Acoustic matrix diplexers and radios using acoustic matrix diplexers

Patent metadata

Field	Value
Publication number	US-11984873-B2
Application number	US-202217693268-A
Country	US
Kind code	B2
Filing date	Mar 11, 2022
Priority date	Oct 5, 2020
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

There are disclosed acoustic diplexers and radios incorporating the acoustic diplexers. A diplexer includes common port, a low band port, a high band port, n low band sub-filters, and n high band sub-filters, where n is an integer greater than one. Each low band sub-filter has a first sub-filter port connected to the common port and a second sub-filter port connected to the low band port. Each high band sub-filter has a first sub-filter port connected to the common port and a second sub-filter port connected to the high band port. A first acoustic resonator is connected from the common port to ground and a second acoustic resonator is connected from the low band port to ground. The first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of a passband of the diplexer.

First claim

It is claimed:

1. A matrix filter, comprising:
a first filter port and a second filter port;
n sub-filters, where n is an integer greater than one, each sub-filter having a first sub-filter port connected to the first filter port and a second sub-filter port connected to the second filter port;
the n sub-filters having contiguous passbands such that a bandwidth of the matrix filter is equal to a sum of the bandwidths of each of the n sub-filters;
a first acoustic resonator connected between the first filter port and ground; and
a second acoustic resonator connected between the second filter port and ground, wherein
the first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of the bandwidth of the matrix filter.

2. The matrix filter of claim 1 , wherein
the passband of the matrix filter is equal to a sum of passbands of the sub-filters.

3. The matrix filter of claim 1 wherein the first and second acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs).

4. The matrix filter of claim 1 , further comprising:
a third acoustic resonator connected between the first filter port and ground; and
a fourth acoustic resonator connected between the second filter port and ground, wherein
the third and fourth acoustic resonators are configured to create transmission zeros adjacent to an upper edge of the bandwidth of the matrix filter.

5. The matrix filter of claim 4 wherein the third and fourth acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs).

6. The matrix filter of claim 1 , each of the sub-filters comprising:
m acoustic resonators connected in series between the first sub-filter port and the second sub-filter port, where m is an integer greater than one; and
m−1 capacitors, each capacitor connected between ground and a node between a respective pair of acoustic resonators from the m acoustic resonators.

7. The matrix filter of claim 6 wherein the m acoustic resonators in each of the sub-filters are transversely-excited film bulk acoustic resonators (XBARs).

8. The matrix filter of claim 6 , wherein
the m acoustic resonators of each of the sub-filters include a first end acoustic resonator connected to the first sub-filter port, a second end acoustic resonator connected to the second sub-filter port, and one or more middle acoustic resonators connected between the first and second end acoustic resonator, and
each of the sub-filters further comprises a switch in series with one of the one or more middle resonators.

9. A time division duplex (TDD) radio, comprising:
a matrix filter, comprising:
a first filter port configured for connection to an antenna and a second filter port;
n sub-filters, where n is an integer greater than one, each sub-filter having a first sub-filter port connected to the first filter port and a second sub-filter port connected to the second filter port;
the n sub-filters having contiguous passbands such that a bandwidth of the matrix filter is equal to a sum of the bandwidths of each of the n sub-filters;
a first acoustic resonator connected between the first filter port and ground; and
a second acoustic resonator connected between the second filter port and ground, wherein
the first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of the bandwidth of the matrix filter;

a transmitter having an output connected to the second filter port; and
a receiver having an input connected to the second filter port.

10. The radio of claim 9 , wherein
the passband of the matrix filter is equal to a sum of passbands of the sub-filters.

11. The radio of claim 9 wherein the first and second acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs).

12. The radio of claim 9 , further comprising:
a third acoustic resonator connected between the first filter port and ground; and
a fourth acoustic resonator connected between the second filter port and ground, wherein
the third and fourth acoustic resonators are configured to create transmission zeros adjacent to an upper edge of the bandwidth of the matrix filter.

13. The radio of claim 12 wherein the third and fourth acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs).

14. The radio of claim 9 , each of the sub-filters comprising:
m acoustic resonators connected in series between the first sub-filter port and the second sub-filter port, where m is an integer greater than one; and
m−1 capacitors, each capacitor connected between ground and a node between a respective pair of acoustic resonators from the m acoustic resonators.

15. The radio of claim 14 wherein the m acoustic resonators in each of the sub-filters are transversely-excited film bulk acoustic resonators (XBARs).

16. The radio of claim 14 , wherein
the m acoustic resonators of each of the sub-filters include a first end acoustic resonator connected to the first sub-filter port, a second end acoustic resonator connected to the second sub-filter port, and one or more middle acoustic resonators connected between the first and second end acoustic resonator, and
each of the sub-filters further comprises a switch in series with one of the one or more middle resonators.

17. The radio of claim 9 , further comprising the antenna.

Assignees

• Murata Manufacturing Co

Inventors

• Guyette Andrew
• Fenzi Neal

Classifications

• H03H9/205 Primary

  having multiple resonators (crystal tuning forks H03H9/21) · CPC title

• H03H9/54

  comprising resonators of piezoelectric or electrostrictive material (comprising resonators using surface acoustic waves H03H9/64) · CPC title

• H03H9/542

  including passive elements (H03H9/545 takes precedence) · CPC title

• H03H9/706

  Duplexers · CPC title

• H04B1/0057 Primary

  using diplexing or multiplexing filters for selecting the desired band · CPC title