square law power detector 1dB compression point

[elektr0]

Hello,

sometimes the linear dynamic range of square law power detectors is defined between
the TSS power level (tangential signal sensitivity) and the 1dB compression point.

The books from Maas explain how the TSS value is measured.
The term "1dB compression point" is normally used for amplifiers and is defined for power levels.
Does anybody know how we can use this term in case of detectors (with DC voltage at the output and RF power at the input) ?

Thank you very much.

-e

 

[Element_115]

Hello,

sometimes the linear dynamic range of square law power detectors is defined between
the TSS power level (tangential signal sensitivity) and the 1dB compression point.

The books from Maas explain how the TSS value is measured.
The term "1dB compression point" is normally used for amplifiers and is defined for power levels.
Does anybody know how we can use this term in case of detectors (with DC voltage at the output and RF power at the input) ?

Thank you very much.

-e

The RF Power will cause the DC from the detector. "1dB Compression Point" is for characterizing non-linearities,
and detectors (didoes) are non-linear. But for a detector you can characterize it's curve, and determine where
it's useful range is(for your application).

Also if you have high power, you can use a Pi pad attenuator to shift the range down to a "preferred"
level/window.

Cheers.

 

[jiripolivka]

The RF Power will cause the DC from the detector. "1dB Compression Point" is for characterizing non-linearities,
and detectors (didoes) are non-linear. But for a detector you can characterize it's curve, and determine where
it's useful range is(for your application).

Also if you have high power, you can use a Pi pad attenuator to shift the range down to a "preferred"
level/window.

Cheers.

Generally, detectors are either used in "linear" mode, with a response to very low-level signals or noise. The lowest limit is TSS, the highest limit is ~ -20 dBm input, and the output (video) load impedance is high, e.g. 10 kOhms.

Or, detectors are used with higher input power, like >-20 dBm to 0 dBm or more, with a low video load for a fast response. Then their power response is non-linear, with a 1-dB compression point.

 

[burton]

Generally, detectors are either used in "linear" mode, with a response to very low-level signals or noise. The lowest limit is TSS, the highest limit is ~ -20 dBm input, and the output (video) load impedance is high, e.g. 10 kOhms.

Or, detectors are used with higher input power, like >-20 dBm to 0 dBm or more, with a low video load for a fast response. Then their power response is non-linear, with a 1-dB compression point.

It seems that "square-law" detector is used for low-level signals or noise, "linear" mode is used for higher power.