Types of RF Power Sensors

摘要

Historically, ther-mocouples were one of the first sensors to be used. They produce such a small output voltage that wide dynamic range and high accuracy have only recently become available at a reasonable cost. Very low-level signal processing involves chopper amplifiers, averaging, filtering, and much attention to thermal effects. However, when these considerations are all addressed, the thermocouple sensor power meter is a truly universal instrument. Voltage out is proportional to power in because the sensor inherently has a square law transfer function. The dynamic range is about 50 dB from -30 dBm to +20 dBm.