Radiaition Pattern reconfigurable Antenna at 400 MHz

How can I make a microstrip antenna having reconfigurable radiation pattern at 400MHz?
Dielectric constant of substrate is 1.35 (Fabric).
If I use normal technique, size of antenna will be very big.
Many thanks

Dear nvt088,
please explain what is the "reconfigurable radiation pattern", and what antenna options you are interested in - gain, directional characteristics, size, etc ...
and it seems to me that the frequency 400 MHz too low for microstrip technology.

antp

Thank antp,

Reconfigurable radiation pattern means beam-steering. I want to steer antenna's beam by PIN diodes.

Sizes of antennas is limitted by 10x10 cm2 or 15x15 cm2, gain is 2-3 dB.

I want to use microstrip antenna because it's a directional one. Can you suggest me other types of directional antennas?

If we make normal microstrip antenna --> It's too big. Is these any technique to make a small microstrip antenna at 400MHz, for example, spiral microstrip antenna?

Many thanks!