A novel adder by using the unidirectional CIL

This paper describes a novel Josephson adder using unidirectional CIL gates. An unidirectionality of a signal is achieved by introducing a decoupling coil to output line of CIL gate. Furthermore a high speed carry propagation technique is introduced. These lessen the total turn-on time for the gate and make the construction of circuit simple. The principle of the operation and design criteria are described in detail. The results of the simulation show that the delay time of the adder is about 33ps/stage and power consumption is 1.7 μW/stage.