1nh measurement

May I know PNA network analyzer can measure inductance less than 1nH? such as 0.5 nH accurately? Somebody try before?

Thanks.

No, is not accurate below 1nH.
For greater accuracy try to use a dedicated LCR meter.
http://cp.literature.agilent.com/lit...5968-5758E.pdf

Hi Vfone,

What is the uncertainty if I use PNA to measure sub-nH inductor? below 10%?

Below 1nH I would go for an accuracy no better than +/-30% (maybe worst).
Inductance measurement in a PNA is an indirect measurement, calculated from an impedance measurement.

You can use a VNA to measure inductance. You just need to measure at a high enough frequency so 1 nH presents a impedance near 50 ohms. That also means you need a good calibration. You can use either 1 port or 2 port measurements, preferably both.

The 4287A is just a 1-port VNA anyway. The bridge type LCR meters are probably too low in frequency to measure 1 nH, however they are very accurate for certain ranges.

You don't have to measure the inductance directly. You can resonant it with a known capacitance and measure the **** out. There are methods using transmission lines too. One method may be better a finding the Q, another better for L or SRF. You need to research the different methods.

Hi all,

Thanks for your reply.

In this case, I would prefer to measure L and Q over wide frequency band. Hence using LC oscillator is not suitable for my application.

But madengr gives a very good idea: Is it if |Zin| near to 50ohm, measurement accuracy can be greatly improve, assume inductor are measured using 2ports VNA?