how to determine value of inductance and value of capacitance if use L-match network

[SU-4]

Hello to all,
I am working on a project for Automatic Antenna Tuner for HF, i want to know how to determine value of inductance and value of capacitance if i use L-match network with 1.5 Meter antenna whip.
I have found some information about the value but I would appreciate any additional info that you can give me.
Thanks in advance

 

[E Kafeman]

You can't do anything without measuring your antenna impedance for whole frequency range.
Then plot your antenna impedance in a Smith chart and solve it manually with a pen and a ruler. It is an important knowledge how to use a Smith chart to solve impedance matching. **broken link removed**
Most RF simulation tools have an automatic optimizing function that can find needed values for L and C.
If you have a S1P file for the antenna, upload it, as I have a software specialized in finding optimal solution for this kind of problem.

 

[SU-4]

You can't do anything without measuring your antenna impedance for whole frequency range.
Then plot your antenna impedance in a Smith chart and solve it manually with a pen and a ruler. It is an important knowledge how to use a Smith chart to solve impedance matching. **broken link removed**
Most RF simulation tools have an automatic optimizing function that can find needed values for L and C.
If you have a S1P file for the antenna, upload it, as I have a software specialized in finding optimal solution for this kind of problem.

thanx before for your reply e kafeman, i want to know your software for finding optimal solution, how could i get software like that?

 

[E Kafeman]

You needed to find optimized discreet L and C values from 150 MHz and downward for a number of fixed frequency ranges, forming a continuous, switchable frequency range?
My software is not public, it is developed for personal use and lacking understandable user interface. Have not time to clean it up and release it public. Sorry.
As alternative, have solved similar problems in Microwave Office. Easy to work with but it requires a lot of settings of rules to get right when you have several scenarios that should be optimized. Start optimize less complex impedance problem and verify that you got it right. Have not tried it in Mathlab but it can be a better solution as it is simpler to define several optimizing goals.
In AnTune is it very easy to optimize a lot of scenarios for a single frequency range solution, so you can probable find best solution by a few test runs, but you must manually adjust C and L table in a configuration file as existing values only covers typical values needed for cellphone frequencies and upward. You can test this software for free.

Plot your antenna impedance in a Smith chart and try to solve your problem manually. Finding LC network for one frequency is very simple and give valuable understanding when you later set parameters and complex rules in a software for which you not else can verify if calculated results are reasonable.