A K-Band CMOS Voltage Controlled Delay Line Based on an Artificial Left-Handed Transmission Line

A K-band voltage controlled delay line based on a left-handed transmission line (LHTL) with cascaded metal-oxide-semiconductor (MOS) varactors and shunt inductors using CMOS technology is demonstrated for the first time. A variable time delay can be obtained by changing the capacitance of MOS varactors without any power consumption. The figure of merit is 10.9deg/dB at 18 GHz. This result is better than other variable LHTL in similar frequency band. A time delay ranging from 56.8 ps to 76.4 ps is achieved at 18 GHz. It allows about 30 times longer time delay than that of a traditional right-handed one with the same length. The chip size, including the pads, is 410 mum times 640 mum.