Duplexer with transmission and reception filters each including resonators formed on different chips

A duplexer including a transmission filter and a reception filter, a passband of one filter of the transmission filter and the reception filter being lower than a passband of the other of the transmission filter and the reception filter, wherein:

• each of the transmission filter and the reception filter includes a series resonator and a parallel resonator connected in a ladder shape,
• first resonators that are the series resonator of the one filter and the parallel resonator of the other filter and are formed on a first chip, and
• second resonators that are the series resonator of the other filter and the parallel resonator of the one filter and are formed on a second chip that is different from the first chip,
• wherein
• each of the first resonators is a temperature compensated type piezoelectric thin film resonator that is made of layers including a piezoelectric thin film and lower and upper electrodes facing each other across the piezoelectric thin film, and includes a temperature compensation film having a temperature coefficient of an elastic constant opposite in sign to a temperature coefficient of an elastic constant of the piezoelectric thin film and sandwiched between the upper electrode and the lower electrode, and each of the second resonators is a temperature non-compensated type piezoelectric thin film resonator that is made of layers including a piezoelectric thin film and lower and upper electrodes facing each other across the piezoelectric thin film, and in which a temperature compensation film is not sandwiched between the upper electrode and the lower electrode.

A duplexer including a transmission filter and a reception filter, a passband of one filter of the transmission filter and the reception filter being lower than a passband of the other of the transmission filter and the reception filter, wherein:

• each of the transmission filter and the reception filter includes a series resonator and a parallel resonator connected in a ladder shape,
• first resonators that are the series resonator of the one filter and the parallel resonator of the other filter and are formed on a first chip, and
• second resonators that are the series resonator of the other filter and the parallel resonator of the one filter and are formed on a second chip that is different from the first chip,
• wherein
• each of the first resonators is a temperature compensated type piezoelectric thin film resonator that is made of layers including a piezoelectric thin film and lower and upper electrodes facing each other across the piezoelectric thin film, and includes a temperature compensation film having a temperature coefficient of an elastic constant opposite in sign to a temperature coefficient of an elastic constant of the piezoelectric thin film and sandwiched between the upper electrode and the lower electrode, and each of the second resonators is a surface acoustic wave resonator using a lithium tantalate substrate.

A duplexer including a transmission filter and a reception filter, a passband of one filter of the transmission filter and the reception filter being lower than a passband of the other of the transmission filter and the reception filter, wherein:

• each of the transmission filter and the reception filter includes a series resonator and a parallel resonator connected in a ladder shape,
• first resonators that are the series resonator of the one filter and the parallel resonator of the other filter and are formed on a first chip, and
• second resonators that are the series resonator of the other filter and the parallel resonator of the one filter and are formed on a second chip that is different from the first chip,
• wherein
• each of the first resonators is a temperature compensated type piezoelectric thin film resonator that is made of layers including a piezoelectric thin film and lower and upper electrodes facing each other across the piezoelectric thin film, and includes a temperature compensation film having a temperature coefficient of an elastic constant opposite in sign to a temperature coefficient of an elastic constant of the piezoelectric thin film and sandwiched between the upper electrode and the lower electrode, and each of the second resonators is a surface acoustic wave resonator using a substrate made by bonding a lithium tantalate substrate on a sapphire substrate.

A duplexer including a transmission filter and a reception filter, a passband of one filter of the transmission filter and the reception filter being lower than a passband of the other of the transmission filter and the reception filter, wherein:

• each of the transmission filter and the reception filter includes a series resonator and a parallel resonator connected in a ladder shape,
• first resonators that are the series resonator of the one filter and the parallel resonator of the other filter and are formed on a first chip, and
• second resonators that are the series resonator of the other filter and the parallel resonator of the one filter and are formed on a second chip that is different from the first chip,
• wherein
• each of the first resonators is a temperature compensated type piezoelectric thin film resonator that is made of layers including a piezoelectric thin film and lower and upper electrodes facing each other across the piezoelectric thin film, and includes a temperature compensation film having a temperature coefficient of an elastic constant opposite in sign to a temperature coefficient of an elastic constant of the piezoelectric thin film and sandwiched between the upper electrode and the lower electrode, and each of the second resonators is a Love wave type surface acoustic wave resonator.

A duplexer including a transmission filter and a reception filter, a passband of one filter of the transmission filter and the reception filter being lower than a passband of the other of the transmission filter and the reception filter, wherein:

• each of the transmission filter and the reception filter includes a series resonator and a parallel resonator connected in a ladder shape,
• first resonators that are the series resonator of the one filter and the parallel resonator of the other filter and are formed on a first chip, and
• second resonators that are the series resonator of the other filter and the parallel resonator of the one filter and are formed on a second chip that is different from the first chip,
• wherein
• the first chip and the second chip are flip-chip mounted on a mounting substrate.