AM to PM Conversion
- Download Free How To Measure Am To Pm Conversion For Mac Os
- Download Free How To Measure Am To Pm Conversion For Mac X
- Download Free How To Measure Am To Pm Conversion For Mac 7
AMtoPM is used to measure the AM to PM conversion of a circuit. The measurement will compute the angle of the voltage of the fundamental at the Voltage Output Component location. This measurement is identical to Vcomp with the Harmonic Index set to 1 and the complex modifier set to Angle. This measurement is not defined for multi-tone analysis. We use both open source and custom software to make sure our conversions are of the highest quality. In most cases, you can fine-tune conversion parameters using “Advanced Settings” (optional, look for the icon). Our MP4 Converter is free and works on any web browser.
This describes AM-PM conversion basics in PA, its cause and mention its effect on constellation point of modulated signal.
AM to PM conversion is the measure of AM-PM distortion (nonlinear) in power amplifier (PA).This happens due to undesired amplitude changes due to temperature as well as power supplyvariations and multipath fading on the way of RF signal. This type of distortion more prominentin phase modulated signals such as QPSK, PM etc.
As shown in fig.1 X (t) should be as mentioned in equation 1, but due to nonlinear distortionit will be as mentioned in equation 2, here ψ[A(t)] contribute for AM-PM conversion to occur.AM-PM conversion usually results due to nonlinear capacitors in power amplifier circuit.
Fig.1 AM-AM/AM-PM conversion Equation
Unit of AM-PM conversion is deg/dB
QPSK constellation changes as shown in the fig. 2 due to AM-PM-conversion,but due to other impairments in the system such as AM-AM distortion, I-Q mismatch,phase noise etc. one cannot distinct whether the effect (constellation change) is due towhich of the impairments.
AM-PM measurement
Refer our page RF measurement tutorialwhich mentions test set up for AM-PM measurement.
Useful Link
AM-AM-conversion, Read More.
MATLAB CODE
PA nonlinearity