There are many tools and applets out there making use of (W/d) ratios to calculate the specific microstrip width for a specified characteristic impedance. All these formulas take into acount a relatively big ground plane. What if the ground plane was tapered and not considered to be big enough. Are there any formulas that calculate the width of the line for a specific impedance?
The application of this is a microstrip tapered balun.
But at the end of a balun, the ground plane strip width (bottom conductor) is as wide as the upper conductor. How does one account for these width given a desired characteristic impedance?
Re: Microstrip Width Calculation for a Specified Char Impeda
It is a common problem. The best is to start with schematic simulation such as ADS or AWR or others. Next jump to an EM simulation. I like the Momentum of ADS, but there are others. In order to simulate an finit ground you have to define correctly the RF ports.
Re: Microstrip Width Calculation for a Specified Char Impeda
when Wu/Wb>11(Wu|:upper strip width,Wb:bottom strip width),we can consider the bottom strip as the infinite-width!if you want detail,you can
read "Microstrip Transmission Line With Finite-Width Dielectric and Ground Plane" by CHARLES E.SMITH and RAY-SUN CHANG