Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine a guard period associated with switching from a first communication mode to a second communication mode. The UE may be operating in a half-duplex frequency division duplexing mode of operation. The guard period may be determined based at least in part on at least one of: a number of phased locked loops to be used for the first communication mode and the second communication mode, and a particular subcarrier spacing associated with the UE. The UE may switch from the first communication mode to the second communication mode based at least in part on the guard period. Numerous other aspects are provided.