Yagi antennas for frequencies this high are ridiculously compact and
easy to build! A full wave is only in the 33 CM area, so a "long" Yagi
with 6 or 7 elements would look like a yardstick with 5 inch wires
bristling from it. If you only need to send signal in a particular
direction, this is the way to go-and reduces the chance of unwanted
"listeners" in another direction.

If you need omnidirectional gain, stacked turnstiles floor to ceiling
, looking like a pole lamp brisling with 5" crosses, would do it,
yielding maybe 9dB or so of gain by flattening out the pattern.
Multiple half waves in phase (vertical with 1/2 wave phaseing sections)
will do it with vertical polarization. In stacking anything, you get
about 3dB gain for each doubling of the number of elements.

****, hams on 1215 MHZ and 1KW amps are communicating by bouncing
signals off the MOON, with antennas yielding 30dB plus gain being
reasonable in size due to short UHF wavelengths.