Parallel hybrid acoustic passive filter

Abstract

Several aspects of this application relate to a parallel hybrid acoustic passive filter. The parallel hybrid acoustic passive filter includes a first sub-filter and a second sub-filter. The first sub-filter includes a first acoustic resonator and a first non-acoustic passive component. The second sub-filter includes a second acoustic resonator and a second non-acoustic passive component. The first and second sub-filters are arranged together to filter radio frequency signals. For example, the parallel hybrid acoustic filter can be a bandpass filter or a bandstop filter. Related multiplexers, wireless communication devices, and methods are also disclosed.

Description

[0001] Cross-references to related applications

[0002] Any and all applications that identify foreign or domestic priority claims in the application data sheet filed with this application, based on 37 CFR § 1.57, are hereby incorporated herein by reference. This application claims priority to U.S. Provisional Patent Application No. 62 / 700,142, filed July 18, 2018, entitled “HYBRID ACOUSTIC LC FILTER CASCADED WITH LC FILTER”; U.S. Provisional Patent Application No. 62 / 700,148, filed July 18, 2018, entitled “PARALLEL HYBRIDACOUSTIC PASSIVE FILTER”; and U.S. Provisional Patent Application No. 62 / 700,146, filed July 18, 2018, entitled “HYBRID ACOUSTIC LC FILTER WITH HARMONIC DETPRESSION”. The entire disclosure of each of these priority applications is hereby incorporated herein by reference. Technical Field

[0003] Embodiments of this application relate to a hybrid acoustic LC (inductor-capacitor) filter. Background Technology

[0004] Acoustic filters may include multiple acoustic resonators arranged to filter radio frequency (RF) signals. These multiple acoustic resonators may be arranged as a ladder filter to filter the RF signals. Example acoustic filters include surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters. Acoustic filters can be implemented in radio frequency (RF) electronic systems. For example, filters in the RF front-end of a mobile phone may include acoustic filters.

[0005] An LC filter includes at least an inductor and a capacitor. An LC filter is a non-acoustic filter that includes passive components. LC filters can filter radio frequency signals.

[0006] Filtering relatively high-frequency radio frequency signals while meeting stringent filtering specifications can be challenging. Therefore, improved filters are desired to filter relatively high-frequency signals and meet performance specifications. Summary of the Invention

[0007] Each of the novel inventions described in the claims has several aspects, but no single aspect is solely responsible for its desired properties. Without limiting the scope of the claims, some of the prominent features of this application will now be briefly described.

[0008] One aspect of this application is a cascaded filter for radio frequency (RF) filtering. The cascaded filter includes a hybrid acoustic LC filter and a non-acoustic LC filter cascaded with the hybrid acoustic LC filter. The hybrid acoustic LC filter is configured to filter RF signals. The hybrid acoustic LC filter includes a first acoustic resonator on an acoustic resonator die, a second acoustic resonator, a capacitor external to the acoustic resonator die, and an inductor external to the acoustic resonator die. The non-acoustic LC filter includes an LC circuit.

[0009] The hybrid acoustic LC filter may also include a second inductor connected in parallel with the second acoustic resonator, wherein the second acoustic resonator is arranged as a shunt resonator connected in series with the inductor.

[0010] The first and second acoustic resonators can be shunt resonators. Capacitors and inductors can be arranged as an LC tank coupled between the first and second acoustic resonators.

[0011] The first acoustic resonator can be coupled to a node in the signal path between the LC circuit and the inductor and capacitor.

[0012] The first and second acoustic resonators can be bulk acoustic resonators. For example, the first and second acoustic resonators can be thin-film bulk acoustic resonators.

[0013] The LC circuitry of a non-acoustic LC filter may include integrated passive devices on an integrated passive device wafer. The inductor of a hybrid acoustic LC filter may be a surface mount inductor. The inductor of a hybrid acoustic LC filter may include conductive traces on a substrate. Integrated passive devices may include LC shunt circuits and series LC resonant circuits.

[0014] The LC circuit of a non-acoustic LC filter may include a series LC resonant circuit and an LC shunt circuit. The series LC resonant circuit may include a parallel LC circuit. The LC shunt circuit may include a series LC circuit. The LC circuit of a non-acoustic LC filter may also include a second shunt series LC circuit.

[0015] The passband of the cascaded filter can be set using a non-acoustic LC filter. The first acoustic resonator can be arranged to provide rejection in a frequency band outside this passband. The lower limit of this passband can be at least 3 gigahertz. The passband can span from at least 3.3 gigahertz to 4.2 gigahertz.

[0016] Another aspect of this application is a multiplexer comprising a first filter coupled to a common node and a second filter coupled to the common node. The first filter is configured to filter radio frequency signals. The first filter includes a hybrid acoustic LC filter and a non-acoustic LC filter cascaded with the hybrid acoustic LC filter. The hybrid acoustic LC filter includes a first acoustic resonator on an acoustic resonator wafer, a second acoustic resonator, a capacitor outside the acoustic resonator wafer, and an inductor outside the acoustic resonator wafer.

[0017] The multiplexer may also include a third filter coupled to a common node. The second filter may include a second hybrid acoustic LC filter. The second filter may also include a second non-acoustic LC filter.

[0018] Another aspect of this application is a wireless communication device including an antenna and a radio frequency (RF) front-end communicating with the antenna. The RF front-end includes a filter configured to filter RF signals for transmission via the antenna. The filter includes a hybrid acoustic LC filter and a non-acoustic LC filter cascaded with the hybrid acoustic LC filter. The hybrid acoustic LC filter includes an acoustic resonator on an acoustic resonator wafer, a capacitor external to the acoustic resonator wafer, and an inductor external to the acoustic resonator wafer.

[0019] Wireless communication devices can be mobile phones.

[0020] Another aspect of this application is a cascaded filter circuit for radio frequency (RF) filtering, comprising a hybrid acoustic LC filter, a non-acoustic LC filter including an LC circuit, and a switch configured to selectively couple the hybrid acoustic LC filter and the non-acoustic LC filter. The hybrid acoustic LC filter is configured to filter RF signals. The hybrid acoustic LC filter includes an acoustic resonator on an acoustic resonator wafer, a capacitor outside the acoustic resonator wafer, and an inductor outside the acoustic resonator wafer.

[0021] The cascaded filter circuit may further include a second non-acoustic LC filter, wherein the switch is configured to couple the hybrid acoustic LC filter and the non-acoustic LC filter in a first state, and wherein the switch is configured to couple the hybrid acoustic LC filter and the second non-acoustic LC filter in a second state. The non-acoustic LC filter may be a transmitting filter, and the second non-acoustic LC filter may be a receiving filter.

[0022] The cascaded filter circuit may further include a second hybrid acoustic LC filter, wherein the switch is configured to couple the hybrid acoustic LC filter and the non-acoustic LC filter in a first state, and wherein the switch is configured to couple the second hybrid acoustic LC filter and the non-acoustic LC filter in a second state.

[0023] The hybrid acoustic LC filter may also include a second inductor connected in parallel with the acoustic resonator, wherein the acoustic resonator is arranged as a shunt resonator connected in series with the inductor.

[0024] The hybrid acoustic LC filter may also include a second acoustic resonator. The first and second acoustic resonators may be shunt resonators. Capacitors and inductors may be arranged in an LC slot between the acoustic resonators and the second acoustic resonator. The hybrid acoustic LC filter may also include a second inductor connected in series with the first acoustic resonator and a third inductor connected in series with the second acoustic resonator.

[0025] An acoustic resonator can be a bulk acoustic resonator.

[0026] The LC circuitry of a non-acoustic LC filter may include integrated passive devices such as integrated passive device chips. The inductor of a hybrid acoustic LC filter may be a surface-mount inductor. The inductor of a hybrid acoustic LC filter may also include conductive traces on a substrate.

[0027] The passband of a cascaded filter consisting of a non-acoustic LC filter and a hybrid acoustic LC filter can be set using a non-acoustic LC filter. The lower limit of this passband can be at least 3 GHz.

[0028] Another aspect of this application is a method for filtering radio frequency (RF) signals. The method includes: coupling a hybrid acoustic LC filter and a non-acoustic LC filter together using a switch. The hybrid acoustic LC filter includes an acoustic resonator on an acoustic resonator wafer, a capacitor external to the acoustic resonator wafer, and an inductor external to the acoustic resonator wafer. The method further includes: filtering the RF signal while coupling the hybrid acoustic LC filter and the non-acoustic filter together.

[0029] The method may further include: decoupling the hybrid acoustic LC filter from the non-acoustic LC filter using a switch; and coupling the hybrid acoustic LC filter and the second non-acoustic LC filter using a switch. The method may also include: providing an RF signal to the non-acoustic LC filter using a power amplifier; and amplifying the filtered signal provided by the second non-acoustic filter using a low-noise amplifier.

[0030] Filtering may include: using an acoustic resonator with a hybrid acoustic LC filter to provide rejection outside the passband of a filter that includes both hybrid acoustic LC filters and non-acoustic LC filters.

[0031] Radio frequency signals can have frequencies ranging from 3 GHz to 5 GHz.

[0032] Another aspect of this application is a wireless communication device including an antenna and a radio frequency (RF) front-end communicating with the antenna. The RF front-end includes a filter configured to filter RF signals for transmission via the antenna. The filter includes a hybrid acoustic LC filter, a non-acoustic LC filter, and a switch configured to selectively couple the hybrid acoustic LC filter and the non-acoustic LC filter. The hybrid acoustic LC filter includes an acoustic resonator on an acoustic resonator wafer and LC components external to the acoustic resonator wafer.

[0033] Wireless communication devices can be mobile phones.

[0034] Another aspect of this application is a parallel hybrid acoustic passive filter, comprising a first sub-filter and a second sub-filter coupled in parallel with the first sub-filter. The first sub-filter includes a first acoustic resonator and a first non-acoustic passive component. The second sub-filter includes a second acoustic resonator and a second non-acoustic passive component. The first and second sub-filters are arranged together to filter radio frequency signals.

[0035] The first and second sub-filters can be arranged together as a bandpass filter with passbands. The frequency response of the parallel hybrid acoustic passive filter can have a first sub-passband corresponding to the first sub-filter, a second sub-passband corresponding to the second sub-filter, and a notch at the notch frequency between the first and second sub-passbands.

[0036] The first and second sub-filters can be arranged together as a band-stop filter with a stopband. The band-stop filter can have a notch in the stopband.

[0037] The first sub-filter may include a bulk acoustic resonator, which includes an acoustic resonator.

[0038] The first non-acoustic passive component may include a first inductor and a second inductor, wherein the first inductor is connected in parallel with an acoustic resonator, and wherein the acoustic resonator is arranged as a shunt resonator connected in series with the second inductor.

[0039] The first sub-filter may also include an additional acoustic resonator, wherein the first acoustic resonator and the additional acoustic resonator are shunt resonators, and wherein the first non-acoustic passive component includes a capacitor and an inductor arranged as an LC slot coupled between the first acoustic resonator and the additional acoustic resonator.

[0040] The second non-acoustic passive component may include integrated passive devices.

[0041] The first and second sub-filters can have different passbands. The lower limit of the passband of the parallel hybrid acoustic passive filter can be at least 2 GHz.

[0042] Another aspect of this application is a multiplexer with parallel hybrid acoustic passive filters. The multiplexer includes a first filter coupled to a common node and a second filter coupled to the common node. The first filter is configured to filter radio frequency signals. The first filter includes a first sub-filter connected in parallel with the second sub-filter. The first sub-filter includes a first acoustic resonator and a first non-acoustic passive component. The second sub-filter includes a second acoustic resonator and a second non-acoustic passive component.

[0043] The first filter can be a bandpass filter. The frequency response of the first filter may have a first sub-passband corresponding to the first sub-filter, a second sub-passband corresponding to the second sub-filter, and a notch at the notch frequency between the first and second sub-passbands. The second filter can be a bandstop filter.

[0044] The first filter can be a band-stop filter having a stopband and a notch in that stopband.

[0045] The second filter may include another acoustic resonator and another non-acoustic passive component.

[0046] The first filter may have a first passband, the second filter may have a second passband, and the first passband may have a lower edge at a higher frequency than the upper edge of the second passband.

[0047] The multiplexer may also include a third filter coupled to a common node.

[0048] The multiplexer may also include a shared filter connected in series between the first filter and the common node, wherein the shared filter is also connected in series between the second filter and the common node. The shared filter may be a high-pass filter.

[0049] Another aspect of this application is a wireless communication device including a radio frequency (RF) front-end and an antenna communicating with the RF front-end. The RF front-end includes a filter configured to filter RF signals. The filter includes a first sub-filter connected in parallel with a second sub-filter. The first sub-filter includes a first acoustic resonator and a first non-acoustic passive component. The second sub-filter includes a second acoustic resonator and a second non-acoustic passive component.

[0050] Another aspect of this application is a multiplexer with hybrid acoustic passive filters. The multiplexer includes: a plurality of filters configured to filter various radio frequency signals; a shared filter coupled between each of the plurality of filters and a common node; and a radio frequency filter coupled to the common node. Each of the plurality of filters has a different passband. At least a first filter of the plurality of filters includes a plurality of acoustic resonators and non-acoustic passive components.

[0051] The plurality of filters may include a first filter, a second filter, and a third filter. The first filter may be a first bandpass filter having a first passband. The second filter may be a second bandpass filter having a second passband. The third filter may be a bandstop filter having a stopband that includes both the first and second passbands.

[0052] A shared filter can be a high-pass filter. An RF filter can be a low-pass filter.

[0053] A shared filter can be a non-acoustic LC filter. A shared filter may include a second acoustic resonator and LC components.

[0054] Non-acoustic passive components may include an inductor arranged in parallel with the first acoustic resonator of a plurality of acoustic resonators.

[0055] Acoustic resonators can be implemented on an acoustic resonator wafer. Non-acoustic passive components may include inductors and capacitors located outside the acoustic resonator wafer.

[0056] The second filter in a plurality of filters may include a plurality of second acoustic resonators and second non-acoustic passive components. The first filter may have a first passband, and the second filter may have a second passband. Both the first and second passbands are in the frequency range from 2 GHz to 5 GHz. Both the first and second passbands are in the frequency range from 2 GHz to 3 GHz.

[0057] Multiplexers can be arranged as quadplexers.

[0058] Another aspect of this application is a wireless communication device including an antenna and a multiplexer communicating with the antenna. The multiplexer includes: a plurality of filters configured to filter various radio frequency signals; a shared filter coupled between each of the plurality of filters and a common node; and a radio frequency filter coupled to the common node. The plurality of filters includes a first filter comprising a plurality of acoustic resonators and non-acoustic passive components.

[0059] The second filter of the plurality of filters may include a plurality of second acoustic resonators and a second non-acoustic passive component. The wireless communication device may be configured to support carrier aggregation at a common node. Carrier aggregation may include a first carrier and a second carrier, wherein the first carrier is within a first passband of the first filter, and wherein the second carrier is outside the first and second passbands of the second filter.

[0060] Another aspect of this application is a multiplexer with hybrid acoustic passive filters. The multiplexer includes: a plurality of filters, including a first filter and a second filter with different radio frequency passbands; a shared high-pass filter coupled between each of the plurality of filters and a common node; and a low-pass filter coupled to the common node. The first filter includes a plurality of first acoustic resonators and a first LC circuit. The second filter includes a plurality of second acoustic resonators and a second LC circuit.

[0061] The plurality of filters may also include band-stop filters having a stopband that includes the passband of the first filter and the second filter.

[0062] Another aspect of this application is a hybrid acoustic LC filter with harmonic suppression. The hybrid acoustic LC filter includes a hybrid passive / acoustic filter configured to filter radio frequency signals and a non-acoustic LC filter cascaded with the hybrid passive / acoustic filter. The hybrid passive / acoustic filter includes multiple acoustic resonators and non-acoustic passive components. The non-acoustic LC filter is configured to suppress harmonics of the radio frequency signal.

[0063] A non-acoustic LC filter can be a notch filter. The frequency response of a notch filter can have a notch corresponding to the second harmonic of the radio frequency signal. Alternatively, the frequency response of a notch filter can have two notches corresponding to different harmonics of the radio frequency signal.

[0064] Non-acoustic LC filters can be low-pass filters.

[0065] Non-acoustic LC filters may include integrated passive devices such as integrated passive device wafers.

[0066] The plurality of acoustic resonators may include a plurality of bulk acoustic resonators.

[0067] Non-acoustic passive components may include a first inductor and a second inductor. The acoustic resonator may include a first shunt acoustic resonator arranged in series with the first inductor and in parallel with the second inductor.

[0068] The plurality of acoustic resonators may include a first shunt acoustic resonator and a second shunt acoustic resonator. Non-acoustic passive components may include an LC slot coupled between the first shunt acoustic resonator and the second shunt acoustic resonator.

[0069] Another aspect of this application is a multiplexer comprising a first filter configured to filter a radio frequency (RF) signal and a second filter coupled to the first filter at a common node. The first filter includes a hybrid passive / acoustic filter and a non-acoustic LC filter cascaded with the hybrid passive / acoustic filter. The hybrid passive / acoustic filter includes multiple acoustic resonators and non-acoustic passive components. The non-acoustic LC filter is configured to suppress harmonics of the RF signal.

[0070] The second filter may include multiple second acoustic resonators and second non-acoustic passive components. The first filter may be a mid-frequency band filter, and the second filter may be a high-frequency band filter. The multiplexer may also include a low-frequency band filter coupled to the first and second filters at a common node.

[0071] Non-acoustic LC filters may include integrated passive devices such as integrated passive device wafers.

[0072] The non-acoustic passive components may include a first inductor and a second inductor. The plurality of acoustic resonators may include a first shunt acoustic resonator arranged in series with the first inductor and in parallel with the second inductor.

[0073] Multiple acoustic resonators may include a first shunt acoustic resonator and a second shunt acoustic resonator. Non-acoustic passive components may include an LC slot coupled between the first shunt acoustic resonator and the second shunt acoustic resonator.

[0074] Multiple acoustic resonators may include bulk acoustic resonators.

[0075] Another aspect of this application is a wireless communication device including a radio frequency (RF) front-end and an antenna communicating with the RF front-end. The RF front-end includes a filter configured to filter RF signals. The filter includes a hybrid passive / acoustic filter and an LC filter cascaded with the hybrid passive / acoustic filter. The hybrid passive / acoustic filter includes multiple acoustic resonators and non-acoustic passive components. The non-acoustic LC filter is configured to suppress harmonics of the RF signal. The antenna is configured to transmit a filtered version of the harmonic-suppressed RF signal.

[0076] Wireless communication devices can be configured as mobile phones.

[0077] Wireless communication devices may also include a baseband processor and a transceiver, wherein the transceiver communicates with the radio frequency front end and also with the baseband processor.

[0078] For the purpose of summarizing this application, some aspects, advantages, and novel features of the new invention have been described herein. It should be understood that not all of these advantages can necessarily be implemented according to any particular embodiment. Therefore, the various new inventions may be implemented or performed in a manner that implements or optimizes one or more of the advantages taught herein, without necessarily implementing other advantages that may be taught or suggested herein. Attached Figure Description

[0079] Embodiments of this application will be described by way of non-limiting examples and with reference to the accompanying drawings.

[0080] Figure 1A This is a schematic block diagram of a cascaded filter according to one embodiment, the cascaded filter including a hybrid acoustic LC filter and an LC filter.

[0081] Figure 1B This is a schematic block diagram of a radio frequency system according to one embodiment, the radio frequency system including a cascaded filter in the signal path between a power amplifier and an antenna.

[0082] Figure 1C This is a schematic block diagram of a radio frequency system according to one embodiment, the radio frequency system including a cascaded filter in the signal path between an antenna and a low-noise amplifier.

[0083] Figure 2A This is a schematic block diagram of a cascaded filter circuit according to one embodiment, the cascaded filter circuit including a hybrid acoustic LC filter coupled to an LC filter via a switch.

[0084] Figure 2B This is a schematic block diagram of a cascaded filter circuit according to one embodiment, the cascaded filter circuit including an LC filter coupled to a hybrid acoustic LC filter via a switch.

[0085] Figure 3A This is a schematic block diagram of a radio frequency system according to one embodiment, the radio frequency system having a cascaded filter circuit.

[0086] Figure 3B This is a schematic block diagram of a radio frequency system according to another embodiment, which has a cascaded filter circuit.

[0087] Figure 3C This is a schematic block diagram of a radio frequency system according to another embodiment, which has a cascaded filter circuit.

[0088] Figure 4A This is a schematic block diagram of a multiplexer according to one embodiment, the multiplexer including a cascaded filter and another filter.

[0089] Figure 4B This is a schematic block diagram of a multiplexer according to another embodiment, the multiplexer including a cascaded filter and another filter.

[0090] Figure 5A This is a schematic block diagram of a multiplexer according to one embodiment, the multiplexer including a cascaded filter and another filter coupled to a common node via a switch.

[0091] Figure 5B This is a schematic block diagram of a multiplexer according to another embodiment, the multiplexer including a cascaded filter and another filter coupled to a common node via a switch.

[0092] Figure 6A This is a schematic diagram of a cascaded filter according to one embodiment.

[0093] Figure 6B yes Figure 6A A graph showing the frequency response of the cascaded filter.

[0094] Figure 7 This is a schematic diagram of a cascaded filter according to another embodiment.

[0095] Figure 8 This is a schematic diagram of a cascaded filter according to another embodiment.

[0096] Figure 9 This is a schematic diagram of a cascaded filter according to another embodiment.

[0097] Figure 10 This is a schematic diagram of a cascaded filter according to another embodiment.

[0098] Figure 11A This is a schematic diagram of a hybrid resonator according to one embodiment.

[0099] Figure 11B yes Figure 11A A graph showing the frequency response of the hybrid resonator.

[0100] Figure 12 This is a schematic diagram of a hybrid resonator according to another embodiment.

[0101] Figure 13 This is a schematic block diagram of a hybrid parallel bandpass filter according to one embodiment.

[0102] Figure 14 This is a schematic block diagram of a duplexer according to one embodiment, which includes a hybrid parallel bandpass filter.

[0103] Figure 15This is a schematic block diagram of a triplet according to one embodiment, which includes a hybrid parallel bandpass filter.

[0104] Figure 16 This is a schematic block diagram of a tripod according to one embodiment, the tripod including a shared high-pass filter and a hybrid parallel band-pass filter.

[0105] Figure 17 This is a schematic block diagram of a quadrupler according to one embodiment, the quadrupler including a shared high-pass filter and a hybrid band-pass filter.

[0106] Figure 18 This is a schematic diagram of a tripod according to one embodiment, the tripod including a hybrid parallel bandpass filter.

[0107] Figure 19A Show Figure 18 The simulation results of the three-stage instrument.

[0108] Figure 19B Show Figure 18 A graph showing the simulation results of the three-way converter compared to the previous design.

[0109] Figure 20 This is a schematic block diagram of a hybrid parallel band-stop filter according to one embodiment.

[0110] Figure 21 This is a schematic diagram of a hybrid parallel band-stop filter according to one embodiment.

[0111] Figure 22 yes Figure 21 A graph showing the frequency response of a hybrid parallel band-stop filter.

[0112] Figure 23A This is a schematic block diagram of a radio frequency system according to one embodiment, the radio frequency system including a hybrid acoustic LC filter cascaded with a low-pass filter.

[0113] Figure 23B This is a schematic block diagram of a radio frequency system according to one embodiment, the radio frequency system including a hybrid acoustic LC filter cascaded with a second harmonic notch filter.

[0114] Figure 24A This is a schematic diagram of an example low-pass filter.

[0115] Figure 24B This is a schematic diagram of another example of a low-pass filter.

[0116] Figure 24C This is a schematic diagram of an example second harmonic notch filter.

[0117] Figure 24DThis is a schematic diagram of an example harmonic notch filter.

[0118] Figure 24E This is a schematic diagram illustrating an example of a second harmonic notch filter and a low-pass filter.

[0119] Figure 25A This is a schematic block diagram of a tripod according to one embodiment, the tripod including a hybrid acoustic LC filter cascaded with a low-pass filter.

[0120] Figure 25B This is a schematic block diagram of a tripod according to one embodiment, the tripod including a hybrid acoustic LC filter cascaded with a second harmonic notch filter.

[0121] Figure 26 This is a schematic diagram of a radio frequency module according to one embodiment, which has a transmit path including a filter.

[0122] Figure 27 This is a schematic diagram of a radio frequency module according to one embodiment, which has a receive path including a filter.

[0123] Figure 28 This is a schematic diagram of a radio frequency module according to one embodiment, the radio frequency module including a filter.

[0124] Figure 29 This is a schematic diagram of a wireless communication device according to one embodiment, the wireless communication device including a filter.

[0125] Figure 30 This is a schematic diagram of a wireless communication device according to another embodiment, which includes a filter. Detailed Implementation

[0126] The following detailed descriptions of some embodiments present various descriptions of particular embodiments. However, the new invention described herein can be implemented in many different ways, for example, as defined and covered by the claims. In this description, reference is made to the accompanying drawings, wherein similar reference numerals may indicate the same or functionally similar elements. It should be understood that the elements illustrated in the drawings are not necessarily drawn to scale. Moreover, it should be understood that some embodiments may include more elements than illustrated in the drawings and / or a subset of the elements illustrated in the drawings. Additionally, some embodiments may incorporate any suitable combination of features from two or more drawings. The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claims.

[0127] This application relates to filters comprising acoustic and non-acoustic passive components. Some embodiments relate to hybrid acoustic LC filters cascaded with LC filters. Such filters achieve relatively wide passbands and also meet stringent out-of-band rejection specifications. Some embodiments relate to filters having acoustic and non-acoustic passive components arranged in parallel with each other. Such filters achieve relatively wide bandwidths and high rejection at the stopband relatively close to the passband, with no high losses in the passband. Embodiments disclosed herein relate to non-acoustic LC filters cascaded with hybrid passive / acoustic filters, wherein the non-acoustic LC filters are arranged to suppress harmonics of the radio frequency signal provided by the hybrid passive / acoustic filters. Such filters achieve relatively high bandwidths and high rejection while suppressing self-generated harmonics. Any suitable combination of features of the embodiments disclosed herein can be combined with each other. In various applications, two or more embodiments can be implemented together.

[0128] Hybrid acoustic LC filter cascaded with an LC filter

[0129] With the development of fifth-generation (5G) wireless communication technology, the design of non-acoustic wideband ultra-high band (UHB) filters has encountered difficulties in meeting new carrier aggregation specifications. New carrier aggregation typically generates more intermodulation frequencies, which can reduce receiver-side sensitivity. Therefore, carrier aggregation specifications may have stricter intermodulation distortion (IMD) rejection specifications for filters.

[0130] LC bandpass filters, such as integrated passive device (IPD) bandpass filters, offer advantages such as wide bandwidth and relatively good wide out-of-band rejection. However, LC bandpass filters do not exhibit particularly sharp rejection near the passband frequencies. Compared to acoustic filters, non-acoustic passband filters exhibit significantly worse rolling-off losses at the passband edge frequencies. This is generally undesirable when high rejection near the passband stopband is desired.

[0131] Due to their higher quality factor (Q) than LC resonators, acoustic resonator filters can provide higher rejection at frequencies close to the passband without high edge roll-off losses. Therefore, passive non-acoustic filters can be cascaded with hybrid acoustic LC filters to achieve both wide bandwidth and sharp rejection at the stopband close to the passband.

[0132] To provide a carrier aggregation IMD rejection-compatible filter with relatively sharp rejection at frequencies relatively close to the filter's passband, a hybrid acoustic LC filter can be implemented. This hybrid acoustic LC filter can be a broadband filter comprising one or more capacitors, one or more inductors, and one or more acoustic resonators. The hybrid acoustic LC filter may include multiple hybrid resonators, each comprising an acoustic resonator, at least one inductor, and at least one capacitor.

[0133] Hybrid acoustic LC filters can be cascaded with LC filters to provide a wide passband with relatively low loss and relatively sharp rejection at frequencies relatively close to the passband of the cascaded filter. LC filters may include integrated passive devices (IPDs) on an integrated passive device wafer. Hybrid acoustic LC filters may include one or more bulk acoustic resonators. The combination of bulk acoustic resonators and LC circuit elements in the cascaded filter provides a relatively wide passband and also meets relatively tight out-of-band rejection specifications.

[0134] Several aspects of this application relate to a cascaded filter for filtering radio frequency signals. The cascaded filter includes a hybrid acoustic LC filter and a non-acoustic LC filter cascaded with the hybrid acoustic LC filter. The hybrid acoustic LC filter includes multiple acoustic resonators, capacitors, and inductors. The non-acoustic LC filter includes an LC circuit.

[0135] The cascaded filters discussed in this paper can be implemented for a wide range of frequency bands, including wireless bands, provided that acoustic resonators are available. As an example, the cascaded filters may have a passband with a lower frequency limit of at least 2.5 GHz or at least 3 GHz in some applications. In some applications, the cascaded filters may have a relatively high upper passband limit, such as approximately 4.5 GHz, approximately 6 GHz, approximately 8.5 GHz, or approximately 10 GHz. The cascaded filters discussed in this paper can be implemented in power amplifier modules, diversity receiver modules, or any other suitable RF front-end modules. The cascaded filters discussed in this paper meet the following design specifications: relatively low insertion loss (IL), relatively sharp frequency cutoff, and relatively strong suppression of intermodulation frequencies and harmonics.

[0136] Figure 1AThis is a schematic block diagram of a cascaded filter 10 according to one embodiment, which includes a hybrid acoustic LC filter 12 and an LC filter 14. The cascaded filter 10 has a first port RF1 and a second port RF2. The hybrid acoustic LC filter 12 and the LC filter 14 are arranged in series between the first port RF1 and the second port RF2. In some applications, radio frequency signals can propagate from the first port RF1 to the second port RF2. In various applications, radio frequency signals can propagate from the second port RF2 to the first port RF1.

[0137] The hybrid acoustic LC circuit 12 includes one or more acoustic resonators, one or more inductors, and one or more capacitors. The one or more acoustic resonators may be BAW resonators, such as thin-film bulk acoustic resonators (FBARs). For example, BAW resonators may be more advantageous for filtering signals with higher frequencies, such as those above 2.5 GHz. The one or more acoustic resonators may alternatively or additionally include any other suitable acoustic resonators, such as one or more surface acoustic wave (SAW) resonators, one or more boundary acoustic wave resonators, and / or one or more Lamb wave resonators. The hybrid acoustic LC filter 12 may include capacitors and inductors external to the wafer containing the acoustic resonators. The hybrid acoustic LC filter 12 may be a trapezoidal filter. In some applications, the hybrid acoustic filter 12 may be a fixed filter. In some instances, a fixed filter can be implemented with lower complexity than a tunable filter. In some applications, the hybrid acoustic LC filter 12 may be tunable. When the hybrid acoustic LC filter 12 is tunable, the notch and / or stopband may be tunable.

[0138] The LC circuit 14 includes one or more inductors and one or more capacitors. The LC circuit 14 may include one or more IPDs, one or more surface mount components, one or more passive devices implemented on a package substrate, or any suitable combination thereof. At some frequencies, surface mount components may have a higher quality factor and lower insertion loss than IPDs and passive devices implemented on the package substrate. The one or more capacitors may be explicit capacitors and / or parasitic capacitors. The LC circuit 14 may also achieve impedance matching.

[0139] Figure 1B This is a schematic block diagram of a radio frequency (RF) system 15 according to one embodiment, which includes a cascaded filter 10 in the signal path between a power amplifier 16 and an antenna 17. Figure 1BA cascaded filter 10 is shown to be included in the transmitted signal path. In some applications, the first port RF1 of the cascaded filter 10 may be electrically coupled to the output of the power amplifier 16, and the second port RF2 of the cascaded filter 10 may be electrically coupled to the antenna 17. In some applications, the first port RF1 of the cascaded filter 10 may be electrically coupled to the antenna 17, and the second port RF2 of the cascaded filter 10 may be electrically coupled to the output of the power amplifier 16.

[0140] Figure 1C This is a schematic block diagram of an RF system 18 according to one embodiment, which includes a cascaded filter 10 in the signal path between an antenna 17 and a low-noise amplifier 19. Figure 1C A cascaded filter 10 is shown to be included in the received signal path. In some applications, the first port RF1 of the cascaded filter 10 may be electrically coupled to the input of the low-noise amplifier 19, and the second port RF2 of the cascaded filter 10 may be electrically coupled to the antenna 17.

[0141] Figure 2A This is a schematic block diagram of a cascaded filter circuit 20 according to one embodiment, which includes a hybrid acoustic LC filter 12 coupled to LC filters 14A to 14N via a switch 22. The cascaded filter circuit 20 can share the hybrid acoustic LC filter 12 among multiple LC circuits 14A to 14N. Switch 22 can electrically connect the hybrid acoustic LC filter 12 in series with a selected LC circuit to implement the cascaded filter. The illustrated switch 22 is a multi-throw RF switch. Switch 22 can electrically couple the hybrid acoustic LC filter 12 to the selected LC filter. Switch 22 can have any suitable number of throws, and the cascaded filter circuit 20 can have a corresponding number of LC filters 14A to 14N. Each of the illustrated LC filters 14A and 14N is respectively coupled to a corresponding port RF of the cascaded filter circuit 20. 21 and RF 2N In the cascaded filter circuit 20, the hybrid acoustic LC filter 12 can be combined with one or more selected from LC filters 14A to 14N to achieve relatively sharp blocking at frequencies relatively close to the passband. In some applications, the hybrid acoustic LC filter 12 can be tunable to tune for blocking at frequencies relatively close to the passband for one or more selected from LC filters 14A to 14N electrically coupled thereto.

[0142] Figure 2BThis is a schematic block diagram of a cascaded filter circuit 25 according to one embodiment, which includes an LC filter 14 coupled to hybrid acoustic LC filters 12A and 12N via a switch 22. The cascaded filter circuit 25 can share the LC filter 14 among multiple hybrid acoustic LC circuits 12A to 12N. Switch 22 can electrically connect the LC filter 14 in series with a selected hybrid acoustic LC circuit to implement the cascaded filter. The illustrated switch 22 is a multi-throw RF switch. Switch 22 can electrically couple the LC filter 14 to the selected hybrid acoustic LC filter. Switch 22 can have any suitable number of throws, and the cascaded filter circuit 25 can have a corresponding number of hybrid acoustic LC filters 12A to 12N. Each of the illustrated hybrid acoustic LC filters 12A and 12N is respectively coupled to a corresponding port RF of the cascaded filter circuit 25. 11 and RF 1N .

[0143] Figure 3A This is a schematic block diagram of a radio frequency system 30A with a cascaded filter circuit according to one embodiment. The radio frequency system 30 is implementable Figure 2A An example system of cascaded circuit 20. As shown, antenna 32 is coupled to hybrid acoustic LC filter 12, switch 22 is a transmit / receive switch, and LC filters 14A and 14B are connected to power amplifier 34 and low noise amplifier 36, respectively. Figure 2B The cascaded circuit 25 can be implemented in an RF system similar to the RF system 30A.

[0144] Figure 3B This is a schematic block diagram of a radio frequency system 30B with a cascaded filter circuit according to another embodiment. Figure 3B The LC circuits 14A and 14B are shown to be in different transmission paths having corresponding power amplifiers 34A and 34B. Therefore, the hybrid acoustic LC filter 12 can be included in (a) a cascaded filter circuit having LC filter 14A between power amplifier 34A and antenna 32 and (b) a cascaded filter circuit having LC filter 14B between power amplifier 34B and antenna 32.

[0145] Figure 3C This is a schematic block diagram of a radio frequency system 30C with a cascaded filter circuit according to another embodiment. For example, the cascaded filter of the radio frequency system 30C can be implemented in diversity reception applications. Figure 3CThe LC circuits 14A and 14B are shown to be in different receiving paths with corresponding low-noise amplifiers 36A and 36B. Therefore, the hybrid acoustic LC filter 12 can be included in (a) a cascaded filter circuit with LC filter 14A between low-noise amplifier 36A and antenna 32 and (b) a cascaded filter circuit with LC filter 14B between low-noise amplifier 36B and antenna 32.

[0146] Figure 4A This is a schematic block diagram of a multiplexer 40 according to one embodiment, which includes a cascaded filter and another filter. The multiplexer 40 includes multiple filters coupled to a common node. As shown, the cascaded filter, including an LC filter 14 and a hybrid acoustic LC filter 12, along with other filters 42, are coupled together at the common node. In the multiplexer 40, the LC filter 14 is coupled to the common node via the hybrid acoustic LC filter 12. The multiplexer 40 can be a duplexer with two filters, a triplet with three filters, a quadplexer with four filters, etc. The other filters 42 can include any suitable number of filters. (The other filters 42 can include one or more LC filters (e.g., IPD filters), one or more acoustic filters, one or more hybrid acoustic LC filters, etc., or any suitable combination thereof.)

[0147] Figure 4B This is a schematic block diagram of a multiplexer 45 according to another embodiment, which includes a cascaded filter and another filter. Except for the hybrid acoustic LC filter 12 being coupled to a common node via an LC filter 14, the multiplexer 45... Figure 4A The multiplexer 40 is the same.

[0148] Multiple filters can communicate with a common node, such as an antenna node, via switches. Figure 5A This is a schematic diagram of an RF system 50, which includes a cascaded filter and another filter 42 coupled to a common node via a switch 52. The cascaded filter, the other filter 42, and the switch 52 can implement switch-plexing. Switch-plexing enables on-demand multiplexing.

[0149] Figure 5B This is a schematic block diagram of a radio frequency (RF) system 55 according to another embodiment, which includes a cascaded filter and another filter coupled to a common node via a switch. Except that the hybrid acoustic LC filter 12 and LC filter 14 are arranged in a different order, the RF system 55... Figure 5A The radio frequency system is the same as 50.

[0150] Figure 6AThis is a schematic diagram of a cascaded filter 60 according to one embodiment. The cascaded filter 60 may be a bandpass filter arranged to allow radio frequency signals with frequencies higher than 3 GHz, such as band 42 signals and / or band 43 signals and / or band 48 signals, to pass through. In such applications, the acoustic resonator of the filter 60 may be a BAW resonator. The filter 60 can be used in 5G wireless system applications. 5G technology may be referred to as 5G New Radio (NR). The cascaded filter 60 includes a hybrid acoustic LC filter 62 cascaded with an LC filter 64. The hybrid acoustic LC filter 62 is an example of a hybrid acoustic LC filter 12. The LC filter 64 is an example of an LC filter 14.

[0151] The hybrid acoustic LC filter 62 includes: acoustic resonators A61 and A62; inductors L601, L602, L603, L604, L605, and L606; and capacitors C601, C602, C603, and C604. Acoustic resonators A61 and A62 can be BAW resonators such as FBARs. In some instances, acoustic resonators A61 and A62 may include SAW resonators, temperature-compensated SAW (TCSAW) resonators, boundary acoustic wave resonators, Lamb wave resonators, etc., or any suitable combination thereof. Inductors L601, L602, L603, L604, L605, and L606, and capacitors C601, C602, C603, and C604 are LC / non-acoustic components. The LC / non-acoustic components of the hybrid acoustic LC filter 62 can be implemented outside the wafer including acoustic resonators A61 and A62. The LC / non-acoustic components of the hybrid acoustic LC filter 62 may include one or more surface mount technology (SMT) inductors and / or capacitors. In some cases, the LC / non-acoustic components of the hybrid acoustic LC filter 62 may include one or more inductive traces on one or more IPDs and / or package substrates.

[0152] As shown in the figure, the hybrid acoustic LC filter 62 includes a hybrid resonator structure, wherein inductor L602 is connected in parallel with acoustic resonator A62, and inductor L603 is connected in series with inductor L602 and acoustic resonator A62. (Reference) Figure 11A and Figure 11BFurther details regarding the hybrid resonator structure are provided. The illustrated LC filter 62 also includes LC slots between acoustic nodes, where acoustic resonators A61 and A62 are arranged in series with corresponding inductors L603 and L606 in the shunt circuit, wherein the LC slots include a capacitor C604 and an inductor L605. Reference Figure 12 More details are provided regarding the structure of this hybrid resonator.

[0153] LC filter 64 may be a bandpass filter. For example, LC filter 64 may be a bandpass 42 / bandpass 43 filter. LC filter 64 includes an IPD portion 65 on the IPD wafer, a package substrate portion 66 including traces on the package substrate, and an SMT portion 67 including SMT components. IPD portion 65 includes IPD capacitors C605, C606, C607, C608, C609, and C610, and an IPD inductor L608. Package substrate portion 66 includes inductive traces arranged as inductors L609, L610, L611, and L612. SMT component 67 includes SMT capacitors C611 and C612.

[0154] As shown in the figure, the LC filter 64 includes a bridge capacitor, an LC resonant circuit, coupling capacitors, and a series LC slot. The first bridge capacitor C610 has a first end coupled to the series LC slot and a second end coupled to the input node of the LC filter 64. The series LC slot includes a capacitor C605 and an inductor L608. The first bridge capacitor C610 is connected in parallel with three coupling capacitors C606, C607, and C608.

[0155] The first LC resonant circuit is an LC shunt resonant circuit. As shown in the figure, the first LC resonant circuit includes a shunt inductor L611, which is connected in parallel with a series LC circuit including inductor L612 and capacitor C612. A second bridge capacitor C609 has a first end coupled to the series LC slot and a second end coupled to the first LC resonant circuit. The second bridge capacitor C609 is connected in parallel with two coupled capacitors C606 and C607. The second LC resonant circuit is an LC shunt resonant circuit. As shown in the figure, the second LC resonant circuit includes a shunt inductor L609 connected in parallel with the series LC circuit, which includes inductor L610 and capacitor C611.

[0156] A first coupling capacitor C608 is coupled between the filter input and a node at which it is coupled to a first LC resonant circuit and a second coupling capacitor C607. A second coupling capacitor C607 is coupled in series between the first coupling capacitor C608 and a third coupling capacitor C606. The second coupling capacitor C607 is also coupled between the first LC resonant circuit and the second LC resonant circuit. A third coupling capacitor C606 is coupled between a series LC slot and a node at which it is coupled to a second LC resonant circuit and a second coupling capacitor C607. The series LC slots shown in the diagram are parallel LC circuits.

[0157] Figure 6B yes Figure 6A A graph showing the frequency response of the cascaded filter 60. The curve shown represents... Figure 6A The frequency response of the cascaded filter is 60. The stepped lines represent design specifications or filter masks. Figure 6B The curves in the figure show that, except at 9 GHz, Figure 6A The frequency response of the cascaded filter 60 meets the design specifications. As shown in the figure, the filter response has two zero values ​​(null) generated by the shunt acoustic resonators A61 and A62. The frequency response has a relatively sharp roll-off at the passband edge. Figure 6A The non-acoustic LC filter 64 provides a relatively large bandwidth. The frequency response has a relatively wide bandwidth from approximately 3.1 GHz to 4.2 GHz in the frequency response shown. Therefore, Figure 6A The cascaded filter 60 may have a bandwidth of at least 1 GHz. In some other embodiments, the cascaded filter having a hybrid acoustic LC filter cascaded with a non-acoustic LC filter may have a bandwidth that is significantly wider in range than that determined by the acoustic resonator coupling factor, for example, a bandwidth from about 3.3 GHz to 4.2 GHz or from about 4.4 GHz to 5 GHz.

[0158] Figure 6A The cascaded filter 60 is an example of a non-acoustic LC filter cascaded with a hybrid acoustic LC filter. The principles and advantages discussed in this paper can be implemented in various other filter topologies. Some example filter topologies are shown in... Figures 7 to 10 As shown in the diagram. For example, these filters can be used in 5G applications. These filters include acoustic resonators such as FBARs, as well as inductors and capacitors. Inductors and capacitors may include one or more IPDs, one or more surface mount inductors, one or more surface mount capacitors, one or more inductive traces on a package substrate, or any suitable combination thereof. Figures 7 to 10The example filters illustrate filters for a variety of applications and design specifications. Any suitable combination of the features of these filters can be implemented together with each other and / or according to any other principles and advantages discussed herein.

[0159] Figure 7 This is a schematic diagram of a cascaded filter 70 according to another embodiment. The cascaded filter 70 includes a hybrid acoustic LC filter 72 cascaded with an LC filter 74. The hybrid acoustic LC filter 72 is an example of a hybrid acoustic LC filter 12. The LC filter 74 is an example of an LC filter 14. For example, the cascaded filter 70 may be a receiver filter. In some applications, the cascaded filter 70 may have a passband from 3.4 GHz to 3.7 GHz.

[0160] The hybrid acoustic LC filter 72 includes: acoustic resonators A71, A72, A73, A74, A75, and A76; capacitors C701, C702, and C703; and inductors L701, L702, L703, L704, L705, L706, L707, L708, and L709. Acoustic resonators A71 to A76 may be BAW resonators. Capacitors C701 to C703 may be SMT capacitors. Inductors L701 to L709 may comprise a combination of SMT inductors and conductive traces on a package substrate.

[0161] The illustrated LC filter 74 includes capacitors C704 and C705 and inductors L710 and L711. In some embodiments, the LC filter 74 can be implemented using IPD capacitors and inductors on the IPD wafer. In some other embodiments, the LC filter 74 can be implemented using SMT capacitors and inductors on the IPD wafer.

[0162] Figure 8 This is a schematic diagram of a cascaded filter 80 according to another embodiment. The cascaded filter 80 includes a hybrid acoustic LC filter 82 cascaded with an LC filter 84. The hybrid acoustic LC filter 82 is an example of a hybrid acoustic LC filter 12. The LC filter 84 is an example of an LC filter 14. In one embodiment, the cascaded filter 80 may be a bandpass filter having a passband from about 3.3 GHz to 4.2 GHz. According to another embodiment, the cascaded filter may have a passband from 3.4 GHz to 3.7 GHz. For example, the cascaded filter 80 may be a receiver filter.

[0163] The hybrid acoustic LC filter 82 includes: acoustic resonators A81, A82, A83, A84, and A85; capacitors C801 and C802; and inductors L801, L802, L803, L804, L805, and L806. Acoustic resonators A81 to A85 may be BAW resonators. Capacitors C801 and C802 may be SMT capacitors. Inductors L801 to L805 may include a combination of SMT inductors and conductive traces on a package substrate. The hybrid resonator including inductors L802 and L803 and acoustic resonators A81, A82, and A83 can be used with reference to... Figure 11A and Figure 11B The described hybrid resonator functions similarly. The hybrid trapezoidal structure, including inductors L802 to L805, capacitor C802, and acoustic resonators A81 to A85, is comparable to the reference... Figure 12 The described hybrid trapezoidal structure functions similarly.

[0164] The LC filter 84 shown includes capacitors C803, C804, C805, C806, and C807, and inductors L806, L807, L808, and L809. The LC filter 84 may include one or more IPDs, one or more SMT components, one or more conductive traces on a substrate, or any suitable combination thereof.

[0165] Figure 9 This is a schematic diagram of a cascaded filter 90 according to another embodiment. The cascaded filter 90 includes a hybrid acoustic LC filter 92 cascaded with an LC filter 94. The hybrid acoustic LC filter 92 is an example of a hybrid acoustic LC filter 12. The LC filter 94 is an example of an LC filter 14. In some embodiments, in addition to a shunt inductor coupled between an acoustic resonator and ground, the cascaded filter 90 may include surface-mount passive components, wherein such a shunt inductor may be a printed trace on a package substrate. Thus, in such embodiments, the cascaded filter 90 does not include an IPD. In some instances, the cascaded filter 90 may be a receive filter coupled between an antenna switch and a low-noise amplifier. Compared to a previous design, the cascaded filter 90 may improve insertion loss. The cascaded filter 90 may be a receive filter.

[0166] The hybrid acoustic LC filter 92 includes: acoustic resonators A91, A92, and A93; capacitors C901, C902, C903, and C904; and inductors L901, L902, L903, and L904. Acoustic resonators A91 to A93 may be BAW resonators. Capacitors C901 to C904 may be SMT capacitors. Inductors L901 to L904 may comprise a combination of SMT inductors and conductive traces on a package substrate.

[0167] The illustrated LC filter 94 includes capacitors C903, C904, and C905, and inductors L905, L906, L907, and L908. The LC filter 94 may include one or more IPDs, one or more SMT components, one or more conductive traces on a substrate, or any suitable combination thereof. In one embodiment, the LC filter 94 comprises SMT inductors and capacitors.

[0168] Figure 10 This is a schematic diagram of a cascaded filter according to another embodiment. The cascaded filter 100 includes a hybrid acoustic LC filter 102 cascaded with an LC filter 104. The hybrid acoustic LC filter 102 is an example of a hybrid acoustic LC filter 12. The LC filter 104 is an example of an LC filter 14. In some embodiments, the cascaded filter 100 may include an IPD, surface-mount passive components, inductive traces on a laminated material, and an FBAR. In some instances, the cascaded filter 100 may be a receive filter coupled between an antenna switch and a low-noise amplifier. The cascaded filter 100 may be a bandpass filter having a passband from about 3.3 GHz to 4.2 GHz. In some embodiments, the cascaded filter 100 is a receive filter.

[0169] The hybrid acoustic LC filter 102 includes: acoustic resonators A101, A102, and A103; capacitors C1001 and C1002; and inductors L1001, L1002, L1003, L1004, L1005, and L1006. Acoustic resonators A101 to A103 may be BAW resonators. Capacitors C1001 and C1002 may include SMT capacitors and / or IPD capacitors. Inductors L1001 to L1006 may include one or more SMT inductors, one or more IPD inductors, one or more conductive traces on the package substrate, or any suitable combination thereof. In one embodiment, inductors L1001 to L1006 include at least an SMT inductor, at least one IPD inductor, and at least one conductive trace on the package substrate.

[0170] The hybrid resonator, including inductors L1002 and L1003 and acoustic resonator A102, can be used with a reference. Figure 11A and Figure 11B The described hybrid resonator functions similarly. The hybrid resonator, including inductors L1005 and L1006 and acoustic resonator A103, can be compared with the reference... Figure 11A and Figure 11B The described hybrid resonator functions similarly. The hybrid trapezoidal structure, including inductors L802 to L806, capacitor C1002, and acoustic resonators A102 to A103, is comparable to the reference... Figure 12 The described hybrid trapezoidal structure functions similarly.

[0171] The illustrated LC filter 104 includes capacitors C1003, C1004, C1005, C1006, and C1007, and inductors L1007, L1008, L1009, and L1010. The LC filter 104 may include one or more IPDs, one or more SMT components, one or more conductive traces on a substrate, or any suitable combination thereof. In one embodiment, the LC filter 104 includes at least an SMT component, at least one IPD, and at least one conductive trace on a package substrate.

[0172] The hybrid acoustic LC filters discussed in this article can include various hybrid resonators, which include acoustic resonators and non-acoustic passive components. References will be made to... Figures 11A to 12 Let's discuss example hybrid resonators. These hybrid resonators can be implemented in association with any suitable embodiments discussed herein.

[0173] Figure 11A This is a schematic diagram of a hybrid resonator 110 according to one embodiment. The hybrid resonator 110 includes an acoustic resonator 112, a first inductor 114, and a second inductor 116. The acoustic resonator 112 is arranged as a shunt resonator. For example, the acoustic resonator 112 can be an FBAR. The acoustic resonator 112 can be any other suitable acoustic resonator. The acoustic resonator 112 is connected in parallel with the first inductor 114. The acoustic resonator 112 is connected in series with the second inductor 116. The combination of inductors 114 and 116 with the acoustic resonator 112 can generate a pair of notches relatively close to the passband and having no significant impact on transmission loss. The notches can be in the range of approximately 1.1 GHz to 8.5 GHz from the lower or upper limit of the passband.

[0174] Figure 11B yes Figure 11A A graph showing the frequency response of the hybrid resonator 110. The frequency response is shown in the reference graph. Figure 11A The discussion focuses on a pair of notch filters. The frequency response also shows that the simulated hybrid resonator 110 does not introduce significant transmission loss.

[0175] Figure 12This is a schematic diagram of a hybrid resonator 120 according to another embodiment. The hybrid resonator 120 is a hybrid trapezoidal structure. The hybrid resonator 120 includes a first series shunt circuit, an LC slot, and a second series shunt circuit. The first series shunt circuit includes a first acoustic resonator 122 and a first inductor 123. The second series shunt circuit includes a second acoustic resonator 124 and a second inductor 125. The LC slot includes a capacitor 126 connected in parallel with a third inductor 127. The hybrid resonator 120 includes LC slots between acoustic nodes. This can provide both inter-resonator impedance matching and far-end notch filtering in the frequency response of a filter including the hybrid resonator 120. The hybrid resonator 120 includes a hybrid trapezoidal structure. For example, the hybrid resonator 120 can be used in low-pass filters and / or high-pass filters. The hybrid resonator 120 is a hybrid trapezoidal topology.

[0176] Parallel hybrid acoustic passive filter

[0177] With the development of 5G wireless communication technology, new carrier aggregation (CA) specifications can specify stricter intermodulation distortion (IMD) rejection for filters. This new CA can involve more multiplexed filters than previous CAs. To provide CA IMD rejection-compatible filters with sharp rejection near the passband frequencies, acoustically assisted filters can be designed using hybrid resonators such as hybrid acoustic LC resonators to provide relatively low loss, a wide passband, and relatively sharp rejection near the passband frequencies. Acoustic resonators can generate harmonics when relatively high power is applied. Harmonics generated by surface acoustic wave (SAW) devices or bulk acoustic wave (BAW) devices can leak into higher frequency bands and / or have emission exceeding standard specifications.

[0178] To provide a CA-compatible multiplexed filter with sharp rejection at edge frequency bands, hybrid acoustic LC broadband filters can be included in some or all of the passband arms. To reduce and / or minimize the use of filter acoustic chips and passive components, hybrid acoustic LC filters, or integrated passive device (IPD) filters, or passive low-pass (LP) or high-pass (HP) filters, can be shared by two or more passband arms. Additionally, to provide specific sharp rejection in high-frequency band arms (e.g., Wi-Fi 2.4 GHz) within a bandpass filter (BPF), parallel hybrid acoustic LC filters can be included. In some instances, parallel hybrid acoustic LC filters can be cascaded with another filter, such as a passive non-acoustic filter.

[0179] A hybrid acoustic LC filter with parallel hybrid acoustic LC sub-filters is disclosed. In one embodiment, the parallel acoustic LC filter includes a first sub-filter configured to filter an radio frequency signal and a second sub-filter coupled in parallel with the first sub-filter. The first sub-filter includes a first acoustic resonator and a first LC component. The second sub-filter includes a second acoustic resonator and a second LC component. The parallel hybrid acoustic LC filter can be implemented in a multiplexer that includes multiple filters coupled together at a common node. The parallel hybrid acoustic filter can implement any suitable principles and advantageous aspects of the acoustic LC circuits disclosed herein. As an example, the parallel hybrid acoustic LC filter may include... Figure 11A The hybrid resonator 110. As yet another example, a parallel hybrid acoustic LC filter may include... Figure 12 The hybrid trapezoidal structure 120.

[0180] Parallel hybrid acoustic LC filters can be bandpass filters. Parallel hybrid acoustic LC filters can also be bandstop filters. Parallel hybrid acoustic LC filters can be located in high-frequency band paths. Such filters can reduce and / or minimize design complexity. Additionally, in some applications, such filters can be implemented with fewer passive components and / or less physical area. The parallel hybrid passive filters discussed herein can meet the design specifications of high-frequency band paths, such as desired blocking at specific frequencies (e.g., the Wi-Fi band). This allows the high-frequency band path to be shared by both transmit and receive paths simultaneously.

[0181] Parallel hybrid acoustic LC filters can provide relatively wide bandwidth and strong rejection in a specific frequency band. A parallel hybrid acoustic LC filter can include multiple hybrid filters connected in parallel to each other for different frequency bands and arranged to provide strong rejection for another frequency band. As an example, a parallel hybrid acoustic LC bandpass filter for bands 40 and 41 can provide sufficiently wide bandwidth for both passband 40 and band 41 signals, while also providing strong rejection for the 2.4 GHz Wi-Fi band. In some embodiments, a passive non-acoustic filter can be cascaded with the parallel hybrid acoustic LC filter to achieve wide bandwidth and sharp rejection in the high-frequency path. According to some embodiments, a triplexer can be implemented by a parallel hybrid acoustic LC filter coupled to a common node and two other filters. For example, a triplexer for the low-frequency (LB) / mid-frequency (MB) / high-frequency (HB) band can include an LB filter, an MB filter, and an HB filter implemented by a hybrid acoustic LC filter, which includes a band 40 filter connected in parallel with the band 41 filter. Such a triplet can be effectively used as a quadruplet to benefit system-level carrier aggregation applications.

[0182] Figure 13This is a schematic block diagram of a hybrid parallel bandpass filter 130 according to one embodiment. The parallel hybrid bandpass filter 130 includes a first bandpass filter 132 and a second bandpass filter 134 arranged in parallel with each other. The first bandpass filter 132 and the second bandpass filter 134 are arranged to filter radio frequency signals. The first bandpass filter 132 is a hybrid acoustic passive filter including a first acoustic resonator and a first non-acoustic passive component. The first non-acoustic passive component may include at least an inductor and a capacitor. The second bandpass filter 134 may be a hybrid acoustic passive filter including a second acoustic resonator and a second non-acoustic passive component. The second non-acoustic passive component may include at least an inductor and a capacitor. The first bandpass filter 132 has a first passband, and the second bandpass filter 134 has a second passband. By including two filters in parallel with each other, the bandwidth of the parallel filter can be increased relative to either of the two individual filters included in the parallel filter. The hybrid parallel bandpass filter 130 has a passband including both the first and second passbands. The frequency response of the hybrid parallel bandpass filter 130 can have a notch in its passband between the first and second passbands. For example, the notch can be used in the 2.4 GHz Wi-Fi band. Figure 13 The symbol 135 of the parallel hybrid bandpass filter 130 is also shown.

[0183] While embodiments have been discussed with reference to parallel hybrid acoustic LC filters for high-frequency band filters, any suitable principles and advantages discussed herein may be applied to mid-frequency band filters, low-frequency band filters, or any other filters that may benefit from the features discussed herein.

[0184] The parallel hybrid acoustic LC filter discussed in this article can be implemented in power amplifier modules, diversity receiver modules, or any other suitable RF front-end modules.

[0185] The parallel hybrid acoustic passive filters discussed in this paper can be implemented in a multiplexer comprising multiple filters coupled together at a common node. Such multiplexers can include duplexers, tripplexers, quadplexers, etc. Any suitable number of filters can be coupled together at a common node in the multiplexer. Multiple filters can be coupled together at a common node via multi-throw RF switches to achieve switch multiplexing functionality. (See references...) Figures 14 to 16 This describes some example multiplexers that include parallel hybrid acoustic passive filters. The example multiplexers include... Figure 13 The parallel hybrid acoustic filter 130 can be implemented according to any suitable principle and advantageous aspect of the parallel hybrid acoustic filter 130.

[0186] Figure 14This is a schematic block diagram of a duplexer 140 according to one embodiment, which includes a hybrid parallel bandpass filter 130. The duplexer 140 includes a hybrid parallel bandpass filter 130 and a second filter 144. The parallel hybrid acoustic filter 130 may be a high-frequency band filter, and the second filter 144 may be an intermediate-frequency band filter as shown. The parallel hybrid acoustic filter 130 and the second filter 144 may be coupled together at a common node such as the antenna node ANT shown in the figure. The second filter 144 may be a hybrid acoustic passive filter, a non-acoustic LC filter, or an acoustic filter. The second filter 144 may be a band-stop filter. The stopband of the band-stop filter may include some or all of the first passband of the first bandpass filter 132 and / or the second passband of the second bandpass filter 134.

[0187] Figure 15 This is a schematic block diagram of a tripper 150 according to one embodiment, which includes a hybrid parallel bandpass filter 130. The tripper 150 includes a hybrid parallel bandpass filter 130, a second filter 154, and a third filter 156. The parallel hybrid acoustic filter 130 may be a high-frequency band filter, the second filter 154 may be a mid-frequency band filter, and the third filter 156 may be a low-frequency band filter as shown. The parallel hybrid acoustic filter 130, the second filter 154, and the third filter 156 may be coupled together at a common node, such as the antenna node shown in the figure. The second filter 154 may be a high-pass and band-stop filter. The stopband of the high-pass and band-stop filter may include some or all of the first passband of the first bandpass filter 132 and / or the second passband of the second bandpass filter 134. The second filter 154 may be a hybrid acoustic LC filter, a non-acoustic LC filter, or an acoustic filter. The third filter 156 may be a low-pass filter. The third filter 156 may be a hybrid acoustic LC filter, a non-acoustic LC filter, or an acoustic filter. The third filter 156 allows frequencies below the corresponding passband of the second filter 154 and the hybrid parallel bandpass filter 130 to pass through.

[0188] Figure 16 This is a schematic block diagram of a tripper 160 according to one embodiment, which includes a shared high-pass filter 162 and a hybrid parallel band-pass filter 130. Except that the shared high-pass filter 162 and the hybrid parallel band-pass filter 130 are cascaded together with a second filter 144, and the second filter 144 is a band-stop filter, the tripper 160... Figure 15The tripod 150 is identical. Therefore, a shared high-pass filter 162 is coupled between the parallel hybrid acoustic filter 130 and the common node. The shared high-pass filter 162 is also coupled between the second filter 144 and the common node. For example, the shared high-pass filter 162 can be an LC filter or a hybrid acoustic LC filter. In one embodiment, the shared high-pass filter 162 can be a non-acoustic passive filter. Such a shared high-pass filter 162, together with the parallel hybrid acoustic filter 130, can achieve a relatively wide bandwidth and relatively sharp blocking for high-frequency paths.

[0189] Figure 17 This is a schematic block diagram of a quadrupler 170 according to one embodiment, which includes a shared high-pass filter 162 and a hybrid bandpass filter. The quadrupler 170 is connected to, except that separate terminals are provided for the first bandpass filter 132 and the second bandpass filter 134, respectively. Figure 16 The triplet 160 is identical. This allows for greater freedom in carrier aggregation options. In the quadruplet 170, the first bandpass filter 132 and the second bandpass filter 134 can receive signals in different frequency bands and filter the corresponding signals.

[0190] Figure 17 This is an example of a multiplexer that includes hybrid acoustic passive filters. The first bandpass filter 132 and the second bandpass filter 134 have different passbands, and both are coupled to a common node via a shared high-pass filter 162. Figure 17 The first bandpass filter 132 and / or the second bandpass filter 134 may include multiple acoustic resonators and non-acoustic passive components. The non-acoustic passive components may include inductors and capacitors located outside the wafer including the acoustic resonators. The non-acoustic passive components may include an inductor connected in parallel with one of the multiple acoustic resonators. The first bandpass filter 132 and / or the second bandpass filter 134 may include any suitable combination of the features of the hybrid acoustic passive filters disclosed herein. In some embodiments, each of the first bandpass filter 132 and the second bandpass filter 134 has a passband in a frequency range from 2 GHz to 5 GHz, for example, in a frequency range from 2 GHz to 3 GHz.

[0191] A band-stop filter 144 is coupled to a common node via a shared high-pass filter 162. The band-stop filter 144 includes a stopband that includes the passbands of a first band-pass filter 132 and a second band-pass filter. A low-pass filter 156 is coupled to the common node.

[0192] Using a four-tool 170, it can be compared to Figure 16The quadplexer 160 improves certain carrier aggregation performance. For example, a wireless communication device including a quadplexer can support carrier aggregation at a common node including a first carrier and a second carrier. In this example, the first carrier is respectively within the passband of the first bandpass filter 132 and outside the passband of the second bandpass filter 134, and the second carrier is outside the passband of both the first bandpass filter 132 and the second bandpass filter 134. By not filtering the first carrier with the second bandpass filter 134, less insertion loss degradation can exist in the quadplexer 170 compared to the quadplexer 160.

[0193] Figure 18 This is a schematic diagram of a tripod 180 according to one embodiment, which includes a hybrid parallel bandpass filter 182. Figure 18 The figure shows an example multiplexer with a hybrid parallel bandpass filter. As shown, the multiplexer 180 includes a hybrid parallel bandpass filter 182, a hybrid acoustic LC filter 184, a non-acoustic LC filter 186, and a harmonic notch filter 188.

[0194] The hybrid parallel bandpass filter 182 is an example of the hybrid parallel bandpass filter 130. The hybrid parallel bandpass filter 182 is a high-frequency bandpass filter in the tripod 180. The hybrid parallel bandpass filter 182 is an example filter topology of acoustic resonators and inductors. As shown, a high-frequency bandpass signal is supplied to the hybrid parallel bandpass filter 182 via inductors L1801 and L1802. The hybrid parallel bandpass filter 182 includes a first sub-filter comprising acoustic resonators A1801, A1802, A1803, A1804, A1805, A1806, A1807, A1808, A1809, and A1810, and inductors L1803, L1804, and L1805. The hybrid parallel bandpass filter 182 further includes a second sub-filter comprising acoustic resonators A1811, A1812, A1813, A1814, A1815, A1816, A1817, A1818, A1819, and A1820, and inductors L1806 and L1807. The hybrid parallel bandpass circuit 182 includes... Figure 18 Parasitic capacitances are not shown, although these parasitic capacitances are part of the LC circuitry of the hybrid parallel bandpass filter 182. The inductors of the hybrid parallel bandpass filter 182 may include one or more SMT inductors and / or one or more conductive traces on the substrate. The acoustic resonators of the hybrid parallel bandpass filter 182 may include one or more BAW resonators, such as one or more FBARs.

[0195] The hybrid acoustic LC filter 184 includes acoustic resonators, inductors, and capacitors. As shown in the figure, the hybrid acoustic LC filter 184 includes: acoustic resonators A1821, A1822, A1823, A1824, A1825, A1826, A1827, A1828, and A1829; inductors L1808, L1809, L1810, L1811, and L1812; and capacitors C1801 and C1802. The hybrid acoustic LC filter 184 can be implemented according to any suitable principles and advantageous aspects of the hybrid acoustic LC filter disclosed herein. The hybrid acoustic LC filter 184 is a mid-frequency band filter in the triode 180.

[0196] The non-acoustic LC filter 186 is a low-frequency band filter in the tripod 180. The non-acoustic LC filter 186 can be a low-pass filter. For example, such a low-pass filter can be based on... Figure 24A and / or Figure 24B To implement a low-pass filter using any appropriate principle and advantageous aspect.

[0197] Harmonic notch filter 188 can provide a notch at the harmonics of a radio frequency signal to filter out the harmonics. For example, harmonic notch filter 188 can be based on... Figure 24D The low-pass filter can be implemented using any suitable principle and advantageous aspect. The harmonic notch filter 188 shown includes capacitors C1803, C1804, C1805, and C1806, and inductors L1813 and L1814. The harmonic notch filter 188 can provide notch filtering at two harmonic frequencies.

[0198] Figure 19A Show Figure 18 The simulation results of the three-way actuator 180. Figure 19A The passbands of filters 182, 184, and 186 of the tripod 180 are shown. The low-pass filter 186 has a passband indicated by a curve using a solid line. The mid-band filter 184 has a passband indicated by a first dashed curve. The passband of the parallel hybrid acoustic bandpass filter 182 is indicated by a different dashed curve. The parallel hybrid acoustic bandpass filter 182 has a notch in the middle portion of its passband. This notch corresponds to the frequency range between two different frequency bands through which the parallel hybrid acoustic bandpass filter 182 is arranged. Simulation results show that isolation is improved across the mid-band and high-band filters in the tripod 180 compared to previous designs. With a load pull ratio of 9:1... Figure 18 Reasonable insertion loss exists in the simulation of the 180-degree-of-freedom triplet.

[0199] Figure 19B Showing a comparison with the previous design Figure 18The simulation results for the tripod 180 are presented in graphs. These simulation results show that, compared with the previous design, both insertion loss and isolation are improved by using the tripod 180.

[0200] While the embodiments of parallel hybrid acoustic filters discussed herein relate to bandpass filters, any suitable principles and advantages of the parallel hybrid acoustic filters discussed herein can be applied to bandstop filters. Parallel hybrid acoustic bandstop filters can be implemented as standalone filters or within multiplexers. References will be made to... Figures 20 to 22 An exemplary parallel hybrid acoustic bandstop filter is discussed.

[0201] Figure 20 This is a schematic block diagram of a hybrid parallel band-stop filter 200 according to an embodiment. The hybrid parallel band-stop filter 200 can generate a relatively wide band rejection in the passband very close to another filter without using an LC notch filter, which can more significantly reduce in-band loss.

[0202] The parallel hybrid band-stop filter 200 includes a first band-stop filter 202 and a second band-stop filter 204 arranged in parallel with each other. The first band-stop filter 202 and the second band-stop filter 204 are arranged for filtering radio frequency signals. The first band-stop filter 202 is a hybrid acoustic passive filter including a first acoustic resonator and a first non-acoustic passive component. The first non-acoustic passive component may include at least an inductor and a capacitor. The second band-stop filter 204 is a hybrid acoustic passive filter including a second acoustic resonator and a second non-acoustic passive component. The second non-acoustic passive component may include at least an inductor and a capacitor. The first band-stop filter 202 has a first stopband, and the second band-stop filter 204 has a second stopband. By including two filters in parallel with each other, the stopband of the parallel hybrid band-stop filter 200 can be increased relative to either of the two individual filters 202 or 204 included in the parallel filter.

[0203] The hybrid parallel band-stop filter 200 has stopbands, which include a first stopband and a second stopband. The frequency response of the hybrid parallel band-stop filter 200 may have a notch in its stopband between the first and second stopbands. Figure 20 The label 205 of the parallel hybrid bandpass filter 200 is also shown.

[0204] Figure 21 This is a schematic diagram of a hybrid parallel band-stop filter 210 according to one embodiment. The hybrid parallel band-stop filter 210 is... Figure 20 Example of a hybrid parallel band-stop filter 200. Hybrid parallel band-stop filter 210 is an example filter topology combining an acoustic resonator and an inductor. Hybrid parallel band-stop filter 210 includes... Figure 21Parasitic capacitances not shown, although these parasitic capacitances are part of the LC circuitry of the hybrid parallel band-stop filter 210.

[0205] As shown in the figure, radio frequency signals can be provided to a hybrid parallel band-stop filter 210 via inductors L2101 and L2102. The hybrid parallel band-stop filter 210 includes a first sub-filter 212, which includes acoustic resonators A2101, A2102, A2103, A2104, and A2105, and inductors L2103, L2104, L2105, L2106, and L2107. The hybrid parallel band-stop filter 210 also includes a second sub-filter 214, which includes acoustic resonators A216, A217, A218, A219, and A220; inductors L2108, L2109, and L2110; and a capacitor C2101. The inductors of the hybrid parallel band-stop filter 210 may include one or more SMT inductors and / or one or more conductive traces on the substrate. The acoustic resonator of the hybrid parallel band-stop filter 210 may include one or more BAW resonators, such as one or more FBARs.

[0206] Figure 22 yes Figure 21 A graph showing the frequency response of the hybrid parallel band-stop filter 210. Figure 22 The frequency response in the figure shows that a relatively wide stopband can be achieved using a parallel hybrid acoustic bandstop filter 210.

[0207] Hybrid acoustic LC filter with harmonic suppression

[0208] With the development of 5G wireless communication technology, new carrier aggregation (CA) can specify more stringent intermodulation distortion (IMD) rejection for filters. To provide CAIMD rejection-compatible filters with sharp rejection near the passband frequencies, acoustically assisted filters can be designed using hybrid resonators, such as hybrid acoustic LC resonators, to provide relatively low loss, a wide passband, and relatively sharp rejection near the passband frequencies. Acoustic resonators can generate harmonics when relatively high power is applied. Harmonics generated by surface acoustic devices or bulk acoustic devices can leak into higher frequency bands and / or have efferentiations exceeding standard specifications.

[0209] Because acoustic resonator filters can generate harmonics at relatively high power, passive non-acoustic filters can be cascaded with hybrid acoustic LC filters to achieve both rejection and suppression of harmonics generated by the resonator. Therefore, non-acoustic LC filters, such as integrated passive device (IPD) filters, can be cascaded with hybrid acoustic LC filters to achieve relatively wide bandwidth and relatively high rejection while suppressing self-generated harmonics.

[0210] The hybrid acoustic LC filters and / or multiplexers discussed herein may include harmonic suppression filters to suppress one or more harmonic frequencies. Harmonic suppression filters may be low-pass filters and / or notch filters. The disclosed harmonic suppression filters include non-acoustic filters. For example, a harmonic suppression filter may be an IPD filter. Harmonic suppression filters are cascaded with hybrid acoustic LC filters. These cascaded filters may be coupled between a power amplifier and an antenna port. For example, a harmonic suppression filter may be coupled between an antenna port and a hybrid acoustic LC filter.

[0211] Several aspects of this disclosure relate to a hybrid acoustic LC filter with harmonic suppression. The hybrid acoustic LC filter includes a hybrid passive / acoustic filter and a non-acoustic LC filter, the hybrid passive / acoustic filter being configured to filter radio frequency (RF) signals, and the non-acoustic LC filter being configured to suppress harmonics of the RF signals. The hybrid passive / acoustic filter includes multiple acoustic resonators and non-acoustic passive components. The non-acoustic LC filter is cascaded with the hybrid passive / acoustic filter.

[0212] Non-acoustic LC filters can be notch filters. The frequency response of a notch filter can have a notch corresponding to the second harmonic of the radio frequency signal. The frequency response of a notch filter can also have a notch corresponding to the third harmonic of the radio frequency signal. Non-acoustic LC filters can also be low-pass filters. Non-acoustic LC filters can include integrated passive devices with integrated passive device chips.

[0213] Hybrid passive / acoustic filters can be implemented based on any suitable principles and advantageous aspects of any hybrid resonator disclosed herein. For example, a hybrid passive / acoustic filter may include... Figure 11A Hybrid resonators and / or Figure 12 Hybrid resonators. Acoustic resonators may include bulk acoustic resonators.

[0214] Hybrid acoustic LC filters with harmonic suppression can be implemented in a variety of applications, such as standalone filters, multiplexers comprising multiple filters arranged to filter radio frequency signals, and wireless communication devices such as mobile phones. The hybrid acoustic LC filters with harmonic suppression discussed in this paper can be implemented in power amplifier modules, diversity receiver modules, or any other suitable radio frequency front-end modules.

[0215] Figure 23AThis is a schematic block diagram of a radio frequency (RF) system according to one embodiment, including a filter 230 comprising a hybrid acoustic LC filter 232 cascaded with a low-pass filter 233. The RF system also includes a power amplifier 231 and an antenna 234. As shown, the hybrid acoustic LC filter 232 can receive an RF signal from the power amplifier 231. The RF signal from the power amplifier 231 can have relatively high power. The acoustic resonator of the hybrid acoustic LC filter 232 can generate one or more harmonics. The low-pass filter 233 can filter out such harmonics. Therefore, filter 230 is a hybrid acoustic LC filter with harmonic suppression. As shown, the low-pass filter 233 is coupled between the output of the hybrid acoustic LC filter 232 and the antenna 234. The antenna 234 can transmit a filtered version of the RF signal provided by the power amplifier 231.

[0216] The hybrid acoustic LC filter 232 may include acoustic resonators and non-acoustic passive components. The acoustic resonators may include one or more bulk acoustic resonators such as FBAR, one or more SAW resonators, one or more boundary wave resonators, one or more Lamb wave resonators, etc., or any suitable combination thereof. The hybrid acoustic LC filter 232 may include an LC circuit comprising one or more inductors and one or more capacitors. The one or more capacitors may include one or more IPD capacitors, one or more surface mount capacitors, one or more parasitic capacitors, etc., or any suitable combination thereof. The one or more inductors may include one or more IPD inductors, one or more surface mount conductors, one or more inductors implemented as conductive traces on a package substrate, etc., or any suitable combination thereof. The hybrid acoustic LC filter 232 may be implemented according to any suitable principles and advantages of the hybrid acoustic LC filters disclosed herein. In some instances, the hybrid acoustic LC filter 232 may include... Figure 11A The hybrid resonator 110. In some applications, the hybrid acoustic LC filter 232 may include... Figure 12 The hybrid trapezoidal structure 120.

[0217] In some applications, the hybrid acoustic LC filter 232 may have a passband from 3.3 GHz to 4.2 GHz. Depending on other applications, the hybrid acoustic LC filter 232 may have a passband from 4.4 GHz to 5 GHz. In various embodiments, the hybrid acoustic LC filter 232 may provide blocking for (a) a carrier aggregation transmit blocker and (b) a continuous wave out-of-band blocker.

[0218] The low-pass filter 233 allows signals below the cutoff frequency to pass through and suppresses signals above the cutoff frequency. Therefore, the cutoff frequency of the low-pass filter 233 can be selected to allow radio frequency signals from the hybrid acoustic LC filter 232 to pass through and suppress one or more harmonics of the radio frequency signal. For example, the cutoff frequency can be set to be higher than the frequency of the radio frequency signal and lower than the frequency of the second harmonic of the radio frequency signal. In some embodiments, the hybrid acoustic LC filter 232 is a bandpass filter, and the cutoff frequency of the low-pass filter 233 is higher than the passband of the bandpass filter and lower than the second harmonic of the radio frequency signal passed by the bandpass filter.

[0219] The low-pass filter 233 may be a non-acoustic LC filter. The low-pass filter 233 may include one or more capacitors and one or more inductors. The low-pass filter 233 may include one or more IPDs, one or more surface-mount passive components, one or more passive components of the package substrate (such as one or more inductor traces on the package substrate), or any suitable combination thereof. (See reference...) Figure 24A and 24B An example circuit topology for a low-pass filter 233 is discussed.

[0220] Figure 23B This is a schematic block diagram of a radio frequency system according to one embodiment, the radio frequency system including a filter 235, the filter 235 including a hybrid acoustic LC filter 232 cascaded with a harmonic notch filter 236. Besides Figure 23A The filter 230 was Figure 23B In addition to replacing the 235 filter in the original, Figure 23B radio frequency system and Figure 23A The radio frequency system is the same. Except for replacing the one from... Figure 23A In addition to the low-pass filter 233 of filter 230, which includes harmonic notch filter 236, filter 235 and Figure 23A The filter 230 is the same. As shown in the figure, the harmonic notch filter 236 is coupled between the output of the hybrid acoustic LC filter 232 and the antenna 234.

[0221] Harmonic notch filter 236 may have one or more notches in its frequency response to filter out one or more corresponding harmonics of the radio frequency signal from hybrid acoustic LC filter 232. The second harmonic generated by the acoustic resonator of hybrid acoustic resonator LC filter 232 may be the most prominent harmonic. Therefore, harmonic notch filter 236 may be a second harmonic notch filter with a notch at the second harmonic in its frequency response. Harmonic notch filter 236 may have notches at one or more other harmonics. In some embodiments, a harmonic notch filter cascaded with hybrid acoustic LC filter 232 may have two or more notches at any suitable harmonic. As an example, the harmonic notch filter may have notches at the second and third harmonics. By utilizing the notches at the harmonics of the radio frequency signal provided by hybrid acoustic LC filter 232, harmonic notch filter 236 may suppress harmonics generated by the acoustic resonator of hybrid acoustic LC filter 232.

[0222] The harmonic notch filter 236 may be a non-acoustic LC filter, which includes one or more capacitors and one or more inductors. The harmonic notch filter 236 may include one or more IPDs, one or more surface-mount passive components, one or more passive components of the package substrate, such as one or more inductor traces on the package substrate, etc., or any suitable combination thereof. (See reference...) Figure 24C and 24D This paper discusses example circuit topologies for use with harmonic notch filter 236 and / or other suitable harmonic notch filters.

[0223] Figure 24A This is a schematic diagram of an example low-pass filter 240. Low-pass filter 240 is... Figure 23A An example of a low-pass filter 233. Low-pass filter 240 includes a series inductor L1 and a shunt capacitor C1 arranged to filter out frequencies above the cutoff frequency. The inductance of the series inductor L1 and the capacitance of the shunt capacitor C1 together set the cutoff frequency in low-pass filter 240.

[0224] Figure 24B This is a schematic diagram of another example of a low-pass filter 242. Low-pass filter 242 is... Figure 23A An example of a low-pass filter 233. Low-pass filter 242 includes series inductors L1 to LN and shunt capacitors C1 to CN. The inductance of the series inductors L1 to LN and the capacitance of the shunt capacitors C1 to CN together set the cutoff frequency in low-pass filter 242.

[0225] Figure 24C This is a schematic diagram of an example harmonic notch filter 243. The harmonic notch filter 243 is... Figure 23BAn example of a harmonic notch filter 236. Harmonic notch filter 243 includes a shunt series LC circuit. The inductor Ls and capacitor C1 of the shunt series LC circuit can set the frequency of the notch. The different impedances of the inductor Ls and capacitor C1 can together generate notches at different corresponding frequencies. A notch can be provided at any suitable harmonic frequency. For example, the notch can be set to the second harmonic of the RF signal supplied to harmonic notch filter 243. As another example, the notch can be set to the third harmonic of the RF signal supplied to harmonic notch filter 243.

[0226] Figure 24D This is a schematic diagram of an example harmonic notch filter 244. The harmonic notch filter 244 is... Figure 23B An example of a harmonic notch filter 236 is provided. The harmonic notch filter 244 includes two shunt series LC circuits. The first shunt series LC circuit includes a capacitor C1 and an inductor Ls1. The second shunt series LC circuit includes a capacitor C2 and an inductor Ls2. The two shunt series LC circuits can provide notches at different harmonics, such as the second and third harmonics. Therefore, the harmonic notch filter 244 shown can provide notches at two different harmonics. The impedance of each shunt series LC circuit can set the corresponding frequency of each notch. Other harmonic notch filters can provide notches at three or more harmonics.

[0227] Figure 24E This is a schematic diagram of an example harmonic notch and low-pass filter 245. The harmonic notch and low-pass filter 245 provides a low-pass filter that also includes a notch at the harmonics in the frequency response. A shunt series LC circuit provides the harmonic notch. The shunt series LC circuit includes a capacitor C1 and an inductor Ls. The series inductor L1, together with the shunt capacitor C2, provides low-pass filter characteristics.

[0228] The hybrid acoustic LC filter with harmonic suppression discussed in this paper can be implemented in a multiplexer comprising multiple RF filters coupled together at a common node. Example multiplexers include duplexers, tripplexers, quadplexers, etc. Any suitable number of filters can be coupled together at a common node in the multiplexer. Multiple filters can be coupled together at a common node via a multi-throw RF switch to achieve switch multiplexing functionality. (See references...) Figures 25A to 25B The description includes some example multiplexers with hybrid acoustic LC filters featuring harmonic suppression. While the multiplexers in these example embodiments are triplexers, the principles and advantages associated with these embodiments can be applied to any other suitable multiplexer. Other suitable multiplexers include duplexers, quadplexers, etc.

[0229] Figure 25AThis is a schematic block diagram of a tripper 250 according to one embodiment, the tripper 250 including a hybrid acoustic LC filter 232 cascaded with a low-pass filter 233. The tripper 250 includes... Figure 23A The system includes a filter 230, a high-frequency band filter 252, and a low-frequency band filter 254. Filters 230, 252, and 254 are coupled together at a common node, which is the antenna node in the tripeller 250. Filter 230 is an intermediate frequency (IF) band filter in the tripeller 250. The high-frequency band filter 252 can be a bandpass filter or a high-pass filter. The high-frequency band filter 252 is arranged to filter high-frequency radio frequency (RF) signals. The high-frequency band filter 252 can be a hybrid acoustic LC filter implemented according to any suitable principles and advantageous aspects discussed herein. As an example, the high-frequency band filter may include parallel hybrid acoustic passive filters. In some other embodiments, the high-frequency band filter 252 may be implemented by any other suitable circuit element (e.g., a non-acoustic LC circuit element). The low-frequency band filter 254 can be a low-pass filter or a bandpass filter. The low-frequency band filter 254 is arranged to filter low-frequency radio frequency (RF) signals. The low-frequency filter 254 can be a hybrid acoustic LC filter implemented according to any suitable principles and advantages discussed herein. In some other embodiments, the low-frequency filter 254 can be implemented by any other suitable circuit element (e.g., a non-acoustic LC circuit element).

[0230] Figure 25B This is a schematic block diagram of a tripod 255 according to one embodiment, which includes a hybrid acoustic LC filter 232 cascaded with a harmonic notch filter 236. The tripod 255 includes filter 235 in place of filter 230, and... Figure 25A The tripod 250 is identical to the one described above. Filter 235 includes a harmonic notch filter 236, which is arranged to suppress harmonics in the radio frequency signal provided by the hybrid acoustic LC filter 232. In some applications, the harmonic notch filter 236 may provide notch filtering for two or more harmonics. In some embodiments, the filter of the multiplexer may include a hybrid acoustic LC filter cascaded with a low-pass and harmonic notch filter.

[0231] RF module

[0232] The filters disclosed herein can be implemented in various package modules. Several example package modules will now be disclosed, in which any suitable principles and advantages of the filters and / or multiplexers disclosed herein can be implemented. Example package modules may include a package enclosing the circuit elements shown. A module including radio frequency components may be referred to as a radio frequency module. The circuit elements shown may be deployed on a common package substrate. For example, the package substrate may be a laminated substrate. Figures 26 to 28This is a schematic block diagram of exemplary packaged modules according to certain embodiments. Any suitable combination of features of these packaged modules can be implemented with respect to each other. Although in Figures 26 to 28 The example encapsulation module shows a filter, but any such filter can be implemented in a suitable multiplexer.

[0233] Figure 26 This is a schematic diagram of an RF module 260 according to one embodiment, having a transmit path including a filter 262. The illustrated module 260 includes a filter 262, a power amplifier 263, and an RF switch 264. An RF module including a power amplifier may be referred to as a power amplifier module. The power amplifier 263 amplifies RF signals. The RF switch 264 may be a multi-throw RF switch. The RF switch 264 electrically couples the output of the power amplifier 263 to the filter 262. The filter 262 is a transmit filter arranged to filter the transmitted RF signal. The filter 262 may include any suitable combination of the features of the filters disclosed herein. In some other instances, the RF switch may selectively electrically connect the transmit signal path to the input of the power amplifier 263.

[0234] Figure 27 This is a schematic diagram of an RF module 270 according to one embodiment, having a receive path including a filter 272. The illustrated module 270 includes a filter 272, a low-noise amplifier 274, and an RF switch 274. The filter 272 is a receive filter arranged to filter a received RF signal. The filter 272 may include any suitable combination of the features of the filters disclosed herein. The low-noise amplifier 274 amplifies the filtered received RF signal provided by the filter 272. The RF switch 274 electrically couples the output of the low-noise amplifier 274 to the receive path. In some embodiments, the RF switch 276 may be a multi-throw RF switch arranged to selectively electrically couple the output of the low-noise amplifier 274 to one or more selected receive paths. In such embodiments, an RF splitter (not shown) may be coupled between the low-noise amplifier 274 and the RF switch 276.

[0235] Figure 28 This is a schematic diagram of an RF module 280 according to one embodiment, which includes a filter 282. The illustrated module 280 includes one or more filters 282, an RF switch 284, a power amplifier 263, and a low-noise amplifier 274. The one or more filters 282 may include any suitable combination of the features of the filters disclosed herein. The RF switch 284 may electrically couple one or more filters 282 to the power amplifier 263 and / or the low-noise amplifier 274.

[0236] Wireless communication devices

[0237] The filters discussed in this article can filter radio frequency signals in wireless communication devices. (Refer to...) Figure 29 and Figure 30 Let's discuss an example wireless communication device.

[0238] Figure 29 This is a schematic diagram of a wireless communication device 290 according to one embodiment, which includes a filter 293 in an RF front-end 292. The wireless communication device 290 can be any suitable wireless communication device. For example, the wireless communication device 290 can be a mobile phone such as a smartphone. As shown, the wireless communication device 290 includes an antenna 291, an RF front-end 292 including the filter 293, a transceiver 294, a processor 295, a memory 296, and a user interface 297. The antenna 291 can transmit RF signals provided by the RF front-end 292. Such RF signals may include carrier aggregation signals. The antenna 291 can provide received RF signals to the RF front-end 292 for processing. Such RF signals may include carrier aggregation signals.

[0239] RF front end 292 may include one or more power amplifiers, one or more low-noise amplifiers, RF switches, receive filters, transmit filters, duplex filters, multiplexers, frequency multiplexing circuitry, or any combination thereof. RF front end 292 can transmit and receive RF signals associated with any suitable communication standard. Filter 293 may be implemented according to any suitable principles and advantageous aspects of the filters discussed herein. For example, filter 293 may be implemented with reference to Figures 1 to... Figure 25B Any suitable combination of any of the features discussed herein. Two or more filters of the RF front end 292 may be implemented according to any suitable principles and advantages disclosed herein.

[0240] Transceiver 294 provides RF signals to RF front-end 292 for amplification and / or other processing. Transceiver 294 also processes the RF signals provided by the low-noise amplifier of RF front-end 292. Transceiver 294 communicates with processor 295. Processor 295 may be a baseband processor. Processor 295 may provide any suitable baseband processing functions to wireless communication device 290. Memory 296 is accessible by processor 295. Memory 296 may store any suitable data from wireless communication device 290. Processor 295 also communicates with user interface 297. User interface 297 may be any suitable user interface, such as a display.

[0241] Figure 30This is a schematic diagram of a wireless communication device 300 according to one embodiment, which includes a filter 293 in a radio frequency front-end 292 and a second filter 303 in a diversity reception module 302. In addition to including diversity reception features, the wireless communication device 300 also includes other features... Figure 29 The wireless communication device 290 is the same. For example... Figure 30 As shown, the wireless communication device 300 includes a diversity antenna 301, a diversity module 302, and a transceiver 304. The diversity module 302 is configured to process signals received by the diversity antenna 301 and includes a filter 303. The transceiver 304 communicates with both the radio frequency front-end 292 and the diversity receiving module 302. The filter 303 can be implemented according to any suitable principles and advantages of the filters discussed herein. For example, the filter 303 can be implemented with reference to Figures 1 to 2018. Figure 25B Any suitable combination of any of the features discussed herein. The two or more filters of diversity receiving module 302 may be implemented according to any suitable principles and advantages disclosed herein.

[0242] in conclusion

[0243] Any principles and advantages discussed herein can be applied to other suitable systems, modules, chips, filter assemblies, filters, wireless communication devices, and methods, and are not limited to those described above. Elements and operations of the various embodiments described above can be combined to provide further embodiments. Any principles and advantages discussed herein can be implemented in association with radio frequency circuits configured to process signals with frequencies ranging from about 30 kHz to 300 GHz (e.g., frequencies ranging from about 450 MHz to 8.5 GHz).

[0244] The various aspects of this disclosure can be implemented in a variety of electronic devices. Examples of electronic devices include, but are not limited to, consumer electronics products, components of consumer electronics products such as chips and / or packaged radio frequency modules, electronic test equipment, uplink wireless communication equipment, personal area network communication equipment, etc. Examples of consumer electronics products include, but are not limited to, mobile phones such as smartphones, wearable computing devices such as smartwatches or headphones, telephones, televisions, computer monitors, computers, routers, modems, handheld computers, laptop computers, tablet computers, personal digital assistants (PDAs), in-vehicle electronic systems such as automotive electronic systems, microwave ovens, refrigerators, stereo systems, digital music players, cameras such as digital cameras, portable memory chips, home appliances, etc. Furthermore, electronic devices may include unfinished products.

[0245] Unless otherwise stated or otherwise understood, the conditional language used herein, such as “may,” “can,” “possibly,” “able to,” “e.g.,” “as,” “like,” etc., is generally intended in the context in which it is used to express that certain embodiments include certain features, elements, and / or states, while other embodiments do not. The term “coupled” as generally used herein refers to two or more elements that can be directly connected or connected via one or more intermediate elements. Similarly, the term “connected” as generally used herein refers to two or more elements that can be directly connected or connected via one or more intermediate elements. Furthermore, the phrases “in this document,” “above,” “below,” and similar expressions, when used in this application, should refer to the entire application and not any particular part of it. Where the context permits, singular or plural words used in the above specific embodiments may also include plural or singular, respectively. Regarding the word “or” when referring to a list of two or more items, the word covers all of the following interpretations: any item in the list; all items in the list; and any combination of items in the list.

[0246] While certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of this application. In fact, the novel devices, filters, filter assemblies, chips, methods, apparatuses, and systems described herein can be implemented in a variety of other forms. Moreover, various omissions, substitutions, and changes can be made to the form of the methods, apparatuses, and systems described herein without departing from the spirit of this application. For example, circuit blocks described herein can be deleted, moved, added, subdivided, combined, and / or modified. Each of these circuit blocks can be implemented in a variety of different ways. The appended claims and their equivalents are intended to cover any such forms or modifications falling within the scope and spirit of this application.

Claims

1. A parallel hybrid acoustic passive filter, comprising: The first sub-filter includes at least a first shunt circuit and a second shunt circuit connected in parallel with each other. The first shunt circuit has at least a first shunt acoustic resonator connected in series with the first shunt inductor. The second shunt circuit has only a second shunt inductor connected in parallel with the first shunt acoustic resonator and the first shunt inductor. A second sub-filter is coupled in parallel with the first sub-filter at the input common node and the output common node. The second sub-filter includes a third shunt circuit and a fourth shunt circuit connected in parallel with each other, and at least one capacitor connected in parallel with the third shunt circuit and the fourth shunt circuit. The third shunt circuit has at least a second shunt acoustic resonator connected in series with a third shunt inductor. The fourth shunt circuit has only a fourth shunt inductor connected in parallel with the second shunt acoustic resonator and the third shunt inductor. A first series inductor is connected to the input common node such that the first series inductor is connected in series with the first sub-filter and the second sub-filter; The fifth shunt inductor is connected to the input common node; as well as The sixth shunt inductor is connected to the output common node. The first sub-filter and the second sub-filter are arranged together to filter the radio frequency signal.

2. The shunt hybrid acoustic passive filter of claim 1, wherein, The first sub-filter and the second sub-filter are arranged together as a bandpass filter with a passband.

3. The shunt hybrid acoustic passive filter of claim 1, wherein, The frequency response of the parallel hybrid acoustic passive filter has a first sub-passband corresponding to the first sub-filter, a second sub-passband corresponding to the second sub-filter, and a notch at the notch frequency between the first sub-passband and the second sub-passband.

4. The shunt hybrid acoustic passive filter of claim 1, wherein, The first sub-filter and the second sub-filter are arranged together as a band-stop filter with a stopband.

5. The shunt hybrid acoustic passive filter of claim 4, wherein, The band-stop filter has a notch in the stopband.

6. The shunt hybrid acoustic passive filter of claim 1, wherein, The first sub-filter includes a plurality of bulk acoustic resonators, the plurality of bulk acoustic resonators including the first shunt acoustic resonator.

7. The parallel hybrid acoustic passive filter according to claim 1, wherein, The first sub-filter includes a series acoustic resonator connected in series with the first shunt acoustic resonator, and the series acoustic resonator is connected in parallel with an inductor.

8. The shunt hybrid acoustic passive filter of claim 1, wherein, The first sub-filter also includes a third shunt acoustic resonator.

9. The shunt hybrid acoustic passive filter of claim 1, wherein, The second shunt inductor is part of an integrated passive device.

10. The shunt hybrid acoustic passive filter of claim 1, wherein, The first sub-filter and the second sub-filter have different passbands.

11. The shunt hybrid acoustic passive filter of claim 1, wherein, The lower limit of the passband of the parallel hybrid acoustic passive filter is at least 2 GHz.

12. A multiplexer with a parallel hybrid acoustic passive filter, the multiplexer comprising: A first filter configured to filter radio frequency signals includes a first sub-filter connected in parallel with a second sub-filter at an input common node and an output common node. The first sub-filter includes at least a first shunt circuit and a second shunt circuit connected in parallel with each other. The first shunt circuit has at least a first shunt acoustic resonator connected in series with a first shunt inductor. The second shunt circuit has only a second shunt inductor connected in parallel with the first shunt acoustic resonator and the first shunt inductor. The second sub-filter includes a third shunt circuit and a fourth shunt circuit connected in parallel with each other, and at least one capacitor connected in parallel with the third shunt circuit and the fourth shunt circuit. The third shunt circuit has at least a second shunt acoustic resonator connected in series with a third shunt inductor. The fourth shunt circuit has only a fourth shunt inductor connected in parallel with the second shunt acoustic resonator and the third shunt inductor. A first series inductor is connected to the input common node such that the first series inductor is connected in series with the first sub-filter and the second sub-filter; The fifth shunt inductor is connected to the input common node; The sixth shunt inductor is connected to the output common node; as well as A second filter is coupled to the input common node and the output common node.

13. The multiplexer of claim 12, wherein, The first filter is a bandpass filter.

14. The multiplexer of claim 13, wherein, The frequency response of the first filter has a first sub-passband corresponding to the first sub-filter, a second sub-passband corresponding to the second sub-filter, and a notch at the notch frequency between the first sub-passband and the second sub-passband.

15. The multiplexer of claim 13, wherein, The second filter is a band-stop filter.

16. The multiplexer of claim 12, wherein, The first sub-filter includes a series acoustic resonator connected in series with the first shunt acoustic resonator, and the series acoustic resonator is connected in parallel with an inductor.

17. The multiplexer of claim 16, wherein, The second filter is a high-pass filter.

18. The multiplexer of claim 12, wherein, The first filter has a first passband, the second filter has a second passband, and the first passband has a lower edge at a frequency higher than the upper edge of the second passband.

19. The multiplexer of claim 12, further comprising a third filter coupled to at least one of the input common node and the output common node.

20. The multiplexer of claim 12 further includes a shared filter connected in series between the first filter and the input common node or the output common node, the shared filter being further connected in series between the second filter and the input common node or the output common node.

21. The multiplexer of claim 20, wherein, The shared filter is a high-pass filter.

22. A wireless communication device, comprising: A radio frequency front-end, the radio frequency front-end comprising a parallel hybrid acoustic passive filter according to any one of claims 1 to 11; as well as Antenna that communicates with the radio frequency front end.

23. A multiplexer, comprising: A plurality of filters configured to filter corresponding radio frequency signals, each of the plurality of filters having a different passband, and at least a first filter of the plurality of filters comprising a parallel hybrid acoustic passive filter according to any one of claims 1 to 11. A shared filter, which is coupled between each of the plurality of filters and a common node; as well as The radio frequency filter is coupled to the common node.

24. The multiplexer of claim 23, wherein, The plurality of filters includes a first filter, a second filter, and a third filter.

25. The multiplexer of claim 24, wherein, The first filter is a first bandpass filter having a first passband, and the second filter is a second bandpass filter having a second passband.

26. The multiplexer of claim 25, wherein, The third filter is a band-stop filter, which has a stopband that includes the first passband and the second passband.

27. The multiplexer of claim 23, wherein, The shared filter is a high-pass filter.

28. The multiplexer of claim 27, wherein, The radio frequency filter is a low-pass filter.

29. The multiplexer of claim 23, wherein, The shared filter is a non-acoustic LC filter.

30. The multiplexer of claim 23, wherein, The shared filter includes multiple second acoustic resonators and LC components.

31. The multiplexer of claim 23, wherein, The second filter among the plurality of filters includes a plurality of second acoustic resonators and a second non-acoustic passive component.

32. The multiplexer of claim 31, wherein, The first filter has a first passband, and the second filter has a second passband, both of which are in the frequency range from 2 GHz to 5 GHz.

33. The multiplexer of claim 31, wherein, The first filter has a first passband, and the second filter has a second passband, both of which are in the frequency range from 2 GHz to 3 GHz.

34. The multiplexer of claim 23, wherein, The multiplexer is arranged as a quad.

35. A wireless communication device, comprising: antenna; as well as A multiplexer communicating with the antenna, the multiplexer including a plurality of filters configured to filter various radio frequency signals, a shared filter coupled between each of the plurality of filters and a common node, and a radio frequency filter coupled to the common node, wherein at least a first filter of the plurality of filters includes a parallel hybrid acoustic passive filter according to any one of claims 1 to 11.

36. The wireless communication device of claim 35, wherein, The second filter among the plurality of filters includes a plurality of second acoustic resonators and a second non-acoustic passive component.

37. The wireless communication device of claim 36, wherein, The wireless communication device is configured to support carrier aggregation at the common node, the carrier aggregation including a first carrier and a second carrier, the first carrier being within a first passband of the first filter and the second carrier being outside the first passband and a second passband of the second filter.

38. A multiplexer, comprising: Multiple filters, including a first hybrid acoustic passive filter and a second filter, wherein the first hybrid acoustic passive filter includes a parallel hybrid acoustic passive filter as described in any one of claims 1 to 11, and the first hybrid acoustic passive filter and the second filter have different radio frequency passbands; A shared high-pass filter is coupled between each of the plurality of filters and a common node; as well as A low-pass filter, which is coupled to the common node.

39. The multiplexer of claim 38, wherein, The plurality of filters further includes a bandstop filter having a stop band that includes a passband of the first hybrid acoustic passive filter and the second filter.

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