کنفرانس مهندسی برق ایران

صفحه اصلی / سی و چهارمین کنفرانس بین المللی مهندسی برق

8-Bit Vector-sum phase shifter in S-band using 180-nm CMOS Technology

نویسندگان :

Nafiseh Ghodrati Pour¹ Sayed vahid Mir-Moghtadaei² Mohammad Narimani³

1- Information and Communication Technology Institute (ICTI) Isfahan University of Technology 2- Faculty of Technology and Engineering Shahrekord University 3- Information and Communication Technology Institute (ICTI) Isfahan University of Technology

کلمات کلیدی :

phase shifter،S-band،self-calibration،poly-phase filter،variable gain amplifier

چکیده :

This paper presents a vector-sum phase shifter in S-band (2.5–3.5 GHz) using 180-nm CMOS technology. Leveraging the inherent symmetry of the vector-sum architecture, phase synthesis is confined to the first quadrant (0°–45°), with a dedicated sign-selection block employing three control bits to map the synthesized vectors to the remaining quadrants. This strategy minimizes digital control overhead and requires only two pairs of differential variable-gain amplifiers (VGAs), thereby reducing circuit complexity, easing layout constraints, and enhancing component matching precision. Accurate wideband quadrature (I/Q) signals are produced via a closed-loop self-calibrating polyphase filter, ensuring improved amplitude and phase balance against process, voltage, and temperature variations. simulation results using Cadence Spectre-RF demonstrate around 360° phase coverage with ~1.4° resolution, RMS phase error and RMS gain error below 0.5°, and below 0.3 dB respectively. Also, the average insertion gain is -6 dB (with maximum ripple of 0.9 dB). The input and output return loss are better than -17 dB and -27 dB at 3 GHz, respectively. The self-calibration loop to generate I/Q signals settles less than 40 ns. The power consumption from a 1.8-V supply is 80 mW .