# US 11,309,865 B1 · Acoustic matrix diplexers and radios using acoustic matrix diplexers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,865 B1 - Document ID: US11309865B1 - Status: Granted - Kind: B1 - Application number: 17/122,986 - Filed: 2020-12-15 - Published: 2022-04-07 - Granted: 2022-04-19 - Earliest claimed: 2020-10-05 - Assignees: Resonant Inc. - Applicants: Resonant Inc. - Inventors: Andrew Guyette; Neal Fenzi - Web page: https://patentgrep.com/patent/US11309865B1 ## CPC - H03H 9/205: having multiple resonators (crystal tuning forks H03H9/21) - H03H 9/02228: {Guided bulk acoustic wave devices or Lamb wave devices having interdigital transducers situated in parallel planes on either side of a piezoelectric layer} - H03H 9/54: comprising resonators of piezoelectric or electrostrictive material (comprising resonators using surface acoustic waves H03H9/64) - H03H 9/542: {including passive elements (H03H9/545 takes precedence)} - H03H 9/564: {implemented with thin-film techniques} - H03H 9/568: {consisting of a ladder configuration} - H03H 9/706: {Duplexers} - H04B 1/0057: {using diplexing or multiplexing filters for selecting the desired band} - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H04B: TRANSMISSION ## 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. ## Claims ### Claim 1 A diplexer, comprising: a common port, a low-band port, and a high-band port; n low-band sub-filters, where n is an integer greater than one, each low-band sub-filter having a first 1 sub-filter port connected to the common port and a second sub-filter port connected to the low band port; n high-band sub-filters, each high-band sub-filter having a first h sub-filter port connected to the common port and a second sub-filter port connected to the high band port; a first acoustic resonator connected between the common port and ground; and a second acoustic resonator connected between the low-band port and ground, wherein the first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of a passband of the diplexer. ### Claim 2 (depends on 1) The diplexer of claim 1, wherein the passband of the diplexer is equal to a sum of passbands of the 2n high-band and low-band sub-filters. ### Claim 3 (depends on 1) The diplexer of claim 1 wherein the first and second acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs). ### Claim 4 (depends on 1) The diplexer of claim 1, further comprising: a third acoustic resonator connected between the common port and ground; and a fourth acoustic resonator connected between the high-band port and ground, wherein the third and fourth acoustic resonators are configured to create transmission zeros adjacent to an upper edge of the passband of the diplexer. ### Claim 5 (depends on 4) The diplexer of claim 4 wherein the third and fourth acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs). ### Claim 6 (depends on 1) The diplexer of claim 1, each of the 2n low-band and high-band 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 in acoustic resonators. ### Claim 7 (depends on 6) The diplexer of claim 6 wherein the in acoustic resonators in each of the 2n low-band and high-band sub-filters are transversely-excited film bulk acoustic resonators (XBARs). ### Claim 8 (depends on 6) The diplexer of claim 6, wherein the in acoustic resonators of each of the 2n low-band and high-band 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 2n low-band and high-band sub-filters further comprises a switch in series with one of the one or more middle resonators. ### Claim 9 A frequency division duplex (FDD) radio, comprising: a matrix diplexer, comprising: a common port configured for connection to an antenna, a low band port, and a high band port; n low band sub-filters, where n is an integer greater than one, each low band sub-filter having a first sub-filter port connected to the common port and a second sub-filter port connected to the low band port; n high band sub-filters, each high band sub-filter having 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 connected between the common port and ground; and a second acoustic resonator connected between the low band port and ground, wherein the first and second acoustic resonators are configured to create respective transmission zeros adjacent to a lower edge of a passband of the diplexer; a transmitter having an output connected to one of the low band port and the high band port; and a receiver having an input connected to the one of the low band port and the high band port that is not connected to the transmitter. ### Claim 10 (depends on 9) The radio of claim 9, wherein the passband of the diplexer is equal to a sum of passbands of the 2n low-band and high-band sub-filters. ### Claim 11 (depends on 9) The radio of claim 9 wherein the first and second acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs). ### Claim 12 (depends on 9) The radio of claim 9, further comprising: a third acoustic resonator connected between the common port and ground; and a fourth acoustic resonator connected between the high band port and ground, wherein the third and fourth acoustic resonators are configured to create transmission zeros adjacent to an upper edge of the passband of the diplexer. ### Claim 13 (depends on 12) The radio of claim 12 wherein the third and fourth acoustic resonators are transversely-excited film bulk acoustic resonators (XBARs). ### Claim 14 (depends on 9) The radio of claim 9, each of the 2n low-band and high-band 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 in acoustic resonators. ### Claim 15 (depends on 14) The radio of claim 14 wherein the in acoustic resonators in each of the 2n low-band and high-band sub-filters are transversely-excited film bulk acoustic resonators (XBARs). ### Claim 16 (depends on 14) The radio of claim 14, wherein the in acoustic resonators of each of the 2n low-band and high-band 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 2n low-band and high-band sub-filters further comprises a switch in series with one of the one or more middle resonators. ### Claim 17 (depends on 9) The radio of claim 9, further comprising the antenna.