Preamplifiers with NI RF Signal Generators Hardware: Modular Instruments>>RF Measurement Devices>>PXI-5690
Problem: Why can't the NI PXI-5690 preamplifier be used with NI PXI-5670/5671/5672 RF vector signal generator for amplifying the signals or increasing their power level after generation? Solution: Preamplifiers are usually designed and optimized to handle very low-level signals. Higher power signals are distorted by the circuitry. Preamplifiers are not the same as power amplifiers. Preamplifiers are subject to distortion at high power levels and are usually only rated to tens of dBm output power because they are designed to feed into RF measurement equipment. This rating is in contrast to power amplifiers that transmit signals, such as in broadcast radio. We have power amplifiers at the transmission end of NI RF vector signal generators to amplify signals before transmission. Also, using a preamplifier at the output of the vector signal generator will amplify the noise floor of the signal also. The preamplifier is meant for signals whose noise floor is lesser than that of the vector signal analyzer. In other words, you'll amplify the noise along with the signal. Related Links: Attachments:
Report Date: 12/26/2007 Last Updated: 01/11/2008 Document ID: 4GPKGVDH |
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