# The relation among power, bandwidth and harmonics

1. ## The relation among power, bandwidth and harmonics

Hi, supposed PA amplifies one CW, in these two conditions, may I ask which one has the highest 2nd harmonics?

A. center frequency =2.4GHz, Bandwidth=100MHz, Power spectrum density(PSD)=2W/MHz
B. center frequency =2.4GHz, Bandwidth=200MHz, Power spectrum density(PSD)=1W/MHz

I think A should the highest 2nd harmonics. My explaining is although BW of B is wider, it cannot affect 2nd harmonics since f2nd=4.8GHz which is too far away.
2W/MHz>1W/MHz, so the output swing of A is bigger that generates more harmonics?
Is that correct?

Based on the above, supposed I have two CW with the same PSD 2W/MHz, one is 100MHz BW, the other is 200MHz BW (supposed all other parameters are the same). Can I say they have the same harmonics level?

Thanks

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2. ## Re: The relation among power, bandwidth and harmonics

Kindly clarify what you mean by 'CW' ? Also what modulation is this which is 100-200Mhz wide?

Lastly, why do you specifically expect 2nd harmonics?

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3. ## Re: The relation among power, bandwidth and harmonics

There is no relationship between Bandwidth and Harmonics.
Harmonics are produced by Non-linear Transfer Function of the Active Devices and they are mathematically related to this function.

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4. ## Re: The relation among power, bandwidth and harmonics

No you cannot say that more BW automatically results in more or less 2nd harmonics.