Impedance Matching for dual-band microstrip patch antenna

[Alfred 1]

Hi everyone, need help here. I have designed a dual-band microstrip patch antenna for LTE and WiFi applications. The antenna operate at 2.6GHz for LTE and 5.0GHz for WiFi. I have started to design this dual-band antenna by designing the 5.0GHz WiFi antenna then introduce 2 inverted U slots to generate the resonant 2.6GHz. I cannot achieve impedance matching for the 2.6GHz LTE antenna. Please help and advice.

 

Thank you. 

2222.cst

[Alfred 1]

The return loss, bandwidth and gain do not satisfy the requirement. Please advice on how to match the impedance for 2.6GHz LTE antenna without affecting the initial 5.0GHz WiFi antenna. 

[Admin 2579]

,,welcome...

you are not included in 2.6GHz frequency, should be amended patch and line adjustment..

for providing impedance 50 ohms..!!!

[Admin 2579]

https://www.pasternack.com/t-calculator-microstrip-ant.aspx

 

[Alfred 1]

My approach is designing the microstrip patch length and width for 5.0GHz then introduce 2 inverted U slots to generate the resonant 2.6GHz LTE antenna. Is that correct?

Thank you. 

[Admin 2579]

5 minutes ago, Alfred said:

My approach is designing the microstrip patch length and width for 5.0GHz then introduce 2 inverted U slots to generate the resonant 2.6GHz LTE antenna. Is that correct?

Thank you. 

,,, I think it should be the other way ... !!!

[Alfred 1]

Meaning I should design the 2.6GHz LTE antenna first then introduce slots to generate resonant 5.0GHz WiFi??

 

Thank you. 

[Alfred 1]

All right. I will try it out your suggestion. Btw any reason for not designing the 5.0GHz WiFi first?

[Admin 2579]

21 hours ago, Alfred said:

All right. I will try it out your suggestion. Btw any reason for not designing the 5.0GHz WiFi first?

,,,see this...http://www.microwavejournal.com/articles/4232-a-low-profile-multi-band-u-shaped-aperture-coupled-microstrip-antenna-with-a-coil

http://www.emagtech.com/wiki/index.php?title=V%26V_Article_3:_Modeling_Broadband_And_Circularly_Polarized_Patch_Antennas_Using_EM.Picasso

[Alfred 1]

Almost done. Left the 2.6GHz impedance not match. Need to eliminate the imaginary part. How? Please advice. Please feel free to edit the design for me.

Thank you. 

33333.cst

[Alfred 1]

Need to make the imaginary -20.34 become 0 and the VSWR near to 1. How? TT

Thank you. 

[Alfred 1]

Ammend patch and feed length do not help. Please help me.

Thank you. 

[Admin 2579]

Alfred, it seems that the antenna is not properly designed, look..

[Admin 2579]

I think it's better to try this ...

[Alfred 1]

Hi, there are some differences between your simulation and my simulation. Any reason? Attached with my result and simulation file. From my result, everything is okay except the imaginary part and gain of the 2.6GHz antenna.

33333.cst

[Admin 2579]

Alfred, you're right, I increased the size ...13,92mm at ..14.52mm(13,92+0,6)

 

,,,I think it must to modify the inset feedding of antenna for a good adaptation line at 50 ohm impedance

[Alfred 1]

 

Any other ways to match the 2.6GHz impedance?

TT

Haiz

I have tried every single method that I know but still cannot match the impedance without affecting the 5.0GHz antenna.

[Admin 2579]

I'll try to do it the simulation cst....!!!

but anyway, you have to try in the future to work with literary parts(not numbers) in the  Parameter List of CST's

[Alfred 1]

Really appreciate your help.

Thanks a lot.

[Admin 2579]

,,,to better elucidate on Inset Fed Microstrip Patch Antenna....http://www.microwavetools.com/inset-fed-microstrip-patch-antenna/

,,, and a calculator for it...

inset_fed_antenna.exe

[Admin 2579]

actually I do not know what makes them,and you try it...

1111.cst

[Alfred 1]

Why it is so hard to match the impedance? Gave up.

[Admin 2579]

2 hours ago, Alfred said:

Why it is so hard to match the impedance? Gave up.

,,, why, never say give up...!!!

[Alfred 1]

Can antenna operate at 2.3GHz for LTE besides 1.8GHz and 2.6GHz?

 

[Admin 2579]

Yes, it's possible..but with a VSWR <1.5.!!!

A good antenna must to have VSWR<1,2