. . . and also correct for polarization. your whip antenna when your plane is upright is vertical polarization. When it's banked(at say 90 degrees) becomes horizontally polarized. In a perfect world a horizontally polarized signal will be completely rejected by a vertically polarized antenna -- meaning no signal through -- but even steep angles will cut your signal sharply.
All this goes away with circular polarization(like made by the cloverleaf antennas). a left-hand circular polarized signal is left hand polarized no matter what orientation it's in. It also has a fair match with Vertical & Horizontal antennas. What it won't match is either a right hand polarized, or reflected left hand polarized signal (which helps cut out multi-path noise), so make sure both sides match.
switch for a cloverleaf, and you'll hold signal to full range no mater what attitude your plane takes.