MULTIPLEXER INCLUDING FILTER WITH TWO TYPES OF ACOUSTIC WAVE RESONATORS

• US 20190319772A1
• Filed: 04/02/2019
• Published: 10/17/2019
• Est. Priority Date: 04/12/2018
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Ando, Yoshiaki, Saito, Yasuyuki, Nakamura, Hiroyuki
• Granted Patent: US 11,101,787 B2
• Time in Patent Office: Days
• CPC Class Codes: H03H 9/0009 using surface acoustic wave devices
• CPC Class Codes: H03H 9/0014 using bulk acoustic wave devices
• CPC Class Codes: H03H 9/02007 of bulk acoustic wave devices
• CPC Class Codes: H03H 9/0566 for duplexers
• CPC Class Codes: H03H 9/105 the enclosure being defined by a cover cap mounted on an element forming part of the BAW device
• CPC Class Codes: H03H 9/1092 the enclosure being defined by a cover cap mounted on an element forming part of the surface acoustic wave [SAW] device on the side of the IDT's
• CPC Class Codes: H03H 9/171 implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type
• CPC Class Codes: H03H 9/205 having multiple resonators crystal tuning forks H03H9/21
• CPC Class Codes: H03H 9/25 Constructional features of resonators using surface acoustic waves devices for manipulating acoustic surface waves in general G10K11/36
• CPC Class Codes: H03H 9/54 comprising resonators of piezoelectric or electrostrictive material H03H9/64 takes precedence
• CPC Class Codes: H03H 9/542 including passive elements H03H9/545 takes precedence
• CPC Class Codes: H03H 9/568 consisting of a ladder configuration
• CPC Class Codes: H03H 9/64 using surface acoustic waves
• CPC Class Codes: H03H 9/6483 Ladder SAW filters
• CPC Class Codes: H03H 9/703 Networks using bulk acoustic wave devices
• CPC Class Codes: H03H 9/706 Duplexers
• CPC Class Codes: H03H 9/72 Networks using surface acoustic waves
• CPC Class Codes: H03H 9/725 Duplexers
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

Multiplexers are disclosed. A multiplexer can include a first filter and a second filter that are coupled to a common node. The second filter can include a first type of acoustic wave resonators (e.g., bulk acoustic wave resonators) and a series acoustic wave resonator of a second type (e.g., a surface acoustic wave resonator) that is coupled between the acoustic wave resonators of the first type and the common node. The first filter can provide a single-ended radio frequency signal. In certain embodiments, the first filter can be a receive filter and the second filter can be a transmit filter.

Claims

1. A multiplexer comprising:

a transmit filter coupled to a common node, the transmit filter including bulk acoustic wave resonators and a series surface acoustic wave resonator coupled between the bulk acoustic wave resonators and the common node, and the transmit filter configured to filter a transmit radio frequency signal; and

a receive filter coupled to the common node, the receive filter configured to provide a single-ended radio frequency receive signal.

2. The multiplexer of claim 1 further comprising a loop circuit coupled to the transmit filter, the loop circuit configured to generate an anti-phase signal to a target signal at a particular frequency, the loop circuit including surface acoustic wave elements.

3. The multiplexer of claim 2 wherein the surface acoustic wave elements and the series surface acoustic wave resonator are included on a common die.

4. The multiplexer of claim 1 wherein the transmit filter and the receiver filter are arranged as a duplexer.

5. The multiplexer of claim 1 wherein the transmit filter includes a shunt surface acoustic wave resonator coupled to a node between the bulk acoustic wave resonators and the common node.

6. The multiplexer of claim 1 wherein the bulk acoustic wave resonators of the transmit filter are at least 80% of resonators of the transmit filter.

7. The multiplexer of claim 1 wherein the receive filter includes surface acoustic wave resonators.

8. The multiplexer of claim 1 wherein the series surface acoustic wave resonator is coupled between all bulk acoustic wave resonators of the transmit wave filter and the common node.

9. The multiplexer of claim 1 further comprising two filters coupled to the common node, the multiplexer configured as a quadplexer.

10. A filter assembly comprising:

a first filter coupled to a common node, the first filter configured to provide a single-ended radio frequency output signal; and

a second filter coupled to the common node and configured to filter a radio frequency signal, the second filter including acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node, the series acoustic wave resonator of the second type having a higher suppression of a second harmonic of a radio frequency signal than the acoustic wave resonators of the first type.

11. The filter assembly of claim 10 wherein the acoustic wave resonators of the first type are bulk acoustic wave resonators and the series acoustic wave resonator of the second type is a surface acoustic wave resonator.

12. The filter assembly of claim 11 wherein the bulk acoustic wave resonators and the series acoustic wave resonator are implemented on a common filter die and enclosed within a common cap.

13. The filter assembly of claim 10 wherein the filter assembly includes a first die that includes the acoustic wave resonators of the first type and a second die that includes the series acoustic wave resonator of the second type.

14. The filter assembly of claim 10 wherein the first filter includes acoustic wave resonators of the first type.

15. The filter assembly of claim 10 further comprising a loop circuit coupled to the second filter, the loop circuit configured to generate an anti-phase signal to a target signal at a particular frequency.

16. The filter assembly of claim 15 wherein the loop circuit includes acoustic wave elements on the same die as the acoustic wave resonators of the second type.

17. The filter assembly of claim 15 wherein the first filter is a receive filter, the second filter is a transmit filter, and the first filter and the second filter are included in a duplexer.

18. A wireless communication device comprising:

an antenna; and

a multiplexer coupled to the antenna, the multiplexer including a receive filter configured to provide a single-ended radio frequency receive signal, and a transmit filter including bulk acoustic wave resonators and a series surface acoustic wave resonator coupled between the bulk acoustic wave resonators and the antenna, the transmit filter configured to filter a transmit radio frequency signal.

19. The wireless communication device of claim 18 further comprising a loop circuit coupled to the transmit filter, the loop circuit configured to generate an anti-phase signal to a target signal at a particular frequency.

20. The wireless communication device of claim 18 wherein the transmit filter and the receiver filter are arranged as a duplexer, and the receive filter includes surface acoustic wave resonators.