FM provides an interesting example of the interaction of theory and experiment in the development of  a scientific discipline. When in 1922 engineers proposed  FM  as a means to reduce transmission bandwidth and thereby reduce noise, J.R.Carson proved analytically to the contrary that FM always needs more bandwidth than AM. While his analysis was correct, his conclusion that therefore FM will always be noisier than AM  was clearly wrong  and it discouraged further work on FM for more than a decade. It was only in 1935 that the great inventor E. Armstrong disregarded Carson’s conclusion and showed experimentally that FM is indeed capable of substantial noise reduction and, amazingly, this noise reduction increases with the spread of RF bandwidth. At the same time he noted that there is a limit to this tradeoff (noise threshold). The reason for the noise reduction with increasing  bandwidth and its limits will be briefly discussed. With the advent of digital basebands, it was conjectured that as we increase the frequency deviation and thereby obtain a less noisy output, the error rates will go down. But, the opposite was found to be true. The reason for this phenomenon and its relation to the noise threshold as first presented in a paper by this speaker will be briefly discussed. --- The speaker finds the world of FM very interesting.

BIOGRAPHY

Jacob Klapper received the BEE degree from The City College of NY, the MSEE degree from Columbia University and the EngScD degree from New York University. Following seven years at RCA’s Advanced Communications Laboratory, he joined the faculty of NJIT where he is a Professor of ECE and a former chairman. He was a consultant to a number of industrial organizations as well as the ERL of Columbia University. He received seven patents, published two books, many papers and presented several tutorial courses under the auspices of the IEEE. He was a David Sarnoff Fellow, received an IEEE award for a paper, was an IEEE Distinguished International Lecturer and won the IEEE Region 1 Award for his contributions to FM and phase-locked loops.

For information, contact Ms. Brenda Walker at (973)596-3513 or at brenda.e.walker@njit.edu, or
         Dr. Andrew U. Meyer at meyer@njit.edu

Information and directions to NJIT are also available on the Web at http://www.njit.edu/University/Directions.html

Click here for Sigma Xi NJIT Chapter Homepage