Applications of artificial transmission lines with active negative reactances to design of ultra-wideband microwave devices

Advantages of artificial transmission lines with negative reactances are considered as applied to design of ultra-wideband microwave devices. The use of specific dispersion properties of the rightand left-handed transmission lines consisting of negative reactances to achieve flat 0°, 90°, and 180° phase characteristics over a wide frequency range is demonstrated. Potential applications are outlined and illustrated by some examples. Practical implementation of negative reactances as negative impedance converters based on a pair of transistors is discussed.