Spectrum Slicer
MEMS for RF Oscillators & Filters
David Giles & Curtis Mayberry
December 7th, 2012
Some Motivation
• Oscillators
– On-chip integration
– High frequencies
• Bandpass Filters
– Many different filters, small area
– Narrow passbands (High Q)
• Good for channel select
• Applications
– RF Receivers (e.g. cellphones)
– Cognitive Radio (spectrum hopping)
2
Piezoelectric Contour-Mode Resonator
• Frequency range: 19 to
656 MHz
• Q’s of around 4000
• Motional resistance: 50 to
700 Ω
• Lithographically defined
center frequencies
• Width vs. lengthextensional modes
3
[Piazza, et al. 2006]
Laterally-Excited SiBAR
• Motional resistance of
35 Ω
• 100 MHz center
frequency
• Aluminum nitride now
sputtered on sidewall
– Use of d33 coefficient
4
[Tabrizian, et al. 2011]
Bandpass Filter
• Capacitive coupling by intrinsic capacitances
[Zuo, et al. 2010]
5
Broadband Tunable TIA for Oscillators
• Low-power broadband current preamp
• 76 dBΩ constant gain up to 1.7 GHz
• Demonstrated operation with 1 GHz, 750 Ω, and a
724 MHz, 150 Ω resonators
6
High Level System Diagram
Channel/Band
Selection Filter Bank
Image Reject
Filter Bank
Downconversion
IF Selection Filter
Bank
IF Amplifier
Mixer
LNA
LO
Ideally a frequency synthesizer
with a PLL would be driven
by a reference LO
7
AlN actuated Lateral
Mode BAW Resonator
MEMS Challenges
• Balancing greater thickness versus a distorted
modeshape to maximize electromechanical
coupling
• Achieving low motional impedance
• Designing an effective model
• Learning COMSOL
8
Electroded Layers
• The two pictures below show the two layers of
Molybdenum electrodes and overall structure of the
device
9
1 GHz Resonator
• Q of 10,000 (1/3 of the
theoretical maximum for
Silicon) was assumed
• One-port admittance
simulated for halfresonator
• Simulated only half of the
device for faster results
(while maintaining
•
accuracy)
10
• Dimensions
• Height = 2um
• Length = 20um
Width = 3.9um (counting AlN)
RLC Extraction – 1 GHz Resonator
11
•
•
•
•
fo = 986.5 MHz
R = 1 V / Total Current = 1 / 3.7mA = 267.3Ω
L = Q*R/ (2*π*fo) = 431.2uH
C = 1 / (L*(2*π*fo)2 = 60.36aF
•
Cft = eo*er*A/d = 10*8.854e-12*(2e-6*20e-6*2 + 20e-6*3.9e-6) / 1e-6 = 14fF
100 MHz Resonator Design
• 98.14601 MHz
• length extensional mode
• Dimensions:
–
–
–
–
W = 40um
L = 400um
H = 20um
TAlN = 2um
Cftt =2.2pF
Cm =254.7aF
R =1.1kΩ
L =11mH
12
Bandpass Filter Theory
13
Simulated Bandpass Filter
• 2nd order BPF
• LCs as given for the 1 GHz resonator
• Ccap = 30fF, Rterm = 250 Ω
Vin
Vout
•
•
•
•
14
3dB bandwidth = 1 MHz
20dB SF = 3
Passband Ripple = 0.3 dB
IL = 2dB
Biasing: Current source
• Supply insensitive due
to cascode
• Provides 3v dc bias to
TIA.
• Provides 15uA current
bias that is used to
generate voltage bias
15
VDD
VDD
VDD
Vbias
VB
M3
VA
VB
VA
M5
Input Stage
• Current amplifier + current to voltage conversion
VDD
3v
VDD
M2
M4
Vout
Iin
M1
M3
𝟏
𝟏
𝒎𝟑
𝒎𝟑
𝑹𝒊𝒏 = 𝒈 ‖𝒓𝒐𝟑 ‖𝒓𝒐𝟒 ⩰ 𝒈
16
𝒊𝒅𝟏 𝑾𝟏
=
𝒊𝒅𝟑 𝑾𝟑
𝒈𝒎𝟏
𝑨𝑹 = −
𝒈𝒎𝟐 𝒈𝒎𝟑
Trans-impedance Amplifier
• Current mirror
amplifier: 1:10 current
amplification
• Common source
second stage with
feedback
• Shunt-shunt feedback
to increase bandwidth
• Total phase shift =
0°as required
17
VDD
3v
M4
VDD
VDD
M2
3v
M6
Vout
Iin
M3
M1
M5
TIA Open Loop Response
• 76.47 dBΩ peak transimpedance gain
• 115 MHz 3dB bandwidth
18
100 MHz Loop Gain
19
20 MHz Loop Gain
20
20 MHz Oscillation (Transient Simulation)
21
Packaging
• Multi-chip-module
• Easily integrated with other
RF dies (LNA, PA, etc.)
• MEMs and interface dies
will be bonded to MCM
directly
• As more components are
designed and integrated on
one die, other solutions may
become more notable
• Can be integrated with
existing technology
22
Ladder Filter Design
Filter Specifications
Value
Ayazi
[11]
Bannon
[25]
Raditek
[26]
Center Frequency
996.5
MHz
600 kHz
7.81 MHz
1220
MHz
2
2
-
-
1,061
1.2 kHz
18 kHz
8 MHz
20dB Shape Factor
3
3.3
2.31
-
40dB Shape Factor
-
10.4
-
-
Insertion Loss (dB)
2
0.2
1.8
3.5
Passband Ripple (dB)
0.3
-
1.5
0.4
Motional Impedance
(Ohms)
50
-
-
-
250
-
-
200
10000
30000
6000
-
Filter Order
3dB Bandwidth (kHz)
Terminating Resistance
Resonator Q
23
“Reciprocal Mixing”
Data Sheet: Oscillator
Oscillator Specifications
This
Work
[21]
[20]
Frequency (MHz)
98.14
724
500
Process
0.5um
0.18um
0.18um
48.5
7.2
9.4
Phase Noise (1 kHz offset) (dBc/Hz)
-
-87
-92
Phase Noise Floor (dBc/Hz)
-
-152
-147
Open Loop Gain (dBΩ)
76.47
76
-
Settling Time (ms)
0.025
-
-
20
-
-
1100
750
-
10000
2000
-
Power Dissipation (mW)
Temperature Sensitivity (ppm/C)
Rm (Ω)
Unloaded Q
24
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. Miri Lavassani, 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 Transimpedance Amplifier 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 Schottky Institut Center for Nanotechnology and Nanomaterials.
http://www.wsi.tum.de/Portals/0/Media/Lectures/20082/98f31639-f453-466d-bbc2-a76a95d8dead/BiosensorsBioelectronics_lecture10.pdf
[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.
25
References
[14] G. Piazza, P.J. Stephanou, A.P. Pisano, “Piezoelectric Aluminum Nitride Vibrating Contour-Mode MEMS Resonators”, Journal of
MicroElectroMechanical Systems, 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 on Micro
Electro Mechanical Systems (MEMS), pp.173-176, 23-27 Jan. 2011.
[16] Sheng-Shian Li; Yu-Wei Lin; Zeying Ren; C.T.-C. Nguyen; , "Disk-Array Design for Suppression of Unwanted Modes in Micromechanical CompositeArray Filters,". Istanbul. 19th IEEE International Conference on Micro Electro Mechanical Systems, 2006, pp.866-869, 2006.
[17] Dongha Shim; Yunkwon Park; Kuangwoo Nam; Seokchul Yun; Duckhwan Kim; Byeoungju Ha; Insang Song, "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.
[20] Lavasani, H.M.; Abdolvand, R.; Ayazi, F.; , "A 500MHz Low Phase-Noise A1N-on-Silicon Reference Oscillator," Custom Integrated Circuits
Conference, 2007. CICC '07. IEEE , vol., no., pp.599-602, 16-19 Sept. 2007
[21] Lavasani, H.M.; Wanling Pan; Harrington, B.; Abdolvand, R.; Ayazi, F.; , "A 76 dB 1.7 GHz 0.18 m CMOS Tunable TIA Using Broadband Current
Pre-Amplifier for High Frequency Lateral MEMS Oscillators," Solid-State Circuits, IEEE Journal of , vol.46, no.1, pp.224-235, Jan. 2011
[22] K. Sundaresan, G. K. Ho, S. Pourkamali, and F. Ayazi, “A Low Phase Noise 100MHz Silicon BAW Reference Oscillator”, Proc. IEEE CICC, pp. 841844, Sept 2006.
[23] Y. Lin, S. Lee, S. Li, Y. Xie, Z. Ren, C.T.-C. Nquyen, “Series-Resonant VHF Michromechanical Resonator Reference Oscillators”, IEEE J. Solid-State
Circuits, vol. 39, no. 12, pp. 2477-2491, Dec 2004.
[24] Chengjie Zuo, Nipun Sinha, and Gianluca Piazza. "Very High Frequency Channel-Select MEMS Filters Based on Self-Coupled Piezoelectric AlN
Contour-Mode Resonators" Sensors and Actuators A: Physical 160.1-2 (2010): 132-140.
[25] Bannon, F.D.; Clark, J.R.; Nguyen, C.T.-C.; , "High-Q HF microelectromechanical filters," Solid-State Circuits, IEEE Journal of , vol.35, no.4, pp.512-526,
April 2000
[26] Raditek, Inc., Datasheet for RSAW-BPF-1217-1224M-0303-3V-S Surface Acoustic Wave Band Pass Filter 2009.
26