group delay equalisation of high-pass filter

I have, and it's not working, which is really annoying. it works fine for a low-pass filter, but with a high-pass network, with different frequency (higher) the networks do not even act as an all-pass filter.

So, does anyone know of any programs that can do this for me with correct answers??

Phil

Oh right,

I'll probably be doing the same. I got the spreadsheet to work, I was copying the numbers into ADS to simulate, and I found that the numbers were so sensitive to change. So the circuit I got is impractiable with normal inductors, so I guess tracks to replace the inductors is needed?

Cheers,

Phil

Cheers,

is there a mathematical method of transforming my inductor values to microstrip length/width rather than empirically guessing at wire lengths?

Just write yourself the calculation for an all pass network in Excel - it is only half a dozen lines.

Pearce Consulting

Well, I'm not in the design business any more, but I once did this for a filter at about 1.5GHz on FR4. I ended up with a small network of fine tracks and chip capacitors. I used the theoretical numbers from my programme and estimated the track lengths that would make an equivalent inductance. A couple of iterations of boards was all it took.

Pearce Consulting

Absolutely - use thinnish single strand copper wire flush against the board to breadboard, then measure and replace with etched copper track for the real thing.

Pearce Consulting

Rough rule of thumb would be about a nanohenry to a millimetre for reasonably thin wire.

Pearce Consulting

so "no" then....?

so "no" then....?

MDS? I have all the information necessary to calculate this.

The answer is yes, but it is complex, and depends on all sorts of factors like substrate material, distance to the cover, copper thickness etc. MDS should be able to help you.

Pearce Consulting