60 GHz Tapered Transmission Line Resonators
Abstract
Millimeter-wave transceivers require a local reference frequency for upconversion from baseband to RF for transmission, or downconversion of received RF signals down to baseband. This reference can also be divided down to a lower frequency for use as the baseband clock signal. Voltage controlled oscillators (VCOs) can provide this local frequency reference either as free-running oscillators or locked to a stable reference using phase locked loops. Typically, VCOs which utilize a resonant tank achieve the best overall performance, and thus are very common in mm-wave applications. The design of CMOS mm-wave VCOs, however, involves a complex set of trade-offs between tuning range, phase noise, DC power consumption, and output power. In many cases, the most important of these metrics are tuning range and phase noise. The tuning range of the VCO must be large enough to cover the desired band of interest taking into account process, voltage, and temperature variations as well as modelling inaccuracies. Phase noise, on the other hand, contributes to the overall noise figure of the transceiver by causing downconversion of noise and any undesired signals located in frequencies adjacent to the desired signal. Both metrics, however, are strongly dependent on the type and quality factor of the resonant tank used, as shown by Leeson's well known equation for the phase noise of an oscillator.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 15, 2008
- Accession Number
- ADA518577
Entities
People
- Ali M. Niknejad
- Cristian Marcu
Organizations
- University of California, Berkeley