Miniaturization of Patch Antenna

[nvt088]

Hi every one.
I want to design a dierectional antenna at 400 MHz. Which type of antena I should choose?

In my case, I choose a Patch antenna. I successfully simulate a Patch antenna, size 9x10 cm, resonate at 500MHz, S11=-13 dB. However gain = -4 dB.
Normal partch antenna without miniaturization is 32x35cm at 400MHz, gain =1.5dB.

My question is that when the size of antenna is smaller, the gain also smaller. Is that right? Because antenna gain is proportional to antenna volume?

Many thanks

 

[Terminator3]

1. Maybe your miniature antenna maximum gain at another frequency, for example 600 MHz.
2. You can try a little more expensive substrate with higher dielectric constant. This gives smaller patch size.
3. You can try use microstrip without ground plane - monopole antenna. At ground side u can put machined cavity (i guess the same as with horn feeding), cavity can be filled with dielectric for smaller size

 

[flanello]

In general, if an antenna is smaller then the gain is also smaller.