A 6.5 GHz CMOS FSK modulator for wireless sensor applications

A 6.5 GHz FSK modulator suitable for low power wireless sensor network is presented. The modulator employs closed loop direct VCO modulation to achieve high data rate, variable loop bandwidth technique for fast start-up rates and /spl Sigma/-/spl Delta/ for reduced power consumption in the divider with fine resolution in channel selection. The synthesizer, implemented in 0.25 /spl mu/m CMOS, achieves 20 /spl mu/s start-up time with an effective data rate of 2.5 Mbps while consuming 22 mW.

[1]  Anantha Chandrakasan,et al.  Energy efficient Modulation and MAC for Asymmetric RF Microsensor Systems , 2001, ISLPED '01.

[2]  Shen-Iuan Liu,et al.  Fast-switching frequency synthesizer with a discriminator-aided phase detector , 2000, IEEE Journal of Solid-State Circuits.

[3]  A. Swaminathan,et al.  A 22 mW Bluetooth RF transceiver with direct RF modulation and on-chip IF filtering , 2001, 2001 IEEE International Solid-State Circuits Conference. Digest of Technical Papers. ISSCC (Cat. No.01CH37177).

[4]  M.H. Perrott,et al.  A 27 mW CMOS fractional-N synthesizer/modulator IC , 1997, 1997 IEEE International Solids-State Circuits Conference. Digest of Technical Papers.

[5]  Dan McMahill.  Automated Calibration of Modulated Frequency Synthesizers , 2001 .

[6]  HongMo Wang.  A 1.8 V 3 mW 16.8 GHz frequency divider in 0.25 /spl mu/m CMOS , 2000 .

[7]  H.R. Rategh,et al.  A CMOS frequency synthesizer with an injection-locked frequency divider for a 5-GHz wireless LAN receiver , 2000, IEEE Journal of Solid-State Circuits.

[8]  S. Mehta,et al.  A single-chip CMOS direct-conversion transceiver for 900 MHz spread-spectrum digital cordless phones , 1999, 1999 IEEE International Solid-State Circuits Conference. Digest of Technical Papers. ISSCC. First Edition (Cat. No.99CH36278).