Interference to digital broadband communications and spread spectrum communications

Interference from DTV signals to cellular 700 MHz wireless phones may limit their acceptance by the public. Such interference has been reported to the FCC. The interference mechanism involved is 3
^rd
order non-linearity of the analog front end of cellular phones. Interference to GPS signal reception has been documented by a Technical Working Group. The author believes that the mechanism is also 3
^rd
order non-linearity of the analog front end of GPS receivers. In both situations, RF selectivity and mixer linearity must be improved.