A self-calibrating shared-component dual synthesizer includes, for example, two frequency synthesizers that are adapted to operate (respectively) in transmit (TX) and receive (RX) modes. Each synthesizer can be selectively arranged to vary and optimize the phase noise in accordance with the TX and RX requirements associated with each mode as well as independently optimized for flexible low area floorplan to achieve low power, spectral fidelity and reduced test time, low cost built in self-calibration. The two frequency synthesizers are also adapted to provide a built-in self-test signals used for intermodulation testing and calibration.