A detector indicates the presence of an RF signal. In some cases it may also indicate the strength of the RF signal it is sensing.
Most commonly, the element doing the detecting is a Schottky diode. The RF signal is rectified by the diode, creating a DC output signal. The DC signal can then be used to adjust control circuitry, for example set the RF power level or power up a circuit that has been "sleeping" to conserve battery power.
RF/ID tag applications commonly use a very simple receiver called a crystal video receiver that consists of only the antenna, optional protection, and a detector diode. The detector senses the presence of an interrogator, extracts modulation (data), and causes the tag to respond.
Detectors can also appear as part of a superheterodyne receiver. For this application they are commonly used either to sense power levels in power control functions or to indicate the presence of a signal, e.g. to sense an incoming signal and trigger the "wake up" of a circuit that has been in "sleep" mode to conserve battery power.
Agilent Technologies Products for Detector Applications
- Discrete Products:
- Biased detector diodes
- Zero bias detector diodes
- Products for millimeter wave Direct Tansmitters, or Upconverting Transmitters