An electronic device may include a printed circuit board (PCB) including a ground plane and having first and second opposing surfaces. The electronic device may also include a radio frequency (RF) directional coupler carried by the first surface of the PCB and including a housing and circuitry therein defining an input port, an output port, and first and second monitoring ports. A first monitoring circuit may be carried by the first surface of the PCB and connected to the first monitoring port. The electronic device may also include a via conductor connected to the second monitoring port and extending through the PCB to the second surface thereof. A second monitoring circuit may also be carried by the second surface of the PCB and connected to the via conductor.