transmission line on chip




When designing circuits on chip, transmission line effects can often be ignored, but at chip boundaries they are very important. Transmission lines have effects that must be considered at these interfaces in order to match the input or output of an RFIC.
Re: transmission line on chip
Any on-chip interconnect can be modeled as a transmission line. Transmission line effects on chip can often be ignored if lines are significantly shorter than a quarter wavelength at the frequency of interest. Thus, transmission line effects are often ignored for frequencies between 0 and 5 GHz. However, as higher frequency applications become popular, these effects will become more important.
Re: transmission line on chip
At RF frequencies, any track on a printed circuit board behaves as a transmission line, such as a microstrip line (MLIN) , a coplanar waveguide (CPWG) , or a coplanar waveguide with ground (CPWG). Differential lines are often designed as coupled microstrip lines (MCLINs) or they can become coupled simply because they are close together, for example, at the pins of an integrated circuit. For these lines, differential and common mode impedance can be defined (in microwave terms, these are described as odd-order and even-order impedance, respectively). On an integrated circuit, all lines are transmission lines, even though it may be possible to ignore transmission line effects for short lines. The quality of such transmission lines may suffer due to lossy ground plane (the substrate) or because of poor connection between coplanar ground and substrate ground.