Reg: Patch Antenna simulation in HFSS

[johnson.mike]

I've simulated GPS Patch Antenna in IE3D and its return loss is around -15dB and i,ve simulated the same antenna in HFSS its giving return loss as -5.3dB
attached here is my design in HFSS.kindly check where i've commited mistake.
I'm new to HFSS
How can we change the position of the port after simulation?

regards,
johnson

 

[hkprakash7]

Mike,
Even I'm new to HFSS. But, I believe you will have to increase the Radiation Boundaries in all the directions. The current design you have is too close to the patch from the sides.

Thanks,
-Prakash

 

[jallem]

Your design is off....The solution frequency is 1.57542
but the RL shows a peak at 3.07.....
The way to move the feed around is giving name to the
x and y position and then make use of optimetrics to
find the optimal. Or if you got the position out equations setup
x and y at those values.

But I would say your design is kind of big. And the reason for it
is because the thickness(h) of the board is too small, z=1.6mm
=62mils....kind of too thin......The size is about 41x41 and still
the frequency is high, so the size should be increased, probably
proportional to 41x3.07/1.5754 ~ 79.89 mm. Even bigger....

 

[johnson.mike]

Hi prakash and jallem,

Thanks for your help.I've reduced patch dimensions and changed the feed position now its returnloss is around -15dB as enclosed in figure.

One more question how to assign radiation boundary if both antenna substrate and ground plane are mutually perpendicular as given in attached figure(structure_antenna.jpg)in this case ground plane is at z=3mm and antenna substrate lower end is at z=0.
In Attached file (structure_antenna_radiation.jpg) we have to go with 1 or 2 ?

 

[zirtapoz]

How would you connect coax outer to ground?? ll you stretch probe??

 

[johnson.mike]

How would you connect coax outer to ground?? ll you stretch probe??

hi zirtapoz,

Its similar like probe feed patch Antenna.(Its SMA connector instead of probe feed in my earlier attached file).