LFTX/LFRX
Contents
Device Overview
The LFTX daughterboard utilizes two high-speed operational amplifiers to allow transmission from 0-30 MHz. The boards accept real-mode only signals. The LFTX is ideal for applications in the HF band, or for applications using an external front end to up-convert and amplify the intermediate signal. The outputs of the LFTX can be processed independently, or as a single I/Q pair. Example applications include HF communications, radios with external front ends and direct signal generation below 30 MHz. The LFTX/LFRX daughterboards are supported by the USRP Hardware Driver™ (UHD) software API for seamless integration into existing applications.
Key Features
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Daughterboard Specifications
Frontends
LFRX
The LFRX has 4 frontends:
- Frontend A: real signal on antenna RXA
- Frontend B: real signal on antenna RXB
- Frontend AB: quadrature frontend using both antennas (IQ)
- Frontend BA: quadrature frontend using both antennas (QI)
LFTX
The LFTX has 4 frontends:
- Frontend A: real signal on antenna TXA
- Frontend B: real signal on antenna TXB
- Frontend AB: quadrature frontend using both antennas (IQ)
- Frontend BA: quadrature frontend using both antennas (QI)
Gains
LFRX
- The LFRX has no tunable elements or programmable gains. Through the magic of aliasing, you can down-convert signals greater than the Nyquist rate of the ADC.
LFTX
- The LFTX has no tunable elements or programmable gains. Through the magic of aliasing, you can up-convert signals greater than the Nyquist rate of the DAC.
Bandwidths
LFRX
- For Real-Mode (A or B frontend): 33 MHz
- For Complex (AB or BA frontend): 66 MHz
LFTX
- For Real-Mode (A or B frontend): 33 MHz
- For Complex (AB or BA frontend): 66 MHz
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 LFRX is +10 dBm.
Hardware Specifications
- Ettus Research recommends to always use the latest stable version of UHD
LFRX
- Current Hardware Revision: 1
- Minimum version of UHD required: 3.8.0
LFTX
- Current Hardware Revision: 1
- Minimum version of UHD required: 3.8.0
Environmental Specifications
Operating Temperature Range
- 0-40 °C
Operating Humidity Range
- 10% to 90% non-condensing
USRP Compatibility
LFRX
- N or X Series
LFTX
- N or X Series
Schematics
LFRX
LFTX
Key Component Datasheets
| Part Number | Description | Schematic ID (Page) |
|---|---|---|
| AD813x | Differential ADC Driver | U2, U3 (1) |
| LT3462 | DC/DC Converter | U3 (1) |
| 24LC025B | EEPROM | U1 (1) |
RF Connectors
- The LFTX / LFRX daughterboard features female SMA connectors for both the TX and RX connectors.
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
LFRX / LFTX Letter of Volatility
