If a transmission line with a characteristic impedance of 50 ohms feeds a folded dipole with a feed point impedance close to 300 ohms, what impedance transformation ratio is needed to match the two?

To match a transmission line to an antenna, you need to find the ratio between their respective impedances. You can calculate this by simply dividing the higher impedance by the lower impedance. In this case, the folded dipole has a feed point impedance of 300 ohms, and the transmission line is 50 ohms. Dividing 300 by 50 gives you 6, meaning you need a 6:1 impedance transformation ratio to properly match them. Other common impedance ratios are used for different setups. For example, a 4:1 ratio would match a 200-ohm antenna to 50 ohms, and a 9:1 ratio would match a 450-ohm antenna to 50 ohms. Using the correct matching transformer ensures maximum power transfer and minimizes your Standing Wave Ratio (SWR).