How to get bandwidth under -10dB in patch antenna?

[neilmallik]

HFSS Matching

Hi,

I am trying to simulate a basic rectangular patch antenna on HFSS
(this will have poor bandwidth, obviously!!!). I have included the
airbox (radiation boundary), an edge-fed rectangular patch
(metallised, perfect-E) and a ground plane that is also a perfect E.
The patch is designed for 1.5 Ghz and I have given the correct
dimensions, and when I request the Return Loss (i.e. S11) against
frequency, I do not get resonance at 1.5GHz, or anywhere else for
that matter. I was wondering if you could help me use a method to get
a bandwidth under -10dB. A quick response is greatly appreciated.

Please respond to neilmallik@yahoo.co.uk. Thank you in advance.

Neil.

 

[Redi]

Re: HFSS Matching

Hi,

There are many methods of increasing bandwidth. Everything depends on how much bandwidth you need and what are your restrictions about size, feeding techniques, substrate, etc.

Greets,
Redi.

 

[caocao]

Re: HFSS Matching

Hi
How bandwith you need is important,10% 20%.....?I think you must change the patch's dimension or other parameter to make it resonant at 1.5G,and could design matching network to develop bandwith.

Thank

 

[Redi]

Re: HFSS Matching

Hi
How bandwith you need is important,10% 20%.....?I think you must change the fix's dimension or other parameter to make it resonant at 1.5G,and could design matching network to develop bandwith.

Thank

Hi,

Only good matching and proper resonant frequency is not enough for broad bandwidth of antennas. To increase the bandwidth you can for instance use thick and low permitivity substrate, change shape of patch etc. From usual rectangular patch you can only get around 2-3 % of bandwidth, if I remember correctly.

Greets,
Redi.

 

[caocao]

Re: HFSS Matching

Hi
It is very right matching network is not enough for broad bandwidth,but
I think that a good matching network could bring about 10% impedance BW of a patch.And I have a good example

Thank!
Caocao
[quote="Redi
Hi,

Only good matching and proper resonant frequency is not enough for broad bandwidth of antennas. Greets,
Redi.[/quote]

 

[Redi]

Re: HFSS Matching

Hi
It is very right matching network is not enough for broad bandwidth,but
I think that a good matching network could bring about 10% impedance BW of a fix.And I have a good example

Thank!
Caocao

You are right, because it depends on substrate you are using. If you use low perimitivity, thick and even lossy substrate, you can get much wider bandwidth even using normal rectangular patch than when you make antenna on thin and high permitivity substrate.

Greets,
Redi.