Base station antennas (BSAs) include at least one feed signal phase shifter having a variable length signal path therein, which provides an adjustable signal delay in response to mechanical actuation thereof. A thermo-electric actuator is provided to support remote electrical tilt operations by mechanically actuating the variable length signal path in response to an actuator drive signal. The thermo-electric actuator may include thermally-deformable components, such as SMA springs and wax motors.