Control of the miniaturization degree in BAW CRF filters

This paper presents the synthesis procedure and circuit transformation for the design of four order CRF BAW filters. Flexibility on the circuit transformation has been included to provide control over the size of the individual resonators and therefore on the size of the overall filter, without much effect on the small signal response of the filter but the losses. For the example presented in this work this process demonstrates a four times reduction on the filter size. This work goes on step further and evaluate the large signal response as well by means of evaluating the nonlinear effects of the final design structure, this is the generation of the second harmonic and IMD. These results reveal the expected increase of nonlinear effects as the size of the filter is reduced.