The TRF3701 is a low noise quadrature direct modulator that is capable of converting complex input signals from 0 300 MHz up to RF. An internal analog combiner sums the real and imaginary components of the RF outputs. This combined output can directly feed the RF pre-amp at frequencies of up to 1.0 GHz. The modulator is implemented as a double balanced mixer. An internal LO phase splitter accommodates a single LO input.