I need to design new RF product. The transmit power is about +6dbm at 433.92Mhz.
It must transmt over 100 meters and all direction in vertical and horizontal.
And the product size is limit at 15cm x3 cm x 1.5 cm with three of AAA battery.
Which type of Antenna will suitable?
loop attenna, patch attenna, slot attenna, chip attenna?
Common low gain omnidirectional antennas are the whip antenna, a vertically orientated dipole antenna, the discone antenna, and the horizontal loop (or halo) antenna (Sometimes known colloquially as a 'circular aerial' because of the shape).
help me with points if my information is useful to you.
For monopole and dipole type, I know it have onmidirectional in azimuth only.
I want to find that radiation pattern is circle in both of elevation and azimuth.
Only an antenna array can give you a pattern like this. For example some Low Orbit satellite phone systems use patch-arrays (six patches at 45 degrees elevation placed on a hexagon, and the seventh patch (horizontal) placed on the top. In this way the array antenna can see the satellites placed at all azimuths and elevations over the earth.