doenisz
Junior Member level 2
Hello, all,
I'm learning HFSS and started with a simple patch antenna simulation designed for 10GHz. I used Balanis' dimensions (W=10mm, L=7.5mm) on a 31mil Rogers RO4350 substrate, extending it more than λ/4 beyond the patch (Wsub=Lsub=30mm). There is a ground plane underneath, and I seeded the radiation boxes with lambda/10 length.
Initially, I used radiation boundaries, expecting the highest gain at θ=0, but the results were different than anticipated, following this weird shape:
Single Patch - radiation boundary, Wsub = Lsub = 30mm
Then I found out that radiation boundary does not perform very well at large angle incidences and PML is preferred for antennas, so I changed all the radiation boundaries to PML, following the wizard, and it improved my accuracy tremendously, even without seeding the boundaries, nor the patch itself:
Single Patch - PML boundary, Wsub = Lsub = 30mm
Next, I was curious about Wsub and Lsub, so I changed them to 30mm, and to my surprise, the results are not good.
Single Patch - PML boundary, Wsub = Lsub = 60mm
Now, my question is, why am I getting result? Is it a numerical error, or something that we would physically expect (i.e., is HFSS correct in giving me this result)? I feel like if I make more adaptive passes, it will converge to the correct result above?
Please help me with this.
I'm learning HFSS and started with a simple patch antenna simulation designed for 10GHz. I used Balanis' dimensions (W=10mm, L=7.5mm) on a 31mil Rogers RO4350 substrate, extending it more than λ/4 beyond the patch (Wsub=Lsub=30mm). There is a ground plane underneath, and I seeded the radiation boxes with lambda/10 length.
Initially, I used radiation boundaries, expecting the highest gain at θ=0, but the results were different than anticipated, following this weird shape:
Single Patch - radiation boundary, Wsub = Lsub = 30mm
Then I found out that radiation boundary does not perform very well at large angle incidences and PML is preferred for antennas, so I changed all the radiation boundaries to PML, following the wizard, and it improved my accuracy tremendously, even without seeding the boundaries, nor the patch itself:
Single Patch - PML boundary, Wsub = Lsub = 30mm
Next, I was curious about Wsub and Lsub, so I changed them to 30mm, and to my surprise, the results are not good.
Single Patch - PML boundary, Wsub = Lsub = 60mm
Now, my question is, why am I getting result? Is it a numerical error, or something that we would physically expect (i.e., is HFSS correct in giving me this result)? I feel like if I make more adaptive passes, it will converge to the correct result above?
Please help me with this.