This is a short video showing how to use LTspice to find the port impedance of a circuit and how to use Smith v4.1 to design a matching circuit. I also show how to export the s-parameters into a file for further processing
Пікірлер: 25
@WolfmanDude Жыл бұрын
Wow that is so great, until now used to draw and calculate the matching networks by hand! It worked perfectly, I really felt like an engineer from the future doing that!
@nDarien6 ай бұрын
Great video and great method to match the impedance!
@michaelreuter75772 ай бұрын
I have the rereflection coefficient and would like to import it into the Smith 4.1 tool. Is this possible and if so I would appreciate a short video.
@oleglosev35102 жыл бұрын
Nice info.. thanks!
@michaelreuter75772 ай бұрын
Where can i download the Smith 4.1 tool?
@christianejikeomeje3145 Жыл бұрын
great tutorial, i tried same using my bjt transistor deign, but am getting negative as my real part
@polprog702 Жыл бұрын
Hm, that is weird, but maybe LTspice took the current draw in the other direction. Just drop the minus from the real part
@rawanfarouk3498 Жыл бұрын
Hi if my center frequency is 900Meg what would my start and stop frequency be?
@polprog702 Жыл бұрын
I think it can be anything, you can try 450 to 1800MHz
@nurhaida1983 Жыл бұрын
Hi. I'm just curious: how do you determine the 1nF capacitor at the input? Is it by using the C=Q/V equation or the Xc equation or both? I'm sorry if this is a weird question to ask😅
@polprog702 Жыл бұрын
I think it was from the top of my head. At this frequency 1nF is a very low impedance. edit: from the Xc equation.
@minazulkhan8287 Жыл бұрын
Great video. Drink some water u seems thirsty!!
@hedleyfurio11 ай бұрын
Agree - mouth noises spoilt an otherwise super video . He could use audacity with a plug in to remove these , or perhaps not have the mic pickup inside the mouth .
@malikusama4758 Жыл бұрын
any refrence for using this method for impedance matching?
@polprog702 Жыл бұрын
You can use it to sweep a circuit across some band but I think QUCS-S is better for that as it does Smith charts and S-parameter plots
@user-vm9is5uh4oАй бұрын
@@polprog702 I used to use QUCS, but it gives weird error reporting. I change one capacitor value, it then shows an error. If I change it back to the original value, it still shows an error!
@dr-mnizam Жыл бұрын
This video shows how to install LTSpice: kzbin.info/www/bejne/nWbXZXZoisl-gKs
@alexgreysukh4875 Жыл бұрын
But how to install Smith 4.1 - it seems not free software.
@johndavis1465 Жыл бұрын
The circuit should have a capacitor coupling the output
@polprog702 Жыл бұрын
that's true, though in practice I put a large one like 100n that has neglible impedance and dont always draw it
@user-vm9is5uh4oАй бұрын
@@polprog702 It will have a neglible impedance, but will change the DC operating parameters of the transistor, which will affect the matching?
@user-vm9is5uh4oАй бұрын
I would think it needs a capacitor at the output, between the 50 ohm resistor and collector. With 50 ohms and a DC voltage present, it will alter the DC load line!
@polprog70229 күн бұрын
@@user-vm9is5uh4o You're right, I did not notice that
@smartsensing656311 ай бұрын
LTSPICE is not for RF use. you need to use HAM radio amateurs ' tool, way much better. probably 100 magnitude better.