Investigation of Constant Transconductance Circuit for Low Power Low-Noise Amplifier

Authors: Wei Yi Lim, M. Annamalai Arasu, M. Kumarasamy Raja, Minkyu Je

Abstract:

In this paper, the design of wide-swing constant transconductance (g_m) bias circuit that generates bias voltage for low-noise amplifier (LNA) circuit design by using an off-chip resistor is demonstrated. The overall transconductance (G_m) generated by the constant g_m bias circuit is important to maintain the overall gain and noise figure of the LNA circuit. Therefore, investigation is performed to study the variation in G_m with process, temperature and supply voltage (PVT).  Temperature and supply voltage are swept from -10 °C to 85 °C and 1.425 V to 1.575 V respectively, while the process conditions are also varied to the extreme and the g_m variation is eventually concluded at between -3 % to 7 %. With the slight variation in the g_m value, through simulation, at worst condition of state SS, we are able to attain a conversion gain (S₂₁) variation of -3.10 % and a noise figure (NF) variation of 18.71 %. The whole constant g_m circuit draws approximately 100 µA from a 1.5V supply and is designed based on 0.13 µm CMOS process. 

Keywords: Transconductance, LNA, temperature, process.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1087702

References:

[1] D. Johns, K. W. Martin, “Analog integrated circuit design,” 2nd edition, pp. 259–260.
[2] T.–K. Nguyem, N.–J. Oh, V.–H. Le and S. –G. Lee, “A Low-Power CMOS Direct Conversion Receiver With 3-dB NF and 30-kHz Ficker- Noise Corber for 915-MHz Band IEEE 802.15.4 ZigBee Standard,” IEEE Trans. On Microwave Theory and Tec., vol. 54, no. 2, pp. 735- 741, Feb. 2006.
[3] T. Lee, “The design of CMOS radio-frequency integrated circuits,” Cambridge University Press, 2004, pp. 277-284.
[4] J. Chen, B. Shi, “Novel Constant Transconductance References and The Comparisons With The Traditional Approach,” SSMSD 2003, pp. 104- 107, 2003.
[5] N. Talebbeydokhti, P. K. Hanurnolu, P. Kurahashi and U.-K. Moon, “Constant Transconductance Bias Circuit with an On-chip Resistor,” ISCAS 2006, pp. 2857-2860, 2006.