Pollution Caused by Electronic Information Products Regulation

Chinese Customers

National Instruments is in compliance with the Chinese policy on the Restriction of Hazardous Substances (RoHS) used in Electronic Information Products. For more information about the National Instruments China RoHS compliance, visit ni.com/environment/rohs_china.

Certificate of Volatility

TwinRX Letter of Volatility

Downloads

FPGA Resources

UHD Stable Binaries

UHD Source Code on Github

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