A monolithic 5.9-GHz CMOS I/Q direct-down converter utilizing a quadrature coupler and transformer-coupled subharmonic mixers

• Published in: IEEE microwave and wireless components letters Vol. 16; no. 4; pp. 197 - 199
• Main Authors: Wang, T, Lu, S-S, Huang, G-W
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2006; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; CMOS; Converters; Coupler; Coupling circuits; Design. Technologies. Operation analysis. Testing; direct-down conversion; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Gain; Integrated circuits; Joining; Linearity; Local oscillators; Microwave transistors; Microwaves; Mixers; Oscillators; Oscillators, resonators, synthetizers; Quadratures; Radio frequency; RF signals; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal convertors; Signal generators; subharmonic mixer (SHM); Switches; Transconductors; transformer; Voltage gain; Electric transformer; Coupler; Direct convertor; Mixer; transformer; Quadrature modulation; Step down convertor; Subharmonic; Local oscillator; Complementary MOS technology; Frequency converter; direct-down conversion; Monolithic integrated circuit; Gain; subharmonic mixer (SHM)
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2006.872123

We report the first monolithic 5.9-GHz CMOS I/Q direct-down converter by using a quadrature coupler and transformer-coupled subharmonic mixers (SHMs). Consuming 3.5mW, each SHM achieves a voltage gain of 10.8dB, 7.9-dBm IIP3, and 54-dBm IIP2. The input-referred dc-offset due to local oscillator self-mixing is -80.9dBm.