A 5-20 GHz 5-Bit True Time Delay Circuit in 0.18 ㎛ CMOS Technology

This paper presents a 5-bit true time delay circuit using a standard 0.18 ㎛ CMOS process for the broadband phased array antenna without the beam squint. The maximum time delay of ~106 ps with the delay step of ~3.3 ps is achieved at 5-20 ㎓. The RMS group delay and amplitude errors are ＜ 1 ps and ＜2 ㏈, respectively. The measured insertion loss is ＜27 ㏈ and the input and output return losses are ＜12 ㏈ at 5-15 ㎓. The current consumption is nearly zero with 1.8 V supply. The chip size is 1.04 × 0.85 ㎟ including pads.