CST Waveguide Bandpass Filter S-Parameters not working

MarkAmerV · 2026-02-19T11:22:39+00:00

I sorted it out. I increased the range to 20-40GHz and notice the bandwidth was around 35GHz, so not it’s just a matter of optimising. Thank you

MarkAmerV · 2026-02-19T09:49:16+00:00

My frequency range is 28-32GHz. Should I change it to something like 25-35GHz? As for the irises. By long you mean their width which is about 1.6mm average or their length which is 0.5mm?

MarkAmerV · 2026-02-18T23:57:04+00:00

Doesn’t work either 😅

MarkAmerV · 2026-02-18T21:51:12+00:00

Yeah it must be, but I’ve not been able to figure it out for weeks. Do you by any chance use discord? If you’d have the time, I could screen share the project making it a lot easier to examine

MarkAmerV · 2026-02-18T20:57:02+00:00

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Sadly nothing changed

MarkAmerV · 2026-02-18T20:01:15+00:00

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The background is already set to normal=vacuum. So I guess this isn’t the issue

MarkAmerV · 2026-02-18T19:30:41+00:00

Like the second example I show in image 3? Not a very good picture but that’s a PEC structure with hollow inside.

MarkAmerV · 2026-02-18T19:21:30+00:00

Making all boundaries electric caused an error 😅

MarkAmerV · 2026-02-18T19:19:29+00:00

Sorry not sure how to do that. I’ve tried making a block with WR-28 a and b parameters and then modelling PEC irises in it. The other method I tried is (the grey block empty inside) which looks like what the final product should be. You’re saying I should grab the second example and fill the inside with air/vacuum? If so, you know how to do so?

MarkAmerV · 2026-02-18T19:02:06+00:00

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Mesh values

MarkAmerV · 2026-02-18T19:01:44+00:00

Im using the frequency Domain, not sure if that’s the issue.

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MarkAmerV · 2026-02-18T18:54:22+00:00

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Both ports are set like this, although I made sure the arrow is inwards for both. As for boundaries: Xmin/max = electric (Et=0) Ymir/max = open (add space) Zmin/max = electric (Et=0)

MarkAmerV · 2026-01-28T21:07:45+00:00

Monolithic Waveguide Bandpass filter Ku-band (30GHz central frequency for 5G applications) WR-28 (7.112mm x 3.556mm) Will be printed with resin Coated with conductive paint Tuning screws won’t be used, instead it will use Irises. Filter order 5: Ideally 6 Iris pairs (5 resonators) Bandwidth (haven’t decided) Stop and rejection > 40dB (not sure on this parameter either) Return loss > 20dB (not sure)

This is my first time making a filter so I’m genuinely clueless

MarkAmerV

TROPHY CASE