A tire pressure monitoring system connectable to a valve stem for supplying air to a respective tire is provided. The system includes a pressure sensing device. A circuit board is configured to receive one or more circuit components associated with the pressure sensing device. A flex circuit is electrically coupled to the circuit board and the pressure sensing device to pass electrical signals between one another. A joining structure is provided for electromechanically connecting the circuit board to a respective valve stem end disposed within the tire. The valve stem may receive one electrical signal indicative of the level of pressure sensed by the pressure sensing device and may radiate the electrical signal to the surrounding environment. The foregoing embodiment may be adapted to applications that do not use any coupling to the valve stem and/or avoid use of any circuit board. In such an adaptation, the antenna may be configured in the flex circuit.