Measuring a wimax signal with bandwidth, max 5MHz BW

I'm measuring a wimax signal with bandwidth of 6MHz but the power sensor I have is max 5MHz BW. What would it impact the power reading? Can I just add a factor of 10log10(6/5) on it? Thanks.

What do you mean by "bandwidth"? The 3 dB down point, the 0.1 dB down point? And what exactly is limiting the bandwidth.

It's the video bandwidth of the power sensor. E9327A is the one I'm using. Its max video BW is 5MHz.

Video Bandwidth means the speed of detecting power variations respectively following the envelope of an amplitude modulated
signal, not the RF bandwidth. If you want to measure the average signal power, it can be ignored.

Does it have something to do with Peak-Average-ratio detecting?