The PH2000 Series of Power Heads is designed for use with the Model PM2000 Series Power Meters. The most critical element of any power meter is the power head. The head is responsible for converting the incident RF or microwave power to an equivalent voltage which can be processed by the power meter. The head must also present to the incident power an impedance, which is closely matched to the transmission system, to avoid mismatch errors. Finally, the head must introduce the smallest drift and noise possible so as not to disturb the measurement.