Surface acoustic wave impedance element ISM duplexer: modeling and optical analysis

Surface acoustic wave (SAW) impedance element antenna duplexers provide compact, high performance, front-end components apt for industrial fabrication. We describe investigations on the design and modeling of a compact ISM antenna duplexer fabricated on a 36/spl deg/ YX-cut LiTaO/sub 3/ substrate based on SAW impedance elements. In particular, we have performed 3-D modeling of the inductive and capacitive electromagnetic couplings caused by the package parasitics for the duplexer. The use of a 1:3 IDT structure for the reduction of the passband width is discussed. The frequency response of the duplexer is predicted with the help of circuit simulation; the modeling is refined by optimization of the model parameters to improve the fit between the measured and simulated responses. We also report scanning optical imaging of the acoustic field within the resonator structures with the help of laser interferometry; this provides insight into the loss mechanisms beyond that attainable in mere electric measurements.

[1]  John Douglas Cockcroft,et al.  Skin effect in rectangular conductors at high frequencies , 1929 .

[2]  E.G.S. Paige,et al.  Surface-Wave Devices for Signal Processing , 1986 .

[3]  Timo Veijola,et al.  APLAC - object-oriented circuit simulator and design tool , 1996 .

[4]  John R. Carson,et al.  LIV. Wave propagation over parallel wires: The proximity effect , 1921 .

[5]  W. Ruile,et al.  Design and performance of a SAW ladder-type filter at 3.15 GHz using SAW mass production technology , 1999, 1999 IEEE MTT-S International Microwave Symposium Digest (Cat. No.99CH36282).

[6]  C. S. Hartmann,et al.  Characteristics of leaky SAWs on 36-LiTaO 3 in periodic structures of heavy electrodes , 1993 .

[7]  M. M. Salomaa,et al.  Asymmetric acoustic radiation in leaky SAW resonators on lithium tantalate , 1999, 1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027).

[8]  S. Kondratiev,et al.  Reduced passband ladder type SAW impedance element filters on strong piezoelectric substrates , 1996, 1996 IEEE Ultrasonics Symposium. Proceedings.

[9]  M. P. D. Cunha.  High velocity pseudo surface waves (HVPSAW): further insight , 1996 .

[10]  K. Hashimoto.  Surface Acoustic Wave Devices in Telecommunications , 2000 .

[11]  Peter Russer,et al.  Investigation of parasitic effects in multi-transducer SAW RF filters , 1994, 1994 Proceedings of IEEE Ultrasonics Symposium.

[12]  C. Hartmann,et al.  Laser probe investigation of leaky surface waves on 41° and 64°-LiNbO3+ , 1994, 1994 Proceedings of IEEE Ultrasonics Symposium.

[13]  H. A. Wheeler.  Formulas for the Skin Effect , 1942, Proceedings of the IRE.

[14]  C. S. Hartmann,et al.  `Patch' improvements to COM model for leaky waves , 1994, 1994 Proceedings of IEEE Ultrasonics Symposium.

[15]  K. Yamanouchi,et al.  10 GHz range extremely low-loss ladder type surface acoustic wave filter , 1998, 1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).

[16]  M. M. Salomaa,et al.  Parasitic BAW excitation in LSAW transducers , 1998, 1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).

[17]  H. Yatsuda.  Modeling of parasitic effects for flip-chip SAW filters , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[18]  M.M. Salomaa,et al.  Investigations on the power tolerance of ladder impedance-element SAW filters , 1996, 1996 IEEE Ultrasonics Symposium. Proceedings.

[19]  M. M. Salomaa,et al.  Mechanism for acoustic leakage in surface-acoustic wave resonators on rotated Y-cut lithium tantalate substrate , 1999 .

[20]  Osamu Ikata,et al.  Development of small antenna duplexer using SAW filters for handheld phones , 1993 .

[21]  K. Nabors,et al.  Multipole-accelerated capacitance extraction algorithms for 3-D structures with multiple dielectrics , 1992 .

[22]  K. Hashimoto,et al.  Optimum leaky-SAW cut of LiTaO/sub 3/ for minimised insertion loss devices , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[23]  H. H. Ou,et al.  Improvement of ladder-type SAW filter characteristics by reduction of inter-stage mismatching loss , 1998, 1998 IEEE Ultrasonics Symposium. Proceedings (Cat. No. 98CH36102).

[24]  R. Saleh.  FastCap : A Multipole Accelerated 3-D Capacitance Extraction Program , 1991 .

[25]  Mitsutaka Hikita,et al.  Precise design technique for a SAW-resonator-coupled filter on 36/spl deg/ YX-LiTaO/sub 3/ for use in a GSM SAW duplexer module for satisfying all GSM system specifications , 1996, 1996 IEEE Ultrasonics Symposium. Proceedings.

[26]  Chi-Taou Tsai,et al.  Package inductance characterization at high frequencies , 1994 .

[27]  T.S. Hickernell,et al.  The surface acoustic wave propagation characteristics of 64/spl deg/ Y-X LiNbO/sub 3/ and 36/spl deg/ Y-X LiTaO/sub 3/ substrates with thin-film SiO/sub 2/ , 1995, 1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium.

[28]  H. Haus,et al.  Analysis of Metal-Strip SAW Gratings and Transducers , 1985, IEEE Transactions on Sonics and Ultrasonics.

[29]  H. Haus,et al.  Coupled-mode theory , 1991, Proc. IEEE.

[30]  A. Pohl,et al.  Comparison between BAW and SAW sensor principles , 1997, Proceedings of International Frequency Control Symposium.

[31]  O. Ikata,et al.  Analysis and optimal SAW ladder filter design including bonding wire and package impedance , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[32]  K. Yamanouchi,et al.  5 GHz Range Low-Loss Wide Band Surface Acoustic Wave Filters Using Electrode Thickness Difference Type Unidirectional Transducers , 1996 .

[33]  Martti M. Salomaa,et al.  Anomalous asymmetric acoustic radiation in low-loss SAW filters , 1999 .

[34]  M. M. Salomaa,et al.  Recent advances in laser-interferometric investigations of SAW devices , 1997, 1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118).

[35]  Colin Campbell,et al.  Surface Acoustic Wave Devices for Mobile and Wireless Communications , 1998 .

[36]  J. Knuuttila,et al.  Scanning Michelson interferometer for imaging surface acoustic wave fields. , 2000, Optics letters.

[37]  Mattan Kamon,et al.  FastHenry: A Multipole-Accelerated 3-D Inductance Extraction Program , 1993, 30th ACM/IEEE Design Automation Conference.

[38]  T. Makkonen,et al.  Acoustic loss mechanisms in leaky SAW resonators on lithium tantalate , 2001 .