Low capacitance probe (<2pf) vs 2pf typical ?

[ahmedtarek]

Hello everyone,

I need help with something,

I am designing an antenna for MFRC522 and i am following AN1445 see attachments,

in page 18 of 65, the application note recommends using a low capacitance probe (<2pf) in order to measure a parameter in the receiving circuit.

i found the following low capacitance probe to use it with my oscilloscope, but it is (2pf) typical

https://www.picotech.com/accessories/passive-oscilloscope-probes/1.5-ghz-scope-probe-bnc 

however, there is another low capacitance probe (0.3 pf), but the cost is relatively higher,

If i use the 2pf probe, will that still comply with An1445, if not, could any one suggest a better choice,

Thank in advance,

ATarek

[weidong_sun · Accepted solution]

Hi Ahmed,

>>will that still comply with An1445, if not, could any one suggest a better choice

No, it will not.

Please use low capacitance probe that capacitance is less than 2pF !

Have a nice day!

TIC weidong