# antenna inductance measurement.

#### dipeshkarli

Joined Sep 27, 2017
3
hi all,

i have designed one pcb antenna. i want to find out exact inductance of pcb antenna.
as well as, i have one another hollow square antenna made up of copper i also find out inductance of this antenna too.

regards,
dipesh karli

#### Papabravo

Joined Feb 24, 2006
12,385
There are two ways to do this.
1. Buy a Network Analyzer to do the measurement at the frequency of interest. NB These devices can run $100,000.00 USD or more at high frequencies. 2. Buy an Anatenna Analyzer. These devices are much cheaper, but may not extend to frequencies above 500 MHz. #### DickCappels Joined Aug 21, 2008 5,875 What inductance do you estimate the antenna (I assume some sort of loop) to have? Thread Starter #### dipeshkarli Joined Sep 27, 2017 3 What inductance do you estimate the antenna (I assume some sort of loop) to have? yes, it is some sort of loop. estimate inductance is 1uH to 1.5uH. #### Papabravo Joined Feb 24, 2006 12,385 yes, it is some sort of loop. estimate inductance is 1uH to 1.5uH. At what frequency are you going to measure the inductance? Thread Starter #### dipeshkarli Joined Sep 27, 2017 3 At what frequency are you going to measure the inductance? frequency of measurement is 13.56MHz. #### Janis59 Joined Aug 21, 2017 765 PCB antenna means JUST the coil. It means that You may use the normal nanohenries measurer, like those 5 USD costing at ebay. They measure starting from 0,1 nH (probably), but I may bet the 10 nH they measure rather good. Other alternative method is take the DIP-meter (what DIY circuits are tons in the internet) and just MEASURE the resonance frequency. Use the known capacitors and voila! Third alternative is network analyzer, but it is high-cost solution. Fourth possibility is to use a SWR measurer because factually You not need to know an inductance, instead You need to know is it matched and when it is matched. This device at ebay costs about 20 USD, so, just click it! #### DickCappels Joined Aug 21, 2008 5,875 Those$5 meters sold on eBay don't go down below about 60 uH.

You can make a simple RF inductance meter with a hex Schmitt trigger and a few passive components.

Article:
http://electronics-diy.com/inductance-meter.php

You can readily scale the circuit for other ranges, but you will need a few inductors in that range with which to calibrate your meter.

#### Janis59

Joined Aug 21, 2017
765
Dick: At least mine I bought few years ago at ebay and it goes down to 0,1 nH however between 0,1 and 10 nH it have very unstable reads what sure are not metrologically right. But starting with 10 nH and up to the 10 uH is my everydays bread where it works more than well.

#### DickCappels

Joined Aug 21, 2008
5,875
Certainly a different \$5 meter from the one I bought.