Electroacoustic filter with low phase delay for multiplexed signals

A wireless communication apparatus, comprising:

• a bandpass filter having a bandpass filter response and including a first acoustic resonator coupled between a circuitry connection port and a communication connection port, the bandpass filter further including a third acoustic resonator coupled to a terminal end of the first acoustic resonator and a reference potential in a shunt path;
• and
• a notch filter having a stopband filter response and including a second acoustic resonator directly coupled in parallel with the first acoustic resonator, the notch filter further including a fourth acoustic resonator coupled to the terminal end of the first acoustic resonator and in parallel with the third acoustic resonator,
• wherein resonance values associated with the first acoustic resonator and the third acoustic resonator forming the bandpass filter are less than resonance values associated with the second acoustic resonator and the fourth acoustic resonator forming the notch filter, and
• wherein a resonant frequency of the second acoustic resonator and an antiresonant frequency of the fourth acoustic resonator are within a range of less than 100 megahertz (MHz).

A method of filtering one or more signals in a wireless communication apparatus, the method comprising:

• receiving a signal at a filter block of the wireless communication apparatus, the filter block including:
• a first acoustic resonator that is part of a first bandpass filter having a first passband, the first acoustic resonator having a first resonator side and a second resonator side, the first resonator side coupled to a circuitry connection port, and the second resonator side coupled to a communication connection port;
• a second acoustic resonator that is part of a notch filter having a stopband, the second acoustic resonator having a first resonator side and a second resonator side, the second acoustic resonator coupled in parallel to the first acoustic resonator with the first resonator side of the second acoustic resonator coupled to the first resonator side of the first acoustic resonator, and the second resonator side of the first acoustic resonator coupled to the second resonator side of the second acoustic resonator;
• a third acoustic resonator that is part of the first bandpass filter, the third acoustic resonator having a first resonator side and a second resonator side, the first resonator side of the third acoustic resonator coupled to the communication connection port, and the second resonator side of the third acoustic resonator coupled to a reference potential;
• and
• a fourth acoustic resonator that is part of one of the notch filter, the fourth acoustic resonator having a first resonator side and a second resonator side, the fourth acoustic resonator coupled in parallel to the third acoustic resonator, with the first resonator side of the fourth acoustic resonator coupled to the communication connection port, and the second resonator side of the third acoustic resonator coupled to the second resonator side of the fourth acoustic resonator and the reference potential;
• and
• filtering the signal using the filter block,
• wherein resonance values associated with the first acoustic resonator and the third acoustic resonator forming the first bandpass filter are less than resonance values associated with the second acoustic resonator and the fourth acoustic resonator forming the notch filter, and
• wherein a resonant frequency of the second acoustic resonator and an antiresonant frequency of the fourth acoustic resonator are within a range of less than 100 megahertz (MHz).