WIFI receiver TIS performance

[arr_baobao]

hi all,

let say i have 6dB OTA(over the air) TIS delta between my WIFI ch6 and ch11. I measure the conducted TIS for both ch6 and ch11 both reading are comparable.
assuming no noise inteference from my device system. can i say my antenna efficiency degrade 75%(6dB) from ch6 to ch11??

thanks

 

[vfone]

It is impossible to blame for losing TIS (total isotropic sensitivity) only the receiving antenna, because TIS is not only measuring the antenna itself, but the receiving and antenna system as a whole.
TIS take into consideration self-interference factors which can cause the overall receiver sensitivity to reduce.
In a receiver system (antenna + receiver) more important that antenna efficiency is the TIS value.

 

[arr_baobao]

It is impossible to blame for losing TIS (total isotropic sensitivity) only the receiving antenna, because TIS is not only measuring the antenna itself, but the receiving and antenna system as a whole.
TIS take into consideration self-interference factors which can cause the overall receiver sensitivity to reduce.
In a receiver system (antenna + receiver) more important that antenna efficiency is the TIS value.

yes, i understand that. that why i said assuming no inteference from the system itself. just wanted to see purely from antenna angle.

let say my wifi antenna is 50% at ch6 and the TIS degrade 6 dB from ch6 to ch11. so there is 70% lose in antenna at ch11 compared to ch6, that mean my ch11 antenna now is (50x0.3(6db)) = 15%?

 

[vfone]

Cannot ignore that the system is noisy, because this is the meaning of the TIS measurement.
May be possible that the sensitivity to get worse with higher antenna gain (antenna pick up more noise from the system), and sensitivity became better with lower antenna gain. But could happen in the other way too, because is never a linear relation between these parameters.
If you want to test the antenna gain and its efficiency vs frequency, shut down the entire system, and do the measurements just for the antenna itself.

 

[arr_baobao]

Cannot ignore that the system is noisy, because this is the meaning of the TIS measurement.
May be possible that the sensitivity to get worse with higher antenna gain (antenna pick up more noise from the system), and sensitivity became better with lower antenna gain. But could happen in the other way too, because is never a linear relation between these parameters.
If you want to test the antenna gain and its efficiency vs frequency, shut down the entire system, and do the measurements just for the antenna itself.

i understand. my point is i wanted to prove to the guy that if he suspect the the TIS degradatio is coming from antenna itself mean our antenna degrade >70% from ch6 to ch11. i just want to confirm my calculation is correct.
50% from ch6, degrade 6db so my ch11 antenna is 10+%?

 

[vfone]

Sorry, you cannot make this assumption about antenna.
Because TIS is about receiver sensitivity, could be other reasons too.