CMOS true‐time delay IC for wideband phased‐array antenna. Issue 6 (11th September 2018)

• Record Type: Journal Article
• Authors: Kim, Jinhyun; Park, Jeongsoo; Kim, Jeong‐Geun
• Is Part Of: ETRI journal. Volume 40:Issue 6(2018)
• Page Start: 693
• Page End: 698
• Publication Date: 2018-09-11
• Subjects: beam squint -- CMOS -- low‐amplitude error -- true‐time delay -- wideband phased‐array antenna; Telecommunication -- Periodicals; Electronics -- Periodicals; Electronics; Telecommunication; Periodicals; Periodicals; 621.38205
• DOI: 10.4218/etrij.2018-0113
• Languages: English
• ISSNs: 1225-6463

Abstract

Abstract : This paper presents a true‐time delay (TTD) using a commercial 0.13‐μm CMOS process for wideband phased‐array antennas without the beam squint. The proposed TTD consists of four wideband distributed gain amplifiers (WDGAs), a 7‐bit TTD circuit, and a 6‐bit digital step attenuator (DSA) circuit. The T‐type attenuator with a low‐pass filter and the WDGAs are implemented for a low insertion loss error between the reference and time‐delay states, and has a flat gain performance. The overall gain and return losses are >7 dB and >10 dB, respectively, at 2 GHz–18 GHz. The maximum time delay of 198 ps with a 1.56‐ps step and the maximum attenuation of 31.5 dB with a 0.5‐dB step are achieved at 2 GHz–18 GHz. The RMS time‐delay and amplitude errors are <3 ps and <1 dB, respectively, at 2 GHz–18 GHz. An output P1 dB of <−0.5 dBm is achieved at 2 GHz–18 GHz. The chip size is 3.3 × 1.6 mm 2, including pads, and the DC power consumption is 370 mW for a 3.3‐V supply voltage. Abstract : Because of their electronic beamforming and low SNR, CMOS‐based phased‐array antennas have been widely applied to radar and communication systems. In this paper, the true‐time delay (TTD), as compared to a phase shifter, provides reduced beam squinting and high resolution through a constant time delay over the applied frequency for wideband phased‐array antennas. In addition, the TTD results in a low insertion loss error and a fl at gain performance with a T‐type attenuator and a distributed amplifi er.