Hairpin filter design issue with S11 and S21
i had done my project to design hairpin filter with 2.44GHz for center frequency. result for simulation at EM Structure i get S11=-14.54dB and S21=-4.896dB by using microwave office software, but the problem now when i measured by using network analyzer the results is difference which S11=-23.475dB and S21=-6.831dB. now i want to know my results for measurement it's ok or not?
which one is better for RL between -23dB and -14.dB?
any one can help me? plZZZZ
What do you mean with RL?
If this mean real life, -23dB is far more better.
RL means Return Loss....!
OK.
But it still stands -23 dB is better.
(Generally S11 should be lesser than -15 dB, and the lesser it is, thats better.)
If you are not sure which method is better (gives more precise results), my opinion is that EM structure simulator is more precise.
Another important thing is version of MWO you are using (there are naturally bugs in every of them, but newer versions have lesser bugs).
thanks guys 4 ur helping...
how about when i add more oders? now im doing 6 poles if i make 10 orders what happen with my results? it is 10 poles is more better then 6 poles?
Added after 6 minutes:
hmm why return loss should be more than -10dB? and insertion loss ≈0? if insertion loss more than -1dB that result is not good? why insertion loss and return loss importand in filter, antena and microwave?
Hi
The larger the order of your filter, the more broadband it gets. But the loss usually also increases, because you add more elements.
Insertion loss (I.L.) tells you how much loss is in your circuit. In a filter you want this to be as low as possible. In real life you cannot have this to be 0 dB but will usually be a couple of dB's depending on the filter type and materials.
The return loss is important in the sense that it indicates how much power is reflected by the filter. So a reflection coefficient of -10 dB(Return loss of 10dB) means it will reflect 10% of the incoming power. This you also want to be as low as possible.
There are several reasons why this is important. First you want to transfer as much power between your devices as possible. Reflected power can cause signal distortion and also lead to permenent damage of for example power amplifiers.
Regards