The traditional analog techniques of amplitude, frequency and phase modulation retain their important position in all branches of communication despite the increasing use of digital modulation. The concept of the FMx family - modulation analysis for today's requirements - calls for measurement performance weIl beyond that of conventional modulation meters. The predecessor FAM from Rohde&Schwarz was a step in the right direction. Through the innovative FMx family with its range of application-specific models, this development has reached a new peak. The goals of this new design were:
- improved accuracy of all measurements
- higher measurement rates
- improved processing and presentation of the results
- optimization of the model range from the application point of view and
- retention of the basic concepts of the predecessor family FAM.
A standardized interface (the IEEE-488 bus) for applications in automatic test systems was just as important as a weIl-defined family of instruments for applications in stationary and mobile radiocommunication, in sound and TV broadcasting and in many navigation systems. Measurements on FM stereo signals are a major area of interest. Beyond the classic parameters such as modulation depth, deviation and carrier frequency, comprehensive analysis of the interfering modulation and the baseband source signal is provided for. Among the many other tests catered for are precise measurements of the carrier power and the transient behaviour of the RF carrier.
FMA combines the functions of several measuring instruments all in one unit. It allows fast and accurate analysis of all parameters of modulated signals. Thanks to its versatility, it can also be used as an RF counter, power meter, voltmeter, psophometer, distortion meter, audiogenerator and as an FM stereo decoder. FMA is suitable for measurements in the field of broadcasting (eg on AM and FM transmitters) as well as radio-telephony and in the calibration of signal generators. It can be upgraded for many other measurement tasks.
Modulation Analyser FMAV
FMAV features the versatile measurement functions of the basic model and special functions for the needs of air-traffic control authorities, airport operators as well as manufacturers of air-navigation airborne and test systems.
It measures with utmost precision all modulation parameters relevant in VOR and ILS air navigation systems, for example ILS-DDM to an uncertainly of +/- 0.0002 DDM and VOR phase to an uncertainly of < 0,1°. With its extremely low measurement error achieved by means of digital signal processing, FMAV meets the stringent requirements placed on measuring instruments for ILS systems of category III.
Its high accuracy makes FMAV also ideal for use as a calibrator for VOR and ILS signal generators like Radio-communication Service Monitor CMS 57. With CMS 57 as a signal generator used in conjunction with FMAV as a demodulator, Rohde & Schwarz offers a complete, state-of-the-art test system for aeronautical radio.