In high-frequency applications, reflections occur if signals are not properly terminated. Figure 6-7 shows a properly terminated signal while Figure 6-8 shows an improperly terminated signal.

Figure 6-7 Properly Terminated Signal

Figure 6-8 Improperly Terminated Signal

To minimize reflection, use coaxial cable with matching characteristic impedance to the signal source. Terminate the other end of the cable with the same-value terminator or resistor. For commonly used cables, RG59 has a 75Ω characteristic impedance, and RG58 has a 50Ω characteristic impedance.