The title is WiFi channel and Bandwidth then you ask about amplitude. WiFi uses FM so you may be seeing the transmission being on that frequency the most and well, AM is not used here so your question needs to be re-worked.
Me? Just an electronics engineer with some RF work over the years.
I am having this query for channel and bandwidth which I will explain with scenarios
Scenario 1: I have configured my Texas Instrument wifi module for 2.4GHz band for the bandwidth 40MHz and channel 5. However when I observed on the analyzer the maximum amplitude signal is coming on 2.442GHz(in range of Bandwidth 2.421 to 2.443GHz ) instead of central frequency i.e. 2.432GHz
Scenario 2: I have configured my Texas Instrument wifi module for 2.4GHz band for the bandwidth 20MHz now and channel 5.The maximum amplitude is at central frequency i.e. 2.432GHz
Question : Is this maximum signal strength at 2.442GHz is correct rather than centeral frequency i.e. 2.432GHz for 40MHz bandwidth