SWITCHED-CAPACITOR MODULATOR FOR QUADRATURE MODULATION

摘要

A switched-capicitor modulator for quadrature modulation is disclosed. The modulator of the present invention provides a means for simultaneous modulation of two carrier signals in quadrature by two input signals in such a way that the gains of the two modulations are exactly the same. In accordance with the invention a switched-capacitor modulator is provided having a plurality of input signal sources for quadrature amplitude modulation. The invention provides for a single common switched-capacitor network with multiple switches or multiple switched-capacitor networks for each incoming modulating signal. A switchedcapacitor network utilized to form and modulate a carrier signal for shaping the carrier to reduce sidebands of the third and fifth harmonics in the modulated signal is also disclosed.