L3Harris NARDA PMM ER8000 User Manual page 31

3.3 Detectors
3.3.1 RMS-AVG
Definition
3.3.2 C-AVG
Definition
PMM ER8000 has been designed to allow the use of many kinds of detectors.
CISPR Standard has introduced the application of two detectors that are
derived from the Root Mean Squared and from the Average ones.
The RMS-Average detector is a special function, defined by the CISPR
standard, implemented in the PMM ER8000 receiver.
RMS-Average detector is manufactured under license of Rohde &
Schwarz GmbH & Co. KG.
The RMS-Average detector, according to the CISPR 16-1-1 standard, supplies
a reading of the input signal that is weighted, for repeated pulses, such that for
a constant indication, the relationship between amplitude and repetition
frequency is in accordance with the following rule:
The Amplitude is proportional to (repetition frequency)-1/2
The value is the maximum level during the measurement time (Hold Time) and
the averaging is carried out with a lowpass filter of the 2
mechanical instrument.
The calibration is in reference to the RMS value of an unmodulated sine wave
signal.
CISPR 16-1-1 defines the Average detector as designed to indicate the
weighted average value of the maximum value of the envelope of the signal
passed through the pre-detector stages:
up to 1000 MHz, is defined as the response of the measuring receiver to
pulses of repetition rate n Hz and impulse area of 1,4/n mVs emf at
50Ω source impedance that shall be equal to the response to an unmodulated
sine-wave signal at the tuned frequency having an emf with rms value of 66
dBµV.
The value of n shall be 500 for Band B, and 5000 for Bands C and D.
The average detector is useful to measure narrowband signals to overcome
problems associated with either modulation content or the presence of
broadband noise.
When the Average is measured according to CISPR 16-1-1, the maximum
value of the linear mean envelope during the measurement interval is showwn.
The detector is used, for example, to measure pulsed sinusoidal signals with a
low pulse repetition rate. It is calibrated with the rms value of an unmodulated
sine wave signal. Averaging is carried out with lowpass filters of the 2nd order
(simulating a mechanical instrument).
nd
order to simulate a
Operating Instructions 3-3