I'm trying to shield 6 flat cables that give me some communication issues because I thought that there might be cross-talk or other sources of interference that cause the problem. The shielding is not connected to ground. For now, it's just an improvised aluminium foil wrapped around each cable.
Leaving aside that it's not really a good shield, I was wondering if, theoretically speaking, this shielding might affect the signal integrity of digital and/or analogue signals. The curiosity comes from the fact that the shielding changed drastically the distribution of E field around the flat cable, so it's not the one the cable would normally generate anymore.
In other words, when the distribution of E and/or H field is changed by external factors, is the signal integrity affected? And how?
- 6 flat cables (24 pins) are connected on one end to the same board at a distance of approximately 2 cm to each other, at the other end are connected to different boards at a distance of approximately 50cm to each other;
- All flats carry the same signals, the highest frequency is 10 MHz clock with a rise time of 8-9ns, which is present at just one wire. All the other wires of the flat carry low frequency signals (below 500 kHz);
- Flat length is 1.5m;
- Two 150W switching regulators are present and at a distance of 30cm from the board where all flats are connected.