Calibration-Free Return Loss Measurement

Return loss in a wired or wireless transmitter is the ratio of transmitted power to reflected power when power is being delivered to a load. It is a critical parameter that describes transmission efficiency and can be used as an indicator that excessive power is being reflected from a load back to the source. In a wireless transmitter with poor antenna return loss, a high level of reflected power can damage the power amplifier that is driving the antenna. This article presents a novel method to accurately measure return loss in a wired or wireless transmitter in real time over a broad frequency range (2 GHz to 26 GHz) without the need for any system calibration