Editing Single-sideband modulation (section)

===Weaver modulator===
Another variation, the '''Weaver modulator''',<ref>"A Third Method of Generation and Detection of Single-Sideband Signals" D K Weaver Jr. Proc. IRE, Dec. 1956</ref> uses only lowpass filters and quadrature mixers, and is a favored method in digital implementations.

In Weaver's method, the band of interest is first translated to be centered at zero, conceptually by modulating a complex exponential <math>\exp(j\omega t)</math> with frequency in the middle of the voiceband, but implemented by a quadrature pair of sine and cosine modulators at that frequency (e.g. 2&nbsp;kHz).  This complex signal or pair of real signals is then lowpass filtered to remove the undesired sideband that is not centered at zero.  Then, the single-sideband complex signal centered at zero is upconverted to a real signal, by another pair of quadrature mixers, to the desired center frequency.