Latest PCB Report

PCB Report

A report which compares the radiated emissions from twelve different PCB layouts measured over the 25MHz to 10GHz frequency range, as well as the level of emissions when compared to commercial limits (FCC part 15 and CISPR11/22/EN55022). This large report can be freely downloaded and will be available, in part, at the end of this year. The full report will cover measurements due to predominantly common mode sourced radiation at high frequency from microstrip, stripline and image plane PCBs. Measurement will be made with and without a wire connected to the ground plane.

This new set of measurements will use single ended and differential ECLinPS and differential Gigahertz LVDS sources terminated in 50 (Ohm) and 100 (Ohm). The source of emissions will be swept clocks from 25MHz to 2GHz and emissions up to 10GHz will be measured. These measurements will look at image plane PCBs, used for differential trace layouts, as well as different microstrip, stripline and transmission line layouts. It will also examine the importance of via spacing in the stripline configuration as well as compare differential image plane to microstrip PCB radiation.

In addition to the very high speed logic some of the new 3.3V logic such as ALVC, ALB, LVT and 5V logic such as GTL and FB will be used, both with matched loads and typical unterminated high impedance loads. Measurements using this type of logic will use clocks swept from 25MHz to as high as the logic family will allow (150MHz to 250MHz).