A shorted transmission line stub placed at the feed point of a Yagi antenna to provide impedance matching✓Bonne réponse
A 1/4 wavelength section of 75-ohm coax in series with the feed point of a Yagi to provide impedance matching
A series capacitor selected to cancel the inductive reactance of a folded dipole antenna
A section of 300-ohm twin-lead transmission line used to match a folded dipole antenna
Explication
A beta or hairpin match is a shorted stub of transmission line, electrically an inductor, connected across the feed point. Used with a driven element cut slightly short so it looks capacitive, it forms an L network that transforms the low feed point impedance up to the feed line impedance.