RF Power Detectors

Analog Devices’ family of Envelope Detectors provide instantaneous detection and measurement of signal amplitude across frequencies ranging from dc to 67 GHz. These fast-responding, temperature-compensated devices provide a variety of output formats such as instantaneous envelope output voltage, peak-hold, or a digital threshold detection indicator. Envelope Detectors are ideally suited for use in applications such as Envelope Tracking in Power Amplifier bias control, Pulse Detection, Input Protection of Receivers, High-Power Amplifier Protection and LO Leakage correction of IQ Modulators.

Logarithmic Detectors are particularly suited to perform high dynamic range power measurements and are used in a wide range of automatic gain control and pulse detection applications. These devices produce a low frequency (DC) output that is logarithmically (“linear in dB”) related to the input signal level. ADI has an exceptionally broad portfolio of Logarithmic Detectors, operating from DC to 30GHz, with dynamic ranges up to 100dB, various package and bare die options, low-power optimized devices and much more. Our Logarithmic Detectors are used in a broad range of applications such as Transmit Power Control, Received Signal Strength Indicators (RSSI), Input Protection, Return Loss Measurement, Pulse Detection, and Precise RF Power Measurement in Test and Measurement, Materials Analysis and Medical applications.

Logarithmic RMS Detectors are particularly suited to applications that require waveform agnostic (TruPwr™ RMS) power measurement over a wide dynamic range (up to 70dB). The logarithmic “linear in dB” response, changing the output voltage by the same amount for every dB change in true RF input power, enables accurate wide dynamic range measurement of complex, high-crest factor waveforms. An accurate digital representation can be obtained through interfacing with only a moderate resolution analog-to-digital converter. The combination of wide dynamic range and TruPwr™ measurement finds use in a wide range of applications, such as various types of wireless communications systems, instrumentation and measurement equipment, military equipment and much more.

TruPwr™ RMS detectors provide high accuracy, waveform agnostic power measurements. As modern communication systems use a variety of complex waveform adaptive modulation techniques, such as OFDM, CDMA, QAM, the ability to provide accurate power measurements irrespective of the waveform significantly reduces the required amount of system calibrations. ADI’s RMS Detectors produce an accurately scaled DC output voltage that changes linearly with the RMS value of the input waveform. These devices are optimized to provide very high accuracy (to within ±0.2dB), temperature independent RMS power measurements over a limited dynamic range, used e.g. in low-power and portable radios and test equipment. The related family of Logarithmic RMS Detectors is optimized for wider dynamic ranges.

Analog Devices Successive Detection Log Video Amplifiers (SDLVA) measure RF power at frequencies from below 1 GHz to tens of GHz. They exhibit a flat frequency response and faster rise and fall times compared to other RF detectors. These ICs are provided as bare die or in compact SMT ceramic packages. SDLVAs are ideally suited for use in applications such as Radar, Electronic Intelligence (ELINT), Electronic Warfare (EW), Instantaneous Frequency Measurement (IFM) Receivers, Direction Finding Receivers and Broadband Test and Measurement.

The Vector Power Measurement family extends Analog Devices’ broad RF Power Detector portfolio beyond (scalar) signal strength (power magnitude) measurement. In addition, Vector Power Measurement devices provide phase measurement and/or power measurement of waveforms traveling in the forward and reverse directions along a transmission line. They provide an easy-to-use, broad band and very compact solution for measurement of Scattering Parameters (s-parameters). Applications for Vector Power Measurement devices include antenna tuning in wireless transmitters, built-in test in modular systems, materials analysis, production test equipment and other instrumentation and measurement systems for scientific and industrial use.