On the Optimum Length for Transmission Lines Used as Circuit Elements

The existence of an optimum length for transmission lines which are tuned by low-loss capacitor to give maximum sending-end impedance is discussed. This optimum length is found to be 0.185λ for a shorted line and 0.472λ for an open-circuited line, resulting in impedances 14 and 3 per cent higher, respectively, than can be obtained from lines without tuning condensers.