National Instruments 781036-01 2-Channel RF Attenuator

The National Instruments 781036-01 is a 2-channel RF attenuator which is also identified as PXI-5695. It operates within a frequency range of 50 MHz to 8.0 GHz. This device features two distinct channels: one fixed (CH 0) and one programmable (CH 1) that caters to various RF attenuation requirements. Channel 0 (fixed path) of NI 781036-01 exhibits a level calibration accuracy of ±0.7 dB. It can handle a maximum input power of +33 dBm along with an absolute maximum to avoid damage at the same level. This channel also supports DC coupling with an input voltage tolerance of ±10 V. The direct path in Channel 0 maintains the same level of accuracy and input power capacity along with the relay switch time capped at 5 ms.

Channel 1 (programmable path) offers an attenuation resolution of +0.5 dB. It has a level calibration accuracy of ±0.7 dB and an attenuation settling time of +4 μs. The maximum input power for this channel during operation is +27 dBm along with an absolute limit of +27 dBm to prevent damage. The maximum reverse power is rated at +26 dBm.
The NI 781036-01 module necessitates a +3.3 VDC rail with a maximum current draw of 660 mA and a typical current of 250 mA. The maximum power consumption of the unit is 2.2 W. For the +12 VDC rail, the maximum current is 528 mA that leads to a maximum power draw of 7.0 W and the -12 VDC rail requires 508 mA for a power consumption of 6.1 W.

The NI 781036-01 RF attenuator is built with SMA female connectors for all input and output ports that ensure 50 Ω impedance. Channel 0 features DC coupling for both input and output, whereas Channel 1 utilizes AC coupling for the main path. The 781036-01 is a compact one-slot PXI module with dimensions of 21.6 cm × 2.0 cm × 13.0 cm and weighs 263 g. The module is designed for indoor use and is compliant with IEC 61010-1, EN 61010-1, UL 61010-1, and CSA C22.2 No. 61010-1 safety standards. It operates efficiently within an ambient temperature range of 0 to 55 °C and can be stored at temperatures between -40 to 71 °C. The NI 781036-01 supports relative humidity ranges of 10% to 90% during operation and 5% to 95% in storage, both non-condensing.