Rms and envelope detector

A method of detecting power of an RF input signal, comprising the steps of:

• detecting the average power level of an RF input signal using a logarithmic RMS detector;
• detecting the voltage envelope of the RF input signal using a linear envelope detector;
• wherein the logarithmic RMS detector and the envelope detector are integrated in a single package.

A power detector, comprising:

• a logarithmic RMS detector receiving an RF input signal and detecting the average power level of the RF input signal, the logarithmic RMS detector including a series of gain or attenuation stages that progressively amplify or attenuate the RF input signal, the logarithmic RMS detector also including a plurality of mean square detectors, at least some of which are driven with amplified or attenuated versions of the RF input signal from the series of gain or attenuation stages;
• and
• a linear envelope detector for detecting the voltage envelope of the RF input signal, the envelope detector being selectively coupled to an RF input for receiving the RF input signal or to one of a plurality of gain or attenuation taps of the series of gain or attenuation stages of the RMS detector for receiving an amplified or attenuated version of the RF input signal to shift the operating range of the envelope detector.

A linear envelope detector for detecting the voltage envelope of an RF input signal, comprising a plurality of bipolar triple-tail cells, each triple-tail cell including two differential transistors and a center transistor,

• wherein in each triple-tail cell, each of the transistors has a common emitter node coupled to a current source generating a tail-current,
• wherein the collectors of the differential transistors of each triple-tail cell are coupled together to form an output of the envelope detector, and
• wherein in each triple-tail cell, a differential input voltage is applied between the bases of the differential transistors with a DC voltage component, and an input voltage with only a DC voltage component is applied to the base of the center transistor.

A linear envelope detector for detecting the voltage envelope of an RF input signal, comprising a plurality of bipolar triple-tail cells, each triple-tail cell including two differential transistors and a center transistor,

• wherein in each triple-tail cell, each of the transistors has a common emitter node coupled to a current source generating a tail-current,
• wherein the collectors of the differential transistors of each triple-tail cell are coupled together to form an output of the envelope detector, and
• wherein in each triple-tail cell, a first signal is applied between the bases of a first one of the two differential transistors and the center transistor and a second signal is applied between the bases of a second one of the differential transistors and the center transistor, wherein the first and the second signals form a differential signal.

A linear envelope detector for detecting the voltage envelope of an RF input signal, comprising a plurality of bipolar triple-tail cells, each triple-tail cell including two differential transistors and a center transistor,

• wherein in each triple-tail cell, each of the transistors has a common emitter node coupled to a current source generating a tail-current,
• wherein the collectors of the differential transistors of each triple-tail cell are coupled together to form an output of the envelope detector, and
• wherein in each triple-tail cell, a differential input voltage is applied between the bases of the differential transistors with a DC voltage component, and an input voltage with a parasitic RF component is applied to the base of the center transistor.