The RF2422 is a monolithic integrated quadrature modulator IC capable of universal direct modulation for highfrequency AM, PM, or compound carriers. This low-cost IC implements differential amplifiers for the modulation inputs, 90 carrier phase shift network, carrier limiting amplifiers, two matched double-balanced mixers, summing amplifier, and an output RF amplifier which will drive 50 from 800MHz to 2500MHz. Component matching, which can only be accomplished with monolithic construction, is used to full advantage to obtain excellent amplitude balance and phase accuracy.