Does anyone know how to calculate the inductance ofmicrostip

[hanway]

I want to design a distributed inductance using the sub. RO3003(er=3.0, t=1.524mm) ,the L value is 17.56nH. but distributed inductance seems to designed to 13.5nH. I have already make the line 0.1mm wide.
I have a question: how to make the inductance of microstrip large ?

 

[wlcsp]

Re: Does anyone know how to calculate the inductance ofmicro

I want to design a distributed inductance using the sub. RO3003(er=3.0, t=1.524mm) ,the L value is 17.56nH. but distributed inductance seems to designed to 13.5nH. I have already make the line 0.1mm wide.
I have a question: how to make the inductance of microstrip large ?

I think you can simply make the signal line narrower. This will definitely increase the inductance. However, this will increase the resistance as well. To calculate the inductance of a microstrip you need first to find the characteristic impedance of your microstrip, then:
L is the imaginary part of (gamma*Z)/(2pi*freq)
See the paper attached for more complete explanation.

The inductance of a rectangular line (without the ground plane beneath) is as follows:
L=2*length*(ln(2*length/(w+t))+0.5+(w+t)/(3*length))
where w:width; t:thickness.

 

[hanway]

Re: Does anyone know how to calculate the inductance ofmicro

Wlcsp: thanks a lot! I can use "Serenade 8.7" calculate the impedence of microstrip. because of technique limit, we only assure the precision of 0.1mm wider microstrip.
I don't understand the formula that you mantioned. can you list some related article .thanks ! Are there any other methods to make the inductance larger besides making the line narrower.Thanks!

 

[wlcsp]

Re: Does anyone know how to calculate the inductance ofmicro

Wlcsp: thanks a lot! I can use "Serenade 8.7" calculate the impedence of microstrip. because of technique limit, we only assure the precision of 0.1mm wider microstrip.
I don't understand the formula that you mantioned. can you list some related article .thanks ! Are there any other methods to make the inductance larger besides making the line narrower.Thanks!

Well, there is always a trade-off when you want to optimize something. As I mentioned earlier, making the line width narrower, increases the resistance. Why don't you try the 2D Extractor to reach the your desired inductance. Just curious, why do you use microstrip to get inductive behaviour, why not using inductor? I cannot make a list of related paper for you, it consumes a lot time. I happened to read the article I attached in my previous message.

 

[hanway]

Re: Does anyone know how to calculate the inductance ofmicro

thanks! I have to use microstrip to design the inductance because of other's requirement. Now i can reach the value by change the microstrip to sprial. By the way, what's the 2D Extractor ? where i can download it? Thanks !

 

[katykaty03]

Re: Does anyone know how to calculate the inductance ofmicro

As inductor is more expensive compare to cap, for cost down purpose, many product will try to replace the inductor with microstripline. But I think it's hard to control the inductance variation because of width tolerance, coupling effect..., especially at high operating frequency.