What antenna matching system matches coaxial cable to an antenna by connecting the shield to the center of the antenna and the conductor a fraction of a wavelength to one side?

The Gamma match is an unbalanced matching system commonly used to connect standard 50-ohm coaxial cable to the balanced driven element of a Yagi antenna. It operates by attaching the coax shield directly to the center of the driven element (which is often grounded to the boom) while the center conductor connects to a parallel rod. This parallel rod is attached to the driven element at a specified distance (a fraction of a wavelength) away from the center. The combination of the parallel rod and a series capacitor (often built into the rod assembly) cancels out the antenna's reactance and steps up the low impedance of the driven element to match the 50-ohm feedline.