A Method of Measuring the Distortion of Frequency Modulators and Demodulators
Measuring the distortion or linearity of FM demodulators is usually performed with low-distortion frequency modulators as test sources. Such modulators are expensive and there is no assurance that the distortion of the test signal is lower than that of the demodulator being tested, especially if that demodulator is state of the art. This paper describes a technique which heterodynes two FM generators of modest performance to produce a highly accurate SMPTE or CCIR intermodulation test signal. It then describes an extension of the technique for testing frequency modulators directly, and describes a system using the technique actually implemented to confirm the performance of an FM generator for automatic testing.
Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $20 for non-members, $5 for AES members and is free for E-Library subscribers.