Low loss temperature compensated surface acoustic wave filter and duplexer

An electronic device with an electronics module having at least one radio frequency filter including at least one surface acoustic wave (SAW) resonator comprising:

• at least one set of interdigital transducer (IDT) electrodes disposed on an upper surface of a piezoelectric substrate between first and second reflector gratings;
• a layer of silicon nitride disposed over the at least one set of IDT electrodes and first and second reflector gratings;
• and
• a continuous trench formed in the layer of silicon nitride over portions of bus bar electrodes and tips of electrode fingers of the at least one set of IDT electrodes and over portions of bus bar electrodes and electrode fingers of the first and second reflector gratings to reduce acoustic leakage at electrode fingers of the first and second reflector gratings proximate the at least one set of IDT electrodes.

A surface acoustic wave (SAW) resonator comprising:

• at least one set of interdigital transducer (IDT) electrodes disposed on an upper surface of a piezoelectric substrate between first and second reflector gratings, the first and second reflector gratings each including reduced length electrode fingers with lengths less than a length between bus bar electrodes of the first and second reflector gratings;
• a layer of silicon nitride disposed over the at least one set of IDT electrodes and first and second reflector gratings;
• and
• a trench formed in the layer of silicon nitride over portions of bus bar electrodes and tips of electrode fingers of the at least one set of IDT electrodes and over portions of the bus bar electrodes and electrode fingers of the first and second reflector gratings to reduce acoustic leakage at electrode fingers of the first and second reflector gratings proximate the at least one set of IDT electrodes.