The characteristic impedance (Z) was already introduced in Standex Electronics’ RF part I, and it will be one of the parameters focused upon while looking at the materials and geometry of the reed relay. For best RF performance the characteristic impedance must be consistent along the entire signal path. This includes the entry and exit points in and out of the reed relay. Most RF circuits today are 50 Ohms (Ω). So, at any given point, at the entry, thru the reed relay, and exiting the relay, the characteristic impedance must be maintained at 50 Ω.