Radio frequency multiplexer and electronic equipment
By combining bandpass network and band-stop network in the RF multiplexer, the problem of difficulty in taking into account both isolation and insertion loss in the prior art is solved, and the effects of high isolation, low insertion loss and high integration are achieved, reducing design difficulty and manufacturing cost.
Patent Information
- Application Number
- CN202420584162.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-25
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-03-25
AI Technical Summary
While improving isolation, existing RF multiplexers have difficulty maintaining low insertion losses and require the use of winding inductors to suppress multiple harmonics, resulting in reduced chip integration, increased design difficulty and high manufacturing costs.
By combining a bandpass network and a band-stop network in a radio frequency multiplexer, the band-stop network consists of a third piezoelectric resonator and a fourth piezoelectric resonator close to the TX/RX port, and the notch formed is arranged in the frequency band range that needs to be isolated, thereby increasing isolation and suppressing multiple harmonics without the use of a winding inductor.
It realizes the isolation and integration of RF multiplexers without affecting insertion loss, reducing design difficulty and manufacturing costs.
Smart Images
Figure CN222563792U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of acoustic filters, in particular to a radio frequency multiplexer and electronic equipment. Background Art
[0002] Isolation refers to the stopband attenuation of two equivalent band-stop filters, which can prevent the receiving frequency and the transmitting frequency from intermodulating each other. A higher isolation can meet the performance of the duplexer and is one of the most important indicators in its design. In addition, there are other indicators such as insertion loss and reliability to measure the performance parameters of the duplexer.
[0003] In order to improve the isolation of the duplexer without affecting the insertion loss as much as possible, some methods will build passive devices in the metal layer of the substrate to achieve matching functions, which can bring better isolation. However, when using a multi-layer substrate to build a matching circuit, for some working frequency bands, if the harmonic suppression circuit is not used at the same time, multiple harmonic interference will be caused. Therefore, in order to suppress high-order harmonics, a harmonic suppression circuit must be used at the same time, that is, winding inductors must be used on the substrate, which makes chip integration more difficult and increases design time and manufacturing costs; if the substrate is not used to build the matching circuit, the isolation will be greatly affected.
[0004] Therefore, how to achieve high isolation and low insertion loss, suppress multiple harmonics, improve the integration of the duplexer, and minimize the impact on the insertion loss becomes a key issue to be solved by this technical solution. Utility Model Content
[0005] In order to solve at least one of the technical problems mentioned in the background technology, the purpose of the utility model is to provide a radio frequency multiplexer and an electronic device, which can improve the integration of radio frequency chips, reduce design difficulty and reduce manufacturing costs while achieving high isolation and low insertion loss and suppressing multiple harmonics.
[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0007] In a first aspect, an embodiment of the utility model provides a radio frequency multiplexer, comprising at least two paths, wherein the first ends of the paths are connected as a common end, and the second ends of the paths are separated from each other;
[0008] Any one of the paths includes at least one first piezoelectric resonator connected in series between the first end and the second end, at least one end of the first piezoelectric resonator is grounded through at least one second piezoelectric resonator; and
[0009] at least one third piezoelectric resonator connected in series with the first piezoelectric resonator, the third piezoelectric resonator being adjacent to the second end, and at least one fourth piezoelectric resonator grounding one end of the third piezoelectric resonator;
[0010] wherein the passband range of the bandpass network formed by the first piezoelectric resonator and the second piezoelectric resonator is configured as a first frequency band;
[0011] The stopband range of the band-stop network formed by the third piezoelectric resonator and the fourth piezoelectric resonator is configured to cover at least a first isolation frequency band of the passband range of any other path;
[0012] The first frequency band has no intersection with the first isolation frequency band.
[0013] Further, the resonant frequency of at least one of the first piezoelectric resonators is configured to be close to an upper cutoff frequency of the first frequency band, and the anti-resonant frequency of at least one of the second piezoelectric resonators is configured to be close to a lower cutoff frequency of the first frequency band.
[0014] Further, the anti-resonance frequency of at least one of the third piezoelectric resonators is configured to be close to the lower cutoff frequency of the first isolation frequency band, and the resonant frequency of at least one of the fourth piezoelectric resonators is configured to be close to the upper cutoff frequency of the first isolation frequency band.
[0015] Furthermore, the at least two paths include a first path and a second path; wherein the first path is used to transmit signals, and the second path is used to receive signals.
[0016] Further, in the first path, the fourth piezoelectric resonator is connected to the first end of the third piezoelectric resonator;
[0017] In the second path, the fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator.
[0018] Further, in the first path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator;
[0019] In the second path, the fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator.
[0020] Further, in the first path, the fourth piezoelectric resonator is connected to the first end of the third piezoelectric resonator;
[0021] In the second path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator.
[0022] Further, in the first path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator;
[0023] In the second path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator.
[0024] Furthermore, the first piezoelectric resonator, the second piezoelectric resonator, the third piezoelectric resonator, and the fourth piezoelectric resonator include at least one of SAW and BAW.
[0025] In a second aspect, an embodiment of the utility model further provides an electronic device, comprising any one of the above-mentioned radio frequency multiplexers.
[0026] Compared with the prior art, the beneficial effect of the utility model is as follows: the RF multiplexer provided by the utility model is applied to combine a bandpass network and a bandstop network, and the bandstop network is composed of a third piezoelectric resonator and a fourth piezoelectric resonator close to the TX / RX port. The notch formed by the bandstop network is set in the frequency band range that needs to be isolated, which can improve isolation while ensuring insertion loss, and can suppress multiple harmonics without using winding inductors, thereby improving the integration of RF chips, reducing design difficulty, and reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 A schematic diagram of a harmonic suppression circuit provided by an embodiment of the utility model;
[0028] Figure 2 A curve diagram of a harmonic suppression circuit provided by an embodiment of the utility model;
[0029] Figure 3 A simulation design result diagram provided by an embodiment of the utility model when a substrate is not used;
[0030] Figure 4 A comparison diagram of isolation curves between using a substrate and not using a substrate provided in an embodiment of the utility model;
[0031] Figure 5 A structure of a radio frequency duplexer provided in an embodiment of the utility model Figure 1 ;
[0032] Figure 6 A curve diagram of the frequency band range of a duplexer provided by an embodiment of the utility model;
[0033] Figure 7 A curve diagram reflecting good isolation provided by an embodiment of the utility model;
[0034] Figure 8A curve diagram reflecting better suppression of multiple harmonics provided by the embodiment of the utility model;
[0035] Fig. 9 A comparison diagram of the frequency band range of a duplexer close to / not close to TX / RX solutions provided by an embodiment of the utility model;
[0036] Fig.10 A comparison diagram of isolation curves of a duplexer close to / not close to TX / RX solutions provided by an embodiment of the utility model;
[0037] Fig.11 The structure of the radio frequency duplexer provided by the embodiment of the utility model Figure 2 ;
[0038] Fig.12 The structure of the radio frequency duplexer provided by the embodiment of the utility model Figure 3 ;
[0039] Fig.13 The structure of the radio frequency duplexer provided by the embodiment of the utility model Figure 4 ;
[0040] Fig.14 A structure of a radio frequency multiplexer provided in an embodiment of the utility model Figure 1 ;
[0041] Fig.15 A structure of a radio frequency multiplexer provided in an embodiment of the utility model Figure 2 . DETAILED DESCRIPTION
[0042] The technical solutions in the embodiments of the utility model are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0043] The main function of the duplexer is to isolate the transmit signal from the receive signal, so as to ensure that both the receive end and the transmit end can work normally at the same time; generally speaking, the duplexer consists of two sets of filters with different frequencies (and the filters are often composed of resonators), and is mostly used in RF module products. RF module refers to the RF front-end module (the back end is often a discrete device). Previously, because discrete devices could also meet the needs of manufacturers, there was a clear distinction between high-end devices using modules and low-end devices using discrete devices. Modules can provide higher integration and high performance. In the 5G era, due to the sharp increase in the number of RF components in a single product, the area occupied by discrete solutions exceeds the acceptable limit, and the debugging time will be longer. Therefore, modularization has become a development trend in the mobile communication market. Modules are divided into FEMiD (integrated switch, filter and duplexer), PAMiD (integrated multi-mode multi-band PA and FEMiD), LPAMiD (PAMiD plus LNA), DiFEM (RF switch and filter), LFEM (RF switch, low noise amplifier and filter), etc. The same is true for "multiplexers", except that there are differences in specific design and application scenarios.
[0044] The duplexer must not only couple in weak received signals, but also feed higher-power transmitted signals to the antenna, and both must complete their respective functions without affecting each other. The operating frequency range of the duplexer often needs to be larger than the frequency range required for wireless communication itself, that is, the bandwidth. In practice, the design bandwidth of the duplexer is generally the stopband bandwidth of the band-stop filter, not the passband bandwidth. Isolation refers to the stopband attenuation of two equivalent band-stop filters, which can prevent the receiving frequency and the transmitting frequency from intermodulating with each other. Higher isolation can meet the performance of the duplexer and is one of the most important indicators of its design. In addition, there are other indicators such as insertion loss and stability to measure the performance parameters of the duplexer.
[0045] The core problem that this technical solution attempts to solve is how to improve the isolation of the duplexer without affecting the insertion loss as much as possible. The existing technology often has the following solutions:
[0046] First, the use of a substrate can bring better isolation, but in order to suppress high-order harmonics (mainly second and third harmonics in this solution... This is mainly determined by the frequency band required by the design, but in theory it is applicable to suppressing any number of harmonics), a harmonic suppression circuit is required, and a winding inductor must be used on the substrate, which is not conducive to chip integration; the schematic diagram of the harmonic suppression circuit is shown in Figure 1 As shown, Figure 1 This is a schematic diagram of a harmonic suppression circuit provided by an embodiment of the utility model, and the dotted line portion is the harmonic suppression circuit.
[0047] If the baseplate is used but only the common topology is used, and there is no harmonic suppression circuit, such as Figure 2 As shown, Figure 2 A graph of a harmonic suppression circuit provided in an embodiment of the utility model, wherein the black solid line is the curve of the overall circuit simulation; the black dotted line is the simulation curve of the harmonic suppression part (end resonator); the red and blue curves correspond to the transmitting path and the receiving path, respectively; the interference of multiple harmonics can be seen from the two boxes. Since the working frequency band is around 2 GHz, it is obvious that the purple and blue boxes indicate the positions of the second harmonic and the third harmonic.
[0048] Second, the substrate can be omitted, but the isolation will be greatly affected, such as Figure 3 and Figure 4 As shown, Figure 3 This is a simulation design result diagram provided by an embodiment of the utility model when a substrate is not used. Figure 4 A comparison diagram of isolation curves between using a substrate and not using a substrate provided in an embodiment of the utility model. It can be seen from the box marks that the isolation is greatly affected.
[0049] In order to solve the above problems existing in the prior art, the embodiments of the present utility model provide a radio frequency multiplexer and an electronic device, which are described in detail below.
[0050] In a first aspect, an embodiment of the utility model provides a radio frequency multiplexer.
[0051] First of all, it should be noted that those skilled in the art should realize that the "multiplexer" referred to herein may be a variety of types of devices such as a duplexer, a triplexer, a quadplexer, etc.
[0052] Embodiment 1:
[0053] See also Figure 5 , Figure 5 A structure of a radio frequency duplexer provided in an embodiment of the utility model Figure 1 .
[0054] Figure 5In the circuit, two paths, a transmitting path and a receiving path, are included. The first ends of the two paths are connected to a common end, namely, the antenna end ANT, and the second ends are respectively a transmitting end TX and a receiving end RX. There are four first piezoelectric resonators connected in series (TS1~TS4) between the transmitting end TX and the antenna end ANT, which are called series piezoelectric resonators. At least one end of the series piezoelectric resonator is grounded through four second piezoelectric resonators (TP1~TP4), which are called parallel piezoelectric resonators, and are used to process the signal transmitted through the transmitting end TX and generate an output signal, and then transmit the output signal uplink through the antenna end Ant; there are four first piezoelectric resonators connected in series (RS1~RS4) between the receiving end RX and the antenna end ANT, and four second piezoelectric resonators are connected in parallel (RP1~RP4), which are used to process the signal received by the antenna end ANT and generate an input signal, and the input signal is transmitted downlink through the receiving end RX; one end of each parallel piezoelectric resonator is connected to the ground end to achieve circuit impedance matching.
[0055] like Figure 6 As shown, Figure 6 A curve diagram of the frequency band range of a duplexer provided in an embodiment of the utility model.
[0056] The first piezoelectric resonator and the second piezoelectric resonator on the transmitting path form a bandpass network, and the passband range is set to the transmitting frequency band of 2.10~2.20GHz;
[0057] A band-stop network consisting of a third piezoelectric resonator and a fourth piezoelectric resonator is arranged near the transmitting end, and the stopband range is configured as a receiving frequency band of 1.90~2.00GHz; wherein the fourth piezoelectric resonator is connected to the first end (i.e., the right end) of the third piezoelectric resonator.
[0058] The first piezoelectric resonator and the second piezoelectric resonator on the receiving path form a bandpass network, and the passband range is set to the receiving frequency band of 1.90~2.00GHz;
[0059] A band-stop network consisting of a third piezoelectric resonator and a fourth piezoelectric resonator is arranged near the receiving end, and the stopband range is configured to be a transmission frequency band of 2.10-2.20 GHz; wherein the fourth piezoelectric resonator is connected to the first end (i.e., the right end) of the third piezoelectric resonator.
[0060] Further, the resonant frequency of at least one first piezoelectric resonator is configured to be close to an upper cutoff frequency of the first frequency band, and the anti-resonant frequency of at least one second piezoelectric resonator is configured to be close to a lower cutoff frequency of the first frequency band.
[0061] For example, Figure 5In the example, the resonant frequency of TS1~TS4 is configured to 2.20 GHz, and the anti-resonant frequency of TP1~TP4 is configured to 2.10 GHz; the resonant frequency of RS1~RS4 is configured to 2.00 GHz, and the anti-resonant frequency of RP1~RP4 is configured to 1.90 GHz.
[0062] Since the anti-resonance frequency of a resonator is usually higher than the resonant frequency, if the anti-resonance frequency of the second piezoelectric resonator is configured to be close to the upper cutoff frequency of the first frequency band, the resonant frequency of the second piezoelectric resonator is likely to fall within the first frequency band, thereby increasing the passband insertion loss and reducing the performance of the multiplexer;
[0063] Similarly, if the resonant frequency of the first piezoelectric resonator is configured to be close to the lower cutoff frequency of the first frequency band, the anti-resonant frequency of the first piezoelectric resonator is likely to fall within the first frequency band, increasing the passband insertion loss and affecting the performance of the multiplexer.
[0064] Further, the anti-resonance frequency of at least one third piezoelectric resonator is configured to be close to the lower cutoff frequency of the first isolation frequency band, and the resonant frequency of at least one fourth piezoelectric resonator is configured to be close to the upper cutoff frequency of the first isolation frequency band.
[0065] For example, Figure 5 In the embodiment, the anti-resonance frequency of TS5 is configured to be 1.90 GHz, and the resonant frequency of TP5 is configured to be 2.00 GHz; the anti-resonance frequency of RS5 is configured to be 2.10 GHz, and the resonant frequency of RP5 is configured to be 2.20 GHz.
[0066] Since the anti-resonance frequency of a resonator is usually higher than the resonant frequency, if the resonant frequency of the fourth piezoelectric resonator is configured to be close to the lower cutoff frequency of the first isolation frequency band, the anti-resonance frequency of the fourth piezoelectric resonator is likely to fall within the range of the first isolation frequency band, thereby reducing the suppression capability of the stopband and affecting the isolation of the multiplexer;
[0067] Similarly, if the antiresonance frequency of the third piezoelectric resonator is configured to be close to the upper cutoff frequency of the first isolation frequency band, the resonant frequency of the third piezoelectric resonator is likely to fall within the first isolation frequency band, reducing the suppression capability of the stopband and affecting the isolation of the multiplexer.
[0068] Therefore, by adopting the above-mentioned setting method of the resonant frequency / anti-resonant frequency, the passband insertion loss can be reduced and the isolation of the multiplexer can be improved.
[0069] like Figure 7 As shown, Figure 7 A curve diagram reflecting better isolation provided by an embodiment of the utility model.
[0070] like Figure 8 As shown, Figure 8 A curve diagram reflecting better suppression of multiple harmonics provided in an embodiment of the utility model.
[0071] In order to further illustrate that placing the band-stop network close to the transmitting end / receiving end can bring about the effect of improving isolation, a design scheme of placing the band-stop network not close to the transmitting end / receiving end is given below.
[0072] like Fig. 9 As shown, Fig. 9 A comparison chart of the frequency band range of a duplexer of a close / non-close TX / RX solution provided in an embodiment of the utility model. The transmit frequency band of the two solutions is 2.10~2.20GHz, and the receive frequency band is 1.90~2.00GHz.
[0073] like Fig.10 As shown, Fig.10 This is a comparison diagram of isolation curves of a duplexer in a close / non-close TX / RX solution provided by an embodiment of the utility model. It can be clearly seen from the box mark that the isolation has deteriorated.
[0074] In addition, it should be noted that the above resonator can be any type of resonator belonging to SAW or BAW. The number of resonators in the bandpass network and the bandstop network (including series resonators and parallel resonators) can be multiple, as long as the final bandpass filter and bandstop filter can achieve the preset filtering effect.
[0075] The RF duplexer provided by the utility model combines a bandpass network and a bandstop network, and the bandstop network is composed of a series resonator and a parallel resonator close to the TX / RX port, which can improve isolation while ensuring insertion loss, suppress multiple harmonics, and does not require the use of winding inductors. It can improve the integration of RF chips, reduce design difficulty, and reduce manufacturing costs.
[0076] Embodiment 2:
[0077] In the first path, a fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator;
[0078] In the second path, a fourth piezoelectric resonator is connected to the first end of the third piezoelectric resonator.
[0079] like Fig.11 As shown, Fig.11 The structure of the radio frequency duplexer provided by the embodiment of the utility model Figure 2 In the band-stop network at the TX end, the fourth piezoelectric resonator TP5 is connected to the second end (i.e., the left end) of the third piezoelectric resonator TS5; in the band-stop network at the RX end, the fourth piezoelectric resonator RP5 is connected to the first end (i.e., the right end) of the third piezoelectric resonator RS5.
[0080] The RF duplexer provided by the utility model combines a bandpass network and a bandstop network, and the bandstop network is composed of a series resonator and a parallel resonator close to the TX / RX port, which can improve isolation while ensuring insertion loss, suppress multiple harmonics, and does not require the use of winding inductors. It can improve the integration of RF chips, reduce design difficulty, and reduce manufacturing costs.
[0081] Embodiment three:
[0082] In the first path, a fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator;
[0083] In the second path, a fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator.
[0084] like Fig.12 As shown, Fig.12 The structure of the radio frequency duplexer provided by the embodiment of the utility model Figure 3 In the band-stop network at the TX end, the fourth piezoelectric resonator TP5 is connected to the first end (i.e., the right end) of the third piezoelectric resonator TS5; in the band-stop network at the RX end, the fourth piezoelectric resonator RP5 is connected to the second end (i.e., the left end) of the third piezoelectric resonator RS5.
[0085] The RF duplexer provided by the utility model combines a bandpass network and a bandstop network, and the bandstop network is composed of a series resonator and a parallel resonator close to the TX / RX port, which can improve isolation while ensuring insertion loss, suppress multiple harmonics, and does not require the use of winding inductors. It can improve the integration of RF chips, reduce design difficulty, and reduce manufacturing costs.
[0086] Embodiment 4:
[0087] In the first path, a fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator;
[0088] In the second path, a fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator.
[0089] like Fig.13 As shown, Fig.13 The structure of the radio frequency duplexer provided by the embodiment of the utility model Figure 4 In the band-stop network at the TX end, the fourth piezoelectric resonator TP5 is connected to the second end (i.e., the left end) of the third piezoelectric resonator TS5, and in the band-stop network at the RX end, the fourth piezoelectric resonator RP5 is connected to the second end (i.e., the left end) of the third piezoelectric resonator RS5.
[0090] The RF duplexer provided by the utility model combines a bandpass network and a bandstop network, and the bandstop network is composed of a series resonator and a parallel resonator close to the TX / RX port, which can improve isolation while ensuring insertion loss, suppress multiple harmonics, and does not require the use of winding inductors. It can improve the integration of RF chips, reduce design difficulty, and reduce manufacturing costs.
[0091] Embodiment five:
[0092] The design scheme of any one of the above embodiments 1 to 4 can also be applied to multiplexers other than duplexers. The design scheme is described in detail below by taking a triplexer as an example.
[0093] See also Fig.14 , Fig.14 A structure of a radio frequency multiplexer provided in an embodiment of the utility model Figure 1 . Fig.14 The RF multiplexer in the embodiment is a triplexer, including one transmitting path and two receiving paths. The first ends of the three paths are connected to a common end, namely the antenna end ANT, and the second ends are respectively a transmitting end TX, a first receiving end RX1, a second receiving end RX2, and a third receiving end RX3. There are four first piezoelectric resonators connected in series (TS1~TS4) between the transmitting end TX and the antenna end ANT, which are called series piezoelectric resonators. At least one end of the series piezoelectric resonator is grounded through four second piezoelectric resonators (TP1~TP4), which are called parallel piezoelectric resonators. They are used to process the signal transmitted through the transmitting end TX and generate an output signal, and then transmit the output signal uplink through the antenna end ANT; there are four first piezoelectric resonators connected in series (RS1~RS4) between the receiving end RX1 and the antenna end ANT, and four second piezoelectric resonators are connected in parallel (RP1~RP4), which are used to process the signal received by the antenna end ANT and generate an input signal, and the input signal is transmitted downlink through the receiving end RX1; one end of each parallel piezoelectric resonator is connected to the ground end respectively to achieve circuit impedance matching; the circuit structure between the receiving end RX2 and the antenna end ANT is the same as that of the receiving end RX1, and for the sake of simplicity, it will not be repeated here.
[0094] The first piezoelectric resonator and the second piezoelectric resonator on the transmitting path form a bandpass network, and the passband range is set to the transmitting frequency band of 2.10~2.20GHz;
[0095] The resonant frequency of any one or more of TS1 to TS4 is configured to be 2.20 GHz, and the anti-resonant frequency of any one or more of TP1 to TP4 is configured to be 2.10 GHz; the principle is the same as that of the first embodiment, and will not be repeated here.
[0096] In a possible implementation, two band-stop networks consisting of a third piezoelectric resonator and a fourth piezoelectric resonator are arranged near the transmitting end, the band-stop range of the band-stop filter composed of TS5 and TP5 is set to the first receiving frequency band of 1.90~2.00GHz, and the band-stop range of the band-stop filter composed of TS6 and TP6 is set to the second receiving frequency band of 1.70~1.80GHz; the anti-resonance frequency of TS5 is configured to 1.90GHz, the resonant frequency of TP5 is configured to 2.00GHz, the anti-resonance frequency of TS6 is configured to 1.70GHz, and the resonant frequency of TP5 is configured to 1.80GHz; the principle is the same as that of Example 1 and will not be repeated here.
[0097] The first piezoelectric resonator and the second piezoelectric resonator on the receiving path form a bandpass network, the passband range corresponding to the receiving end RX1 is set to the first receiving frequency band 1.90~2.00GHz, and the passband range corresponding to the receiving end RX2 is set to the second receiving frequency band 1.70~1.80GHz; the resonant frequency of RS1~RS4 is configured to 2.00GHz, and the anti-resonant frequency of RP1~RP4 is configured to 1.90GHz; the resonant frequency of RS6~RS9 is configured to 1.80GHz, and the anti-resonant frequency of RP6~RP9 is configured to 1.70GHz; the principle is the same as that of embodiment 1, and will not be repeated here.
[0098] A band-stop network composed of a third piezoelectric resonator and a fourth piezoelectric resonator is arranged near the receiving end; on the receiving path corresponding to the receiving end RX1, the stopband range of the band-stop filter composed of RS5 and RP5 is configured to be a transmission frequency band of 2.10~2.20GHz, and on the receiving path corresponding to the receiving end RX2, the stopband range of the band-stop filter composed of RS10 and RP10 is configured to be a transmission frequency band of 2.10~2.20GHz; the anti-resonance frequency of RS5 is configured to be 2.10GHz, and the resonant frequency of RP5 is configured to be 2.20GHz; the anti-resonance frequency of RS10 is configured to be 2.10GHz, and the resonant frequency of RP10 is configured to be 2.20GHz; the principle is the same as that of Example 1, and will not be repeated here.
[0099] The number of resonators mentioned above is only an example. The number of resonators can be increased or decreased according to actual needs as long as the preset filtering effect is achieved.
[0100] In this way, for the transmitter, the interference signals from multiple receivers can be suppressed, and for each receiver, the interference signals from the transmitter can be suppressed, and the band-stop network is composed of a series resonator and a parallel resonator close to the TX / RX port, which can improve isolation while ensuring insertion loss, suppress multiple harmonics, and eliminate the need to use winding inductors. This can improve the integration of RF chips, reduce design difficulty, and reduce manufacturing costs.
[0101] In another possible implementation, Fig.15 As shown, Fig.15 A structure of a radio frequency multiplexer provided in an embodiment of the utility model Figure 2 A band-stop network composed of a third piezoelectric resonator and a fourth piezoelectric resonator is arranged near the transmitting end, and the stop band range of the band-stop filter composed of TS5 and TP5 is set to the first receiving frequency band 1.90~2.00GHz or the second receiving frequency band 1.70~1.80GHz.
[0102] In this way, for the transmitting end, although only part of the interference signal of the receiving end is suppressed, the effect of improving isolation is also achieved to a certain extent.
[0103] Similarly, the above design scheme can also be used for other types of multiplexers such as quadplexers. The principle is similar to that of triplexers and will not be repeated here.
[0104] Embodiment six:
[0105] An embodiment of the utility model further provides an electronic device, comprising any one of the radio frequency multiplexers in the above-mentioned embodiments 1 to 5.
[0106] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0107] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0108] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.
Claims
1. A radio frequency multiplexer, characterized in that: The method comprises at least two passages, wherein the first ends of the passages are connected as a common end, and the second ends of the passages are separated from each other; Any one of the paths includes at least one first piezoelectric resonator connected in series between the first end and the second end, at least one end of the first piezoelectric resonator is grounded through at least one second piezoelectric resonator; include at least one third piezoelectric resonator connected in series with the first piezoelectric resonator, the third piezoelectric resonator being adjacent to the second end, and at least one fourth piezoelectric resonator grounding one end of the third piezoelectric resonator; wherein the passband range of the bandpass network formed by the first piezoelectric resonator and the second piezoelectric resonator is configured as a first frequency band; The stopband range of the band-stop network formed by the third piezoelectric resonator and the fourth piezoelectric resonator is configured to cover at least a first isolation frequency band of the passband range of any other path; The first frequency band has no intersection with the first isolation frequency band.
2. The radio frequency multiplexer according to claim 1, characterized in that: The resonant frequency of at least one of the first piezoelectric resonators is configured to be close to an upper cutoff frequency of the first frequency band, and the anti-resonant frequency of at least one of the second piezoelectric resonators is configured to be close to a lower cutoff frequency of the first frequency band.
3. The radio frequency multiplexer according to claim 1, characterized in that: The anti-resonance frequency of at least one of the third piezoelectric resonators is configured to be close to a lower cutoff frequency of the first isolation frequency band, and the resonant frequency of at least one of the fourth piezoelectric resonators is configured to be close to an upper cutoff frequency of the first isolation frequency band.
4. The radio frequency multiplexer according to claim 1, characterized in that: The at least two paths include a first path and a second path; wherein the first path is used to transmit signals, and the second path is used to receive signals.
5. The radio frequency multiplexer according to claim 4, characterized in that: In the first path, the fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator; In the second path, the fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator.
6. The radio frequency multiplexer according to claim 4, characterized in that: In the first path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator; In the second path, the fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator.
7. The radio frequency multiplexer according to claim 4, characterized in that: In the first path, the fourth piezoelectric resonator is connected to a first end of the third piezoelectric resonator; In the second path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator.
8. The radio frequency multiplexer according to claim 4, characterized in that: In the first path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator; In the second path, the fourth piezoelectric resonator is connected to the second end of the third piezoelectric resonator.
9. The radio frequency multiplexer according to claim 1, characterized in that: The first piezoelectric resonator, the second piezoelectric resonator, the third piezoelectric resonator, and the fourth piezoelectric resonator include at least one of SAW and BAW.
10. An electronic device, characterized in that: A radio frequency multiplexer comprising any one of claims 1 to 9.