The Impact of Receivers on Spectrum Management

On April 21, 2022, the U.S. national spectrum regulator for the private sector, the Federal Communications Commission/FCC, formally asked for input on the issue of “the role of receiver performance in (its) spectrum management responsibilities” [1]. A previous issue of this column addressed related issues and the enigmatic question “Which uses the most spectrum: transmitters or receivers?” [2]. That issue described the classic example of early U.S. market UHF TV receivers in the 1950s when UHF technology was first being introduced to consumer electronics. FCC decided at the time that the selectivity and intermodulation issues in consumer grade receivers would limit the use of UHF TV channels to channels spaced six channels apart to avoid interference [3]. Thus, only 1/6 of the apparent number of UHF channels could be used in a given city even if there were no other cities nearby. (With improved electronics and digital television modulation, television channels can now be used with a much higher density.)