Abstract

Variable-gain amplifier (VGA) is one of the basic building blocks of many communication systems. In this paper we present a novel structure of VGA with 22 db of gain range and 220 MHz of bandwidth frequency variation. This circuit combines a voltage to current (V-I) converter and two-stage CMOS amplifier to achieve programmable gain and bandwidth . The gain is varied by changing the input voltage (Vin) from -1V to 0V. The maximum bandwidth is about 300 MHz. The gain can be varied from 38 dB to 60 dB in 1 dB gain steps. The overall circuit draws current from 10µA to 150µA at ±1. 5V power supply. The noise figure of the system at maximum gain is 18dB, and the third-order intermodulation intercept point (IIP3) at minimum gain is -8 dBm. Simulations results with static and dynamic behaviour is presented and validated with the technology AMS 0. 35µm. Eventually we have also succeeded in reducing the static power consumption to 0. 5 mW.

References

• Chun-Hsien Wu and Yeh-Ching Chung :"Heterogeneous Wireless Sensor Network Deployment and Topology Control Based on Irregular Sensor Model," Advances in Grid and Pervasive Computing Lecture Notes in Computer Science, Volume 4459/2007,2007
• E. J, Duarte-Melo and Mingyan Liu : "Analysis of energy consumption and lifetime of heterogeneous wireless sensor networks," Global Telecommunications Conference , 2002. GLOBECOM '02. IEEE, vol. 1, no. , 17-21 Nov 2002
• Trung kien Nguyen, Nam Jin Oh, and Viet Hoang Le, and Sang_Gug Lee, Member IEEE "A Low Power CMOS Direct Conversion Receiver With 3dB NF and 30KHz Flicker-Noise Corner for 915-MHz Band IEEE 802. 15. 4 ZigBee Standard," IEEE Transaction on Microwave Theory and Techniques 2006
• Ahmadreza Rofougaran, Glenn Chang, Jacob J. Rael, James Y. -C. Chang, Maryam Rofougaran, Paul J. Chang, Masoud Djafari, Jonathan Min, Edward W. Roth, Asad A. Abidi, and Henry Samueli, "A Single- Chip 900-MHz Spread-Spectrum Wireless Transceiver in 1-?m CMOS—Part II: Receiver Design," IEEE journal of solid-state circuits, vol. 33, no. 4, april 1998
• Trabelsi. H, Bouzid. Gh, Jaballi. Y, Bouzid. L, Derbel. F and Masmoudi. M : "A 863-870-MHz Spread-Spectrum Direct Conversion Receiver Design for Wireless sensor" IEEE DTIS'06, Tunisia, September, 2006
• Medeiro F. , del Rio R. , de la Rosa J. M. , Pérez-Verdù B. , A Sigma-Delta modulator design exemple : from specs to measurements, Baecelonea, May 6-10, 2002 .
• David Johns and Kenneth W. Martin : "Analog Integrated Circuit Design" John Wiley & Sons, 1997.
• Ahmed Nader Mohieldin, Edgar Sánchez-Sinencio, and José Silva- Martínez : ' Nonlinear effects in pseudo differential OTAs with CMFB', IEEE Transactions On Circuits and Systems-II: Analog and Digital Signal Processing, Vol. 50, No. 10, October 2003.
• K. tanno, O. Ishizuka and Z. Tang : ' Low voltage and low frequency current mirror using a two- MOS subthreshold op-amp', Electronics Letters 28th March 1996 Vol. 32 No. 7
• D. J. Comer and D. T. Comer, Fundamentals of electronic circuit design. NewYork: John Wiley & Sons Inc. , 2003
• Y. Yamaji, N. Kanou, and T. Itakura, "A temperature-stable CMOS variable-gain amplifier with 80 dB linearly controlled gain range," IEEE J. Solid-State Circuits, vol. 37, no. 5, May 2002, pp. 553–558.
• Y. Zheng, J. Yan, and Y. P. Xu, "A CMOS dB-linear VGA with pre-distortion compensation for wireless communication applications," in Proc. IEEE Int. Symp. Circuits Syst. , vol. 1, May 2004, pp. 813–816
• Q. -H. Duong, Q. Le, C. -W. Kim, and S. -G. Lee, "A 95 dB linear low-power variable gain amplifier," IEEE Trans. Circuits Syst. I, vol. 53, no. 8, Aug. 2006, pp. 1648–1657.
• O. Watanabe, S. Otaka, M. Ashida, and T. Itakura, "A 380MHz CMOS linear-indB signal-summing variable gain amplifier with gain compensation technique for CDMA systems," in Digest Tech. Papers Symp. VLSI Circuits, June 2002, pp. 136–139.
• P. -C. Huang, L. -Y. Chiou, and C. -K. Wang, "A 3. 3V CMOS wideband exponential control variable-gain-amplifier," in Proc. IEEE Int. Symp. Circuits Syst. , vol. 1, May1998, pp. 285–288.
• M. Green and S. Joshi, "A 1. 5V CMOS VGA based on pseudo-differential structures," in Proc. IEEE Int. Symp. Circuits Syst. , vol. 4, May 2000, pp. 461–464.
• A. Motamed, C. Hwang, and M. Ismail, "A low-voltage low-power wide-range CMOS variable gain amplifier," IEEE Trans. Circuits Syst. II, vol. 45, no. 7, July 1998, pp. 800–811.
• C. -C. Hsu and J. T. Wu, "A highly linear 125MHz CMOS switched-resistor programmable-gain amplifier," IEEE J. Solid-State Circuits, vol. 38, no. 10, Oct. 2003, pp. 1663–1670.
• H. Elwan and M. Ismail, "Digitally programmable decibel-linear CMOS VGA for low-power mixed-signal applications," IEEE Trans. Circuits Syst. II, vol. 47, no. 5, May 2000, pp. 388–398.
• C. -C. Wang, C. -L. Lee, L. -P. Lin, and Y. -L. Tseng, "Wideband 70 dB CMOS digital variable gain amplifier design for DVB-T receiver's AGC," in Proc. IEEE Int. Symp. Circuits Syst. , vol. 1, May 2005, pp. 356–359.
• J. J. F. Rijns, "CMOS low-distortion high-frequency variable-gain amplifier," IEEE J Solid-State Circuits, vol. 31, no. 7, July 1996, pp. 1029–1034.
• M. A. I. Mostafa, S. H. K. Embadi, and M. A. I. Elmala, "A 60 dB, 246MHz CMOS variable gain amplifier for subsampling GSM receivers," in Proc. Int. Symp. Low Power Electronics and Design, Aug. 2001, pp. 117–122.
• H. Dinc, P. E. Allen, and S. Chakraborty, "A low distortion, current feedback, programmable gain amplifier," in IEEE Int. Symp. Circuits Syst. , vol. 5, May 2005, pp. 4819–4822.
• Y. Fujimoto, H. Tani, M. Maruyama, H. Akada, H. Ogawa, and M. Miyamoto, "A low-power switched-capacitor variable gain amplifier," IEEE J. Solid-State Circuits, vol. 39, no. 7, July 2004, pp. 1213–1216.