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Active broadband quadrature signal generation is typically implemented using a double frequency source and frequency dividers with feedback. This approach limits the maximum operating frequency to half the capability of the host technology due to signal processing at the double frequency. Passive distributed techniques can be used successfully for high frequency quadrature signal generation, but bandwidth is limited to perhaps two octaves which then constrains the minimum operating frequency. A new technique based on trigonometric summation at the fundamental frequency will be presented which is suitable for MMIC or RFIC implementation. A single error signal is extracted which is used to simultaneously correct for both amplitude and phase error in the summation. An MMIC which uses this technique to generate the local oscillator signals for an IQ Modulator / Demodulator function will be presented with measured results as a practical example.