Phan Tuan Anh Dec. 2010

1. Reconfigurable Multiband Multimode LNA for LTE/GSM, WiMAX, and IEEE 802.11.a/b/g/n 17th IEEE ICECS 2010, Athens, Greece. Phan Tuan Anh Dec. 2010

2. Content • Introduction • Design Approach • Proposed Circuitry • Simulation Results • Conclusions

3. Introduction • Radio standards: - Rapid evolution next generation radio with WiMAX (3.5G), LTE (4G) along with existing GSM (2G), WLAN IEEE 802.11 family .. • Reconfigurable Radio… - SoC, SiP, MEMs .. - High demanding for new single device to combine multiple standards, working with different networks for various applications. • CMOS is technology of Choice

4. Next generation: Reconfigurable Radio Fig. 1Source: Bob Iannucci, Nokia 2008 • - Required to support multi standards same chip • Reconfigurable, multiband multimode for various standards •  Tunable input matching ? • - High level of integration, reduce cost • - Maintain the same performance as single radio

5. Design Challenges • LNA is the first block in Rx RF front-end • - Determine the radio condition: Freq channel, provide Gain, suppress Noise to improve channel sensitivity and selectivity • - Input matching for various bands • - Reconfigurable over the band for various applications: • LTE/GSM at 1.9GHz, • WLAN/Bluetooth 802.11.b/g/n at 2.4GHz, • WiMAX at 3.5GHz, • 802.11.a/n WLAN at 5.2GHz. •  Ultimate Goal: Low cost, low power, high performance using CMOS technology. •  Ready for any existing wireless standards

6. Design Approach • Reconfigurable LNA • Selection solely or jointly a bank of cascode LNAs Fig. 2. Reconfigurable Principle of the LNA

7. Proposed Multiband LNA + Switching CG Devices for various band configuration of cascode LNA Fig. 3. Schematic of the proposed multiband LNA

8. Proposed Multiband LNA: Features + Input matching - Inductive degenerative input matching - As M0 varies, LG (~10nH) is varied for better matching. - Bit D1-4 controls the selection of corresponding band. + Load and Buffer - Inductive load LL(4-8nH) and source follower buffer are shared - Reduce the chip size - Different bands are optimized with its own output Cap bank C1-4 + Gain control - Selection of Gm’s device size M0 - Optimize for power consumption

9. Simulation Results: S11 and S22 • Input matching and Output matching • Inductive degeneration Ls is used • for good NF • LG is needed for better matching as M0 size varying for various bands • Good S11 and S22 achieved Fig. 4. S11 and S22 for different standards of proposed LNA

10. Simulation Results: S21 and NF • Good gain over different bands • - NF is quite good at low frequency and reasonable at high band Fig. 5. Typical Gain mode and NF of different standards

11. Simulation Results: Gain variable • Gain Tuning • Varying Gm by selecting bank of M0 devices for sizing and bias current. • From low to maximum gain mode, 10dB range. Fig. 6. Variable gain function over different bands

12. Simulation Results: Linearity • Linearity at various bands • High gain mode shows moderate IIP3 • Power consumption is • 3/3.4/3.4/5.3mW at 1.9/2.4/3.5/5.2GHz bands, respectively. • 1.5V supply @ 0.18um CMOS Fig. 7. Linearity at different bands in Low and High gain modes

13. Performance Summary • Performance summary and comparison

14. Conclusions • A reconfigurable multi-standard LNA operating from 1.9G to 5.2G bands for most popular standard like LTE/GSM, WiMAX, WLAN 802.11 family. • Channel tuning by selection of various combination of cascode bank and input matching • Good performances achieved in 0.18um CMOS • Promising for single chip, next generation radio. Thank You !