Up-conversion based on gated information signal

Abstract

A method and system is described wherein an information signal is gated at a frequency that is a sub-harmonic of the frequency of the desired output signal. In the modulation embodiments, the information signal is modulated as part of the up-conversion process. In a first modulation embodiment, one information signal is phase modulated onto the carrier signal as part of the up-conversion process. In a second modulation embodiment, two information signals are multiplied, and, as part of the up-conversion process, one signal is phase modulated onto the carrier and the other signal is amplitude modulated onto the carrier. In a third modulation embodiment, one information signal is phase modulated onto the “I” phase of the carrier signal as part of the up-conversion process and a second information signal is phase modulated onto the “Q” phase of the carrier as part of the up-conversion process.

What is claimed is: 
     
         1 . A system for modulating and up-converting an information signal, comprising:
 gating means for gating the information signal at a rate that is substantially equal to a desired sub-harmonic of a desired frequency of an output signal, thereby generating a gated information signal, said gated information signal having an amplitude that is a function of the information signal;   differentiating means for differentiating said gated information signal to generate a harmonically rich signal having a plurality of harmonics; and   selecting means for selecting at least one of said plurality of harmonics as a desired output signal, said desired output signal being at said desired frequency.