HP Scherer Art of PN measurement free download

File name Scherer_Art_of_PN_measurement.pdf

I I o The "Arl" of Phase Noise f,lleasurement DieterScherer March1985 o Rf & Mlcrowave Measurement Symposlum ancl txhlbltlon ftE'HF$|IfJJ o O o o DUCTION INTRO Measuring and specifying phase noise has become inereasingly important as phase noise is the limiting facior in many RF and microwave systems,like Doppler radar and space telemetry sy.te-. or communicationlinks. The complexity and subtleties of the 1nuurur.-unt have earned it the reputation of being more art than science. This paper gives an introduction to phase noise measurementfocusing on the two most and useful techniques,the "Two Source Phase Detector" and the "Delay Line Frequenc;- Discriminator" methods. System limitations are pointed 9ut a-swell as the "o--o1 potential ,our"". of erroneousdata when phase noise is measuredin a bench set up. The lt72gc Carrier Noise Test Set is HP's latest contribution in this field, designed to simplify and automate the complex task. A table of comparisons will show where the ttTigC and the various other HP solutions are optimally employed. O 1. Phase Why Measure Noise? Phasenoisecauses . . . environment sensitivity multi-signal o Lowerreceiver in Transmiller H q- DopplerSignal DecorrelatedClutler Noise J_ o Glutter RadarSystems noisein Doppler r Phase systems errorsin digitalcommunication phasenoiseimposes fundamentallimitations wherevera weak signal is processed the presence a in of .tiorrg interferini rij""r. In the aboveexample, phasenoisesidebands the receiverlocal oscillatorare of ti"".i"*"a to thI Ifpioduct of the strong interfering sjsnll and cover up the weak wanted signal. signal in this caseis A similar situatio;exists with cohereit Dopplerradar. The strong interferring p;;;;J ty reflectionsfrom large stationarl' f5;".ts. Phasenoise side bands of this unwanted return