Advanced Designs
To overcome obstacles such as image response, multiple IF stages are used, and in some cases multiple stages with two IFs of different values are used. For example, the front end might be sensitive to 1–30 MHz, the first half of the radio to 5 MHz, and the last half to 50 kHz. Two frequency converters would be used, and the radio would be a double conversion superheterodyne; a common example is a television receiver where the audio information is obtained from a second stage of intermediate-frequency conversion. Receivers which are tunable over a wide bandwidth (e.g. scanners) may use an intermediate frequency higher than the signal to improve image rejection.
Read more about this topic: Superheterodyne Receiver
Famous quotes containing the words advanced and/or designs:
“Only conservatives believe that subversion is still being carried on in the arts and that society is being shaken by it.... Advanced art today is no longer a cause—it contains no moral imperative. There is no virtue in clinging to principles and standards, no vice in selling or in selling out.”
—Harold Rosenberg (1906–1978)
“I have no scheme about it,—no designs on men at all; and, if I had, my mode would be to tempt them with the fruit, and not with the manure. To what end do I lead a simple life at all, pray? That I may teach others to simplify their lives?—and so all our lives be simplified merely, like an algebraic formula? Or not, rather, that I may make use of the ground I have cleared, to live more worthily and profitably?”
—Henry David Thoreau (1817–1862)