National Instruments 781907-01 Software Defined Radio Device

The National Instruments 781907-01 (model name USRP-2921) is a Software Defined Radio (SDR) device designed for a range of communication applications. This module operates as a tunable RF transceiver with a frequency range of 2.4 GHz to 2.5 GHz and 4.9 GHz to 5.9 GHz. This SDR includes both high speed analog-to-digital (ADC) and digital-to-analog converters (DAC) for efficient streaming of baseband I/Q signals to a host computer via a 1 Gigabit Ethernet interface. 

The device is ideal for low power unlicensed devices within the ISM bands and public safety communications including industrial and Japanese wireless networks. The transmitter of the 781907-01 has a gain range of 0 dB to 35 dB, adjustable in 0.5 dB steps, and an output power range of 50 mW to 100 mW (17 dBm to 20 dBm). The maximum instantaneous real-time bandwidth that it can achieve is 24 MHz with a 16-bit sample width and 48 MHz with an 8-bit sample width. With the help of a 16-bit, 400 MS/s DAC, the highest I/Q sample rate is 25 MS/s at 16 bits and 50 MS/s at 8 bits. Furthermore, the DAC's portion has an 80 dB spurious-free dynamic range (sFDR), which reduces undesired spectral content in signal transmissions. The frequency range remains consistent at 2.4 GHz to 2.5 GHz and 4.9 GHz to 5.9 GHz on the receiver side.

The device offers a gain range of 0 dB to 92.5 dB in 2 dB steps with a maximum input power of -15 dBm and a noise figure between 5 dB to 7 dB. The receiver's instantaneous real time bandwidth is up to 19 MHz for 16-bit sample width and 36 MHz for 8-bit sample width. It features a 14-bit 100 MS/s ADC with an sFDR of 88 dB. The NI 781907-01 device operates in half-duplex mode meaning it cannot transmit and receive signals simultaneously. It typically consumes between 12 W to 15 W of power with a maximum power consumption of 18 W and is powered via a 6 V, 3 A external DC power supply. It measures 15.875 cm × 4.826 cm × 21.209 cm and weighs approximately 1.193 kg. The device is designed for indoor use with an operational temperature range of 23 °C ± 5 °C and relative humidity tolerance of 10 % to 90 % non-condensing.