Input Balun Embedded Low-Noise Amplifier With a Differential Structure

In this study, we designed a 5 GHz low-noise amplifier (LNA) with a differential structure using 0.18 μm RFCMOS technology. An input balun is embedded into the LNA to enhance the gain, minimize the noise figure (NF), and miniaturize the overall chip size. The NF is minimized because the loss induced by the passive balun is removed. The first stage of the designed LNA performs the activities of the input balun and serves as the gain stage. To verify the feasibility of the proposed input-balun-embedded amplifier, we designed a typical LNA and the proposed LNA. We obtained a 29.4 dB gain with a NF of 1.85 dB. The measured dc power consumption is approximately 27 mW. The chip size is 1.0×0.74 mm2. From the measured results of the typical and proposed LNAs, we successfully prove the feasibility of the proposed method to minimize the NF and enhance the gain.

[1]  Jeffrey S. Walling,et al.  A 1.6 mW 5.4 GHz transformer-feedback gm-boosted current-reuse LNA in 0.18/μm CMOS , 2010, Proceedings of 2010 IEEE International Symposium on Circuits and Systems.

[2]  Chia-Hung Chang,et al.  A Direct Conversion Merged LNA-I/Q-Mixer With Noise Reduction Using Dual Cross Coupling for WiMAX/WiBro Applications , 2012, IEEE Microwave and Wireless Components Letters.

[3]  D. Heo,et al.  A compact 5.6 GHz low noise amplifier with new on-chip gain controllable active balun , 2004, 2004 IEEE Workshop on Microelectronics and Electron Devices.

[4]  E. Sanchez-Sinencio,et al.  A 2.8-mW Sub-2-dB Noise-Figure Inductorless Wideband CMOS LNA Employing Multiple Feedback , 2011, IEEE Transactions on Microwave Theory and Techniques.

[5]  Keiji Yoshida,et al.  Ultra-wideband low noise amplifier with shunt resistive feedback in 0.18µm CMOS process , 2010, 2010 Topical Meeting on Silicon Monolithic Integrated Circuits in RF Systems (SiRF).

[6]  Ying-Zong Juang,et al.  2.1 dB noise figure 5.2 GHz CMOS low noise amplifier using wafer-level integrated passive device technology with a DC power consumption of 10 mW , 2012 .

[7]  M. Moezzi,et al.  Wideband LNA Using Active Inductor With Multiple Feed-Forward Noise Reduction Paths , 2012, IEEE Transactions on Microwave Theory and Techniques.

[8]  Ming-Dou Ker,et al.  A 5-GHz Differential Low-Noise Amplifier With High Pin-to-Pin ESD Robustness in a 130-nm CMOS Process , 2009, IEEE Transactions on Microwave Theory and Techniques.

[9]  M. K. Raja,et al.  A fully integrated variable gain 5.75-GHz LNA with on chip active balun for WLAN , 2003, IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, 2003.