A Novel Direct Injection-Locked QPSK Modulator Based on Ring VCO in 180 nm CMOS

• Published in: IEEE microwave and wireless components letters 2014-04, Vol.24 (4), p.269-271
• Main Authors: Sang Yeop Lee, Ito, Hiroyuki, Ishihara, Noboru, Masu, Kazuya
• Format: Article
• Language: English
• Subjects: Applied sciences; Circuit properties; Clocks; CMOS; Design. Technologies. Operation analysis. Testing; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Frequency modulation; Injection locking; Injection-locked oscillators; Integrated circuits; Microwaves; modulator; Modulators; Oscillators, resonators, synthetizers; Phase modulation; Phase shift keying; quadrature phase-shift keying (QPSK); Quadratures; ring voltage-controlled oscillator (VCO); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal convertors; Voltage controlled oscillators
• ISSN: 1531-1309; 2771-957X; 1558-1764; 2771-9588
• DOI: 10.1109/LMWC.2014.2299534

A novel quadrature phase-shift keying (QPSK) modulator that employs injection locking for the phase modulation as well as the phase-locked clock generation is presented. By using the proposed simple modulator based on a ring voltage-controlled oscillator (VCO), many blocks in the conventional QPSK modulators are removed, and the total area can be reduced.The proposed QPSK modulator was fabricated in a 180 nm CMOS, and occupies an area of 0.024 mm 2 . The modulator achieves measured error vector magnitude (EVM) of 8.23% at 50.8 Mb/s under QPSK modulation with the total power consumption of lower than 6 mW from a 1.8 V power supply.