UFX-NPR-22 NoiseCom Noise Power Ratio Test Set

The NoiseCom UFX-NPR Series instruments perform automatic distortion measurements in amplifiers and transceivers used in cellular and personal communications systems, satellite communications, MMDS wireless TV, CATV systems, and other equipment operating in multi-signal or frequency division multiplex (FDM) environments.

The UFX-NPR is divided into two sections: Noise Generator Section and Receiver Section. The Noise Generator Section consists of a noise source that is amplified, filtered, and attenuated via a level controller. For frequencies above 70 MHz, this noise is then upconverted. Single conversion is used for fixed frequency outputs, whereas multiple conversions can be supplied for tunable output noise masks with an external local oscillator. Units can be supplied with internal fixed local oscillators or with an external LO input connector to tune the noise bandwidth center frequency.

Noise power with a bandwidth on the order of the overall channel bandwidth is injected into the amplifier or frequency converter. This bandwidth is usually 10 to 40 MHz. Wider and narrower bandwidths along with selection between multiple bandwidths can also be supplied. A bandstop filter (notch filter) is switched in between the noise source and the DUT. The noise power spectral density is increased so that the total power injected into the DUT remains the same as it was before insertion of the bandstop filter. The notch is typically in the center of the noise bandwidth. The standard notch is a fixed multisection high-Q crystal filter with a nominal 50 kHz, 3 dB bandwidth. Multiple notches with customer-specified bandwidths can be installed in the UFX-NPR.