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bvernoux>
What I can say is Return Loss is awful after 1.3Ghz
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bvernoux>
it act like a Low Pass Filter
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bvernoux>
a very ugly one ;)
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bvernoux>
it is expected to have S11 less than -15dB or -20dB from 30KHz to 6GHz
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bvernoux>
and the Impedance also show the issue which seems related to SMA connectors some very cheap connectors ;)
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bvernoux>
I plan to solder on an other board(same batch) some better SMA connector Molex 73251-2120
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azonenberg>
what SMAs did you use?
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azonenberg>
the samtec ones i like, or stupid cheap
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bvernoux>
a cheap chinese one for test purpose ;)
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bvernoux>
to see how they are ugly
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bvernoux>
something which cost 1USD for 10units ;)
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bvernoux>
I will try Molex later
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bvernoux>
I have 3 boards to test different SMA connectors
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bvernoux>
now 2 boards ;)
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bvernoux>
Qucs Simulation is not very good for Coplanar Wave in fact
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bvernoux>
anyway it give an estimation of -10dB to -15dB min for S11
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bvernoux>
also S21 Gain is very bad with some big glitch
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bvernoux>
Also I have very bad connection on back of SMA for GND
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bvernoux>
so that will also affect
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bvernoux>
on bottom side
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bvernoux>
for reference my calibration with Thru Standard provide 100dB of Dynamic Range ;)
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bvernoux>
So the limitation is clearly not my VNA
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bvernoux>
with a S11 Impedance variation of less than +/-0.4 Ohms (with median at 50 hms)
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bvernoux>
due to my SMA Cable
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bvernoux>
using 1 Mini-Circuits FLC-2FT-SMSM+
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bvernoux>
and a very short one Mini-Circuits 141-10SM+
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