A time transfer modem includes a radio frequency integrated circuit (RFIC), a radio frequency (RF) front end, and processing circuitry. The RF front end is configured to receive and up-convert an input for time transfer with a remote station to generate an up-converted timing signal centered at a select frequency that is outside of a frequency range of interest but within an operational frequency range of the RFIC. The RF front end may also be configured to attenuate, via a pre-selection filter, up-converted adjacent signals to generate a filtered timing signal at the select frequency. The RFIC may be configured to down-convert and digitize the filtered timing signal to generate a digitized timing signal for signal processing by the processing circuitry to determine a clock difference between a local clock signal and the digitized timing signal that originated from the remote station.