Acquisition:IQ:IQ Rate (S/s) Property

Acquisition:IQ:IQ Rate (S/s) Property

Short Name: IQ Rate

Property of niRFSA

Specifies the I/Q rate for the acquisition. The value is expressed in samples per second (S/s).

Refer to the Device Instantaneous Bandwidth property for more information about device specific instantaneous bandwidth limits. You can also refer to the specifications document for your device for more information about instantaneous bandwidth device specifications.

Note  For the PXIe-5663/5663E/5665/5667/5668 devices, NI-RFSA enables dithering by default. At I/Q rates above 50 MS/s, the dither noise can affect phase coherency performance and leak into the lower frequencies and the upper frequencies of the IF pass band. Refer to the Digitizer Dither Enabled property for more information about dithering.

Note  For the PXIe-5663/5663E/5665/5667, when you set the Digitizer Sample Clock Timebase Source property to OnboardClock, the downconverter instantaneous bandwidth is greater than or equal to the coerced I/Q rate times 0.8. For the PXIe-5665/5667, the actual signal bandwidth is further limited by the combination of the chosen IF filter and anti-aliasing filter.

PXI-5661—You should not need to configure an I/Q rate higher than 25 megasamples per second (MS/s) because the PXI-5600 RF downconverter bandwidth is 20 MHz. If you configure a higher I/Q rate, you may see aliasing effects at negative frequencies because the IF frequency of the PXI-5600 is 15 MHz.

PXIe-5663/5663E—Your maximum allowed instantaneous bandwidth depends on the downconverter center frequency you use. Refer to the PXIe-5601 RF downconverter overview for more information about instantaneous bandwidth.

PXIe-5665—Your maximum allowed instantaneous bandwidth depends on the downconverter center frequency if you have enabled the preselector (YIG-tuned filter).

PXIe-5667—Your maximum allowed instantaneous bandwidth depends on the selected RF preselector filter and whether the preselector on the RF downconverter is enabled.

PXIe-5668—Your maximum allowed instantaneous bandwidth depends on the downconverter center frequency you use and whether or not you enable the highpass filter or preselector (YIG-tuned filter).

Default Values:

PXIe-5842 (4 GHz bandwidth option) using the 4 GHz Bandwidth personality: 5 GS/s only.

All other devices: 1 MS/s

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5830/5831/5832/5840/5841/5842/5860

Related Topics

I/Q Modulation

Remarks

The following table lists the characteristics of this property.

Datatype
Permissions	Read/Write
High-level VIs	niRFSA Configure IQ Rate
Channel-based	No
Resettable	Yes