[SOLVED] HFSS filter design: Unable to achieve tuning for the filter

I tried to design an edge coupled microstrip Chebyshev BPF at 5.81 GHz.
Specifications:
Bandwidth: 150 MHz
Order=5
Substrate Permittivity: 3.2
Substrate Height: 1.58 mm
Cover Height: 30 mm
Ripple: 0.01 dB

The dimensions of the strips were obtained from Ansoft Designer SV as fpllows:
w1=1.72mm
s1=1.27mm
p1=8.11mm
w2=1.87mm
s2=4.78mm
p2=7.98mm
s3=6.04mm
p3=7.95mm

I designed the filter using these dimensions in hfss. However, the results do not tally with that in designer at all. I am afraid I have made mistakes in the design as I am new to Ansoft. Any help will be greatly appreciated. I am attaching my design for reference.

Twisha said:

I tried to design an edge coupled microstrip Chebyshev BPF at 5.81 GHz.
Specifications:
Ripple: 0.01 dB

Click to expand...

I doubt that is very realistic. Why do you need such a small ripple? I might be tempted to relax that to 0.5 dB and see if Ansoft Designer SV gives you very different parameters. In which case I'd simulate that design. The 0.01 dB ripple might be such an unrealistic requirement that the program can't handle it.

I'd like to thank you for bringing Ansoft Designer SV to my attention. I believe Ansys acquired Ansoft, but a link to the Ansys site I found at

https://www.theengineer.co.uk/news/ansoft-designer-sv/299657.article

produced no results. I can't find Ansoft Designer SV anywhere on the Ansys web site. But others might like to know this free product can be downloaded from the Korean Ansoft web site.

**broken link removed**

The download is pretty slow to the UK (About 9 KB/s), but it is sloowly coming down.

I'm not sure if Ansys only acquired part of Ansoft, and not the Korean bit, or whether the Korean site is just left up and running. But the Korean Ansoft web site certainly has something the ansys.com site does not have.

I wonder what other gems might exist on the Korean site?

Thank you,

Deborah