volume | PIER Journals

Abstract

Reflective filters are characterized by a frequency response with good matching at the band of interest and usually reactive impedance out of those frequencies which may adversely affect the system performance. On the other hand, reflectionless filters are characterized by good matching characteristic not only at the interest frequencies, but in the whole frequency spectrum which improves the overall linearity, efficiency, and reduces instability scenarios at the system level. Although several reflectionless structures can be found in the literature, the concatenation of different reflectionless sections, combined with the use of acoustic resonators has not been exploited yet. The particular electrical behavior of acoustic wave resonators, where two different resonant frequencies are found, allow to obtain a frequency response with high selectivity due to the presence of transmission zeros below and above the passband. A bandpass filter has been designed following the described procedure with a fractional bandwidth FBW = 2%, a pair of transmission zeros below and above the bandpass, and an improved out-of-band rejection with respect conventional topologies.

1. Chappell, W. J., E. J. Naglich, C. Maxey, and A. C. Guyette, "Putting the radio in software-defined radio: Hardware developments for adaptable RF systems," Proceedings of the IEEE, Vol. 102, 307-320, 2014.
doi:10.1109/JPROC.2014.2298491 Google Scholar

2. Morgan, M. A. and T. A. Boyd, "Theoretical and experimental study of a new class of reflectionless filter," IEEE Transactions on Microwave Theory and Techniques, Vol. 59, 1214-1221, 2011.
doi:10.1109/TMTT.2011.2113189 Google Scholar

3. Morgan, M. A. and T. A. Boyd, "Reflectionless filter structures," IEEE Transactions on Microwave Theory and Techniques, Vol. 63, 1263-1271, 2015.
doi:10.1109/TMTT.2015.2403841 Google Scholar

4. Psychogiou, D. and R. Gomez-Garcia, "Reflectionless adaptive RF filters: Bandpass, bandstop and cascade designs," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, 4593-4605, 2017.
doi:10.1109/TMTT.2017.2734086 Google Scholar

5. Lee, T.-H., B. Lee, and J. Lee, "First-order reflectionless lumped-element lowpass filter (LPF) and bandpass filter (BPF) design," IEEE MTT-S International Microwave Symposium (IMS), 1-4, 2016. Google Scholar

6. Morimoto, Y., T. Yuasa, T. Owada, Y. Tahara, H. Miyashita, M. Miyazaki, M. Memarian, and T. Itoh, "A multiharmonic absorption circuit using quasi-multilayered striplines for RF power amplifiers," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, 109-118, 2017.
doi:10.1109/TMTT.2016.2614929 Google Scholar

7. Verdu, J., I. Evdokimova, P. de Paco, T. Bauer, and K. Wagner, "Synthesis methodology for the design of acoustic wave stand-alone ladder filters, duplexers and multiplexers," IEEE International Ultrasonics Symposium, 2017. Google Scholar

8. Triano, A., J. Verdu, P. de Paco, T. Bauer, and K. Wagner, "Relation between electromagnetic coupling effects and network synthesis for aw ladder type filters," IEEE International Ultrasonics Symposium, 2017. Google Scholar

9. Larson III, J., P. Bradley, S. Wartenberg, and R. Ruby, "Modified butterworth-Van dyke circuit for FBAR resonators and automated measurement system," IEEE International Ultrasonics Symposium, 2000. Google Scholar

10. Gimenez, A., J. Verdu, and P. De Paco, "General synthesis methodology for the design of acoustic wave ladder filters and duplexers," IEEE Access, Vol. 6, 1-11, 2011. Google Scholar

11. Gomez-Garcia, R., M. Sanchez-Renedo, B. Jarry, J. Lintignat, and B. Barelaud, "A class of microwave transversal signal-interference dual-passband planar filters," IEEE Microwave and Wireless Components Letters, Vol. 19, 158-160, 2009.
doi:10.1109/LMWC.2009.2013738 Google Scholar

12. Menendez, O., P. de Paco, E. Corrales, and J. Verdu, "Procedure for the design of Ladder BAW Filters taking electrodes into account," Progress In Electromagnetics Research Letters, Vol. 7, 127-137, 2009.
doi:10.2528/PIERL09031605 Google Scholar

13. Verdu, J., P. de Paco, and O. Menendez, "Electric equivalent circuit for the thickened edge load solution in a Bulk Acoustic Wave Resonator," Progress in Electromagnetics Research M, Vol. 11, 13-23, 2010.
doi:10.2528/PIERM09121104 Google Scholar

14. Wang, H., J. Chen, Y. Shi, T. Omori, C. Ahn, and K. Hashimoto, "Design of ladder-type SAW/BAW filters with constant group delay," IEEE International Ultrasonics Symposium, 345-348, 2011. Google Scholar

Dr. Jordi Verdú Tirado

Dr. Daniel Ulinic

Dr. Pedro de Paco