1. A Synthesizer for WLAN with a Fully
Integrated VCO in 0,35 µm SiGe Technology
S. L. Khemchandani, A. Goni-Iturri, J. del Pino Suarez, B. Gonzalez, J. Garcia and A. Hernandez.
Institute for Applied Microelectronics (IUMA), Dto. de Ingeniería Electrónica y Automática (DIEA). Universidad de Las Palmas de Gran Canaria (ULPGC), Spain.
Published in
XX Design of Circuits and Integrated Systems Conference.
Lisboa, Portugal, 2005.
Abstract
In the last years, wireless LAN market has shown an incredible growth, exceeding expectations. This
paper presents a fully integrated LC voltage controlled oscillator in a low cost 0.35 µm SiGe technology
for the 5 GHz band, according to the IEEE 802.11a wireless LAN standard. The tank inductor has been
designed by electromagnetic simulations. In order to test the VCO performance, a synthesizer for IEEE
802.11a has been designed. This work demonstrates the feasibility of a low cost silicon technology for
the design of 5 GHz band circuits.
IEEE 802.11ª Receiver
Results
TABLE I. Valid operating channel numbers by regulatory domain and band for 802.11a.
Fig 9. VCO simulated phase noise. Fig 10. VCO tuning range.
Fig 1. Channel Allocation in IEEE 802.11a standard.
Fig 12. Contributions to synthesizer Fig 14. Transient response of the
phase noise. synthesizer for 5745 MHz to 5805 MHz
Fig 2. Direct conversion receiver for IEEE Fig 3. Synthesizer for IEEE 802.11a receiver. hop.
802.11a.
Conclusions
Design & Implementation Using a low cost technology we have designed a fully integrated
VCO with on chip tank in the 5 GHz band. This fully monolithic
approach provides an extremely easy-to-use VCO, equivalent to a
VCO module suitable for direct conversion architectures. The tank
inductor has been custom designed and simulated with an
electromagnetic simulator. The obtained Q and area fits better with
our VCO than the inductors offered by the foundry. With the proper
VCO topology and the appropriate layout techniques we have
designed a VCO suitable to be used in the 5 GHz band. In order to
Fig 4. (a) General feedback network. (b) An test the VCO, a synthesizer according to IEEE 802.11.a standard
Fig 8. VCO photograph.
LC-tuned oscillator as a feedback circuit.
has been designed. Simulations have been made to test the
synthesizer behavior, showing the VCO phase noise contribution to
the synthesizer.
Acknowledgement
This work is supported by the Spanish Ministry of Science and Technology
Fig 6. Integrated inductor quality factor. Fig 11. Passive three-pole loop filter. (Ministerio de Ciencia y Tecnología, TIC- 2002-04323-C03-03).
INSTITUTO UNIVERSITARIO DE MICROELECTRÓNICA APLICADA (IUMA)
UNIVERSIDAD DE LAS PALMAS DE GRAN CANARIA (ULPGC)