A wireless communications circuit and an associated wireless communications device are provided. The wireless communications circuit may include a power amplifier with integrated filter (PAMiF) module and a two-stage switch module, and the two-stage switch module may include a first switch and a second switch. For example, a first port of the first switch is coupled to a filter port of the PAMiF module, and a second port of the first switch at an opposite side to the first port of the first switch is coupled to a first antenna. In addition, a first port of the second switch is coupled to a third port of the first switch at the opposite side to the first port of the first switch, and a second port of the second switch is coupled to a second antenna.