The TRF1112 / TRF1212 are UHF-VHF down converters with integrated UHF and S-band frequency synthesizers for radio applications in the 2GHz to 4GHz range. The device integrates an image reject mixer, IF gain blocks, automatic gain control (AGC), and two complete phase locked loop (PLL) circuits including: VCOs, resonator circuit, varactors, dividers, and phase detectors.