methods to decrease antenna dimension

[prateek3790]

how to decrease the overall dimension of the antenna. for example for 2.4GHz the dimension of a meander line antenna is few cm. what are the possible ways to optimize these lengths without affecting the overall performance of the antenna.

 

[kthackst]

How to make an antenna smaller without making it worse is most of antenna engineering. Generally physics does not let you get away with much, and at the end of the day, the Chu-Harrington limit is the ultimate barrier on how small an antenna can be and still be useful. Is this an antenna you designed yourself? If you include a picture, as well as your gain and size requirements, its possible some well experienced guru would have tips for how to improve your antenna.

 

[otterboi77]

One way is to identify the area of the antenna that has the majority of current running through it. The geometry outside of that area can be manipulated without interfering with the radiation pattern too much. So long as you do not change it so much that currents cancel each other out.

 

[vfone]

The Chu-Harrington limit, which came all the time in documents related to small antenna design, for some reasons never worked for me.
The dimension limits (to get a specific Q and bandwidth) mentioned and referenced to Chu, for some reasons, most of the time gives a useless antenna gain.
So, if you have the possibility to make the antenna bigger, make it bigger.

 

[Azulykit]

Reducing an antenna size generally will degrade performance. Curving feed lines and cutting down ground plane size is one tactic. Increasing dielectric constants reduces physical size. Bury the thing in a block of dielectric.

In reality the performance degrades with all of these methods. Everyone wants small antennas but usually hates the performance after the size is reduced.

 

[nomigoraya]

One way is to identify the area of the antenna that has the majority of current running through it. The geometry outside of that area can be manipulated without interfering with the radiation pattern too much. So long as you do not change it so much that currents cancel each other out.

Well if an antenna is designed properly I would say there will be nothing left to cut or ignore without compromising the performance rather degrading it. Size of antenna comes basically from frequency and if frequency is fixed I believe there is no way to reduce the size without compromising the performance and fields. The point is always the goal that what this antenna will be used to transfer it is just to be used to say yes when excited and no when not then you need not to be worried about field profiles power lost polarization heating etc