Near-ideal RF upconverters

This paper presents experimental results on the application of a new quadrature modulator compensator, which allows existing quadrature modulators to achieve near-ideal RF upconversion over a wide bandwidth. A test setup using an arbitrary waveform generator and a spectrum analyzer shows that over 70 dB of spurious-free dynamic range may be obtained over a bandwidth of 1.2 MHz using an off-the-shelf Mini Circuits in-phase/quadrature modulator operating at 895 MHz. A conventional compensator provides only 45 dB of sideband suppression in the same experimental setup.