In this new web series, Ask a Product Manager, HIOKI invites you to submit your product and technology questions to our Product Managers. We’ll address them here so our whole community can benefit.
This week’s installment focuses on LCR meter performance with two questions from a prospective customer.
“We currently have a network analyzer but it is very noisy at lower frequency ranges (less than 300kHz). We think it’s partly because our inductor has low inductance value. Do you have any ideas if there will be less noise for the Hioki LCR meters since they are geared towards low frequency?”
Fernando Gomez, Hioki Product Manager, answers:
“For network analyzers (VNAs), I think you are on the right track when you say they are noisy at low frequencies and for that matter, they cannot be substitutes for an impedance analyzer which is designed to work in the low frequencies.
This is because the VNA uses a reference impedance, normally 50 Ohms, that can be easily matched to a transmission line. That allows you to use cables and PCB fixtures that have matched lines, so that you don’t have to worry about parasitic inductance and capacitance in your setup. The higher the frequency, the more this matters. Of course, with a VNA, you can convert S-parameters to impedances, but the reference resistance is always 50 Ohms. This means that impedances that are far from 50 Ohms will be measured with large errors.
Unlike the VNA, reference resistance of an impedance analyzer can be modified based on the required measurement. This improves the accuracy of the measurement, but it also means that the cables and fixtures behave as parasitic elements.
Thus, the VNA is best for high frequencies and the impedance analyzer is best for low frequencies. Typically, impedance analyzers are used from DC to 10s of MHz, and VNAs are used from MHz to 10s of GHz."