gain calculation for patch antenna

Hi All,

I have design a patch antenna for 2.7GHz and the dimension of width and length are 25mm and 25mm respectively. This was done by using CST microwave studio. I get the gain about 6.5dBi in this software.

And I built 2 patch antenna using "brown" copper and attached on both PCB by removing the previous printed copper.

I am testing both patch antenna as transmitter and receiver. The distance is 1.5m. I am transmitting 10dBm and it receive about -38dBm. The cable loss is about -1.67dBm.

I didn't get the nice gain value after calculating from the link budget calculation.

And by using patch antenna calculation through one website, I got the dimension for width and length are 34mm and 26mm respectively.

Which dimension should I follow?


Currently, I am testing both dimensions(25 and 25 , 34 and 26)but still couldn't get nice gain.


Could anybody suggest me how to get the good gain? I am expecting to get about 6dBi.

Waiting for your reply. Urgent!Urgent!

I would be grateful to anyone reply me.


regards,
saran

What material are you using?(FR4, duroid, etc)

the material is FR4

Hi All,

Could anybody give me suggestion based on the question that I shoot to you?

Waiting for your reply.

Regards,
Saran

I think the distance should be increased because the Fariis formula is for far-zone (at least 10*lambda). In addition, the maximum radiation direction of the two antenns should be aligned.

saran7507

6dBi seems a quite high value for a patch in FR4 @2.7 GHz, I would expect roughly 0 dBi.

Did you used the correct substrate loss in CST?
Did you chack for Retrn Loss in simulation and measurement?

Mazz

Hi saran,

distance between Tx and RX antenna should be 2DxD/lamda

regards,
balaguru.