Saw Filter Design To Achieve Its Frequency Stability

Surface Acoustic Wave Filter (SAWF) is a sort of analogue device for signal processing. Owing to the development of signal processing theory, those devices with high-speed and high-performance are needed. Also with the improving of plane manufacture technology for semiconductors, the performance of SAW devices, especially SAW Filter is gradually improved and their work frequency is from 10MHz to 3GHz. Therefore SAW devices are gradually applied in Radio Frequency (RF) signal processing. Among them, SAW Filters have been attained comprehensive application in mobile communication, wireless paging and CATV network, etc.SAW Filter may complete the filtering functions of any magnitude frequency and phase frequency characteristics, which is not impossible for other filter. Because of these, SAW Filter is more and more comprehensively applied in electronic information field, especially in RF signal processing field. At the same time by reason of complicated functions, increased quantities and severely application conditions of devices and system made up of SAW Filter, It is very common that SAW Filter's characteristics are degenerated and abated. And some especial demand in some signal processing brings forward higher requirement for SAW Filter's frequency stability and reliability. So it is worthy of researching and analyzing frequency stability and reliability of SAW Filter.Overseas, devices disabled mechanism is already researched from qualitative analysis to quantitative modeling and computer-aided simulation. Application research and development for devices has been put forward in reliability design and prediction technology, reliably optimal analysis and simulation of circuit design, computer-aided reliability prediction based on all kinds of disabled mechanism model.But the great differences between home and aboard about the research ofIVreliability physics and application is made, later than overseas approximately for 10-15 years, Saying nothing of SAW devices. On account of the widespread application in military communication, electronic scout, civil electronic information field, etc. For SAW devices, the research about reliability physics and application of SAW Filter is beneficial to promote SAW devices design and manufacture in reliability.Before the research for SAW Filter frequency stability, I spare some time to discuss SAW Filter design and implementation. Though SAW Filter is analogue device, we may use FIR digital design method about Chebysheve optimal consistent approximation and Remez exchange algorithm to implement SAW Filter design.From the above, the main achievements of this dissertation can be summaried as follows:(1). In the research of the digital design realization for SAW Filter, the base for the further discussion and research of SAWF's frequency stability is founded.(2). The common physics parameters that affect SAW Filter frequency stability are put forward, and their affection on SAWF frequency stability is analyzed by sensibility analysis method and computer-aided simulation. Then comparison between theory analysis and simulation is performed.(3). Physics mechanism of SAWF Interdigital Transducer degeneration and its corresponding impact on SAWF frequency characteristics are researched, then computer-aided simulation and experimentally analysis are carried out.(4). On basis of SAW Filter design, manufacture and production, we carry out pilot study on the technology solution of improving SAWF reliability.