Characteristics Of SAW Filters Research Articles

Modeling and design of surface acoustic wave filters and their military applications

The operation principles of surface acoustic wave filters (SAW) and materials and technology of their fabrication are presented. A special attention is paid to wide and diverse applications of SAW filters in signal processing, communications and chemical sensors, stressing their military applications. An original method, developed by the authors, for the modeling and prediction of SAW filter characteristics is presented. The abilities of the method are illustrated by the examples of chemical SAW sensors for the detection of warfare chemical agents. The designed and fabricated SAW filter PAT-FPO is the base for the special purpose chemical sensors.

Routeing and filtering in the ETS‐V transponder for mobile communication experiments

AbstractThe Japanese spacecraft ETS‐V implemented an experimental mobile satellite communication system via a transponder called AMEX (aeronautical maritime experimental transponder). L‐band was used for the mobile link and C‐band for the feeder link. For the L‐band two‐beam system routeing and filtering were performed through 12 SAW filters and four switches in the IF part. The effective frequency allocation plan was obtained considering the features of the links used and the characteristics of SAW filters. The filtering to prevent EMC problems was also studied for AMEX, which handles high‐ and low‐level signals simultaneously. AMEX shows good performance in orbit and is being used for a variety of mobile communication experiments by many organizations including the Communications Research Laboratory.

A Theoretical Study of the Characteristics of Leaky-Surface-Acoustic-Wave Filters with Propagation Loss by an Equivalent Circuit Model

Leaky surface waves are very interesting because their temperature stability is extremely high even though a small value of propagation loss must be considered. In this paper, the characteristics of SAW filters on a substrate with propagation losses are theoretically investigated and compared with the ideal properties without losses. The results show that propagation losses are not always disadvantageous for TTE suppression.

Statistical Analysis of the Effects of Finger Dispersion on the Electrical Characteristics of SAW Filters

Dispersion of the electrical characteristics of SAW filters mainly depends on the variations of the finger width and the finger defects of interdigital transducers. Statistical analyses are performed to estimate the effect of variations of the finger parameters on the electrical characteristics, using a Smith's equivalent circuit and Monte Carlo computer technique. This theoretical approach was practically applied to a SAW filter for the NTSC/USA TV system and was compared with experimental results to confirm its validity.