Notable recent success stories-mobile phones, digital media, computing and networking (Internet) or medical systems-illustrate the crucial innovative role that microelectronics has played for the past three decades. In a development prospect of new most integrated resonator filter (RF) systems, single and multifunction IC technologies which are compatible with silicon technologies open an interesting way for the research.
In this context, radiofrequency filters occupy a prominent place in modern communication systems such as cell phones, where they are traditionally designed with surface acoustic wave (SAW) or ceramic technology. SAW filters have a good selectivity and a small chip area, but they are not compatible with silicon integration. For transceiver applications, they are also limited by the power levels of the emission stage. Ceramic filters are largely used as duplexer to manage strong powers, but the dielectric resonators are bulky and not compatible with silicon substrate. A contrario, the bulk acoustic wave (BAW) resonators can be manufactured by using compatible CMOS VLSI materials. The existing technical solutions are using FBAR (film BAW), solidly mounted resonator, or coupled resonator filter technologies.
This Special Issue proposes recent theoretical and experimental results of research for the BAW filters. Paper no. 1 outlines the general procedure to design SMR filter. Paper no. 2 is an example of the integration of a SMR filter in 3G transmitter. Paper no. 3 presents the synthesis of a BAW coupled resonator filter. Paper no. 4 is a theoretical paper on the nonlinear Mason model of a FBAR resonator. Paper no. 5 proposes the tunability of a BAW-SMR filter.