DOI: 10.1109/TMTT.2024.3354937   IEEEXplore: https://ieeexplore.ieee.org/document/10416884    

Synchronous ladder-type, double mode-type and mixed-type surface acoustic wave filters and duplexers derived by direct synthesis

0.9 to 1.2 GHz nominal center frequency depending on the filter demonstrated.

The bandpass-domain direct synthesis technique (DST) incorporating a phase correction approach has higher accuracy and efficiency than the commonly applied lowpass-to-bandpass synthesis approach due in part to 1) no frequency or bandwidth transformations are required, and 2) only the positive frequency passband is synthesized. This filter synthesis approach is also applicable to design non-fully -canonical filters, bulk acoustic wave (BAW) ladder-type filters and mixed ladder and double-mode SAW filters.

The design of almost any acoustic wave filter.

19.5 dB or better simulated return loss for the TX and RX channels by eliminating the loading effect for the Band 8 Duplexer. 55dB or better isolation between the two channels is better over the TX passband and 50 dB within the RX passband range for the Band 8 Duplexer.