Research Projects

mm-Wave High Speed Modulator Design

Maryam Tabesh and Ali Niknejad

Extremely high data rate short-range communication systems are among the emerging applications for the 60 GHz spectrum. Digital CMOS technology is a very favorable candidate for low cost and small size applications. This project explores the potentials for high data-rate, low power 60GHz modulators. A dual-mode fully differential combined DAC-mixer structure has been introduced to improve linearity and power consumption. The quadrature, fully differential modulator can be used in QPSK or 64-QAM mode and has the ability to provide data rates up to 30Gb/sec. As a part of this project, high speed distributed microwave style modulator has also been investigated. As a prototype a first version of the 60GHz modulator has been fabricated in 90nm CMOS technology and is being tested. A current steering DAC structure with programmable tail bias current and thermometer code has been used for matching constraints.

Figure 1: Layout of the 60GHz Modulator.