The TRF1121/TRF1221 are VHF-UHF upconverters with integrated UHF and S-band frequency synthesizers for radio applications in the 2GHz to 4 GHz range. The IC performs the first up-conversion and generates the local oscillator (LO) for the second up-conversion. The device uniquely integrates an image reject mixer, IF gain blocks, 5-bit gain control, and two complete phase locked loop (PLL) circuits including: VCOs, resonator circuit, varactors, dividers, and phase detectors.