A heterogeneous bus bridge circuit and related apparatus are provided. The heterogeneous bus bridge circuit is configured to bridge a radio frequency front-end (RFFE) bus with a number of auxiliary buses that are different from the RFFE bus. Each of the auxiliary buses may support a fixed number of slaves identified respectively by a unique slave identification (USID). In examples discussed herein, the heterogeneous bus bridge circuit can be configured to selectively activate an auxiliary bus for communication with the RFFE bus, thus making it possible to reuse a same set of USIDs among the auxiliary buses without causing potential identification conflict. As such, it may be possible to support more slaves in an apparatus with a single RFFE bus. As a result, it may be possible to reduce pin count requirement for an RFFE master and/or enable flexible heterogeneous bus deployment in the apparatus.