Matching a microstrip patch antenna in IE3D

[rash03]

hi
i design apertur coupled antenna for c band. ground plane height 0.762mm, feed line lenght 11.5mm, width 2.32mm, random lenght/width 17mm with er=2.2.
i get high vswr at 5.6 hz. i want to reduce that.ε

 

[Azulykit]

Re: microwave, antenna

It sounds like you are trying to match a microstrip patch antenna. It is practical to get it into the -10 to -15 dB range for s11. The weasel word answer is that it is possible to get much lower at any specific frequency.

Try looking at the feedline and stub length to see if that changes your match. Try moving them relative to the aperture or changing their dimensions. You might also modify the aperture dimensions slightly. What I would look for is a part of the antenna that modifys the reflection and experiment some to see which way to change the dimension.

If you have a simulator, use that. Otherwise, a roll of copper tape and an exacto knife are the traditional tuniing tools..

Be sure to keep an eye on the patterns and gain. It is easy to get a good match while trashing the antenna characteristics. Don't just tune for low s11.

 

[rash03]

Re: microwave, antenna

thank u.
i use ie3d software. when i reduced the dimension bw is als reduced. if i incresed dimension bw is incresed. i want range from 4.8 - 6 GHZ for vswr<2. what i should do.

 

[Azulykit]

Re: microwave, antenna

If this is a patch antenna increasing the dielectric thickness and/or decreasing the dielectric constant will increase the bandwidth.

Patch antennas are typically less than 15 to 20 % bandwidth so your design is getting into difficult territory. It is practical to get wider bandwidth but it will take some care.
50% bandwidth is possible.

The IEEE Transactions on Antennas and Propagation is a wealth if information on how to increase patch bandwidth.