Spectrum Slicer:

1. Spectrum Slicer: Curtis Mayberry and David Giles Narrowband Micromechanical Resonator Filters for RF Applications *(Picture from [Piazza et al. 2007]) Georgia Tech, October 8th, 2012 ECE 6422—Interface IC Design for MEMS and Sensors

2. Problem Statement • Motivation: • Rapid prototyping of RF Transceivers • Efficient spectrum use • Low cost, small area, fully integrated RF Front-end • Problem: RF Front-ends are currently specially designed for a given application • Considerable design effort for each new design • Conventional filters are not integrable • Objective: Design a reconfigurable RF front-end that can be used for rapid prototyping and development of RF Transceivers. • Specifically we are going to focus on the filtering and downconversion functions Super-heterodyne Transceiver Architecture

3. Conventional Resonators • Not integrable – large offchipsize • Not tunable and only a single center frequency is allowed per die • Piezoelectric Crystals (Quartz widely used) • Other Materials including ceramic piezoelectric materials for low cost applications • Great Temp Stability – Low TCF(10 ppm/oC) • Low Cost • Rmot = 40-100 Ω • Low frequency f < 200 MHz • Surface Accoustic Wave (SAW) • Rayleigh and longitudinal Propagation on the surface of a piezoelectric substrate • Good Temperature Stability • Good Q: up to 7000 • Current Cell standards designed assuming available SAW filtering Technology

4. Thin Film Bulk Acoustic Resonators (FBAR) (Thickness-extensional) • 1.94 GHz Tx filter based on FBARs • Can have fairly high Qs (1000s) and high electromechanical coupling (d33 coefficient) • But—only 1 frequency per wafer • And thickness dimension cannot be as accurately fabricated as lateral dimensions currently [Ueda et al. 2005] [Shim et al. 2005] • Monolithic 7 FBAR ladder filter for a different Tx filter (1.9 GHz)

5. Capacitive Transduction • Require a charge pump • [Pourkamali et al 2004] • Disk Resonators • 150 MHz • Q-F product: 6.8*1012 (Vacuum) • Q = 45700 (Vacuum), 25900 in air • High motional Resistance: 43.3 kΩ (Vacuum • While reducing the capacitive gap size reduces the motional resistance, the sensor output becomes nonlinear below 35nm • Low Mechanical coupling • [Pourkamali et al 2007] • Sibar • Advantages • High Q: 17300 (765 MHz, 5th resonance mode) • Potential CMOS integration • Requires a charge pump • Reduced motional Resistance with larger transduction area • High motional Resistance: 23.7 kΩ

6. Piezoelectric Transduction [Tabrizian& Ayazi 2011] [Piazza et al. 2006] [Nguyen et al. 2011] • AlN-on-Silicon • 99.8 MHz fo • Q = 3500 • Rm = 35 O • Al-AlN-Pt Stack • 224 MHz fo • Q = 2400 • Rm = 56 O • Capacitive/Piezo Combination • Goal: High Q + Low Rm • fo= 50 MHz • Q = 12,750

7. Bandpass Filters Using Resonators [Zuo et al. 2010] [Pourkamali et al. 2003] [Nguyen et al. 2006] [Verdu et al. 2006]

8. Our Solution Channel Select filter bank enables reconfigurable, fully integrated direct downconversion. Noise First Stages most important

9. Filter Implementation • Resonators • Piezoelectric-transduction for low motional resistance • Lateral-mode for lithographically-defined resonance frequency • AlN-on-Si/Diamond for Q enhancement (mass loading versus decreased damping) • Sidewall-transduction—greater kt2 • Electrical coupling—explore several possibilities • Intrinsic capacitively-coupled—potential for small device footprint • Active cascading (amplifier stages between resonators) —Q amplification may be necessary, but increased power dissipation and chip area may be too much • Ladder topology—for higher out-of-band rejection

10. Circuit Suggestions Local Oscillator Phase Noise ideal noisy Noisy Oscillator waveform Broadband: 960 MHz BW (MAX,880 @maxP) Low Power: 9.4 mW(1.5 v design) Low Phase Noise: -92 dBc/Hz and ideal noisy Challenge: Our frequency (~900 MHz) is approaching the bandwidth of this design (~900 MHz) at max gain “Reciprocal Mixing” Noisy Oscillator Spectrum

11. Circuit Suggestions LNA Local Oscillator Large width to handle flicker noise For lower frequency bands Wideband LNA [Razavi 2010] 50 MHZ to 10GHz NF = 2.9 to 5.7 dB Mixer Gilbert Cell • Higher Bandwidth TIA Sustaining Amp • Add current amplifier pre-amp • Noise: Major contributing factor is • M1 and M4 Current Noise:

12. Project 2 Objectives • We will design and simulate • At least two narrowband piezoelectric resonator-based filters, operating with center frequencies around 900 MHz • Good out-of-band rejection • Low insertion loss • Low motional impedance • A resonator-based local oscillator at 900 MHz • Low phase noise • Good TCF • Good drive capability • Low Power

13. Sample Datasheet • Small die area desired for both components <1mm2 • Atmospheric packaging is more economical but vacuum packaging enhances Q. • Monolithic Integration for economic viability and use in RF FPAA • Simultaneously meeting Rm, IL, and SF specs will be challenging!!

14. References [1] B. Razavi, RF Microelectronics, Second Edition, Prentice Hall 2011. [2] R. Aigner, “Innovative RF Filter Technologies: Gaurdrails for the Wireless Data Highway,” Microwave Product Digest. June 2007. [3] S. Pourkamali, G. K. Ho, and F. Ayazi, “Low-impedance VHF and UHF capacitive silicon bulk acoustic wave resonators - Part I: Concept and Fabrication” IEEE Transactions on Electron Devices, May 2007, Vol. 54, No. 8, Aug. 2007, pp. 2017-2023. [4] S. Pourkamali, G. K. Ho, and F. Ayazi, “Low-impedance VHF and UHF capacitive silicon bulk acoustic wave resonators - Part II: Measurement and Characterization,” IEEE Transactions on Electron Devices, Vol. 54, No. 8, Aug. 2007, pp. 2024-2030. [5] Z. Hao, S. Pourkamali, and F. Ayazi, “VHF Single Crystal Silicon Elliptic Bulk-Mode Capacitive Disk Resonators; Part I: Design and Modeling,” IEEE Journal of Microelectromechanical Systems, Vol. 13, No. 6, Dec. 2004, pp. 1043-1053. [6] S. Pourkamali, Z. Hao, and F. Ayazi, “VHF Single Crystal Silicon Elliptic Bulk-Mode Capacitive Disk Resonators; Part II: Implementation and Characterization,” IEEE Journal of Microelectromechanical Systems, Vol. 13, No. 6, Dec. 2004, pp. 1054-1062. [7] H. MiriLavassani, R. Abdolvand, and F. Ayazi, “A 500MHz Low Phase Noise AlN-on-Silicon Reference Oscillator,” Proc. IEEE Custom Integrated Circuits Conference (CICC 2007), Sept. 2007, pp. 599-602. [8] H.M. Lavasani, W. Pan, B. Harrington, R. Abdolvand, and F. Ayazi, “A 76dBOhm, 1.7 GHz, 0.18um CMOS Tunable TransimpedanceAmplifier Using Broadband Current Pre-Amplifier for High Frequency Lateral Micromechanical Oscillators,” IEEE International Solid State Circuits Conference (ISSCC 2010), San Francisco, CA, Jan. 2010, pp. 318-320 [9] B. Razavi, “Cognitive Radio Design Challenges and Techniques,” IEEE Journal of Solid-State Circuits, vol. 45, pp.1542-1553, Aug. 2010. [10] J. Garrido, “Biosensors and Bioelectronics Lecture 10,”Walter SchottkyInstitut Center for Nanotechnology and Nanomaterials. http://www.wsi.tum.de/Portals/0/Media/Lectures/20082/98f31639-f453-466d-bbc2-a76a95d8dead/BiosensorsBioelectronics_lecture10.pdf

15. References (continued) [11] S. Pourkamali, R. Abdolvand, and F. Ayazi, “A 600kHz Electrically Coupled MEMS Bandpass Filter,” Proc. IEEE International Micro Electro Mechanical Systems Conference (MEMS‘03), Kyoto, Japan, Jan. 2003, pp. 702-705. [12] R. Tabrizian and F. Ayazi, "Laterally Excited Silicon Bulk Acoustic Resonator with Sidewall AlN," International Conference on Solid-State Sensors, Acutators and Microsystems (Transducers), Beijing, China, June 2011. [13] C. Zuo, N. Sinha, G. Piazza, “Very High Frequency Channel-Select MEMS Filters based on Self-Coupled Piezoelectric AlN Contour-Mode Resonators”, Sensors and Actuators, A Physical, vol. 160, no. 1-2, pp. 132-140, May 2010. [14] G. Piazza, P.J. Stephanou, A.P. Pisano, “Piezoelectric Aluminum Nitride Vibrating Contour-Mode MEMS Resonators”, Journal of MicroElectroMechanicalSystems, vol. 15, no.6, pp. 1406-1418, December 2006. [15] Li-Wen Hung; Nguyen, C.T.-C.; , "Capacitive-piezoelectric AlN resonators with Q>12,000,"2011 IEEE 24th International Conference onMicro Electro Mechanical Systems (MEMS), pp.173-176, 23-27 Jan. 2011. [16] Sheng-ShianLi; Yu-Wei Lin; ZeyingRen; C.T.-C. Nguyen; , "Disk-Array Design for Suppression of Unwanted Modes in Micromechanical Composite-Array Filters,". Istanbul. 19th IEEE International Conference onMicro Electro Mechanical Systems, 2006, pp.866-869, 2006. [17] DonghaShim; Yunkwon Park; Kuangwoo Nam; Seokchul Yun; Duckhwan Kim; Byeoungju Ha; InsangSong, "Ultra-miniature monolithic FBAR filters for wireless applications," Microwave Symposium Digest, 2005 IEEE MTT-S International, pp. 4 pp., 12-17 June 2005. [18] Ueda, M.; Nishihara, T.; Tsutsumi, J.; Taniguchi, S.; Yokoyama, T.; Inoue, S.; Miyashita, T.; Satoh, Y.; , "High-Q resonators using FBAR/SAW technology and their applications," Microwave Symposium Digest, 2005 IEEE MTT-S International, pp. 4 pp., 12-17 June 2005. [19] Gianluca Piazza, Philip J. Stephanou, Albert P. Pisano, One and two port piezoelectric higher order contour-mode MEMS resonators for mechanical signal processing, Solid-State Electronics, Volume 51, Issues 11–12, November–December 2007, Pages 1596-1608.