Classifications

• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
  • H03H9/46—Filters
  • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
  • H03H9/545—Filters comprising resonators of piezoelectric or electrostrictive material including active elements
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
  • H03H9/46—Filters
  • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
  • H03H9/542—Filters comprising resonators of piezoelectric or electrostrictive material including passive elements
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
  • H01P5/00—Coupling devices of the waveguide type
  • H01P5/12—Coupling devices having more than two ports
  • H01P5/16—Conjugate devices, i.e. devices having at least one port decoupled from one other port
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
  • H03H7/18—Networks for phase shifting
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
  • H03H9/46—Filters
  • H03H9/64—Filters using surface acoustic waves
  • H03H9/6403—Programmable filters
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
  • H03H9/46—Filters
  • H03H9/64—Filters using surface acoustic waves
  • H03H9/6423—Means for obtaining a particular transfer characteristic
  • H03H9/6433—Coupled resonator filters
  • H03H9/6483—Ladder SAW filters
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/14—Two-way operation using the same type of signal, i.e. duplex
  • H04L5/1461—Suppression of signals in the return path, i.e. bidirectional control circuits

Definitions

• the invention relates to RF filters, e.g. can be used in portable communication devices.
• Portable communication devices e.g. Mobile radio devices can meanwhile enable communication in a multiplicity of different frequency bands and with a multiplicity of different transmission systems. For this they include i.A. a plurality of RF filters each provided for the corresponding frequency and the corresponding transmission system.
• modern HF filters can now be produced with small dimensions. Due to their large number and the complexity of their interconnection, the front-end modules in which the filters are arranged are nevertheless relatively large and their manufacture is complex and expensive. Remedy could bring tunable RF filters.
• Such filters have a center frequency that is adjustable, which is why a tunable filter can in principle replace two or more conventional filters.
• Tunable RF filters are e.g. known from the documents US 2012/0313731 AI or EP 2530838 AI. In this case, the electro-acoustic properties of working with acoustic waves resonators are varied by tunable impedance elements.
• the RF filter comprises series-connected basic elements, each with an electroacoustic resonator.
• the filter further comprises series-connected impedance converters in series between the base members.
• the impedance converters are admittance inverters.
• the resonators of the basic elements are only parallel resonators. At least one of the resonators is tunable.
• Basic terms in RF filters are e.g. from ladder-type structures where a fundamental term comprises a series resonator and a parallel resonator.
• a fundamental term comprises a series resonator and a parallel resonator.
• Several such basic elements connected in series essentially cause the filtering effect if the resonant frequencies and the anti-resonant frequencies of the series or parallel resonators are suitably matched to one another.
• Impedance inverters or admittance inverters may be used as impedance converters. While an impedance transformer transforms any transformation of a load impedance into an input impedance, the effect of the impedance inverters or admittance inverters is clearly concretized. Impedance inverter or admittance inverter can be described as follows with the means for two-core.
• the chain matrix with the matrix elements A, B, C, D describes the effect of a two-port, which is gangstor connected with its off ⁇ to a load, by pretending as an incidental to a load voltage U L and by a load flowing current I L is transformed into a voltage U IN applied to the input port and a current I IN flowing into the input port
• the impedance Z is defined as the relationship between voltage and current:
• the load impedance Z L thus looks like the input impedance Z IN from the outside.
• the impedance is inverted.
• the proportionality factor is K 2 .
• the admittance is inverted.
• the proportionality factor is / 2 .
• a series connection of two impedance inverters with a series resonator in between looks like a parallel resonator for its circuit environment.
• a serial A circuit of two admittance inverters with a parallel resonator in between looks like a series resonator for its circuit environment.
• the RF filter so that the impedance transformers are impedance inverters and the resonators are series resonators.
• Such filters do not require parallel resonators. If the filters are designed as bandpass filters or as bandstop filters, they have i.A. a steep right flank.
• the filter can be used in a duplexer. Because of the steep right flank preferred as a transmission filter. Namely, when the transmission tape is below the receiving band. If the relative arrangement of transmit band and receive band is reversed, the filter with series resonators is preferred in the receive filter.
• the RF filter in such a way that the impedance converters are admittance inverters and the resonators are parallel resonators.
• filters do not require series resonators. If the filters are designed as bandpass filters or as bandstop filters, they have i.A. a steep left flank. The filter can also be used in a duplexer. Because of the steep left flank preferred as a receive filter.
• the filter with series resonators is preferred in the transmission filter.
• the impedance converter grasp both capacitive elements and inductive elements as impedance elements to ⁇ . But it is also possible that the impedance converter only capacitive elements or inductive elements only
• the impedance converters consist only of passive circuit elements.
• the impedance converters comprise only a few or no inductive elements, they can easily be realized as structured metallizations in metal layers of a multilayer substrate.
• the impedance converters comprise phase shifter lines in addition to inductive or capacitive elements. But it is also possible that the impedance converter consist of phase shifter lines. Also phase shifter cables can be integrated in a multi-layer substrate in a simple and compact design.
• the filter is described by a symmetrical Be ⁇ writing matrix B.
• a filter circuit interconnected in series three Resona- factors Rl, R2, R3 and includes the input side with a source impedance ZS ⁇ and the output side connected to a load impedance ZL, would have the following form:
• K S1 stands for the impedance inverter between the source impedance Z s and the first resonator.
• K 12 stands for the impedance inverter between the first and the second resonator.
• IA the indices of the sizes of the inverters denote the resonators, between which the respective inverters are arranged.
• Bi B i, that is, the matrix is symmet ⁇ driven with respect to its diagonal.
• the filter circuit associated with equation (9) is shown in FIG.
• the Resonato ⁇ ren be described by variables on the diagonal of the matrix.
• the impedance transducers are described by sizes on the side diagonals directly above and below the diagonal.
• the filter prefferably has a second impedance transformer connected in parallel to a segment of the filter is included.
• the segment includes a series circuit with one base and two impedance transformers.
• the description matrix then contains entries that are above the upper or lower side diagonal, respectively.
• At least one of the resonators of the basic elements is tunable.
• SAW resonators come (SAW
• GBAW Guided Bulk Acoustic Wave
• LC LC resonators
• Resonator elements operating with acoustic waves essentially have an equivalent circuit diagram with a parallel circuit comprising a capacitive element Co on the one hand and a series circuit with an inductive element Li and a capacitive element Ci on the other hand.
• Such a resonator element has its resonance frequency and its anti-resonant frequency
• ⁇ tunable element such as tunable inductive or capacitive elements in series and / or parallel to the resonator are switched, a resonator with variable frequency response is formed.
• the resonance frequency depends on Li and Ci but not on Co.
• the antiresonance also depends on Co.
• a tunable resonator can comprise a field of resonator elements, of which each element can be coupled by means of switches to the resonator or separated from the resonator. It is then an array of m resonator elements per tunable resonator.
• RF filters can build that - can realize m different Filterübertra ⁇ supply curves - depending on active resonator.
• Each of the m resonators can be assigned exactly one filter transfer curve. But it is also possible that a filter transmission curve several simultaneously active resonator elements are arranged to ⁇ .
• m resonator elements allow up to m! (Faculty of m) different filter transfer curves, m can be 2, 3, 4, 5, 6, 7, 8, 9, 10 or even more betra ⁇ conditions. If the resonator elements are connected in parallel, 2 m different filter transfer curves are possible.
• CMOS complementary metal-oxide-semiconductor
• GaAs gallium arsenide
• JFET junction-field FET
• transistor MEMS switches
• MEMS microelectromechanical system
• an impedance converter comprises three parallel capacitive elements. It is also possible that an impedance converter comprises three parallel inductive elements. It is also possible that an impedance converter comprises two parallel inductive elements and one parallel capacitive element. It can be calculated that individual impedance elements have negative impedance values, eg negative inductances or negative capacitances. However, negative impedance values are at least unproblematic if the corresponding impedance elements are to be connected to other impedance elements of the RF filter, so that the interconnection with the other elements in the sum again has positive impedance values. In this case, the connection of the ei ⁇ sionally elements provided by the element with positi ⁇ vem impedance value would be replaced.
• the RF filter of a signal path four ka ⁇ pazitive elements in the signal path, six switchable resonators each having a resonator and a thereto-connected in series in a transverse branch to ground switch and an inductive element to two parallel four capacitive elements is connected.
• FIGS. 9A to 9K show different embodiments of tunable resonators
• FIGS. 11A to 11F show different embodiments of a
• Figs. 12A to 12F various embodiments of a
• FIGS. 13A to 13C show different levels of abstraction in the case of
• FIG. 14A to 14H Various concrete execution ⁇ form an RF filter with two tunable series resonators and three impedance converters 15A to 15H.:.
• FIG. 17 shows the transmission curves of the RF filter of Figure 16 with tunable impedance elements are changed in its impedance to obtain a new location of the Empire fürlassbe ⁇ B.
• Fig. 19:. The RF filter to Figure 18, wherein the impedance values were varied from ⁇ tunable impedance elements to an altered. location of the passband to he ⁇ hold
• Fig. 20 insertion loss (B, ⁇ ⁇ ) of an RF filter in which are by tuning of resonators different frequency locations of the passband received
• Fig. 21 different transmission curves (B, ⁇ ⁇ ) of a RF filter having parallel resonators and admittance inverters in which different impedance values different positions of the passband Be Farming ⁇ ken
• FIG. 17 shows the transmission curves of the RF filter of Figure
• Fig. 22 Insertion losses of a tunable duplexer: The
• Curves Bl and B3 denote a tunable transmission frequency band.
• the curves B2 and B4 represent the insertion losses of an adjustable reception frequency band,
• FIG. 23 shows a possible filter circuit
• FIG. 24 shows a possible form of integration of circuit components in a component
• FIG. 25 Transmission functions of a tunable filter according to FIG. 23.
• FIG. FIG. 1 shows an RF filter circuit F with three resonators and four impedance transformers IW.
• the middle resonator in this case represents a basic element GG.
• the middle resonator may be a parallel resonator P or a series resonator S.
• the two impedance transformers IW which surround the first resonator, cause the resonator to look outwards like a series resonator or as a parallel resonator. If the middle resonator is a parallel resonator, the first resonator can also be a parallel resonator, which looks like a series resonator to the outside.
• the third resonator would be a parallel resonator, which looks like a series resonator to the outside.
• the middle resonator may be a series resonator S.
• the two outer resonators would also be series resonators that look like parallel resonators to the outside.
• Figure 2 shows a filter circuit in which the central resonator is determined by the surrounding impedance converter IW masked so that the filter looks toward the outside as a alternie ⁇ Rende sequence of parallel and series resonators, although only one type of resonator is used.
• FIG. 3 shows a duplexer D in which both the transmission filter TX and the reception filter RX comprise series connections of impedance transformers and resonators, which are connected to one another in such a way that only one type of resonator per filter is necessary. Since series resonators are suitable, a steep right filter edge of a pass band to bil ⁇ the and since transmitting frequency bands generally in terms of frequency are below the receive frequency bands, it is advantageous to use in the transmit filter TX series resonators. Analogously, parallel resonators would have to be used in the receive filter RX. If the transmission frequency band lies above the reception frequency band, then correspondingly series resonators in the reception filter and parallel resonators in the transmission filter would be advantageous.
• the filters TX, RX are connected via an impedance matching circuit IAS with an antenna ANT. From the perspective of Impedanzan ⁇ matching circuit IAS each of the two filter TX, RX looks like a conventional ladder-type filter circuit, so that virtually no additional effort in designing the rest of the circuit components such as antenna and Impedanzanpass- circuit is necessary.
• FIG. 4 correspondingly shows an embodiment in which the middle resonator is designed as a series resonator S.
• a serial Resonatorel ⁇ ement can also be used in the two outer resonators, although the combination of the impedance transformers and the series resonator to the outside as a parallel resonator P looks like and its appearance.
• impedance inverter K are preferably used.
• Figure 5 shows an embodiment of an RF filter F, in which only parallel resonators are used.
• the two outer parallel resonators appear as series resonators S.
• a parallel resonator P the RF filter F forms a quasi-ladder-type structure.
• Figure 6 shows an embodiment in which the two outer resonators directly via another impedance converter, z. As an impedance inverter, are connected. The direct connection of the outer resonators via a further impedance converter represents a new degree of freedom, via which an HF filter can be further optimized.
• Figure 7 shows an example of an embodiment of an RF filter F, which uses parallel resonators and admittance inverter J.
• the two outer resonators are interconnected directly via another admittance inverter J with each other.
• Figure 8 shows a possible embodiment of an RF filter in which the resonators are tunable.
• FIG 9 shows a possible embodiment of a abstimmba ⁇ ren resonator R.
• the resonator R comprising a Resonatorele ⁇ element RE.
• the resonator element RE can be a working with akusti ⁇ rule waves resonator.
• Parallel to the resonator element RE is a capacitive element CE 29al ⁇ tet.
• another capacitive element CE is connected.
• the two capacitive Ele ⁇ mente CE are tunable, ie their capacity can be ⁇ provides.
• the capacity can be set continuously or in discrete values.
• Includes one Capacitive element CE a bank of capacitive Einzelele ⁇ elements, which can be controlled individually by means of one or more switches, the capacity of the corre ⁇ sponding capacitive element CE can be set in discrete steps.
• FIG. 9B shows an alternative possibility of a resonator R, in which the series connection of a tunable capacitive element CE with a resonator element RE is connected in series with a tunable inductive element IE.
• Figure 9C shows a possible embodiment of a abstimmba ⁇ R ren resonator in which a resonator element RE connected in parallel with a tunable inductive element IE. This parallel circuit is connected in series with a tunable capacitive element CE.
• FIG. 9D shows a further alternative embodiment for a tunable resonator R.
• the parallel circuit is connected in series with a tunable inductive element IE.
• FIG. 9E shows a further alternative embodiment of a tunable resonator, in which a resonator element RE is only connected in parallel with a tunable capacitive element CE.
• FIG. 9F shows a further alternative embodiment of a tunable resonator R.
• a resonator element RE is connected in parallel to a tunable inductive element IE.
• FIGS. 9E and 9F show relatively simple embodiments of a tunable resonator R.
• FIGS. 9A to 9D show embodiments of a tunable resonator R, which permit further degrees of freedom in tuning by means of another tunable element.
• the embodiments shown may be connected in series or in parallel with other capacitive and inductive elements of fixed impedance or variable impedance to provide additional degrees of freedom, e.g. For a broader tuning range.
• FIG. 9G shows an embodiment of a tunable resonator R, in which the resonator element RE is connected in parallel with a series connection comprising an inductive element IE and a tunable capacitive element CE.
• FIG. 9H shows an embodiment of a tunable resonator R, in which the resonator element RE is connected in parallel with a parallel connection comprising an inductive element IE and a tunable capacitive element CE.
• FIG. 91 shows an embodiment of a tunable resonator R, in which the resonator element RE is connected in series to a series connection, comprising an inductive element IE and a tunable capacitive element CE.
• Figure 9J illustrates an embodiment of a tunable resonator R, wherein the resonator element RE on the one hand in Se ⁇ rie to a series connection of switches comprising an inductive element IE and a tunable capacitive element CE comparable, and on the other hand parallel to a Parallelverschal ⁇ tung, comprising a inductive element IE and a Abstimmba ⁇ res capacitive element CE, is connected.
• Figure 9K illustrates an embodiment of a tunable resonator R, wherein the resonator element RE on the one hand in Se ⁇ rie to a series connection comprising a tunable inductance element IE and a tunable capacitive element CE, connected on the other hand parallel to a Pa ⁇ rallelverscnies comprising a tunable inductive element IE and a tunable capacitive element CE, ver ⁇ is switched.
• continuously tunable elements such as varactors and switchable elements of constant impedance and switchable tunable elements, such. B. by means of switch-switchable varactors are possible.
• the resonator element may be connected in series with a series network and in parallel with a parallel network.
• the series network and the parallel network can each comprise impedance elements of fixed or variable impedance.
• FIG. 10 shows an additional possible embodiment ei ⁇ nes tunable resonator R, which comprises a large number of resonator elements RE and a plurality of switches SW environmentally.
• FIG. 10A shows resonator elements RE that are interconnected in series in the signal path SP. In order for a voting ⁇ Barer series resonator is shown. By individually opening and closing the individual switches SW, individually adjustable resonator elements RE can be coupled into the signal path SP. If the tunable resonator R in FIG. 10A comprises resonator elements RE, then 2 m different switching states can be obtained.
• FIG. 10B shows an embodiment of a tunable resonator R in which resonator elements connect the signal path SP to ground. Since the order of the individual Resonato rimplantation ⁇ RE in which they are connected to the signal path SP is in principle relevant to m! (m Faculty) under ⁇ different resonator states are obtained.
• Figures IIA to 11F indicate various embodiments of an impedance inverter.
• Figure IIA thus shows one form of an impedance converter, which can ⁇ che represents an impedance inverter.
• Two capacitive Ele ⁇ elements are connected in series in the signal path.
• a kapaziti ⁇ ves element connected to the common circuit node of the capacitive elements in the signal path to ground.
• the ka ⁇ pazitiven elements in the signal path obtained by calculation, a negative capacitance -C.
• the capacitive element in the parallel path to ground is calculated to have a positive capacitance C.
• the capacitance values only result from the calculation rules for two gates.
• the T-circuit shown in Figure IIA therefore need not be so realized in a circuit environment.
• the capacitive elements of negative capacity in the series path with further capacitive elements of positive capacity, which are additionally connected in the series path, are combinatorial ⁇ defined, so that overall each of one or more elements ka ⁇ pazitive positive capacity can be obtained.
• Figure IIB shows a T-circuit of inductive elements, wherein the two inductive elements, which are connected in series in the signal path, have purely formally have a negative inductance.
• Figure HC shows a form of an impedance inverter having as a pi circuit with a capacitive element of negative capacitance in the series path and two capacitive elements of positive capacitance in each case a parallel path.
• Figure HD shows an embodiment of a pi-form impedance inverter in which the inductance of the inductive element in the signal path is negative.
• the inductances of the inductive elements in the corresponding two parallel paths are positive.
• Figure HE shows an embodiment of an impedance inverter with a phase shifter circuit and an inductive element of the inductance L.
• the phase shifter circuit preferably has the characteristic impedance of the signal ⁇ line Zo.
• the phase offset ⁇ by the phase shifter circuit is set appropriately.
• FIG 11E shows an alternative exporting Figure 11F ⁇ approximate shape, wherein the inductive element is replaced by a kapaziti ⁇ ves element of the capacity C.
• FIGS. 12A to 12F show embodiments of an admittance inverter.
• FIG. 12A shows an embodiment of an admittance inverter in T configuration, in which the two capacitive elements in the series path have positive capacitances.
• the kapa ⁇ zitive element in the parallel path nominally has a negative capacitance.
• FIG. 12B shows an embodiment of an admittance inverter in the T configuration, where two inductive signals are present in the signal path
• Elements of the inductance L are connected in series.
• an inductive element with the ne ⁇ gativen inductance L is connected.
• FIG. 12C shows an embodiment of an admittance inverter in pi configuration, wherein the two capacitive elements in the two parallel paths have a negative capacitance.
• the capacitive element in the signal path has a positive capacitance.
• FIG. 12D shows an embodiment of an admittance inverter in Pi configuration with three inductive elements.
• the inductive element in the series path has a positive inductance.
• the two inductive elements in the two parallel paths each have a negative inductance.
• Figure 12E shows an embodiment of admittance inverted ters, in which an inductive element with a positive Induktivi ty ⁇ L is connected between two segments of a phase shift circuit. Each segment of the phase shifter circuit has a characteristic impedance Zo and shifts the phase appropriately.
• Figure 12F shows an execution ⁇ form an admittance inverter which is also based on phase-shifting circuits. Between two segments one
• Phase shifter circuit is a capacitive element with posi ⁇ tive capacity C interconnected.
• Figure 13 shows the use of tunable resonators R together with impedance converters IW.
• the resonator can be a series resonator.
• impedance inverters K as impedance converter IW
• a combination of two impedance transformers IW and a series resonator connected in between results in a total of a parallel resonator.
• FIG. 14A thus shows an HF filter circuit with two tunable resonators and three impedance elements whose impedance is chosen so that one of the two resonators acts as a parallel resonator.
• Figure 14A therefore essentially shows a basic element of a ladder-type filter circuit, although only series resonators are used.
• Figure 14B shows an alternative to the RF filter of Figure 14A, because the inductive element L between the resonators is replaced by a capacitive element C and the capacitive element in the load-side parallel path is replaced by an inductive element.
• Figure 14C shows another embodiment of an RF filter having two resonators, three inductive elements each ⁇ wells connected a parallel path are.
• Figure 14D shows a possible embodiment of an RF filter, in which the left two impedance elements are formed by in ⁇ duktive elements and the right impedance element by a ka ⁇ pazitives element.
• Figure 14E shows an embodiment in which the outer two impedance elements are gebil ⁇ det by inductive elements and the central impedance element through a capacitive element.
• Figure 14F shows an embodiment in which the right two impedance elements are formed by capacitive elements and the left impedance element by an inductive element.
• Figure 14G shows an embodiment in which the right two impedance elements are formed by inductive elements and the left impedance element by a capacitive element.
• Figure 14H shows an embodiment in which all three impedance elements are formed by capacitive elements.
• FIGS. 15A to 15H show further alternatives of the RF filters of FIGS. 14A to 14H, wherein a further impedance element directly interconnects the signal input and the signal output.
• a bridging capacitive element As an alternative to the bridging capacitive element, a bridging inductive element or other embodiments of impedance converters can be used.
• FIG. 16 shows the admittance of a resonator (curve A) and the transfer function of an HF filter with such a resonator (curve B).
• Serial capacitive elements have a value of 2.4 pF.
• Parallel capacitive elements have a value of 0.19 pF.
• Figure 17 shows the corresponding curves wherein serial tunable capacitances have been set to a capacitance value of 30 pF and parallel tunable capacitances to a capacitance value of 3.7 pF.
• the impedance converters of the filters associated with FIGS. 16 and 17 are impedance inversors.
• the resonators are series resonators.
• FIG. 18 shows the characteristic curves of a filter in which serial tunable capacitances have a value of 2.4 pF and parallel tunable capacitive elements have a value of 0.19 pF.
• Figure 19 shows the respective curves of the RF filter in which the serial tunable capacitances have a value of 30 pF and the parallel tunable capacitances have a value of 3.7 pF.
• FIG. 20 shows insertion losses of bandpass filters with admittance inverters and parallel resonators.
• the filter has tunable resonators are tuned by adjustable Kapazitä ⁇ th capacitive elements once on the receiving tape 17 or strip. 5
• the resonators comprise resonator elements which can be coupled by means of switches, as shown in FIG. 10B.
• FIG. 21 shows transmission curves of an HF filter with impedance inverters and series resonators, wherein the tunable values are tuned once to the transmission frequencies of the band 17 and once to the transmission frequencies of the band 5.
• the resonators comprise resonator elements that can be coupled by means of switches, as shown in FIG. 10A.
• FIG. 22 shows the insertion losses of the receive filters of a tunable duplexer, once tuned to band 17 and once to band 15.
• Fig. 23 shows a possible embodiment of the RF filter.
• the switchable resonators comprises a resonator element and a switch connected in series therewith.
• An inductive element is connected in parallel with two of the four capacitive elements.
• FIG. 24 shows how circuit components of the filter circuit can advantageously be integrated in a multilayer module.
• MIM metal metal insulator
• the switches SW can be realized.
• vias can be made, which represent lines of an interface between (semiconductor) switches and the resonator elements. Under the situation with the interface then the resonator elements, for. B. as SAW, BAW, GBAW, ... etc. elements, be arranged.
• FIG. 25 shows calculated transmission curves for the bands 34 and 39, between which switches can be switched over.
• RF filter or duplexer having RF filters can further comprise additional resonators or impedance elements, in particular from ⁇ tunable impedance elements comprise.
• IAS impedance matching circuit
• IW impedance converter
• RE resonator element

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• Computer Networks & Wireless Communication (AREA)
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• Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
• Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

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• 2014
  • 2014-08-20 DE DE102014111904.5A patent/DE102014111904A1/de not_active Withdrawn
• 2015
  • 2015-07-06 CN CN201580050753.6A patent/CN107078718A/zh active Pending
  • 2015-07-06 US US15/315,374 patent/US20170155375A1/en not_active Abandoned
  • 2015-07-06 WO PCT/EP2015/065377 patent/WO2016026607A1/de active Application Filing
  • 2015-07-06 JP JP2016570327A patent/JP6401301B2/ja not_active Expired - Fee Related
  • 2015-07-06 EP EP15735927.4A patent/EP3183814A1/de not_active Withdrawn

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