Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

shorted patch antenna help

Status
Not open for further replies.

simazafrani

Newbie level 6
Joined
Feb 24, 2009
Messages
12
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,368
Hi...
i'm doing project about shorted patch by using CST. what i did was, i design square patch antenna and i make a hole at one part of the patch, which i put a pin with radius of 0.5mm (connected patch to ground). i got a good result in simulation (dual frequency RL <-10dB) , but the efficiency was quite low..which is around 35%. i haven't fabricate the antenna yet, becoz i'm still not sure about this.
what make me wonder is...was i did the right thing to design shorted patch antenna? or i misunderstood the meaning of shorted patch....

Hope someone here can help me in order to understand this...
Big Thanks...
 

ferdows

Advanced Member level 2
Joined
Mar 25, 2009
Messages
559
Helped
190
Reputation
382
Reaction score
186
Trophy points
1,323
Activity points
3,611
hi
u antenna efficiency is lower than normal i think u antenna bandwidth is lower than normal because efficiency related to S11 and when u s11 less than 15 it became good so u should change u antenna matching and restructure u antenna
 

simazafrani

Newbie level 6
Joined
Feb 24, 2009
Messages
12
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,368
Hi..tq for the reply...
FYI...my antenna resonates at 3 different freq at 1.126 GHz (-24.4dB, BW 40MHz), 2.45 GHz (-20.96dB, BW 73 MHz) and at 2.9 GHz (-21dB, BW 91 MHz). I think this result is good enough, but due to its low efficiency..i'm afraid i would not get a good measurement result of the fabricated antenna. Can u give any suggestion for me to improve its efficiency?
Thanks again...

Here i attached the design n S11
 

Attachments


ferdows

Advanced Member level 2
Joined
Mar 25, 2009
Messages
559
Helped
190
Reputation
382
Reaction score
186
Trophy points
1,323
Activity points
3,611
hi
1- i saw u file and u result look true but i think u have wrong in u simulation and i attach a file for more information
2-CST had some problem with resonance antenna like microstrip so i advise u to check u result with HFSS
3- i thick u port definition have fault i want to know how was it
4- i want to know whats u antenna substrate may be can change efficiency by change material
 

Attachments

Last edited:

simazafrani

Newbie level 6
Joined
Feb 24, 2009
Messages
12
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,368
Hi Ferdows....
1. thanks for the attachment
2. Currently, i only have CST software...thats the only choice i have...didn't have HFSS and never have experience with it
3. hmm...port definition? i'm using microstrip line feed which i define port at the end of the line( cover Ground thickness, Substrate thickness and microstrip line thickness)
4. i'm using FR4, Er = 4.7 and thickness 1.6mm

Thanks
 

ferdows

Advanced Member level 2
Joined
Mar 25, 2009
Messages
559
Helped
190
Reputation
382
Reaction score
186
Trophy points
1,323
Activity points
3,611
hi
hfss is easier than CST for design and i suggested that
for wave port u define the length of port must 5 time grater than u micostrip line and height is 2 time grater u substrate
this antenna look simple why u want fabricated it?
 

simazafrani

Newbie level 6
Joined
Feb 24, 2009
Messages
12
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,368
Hi
for wave port u define the length of port must 5 time grater than u micostrip line and height is 2 time grater u substrate
From what u worte, my port definition ok...

this antenna look simple why u want fabricated it?
yup, the antenna look simple...How, this is part of my miniproject..so i have to present simulation n measurement result..

hfss is easier than CST for design and i suggested that
i will try to find this software...hopefully there will be free version for student usage...or at least trial...

Many thanks...
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top