430-470MHz, 6dBi Patch Antenna?

[myebook]

patch antenna for 6 dbi

any proposal for design an antenna with the following spechigh gain and large BW)
Center frequency:450MHz,
Band width,435-465MHz
Beam width:80 deg typ
VSWR:<1.3
Gain:6 dB
F/B ratio:>13dB
Size:aprox 30*33*4.5cm(W*D*H)

Regarding the probe-fed, my deigns in HFSS and CST do not match with the measrements. Any sample design which is compatible with measurement results would be appreciated. (If I don't trust the result of prob-fed simulations, I cannot design the antenna)

 

[kspalla]

Will you share the design completed in CST and also the measurements.

 

[Kohi_boy]

What are the parameters that differ ?

 

[myebook]

My CST design and measurement result:

 

[Kohi_boy]

Do you also have the file in HFSS version 10 ?

 

[myebook]

HFSS file:

 

[myebook]

HFSS file:

 

[myebook]

even this very simple coax fed transmission line does not work (CST file)!!!

 

[kspalla]

Points to consider,
I have not opened the deign in CST
1) what is the thickness of the conductor and feed.
2) After 12mm height conductor is placed with out any support, How to realize it.
3)Is it for study only?

 

[shameemkabir]

I have simulated the structure both in CST and HFSS. they are quite the same, I didn't change anything (like mesh size, accuracy etc.) to bring them closer. Please take a look at the figures.

I know, you have document which shows different results. Would you please build such a structure to see whether the results given in the report is correct or not!

About coax feed transmission line: There is no power really going into the line from the coax (from S11 you can see it). For microstipline structure, it is better to use rectangular waveguide port at the end. You don't need to draw coaxial feed.

 

[myebook]

I also got the same result as you got. but as you compare to the pdf I sent previously these results are quite different from the measurement. so I really cannot design my own patch antenna because I cannot trust the results of the CST and HFSS in this case.
yes you are right I can use rectangular waveport in edge feeding also.
Maybe we should use another software like IE3D as the "microstrip patch antenna" book uses only that software to evaluate the patch antennas. At the moment I don't have this software.

 

[shameemkabir]

I also got the same result as you got. but as you compare to the pdf I sent previously these results are quite different from the measurement.

It may sound bad, however, please don't believe the results from the paper always. That's why I told you to build this antenna by yourself and compare with the simualted results.

Maybe we should use another software like IE3D as the "microstrip patch antenna" book uses only that software to evaluate the patch antennas.

Moment method software are really good for planar antennas. If you have ADS Momentum, you can try that also.

 

[myebook]

My reference book is "compact and broadband microstrip antennas" by Wong.
Yes I have ADS, but it is not good for probe-feds but acts very good for line-fed antennas. The above book uses entirely IE3D and because I tried several antennas from there in HFSS and CST, I guess these softwares are not good for planar structures. Maybe there is something wrong with my simulations, I'm not sure!