Ladder-type reconfigurable filter

FIELD: radio engineering, communication.

SUBSTANCE: ladder-type reconfigurable filter is made on one board and contains two surface acoustic waves (SAWs) resonators, two inductance coils, two capacitors and two voltage variable-capacitance diodes. The outputs of the first voltage variable-capacitance diode, the first capacitor and the first SAW resonator are connected to each other and connected to the input potential terminal of the filter.

EFFECT: provision of the possibility to change the bandwidth of the filter and increasing the number of simultaneously operating bandwidths.

12 dwg

 



 

Same patents:

FIELD: process engineering.

SUBSTANCE: invention relates to cascade connection of several filters. Filter comprises at least one first filter composed by band-rejection filter with the first set of parameters defined by the first material used for its fabrication. Second filter features second set of parameters defined by the second material of its fabrication. Every said filter is the band-rejection filter of band-transmission filter. Filters are interconnected to make composite filter. First and second materials differ. Composite filter has third set of parameters depending on said first and second materials.

EFFECT: wide transmission or rejection bands with one narrow band on one of said transmission or rejection band.

19 cl, 11 dwg

FIELD: physics, acoustics.

SUBSTANCE: invention relates to acoustoelectronics and can be used in making thermally stable surface acoustic wave filters. The thermally stable narrow-band surface acoustic wave filter comprises an acoustic line - a piezoelectric substrate with interdigital transducers formed on its surface; on the reverse side the substrate there is a flat metal or dielectric plate with through-holes on edges of the plate, through which the plate is mounted to the acoustic line and simultaneously to the mounting support of the housing using a rubber-like adhesive with a high coefficient of linear thermal expansion; the plate is mounted in the central part to the acoustic line by a thin layer of a rubber-like adhesive with a high coefficient of linear thermal expansion; between the mounting support of the housing and the plate there is a gap which is greater than the sag of the mounting support of the housing at subzero and above-zero ambient temperatures.

EFFECT: high thermal stability and improved mechanical strength of the structure.

5 dwg

FIELD: radio engineering, communication.

SUBSTANCE: radio-frequency band-rejection filter includes an input port, an output port, a plurality of acoustic resonators, an inductor for matching impedances of the plurality of acoustic resonators, an inductor for connection in the band-rejection filter among the plurality of acoustic resonators, such that static capacitance between the input port and the inductor is basically equal to the static capacitance between the output port and the inductor. The plurality of acoustic resonators can be a plurality of parallel resonators, a plurality of series resonators or a combination of both. The radio-frequency band-rejection filter is made using a surface acoustic wave technology, a bulk acoustic wave thin-film resonator technology or a bulk acoustic wave resonator technology.

EFFECT: limiting energy scattering and eliminating noise.

21 cl, 18 dwg

FIELD: physics.

SUBSTANCE: thermally stable narrow-band surface acoustic wave (SAW) filter has an acoustic line - piezoelectric substrate with interdigital transducers formed on its surface and placed in a housing; on the reverse side of the substrate there is a flat plate with a hole in the middle and holes on the edges, wherein the plate is attached to the acoustic line on the position of the centre hole by a "solid" - hard adhesive with coefficient of linear thermal expansion and simultaneously to the mounting seat of the housing, attached through the holes on the edges to the acoustic line and simultaneously to the mounting seat of the housing by a rubber-like adhesive with high coefficient of linear thermal expansion, wherein the piezoelectric substrate rests on crosspieces on the ends of the flat plate which prevent bending of the substrate.

EFFECT: smaller size of the thermally stable surface acoustic wave filter, higher vibration resistance and thermal stability.

5 cl, 4 dwg

FIELD: radio engineering.

SUBSTANCE: ladder-type filter on surface acoustic waves with increased selectiveness includes piezoelectric acoustic line with structure of parallel and series resonators applied to its surface and connected as per ladder network, or installed in the housing, or immediately on the board, earth terminals of parallel resonators are divided into equal parts between input and output of ladder-type filter and taken as separate microstrip lines to separate earth contact platforms of piezoelectric acoustic line, which are not connected to anything else, which are earthed on the outside of the board at one point as to input and at one point as to output at installation of ladder-type filter on the board, or at installation of piezoelectric acoustic line into housing; contact platforms of piezoelectric acoustic line are connected to separate platforms of housing, which are also earthed on the outside on the board at one point as to input and at one point as to output at installation of packaged ladder-type filter on the board.

EFFECT: increasing out-of-band rejection of signals.

5 dwg

FIELD: electricity.

SUBSTANCE: magnitoelectric resonator consists of composite magnitoelectric material representing multilayer structure of piezoelectric layer, ferromagnetic layer and bias system, at that lay-out of interdigital transducer is applied to piezoelectric layer from side of ferromagnetic layer.

EFFECT: improvement of resonator quality factor, possibility of quality-factor control by magnetic field.

2 dwg

FIELD: physics.

SUBSTANCE: surface acoustic wave (SAW) filter has a piezoelectric acoustic line on whose surface there are input and output wideband transducers and a periodic structure in between in form of a system of ferroelectric domains with opposite polarisation, made using a laser-electrical technique and having the required resonance frequency.

EFFECT: increase in Q-factor to 104 and possibility of adjusting resonance frequency of the SAW filter.

2 dwg

FIELD: physics; radio.

SUBSTANCE: present invention pertains to acouto-electronics and can be used as a high-frequency (10 MHz - 1GHz) frequency-tunable surface acoustic wave filter, made using a wireless communication and signal processing device. The filter has a piezoelectric acoustic line, on the surface of which there are broadband converters, between which there is a photo-induced periodic structure, in the near-surface layer of the acoustic line. This structure has resonance properties, defined by the period of the structure.

EFFECT: possibility of tuning the resonant frequency of the filter.

1 dwg

FIELD: physics; electricity.

SUBSTANCE: surface acoustic wave filter consists of a piezoelectric acoustic line, on the working surface of which there is, in one acoustic channel, a central interdigital transducer - sectional, connected to the input terminal, and two identical lateral interdigital transducers, arranged symmetrically relative the centre and connected to the output terminal. The filter is characterised by that, the electrodes of the central and lateral interdigital transducers with width of λ/4, where λ is the wave length, and height 0.12÷0.15 mcm, are "buried" in the groove of the acoustic line, made with depth of 0.1÷0.12 mcm. The lateral interdigital transducers are uniform, and the central interdigital transducer is made in form of a set of 1+2N sections - middle, and 2N lateral, and symmetrical to it. The length Mo of the middle section and the length Mn of each lateral section in wave length λ, are chosen from the relationship: Σ2Mn≤Mo, where: fo - is the central frequency of the amplitude-frequency response; Δf' - is the given passband of the filter; the number n, determining the phase of each lateral section relative the middle section in the central interdigital transducer, is chosen from the expression: n≥2Mo. The expression from which the envelope curve of the amplitude-frequency response of the central interdigital transducer is determined is given.

EFFECT: improved filter selectivity and reduced distortions of the amplitude-frequency response without increase in losses.

4 dwg

FIELD: radio technology.

SUBSTANCE: invention pertains to wireless communication and can be used for selecting radio signals in input cascades of radio receiving devices. The multi-channel filter on surface acoustic waves has input and output terminals, input and output commutators, each of which consists of N switches on the number of filter channels, with their control inputs, frequency-selective unit with an amplifier, between the input and output commutators and consisting of N channels, each of which has input and output filters on surface acoustic waves, channel input and output switches with their control inputs, first and second group electric bus lines. The input terminal is connected to the inputs of the switch of the input commutator, and the output terminal is connected to the outputs of the switch of the output commutator. There are N-1 amplifiers in the frequency-selective unit. In each channel of the frequency-selective unit the input of the amplifier is connected to the output of the input filter on surface acoustic waves of the first group electric bus line, and the output of the amplifier is connected to the input of the output filter on surface acoustic waves of the second group electric bus line. The input of the channel input switch is connected to the output of the corresponding switch of the input commutator, and the output of the channel input switch is connected to the input of the output filter on surface acoustic waves. The input of the channel output switch is connected to the output of the output filter on surface acoustic waves, and the channel output switch is connected to the input of the corresponding switch of the output commutator. In that case the length of the first and second group electric bus lines does not increase with increase in the number of channels and the central frequency of the input and output filters on surface acoustic waves.

EFFECT: design of a multi-channel filter on surface acoustic waves, providing for lowering distortions of the amplitude-frequency response.

4 dwg

FIELD: acoustoelectronics; narrow-band surface acoustic-wave filters characterized in low temperature coefficient of frequency.

SUBSTANCE: proposed method depends on measurement of distance between interdigital transducers by deforming crystal lattice of piezoelectric substrate. Disposed on underside of piezoelectric substrate is bimetal plate or strip of material whose coefficient of temperature expansion is higher than that of piezoelectric substrate.

EFFECT: enhanced temperature stability of device, reduced central frequency drift at ambient temperature fluctuations.

2 cl, 5 dwg

FIELD: radio-location technologies, in particular, engineering of transponders for system of radio-frequency identification of mobile and immobile objects.

SUBSTANCE: device for encoding at surface acoustic waves for passive transponder has piezo-electric substrate and N opposite-pin transformer pairs, positioned at surface of piezo-electric substrate in parallel rows along its width, while each opposite-pin transformer pair consists of one input opposite-pin transformer and one output opposite-pin transformer and is adjusted for specific working f., N input opposite-pin transformers, to which request signal is sent, are positioned along width of substrate in one plane one below another and are connected electrically in parallel between each other, N output opposite-pin transformers, from which response signal is taken, are positioned in steps along width of substrate in basic positions relatively to input opposite-pin transformers and are also connected electrically in parallel to each other, while at least two pairs of opposite-pin transformers have different working frequencies, selected from M various values, alternation of opposite-pin transformer pairs, having different working frequencies, is individual for each surface acoustic waves device and is appropriate for previously selected code combination, each one of N output opposite-pin transformers can be mounted with shift relatively to base position in one of fixed positions, individual for each surface acoustic waves device and appropriate for previously selected code, so that maximal number of code combinations for current device is (M×L)N, where M - number of working frequencies of device, L - number of fixed positions of output opposite-pin transformers, including base position, N - number of opposite-pin transformer pairs.

EFFECT: increased number of possible code operations without increase of total dimensions of piezo-electric substrate crystal.

3 cl, 4 dwg

FIELD: acoustical electronics, possible use for development and manufacture of narrowband filters on surface acoustic waves with low temperature coefficient of frequency.

SUBSTANCE: thermo-stable filter on surface acoustic wave contains piezo-electric substrate with oppositely-rod transformers formed on the surface and with bimetallic plate fastened to back side of piezo-electric substrate. Bimetallic plate has rigid holder in the center of piezo-electric substrate, while on the ends frequency bimetallic plate spring elements are rigidly held, which are freely pressed to ends of piezoelectric substrate with force, forming preliminary bend of piezoelectric substrate at environment temperature 20-25° and resulting in increase of original central frequency of surface acoustic wave filter for 2-4 kHz.

EFFECT: increased temperature stability of narrowband devices on surface acoustic waves and decreased deviation of central frequency when environment temperature changes.

5 dwg

FIELD: radio electronics; acousto-electronic devices for processing surface acoustic wave signals.

SUBSTANCE: proposed device has piezoelectric acoustic line whose effective surface mounts input and output interdigital transducers. Device also has additional components such as reflectors with short-circuited electrodes and/or shielding structures. Internal region of bus abutting against active region is completely plated with metal. Intermediate region of bus is made in the form of periodically disposed non-metal-plated windows. External region of bus is completely plated with metal and its width is chosen basing on provision for minimizing resistance of bus as a whole.

EFFECT: reducing device aperture by two or three times which accordingly reduces size of piezoelectric acoustic line.

1 cl, 4 dwg

Saw filter // 2308799

FIELD: radio electronics; signal frequency selecting devices for various communication systems, television sets, and the like.

SUBSTANCE: proposed SAW filter has piezoelectric substrate whose effective surface carries input and output interdigital transducers. At least one of transducers has solid spaced metal plating, its shape complying with apodization weighting function value. This transducer is characterized in variable width along acoustic channel and its aperture is maximal at points of highest apodization weighting function value. Its aperture in part abutting against output transducer equals active aperture of output transducer.

EFFECT: enhanced precision of reproducing desired frequency characteristics of filter, reduced size of piezoelectric substrate.

1 cl, 3 dwg

FIELD: radio technology.

SUBSTANCE: invention pertains to wireless communication and can be used for selecting radio signals in input cascades of radio receiving devices. The multi-channel filter on surface acoustic waves has input and output terminals, input and output commutators, each of which consists of N switches on the number of filter channels, with their control inputs, frequency-selective unit with an amplifier, between the input and output commutators and consisting of N channels, each of which has input and output filters on surface acoustic waves, channel input and output switches with their control inputs, first and second group electric bus lines. The input terminal is connected to the inputs of the switch of the input commutator, and the output terminal is connected to the outputs of the switch of the output commutator. There are N-1 amplifiers in the frequency-selective unit. In each channel of the frequency-selective unit the input of the amplifier is connected to the output of the input filter on surface acoustic waves of the first group electric bus line, and the output of the amplifier is connected to the input of the output filter on surface acoustic waves of the second group electric bus line. The input of the channel input switch is connected to the output of the corresponding switch of the input commutator, and the output of the channel input switch is connected to the input of the output filter on surface acoustic waves. The input of the channel output switch is connected to the output of the output filter on surface acoustic waves, and the channel output switch is connected to the input of the corresponding switch of the output commutator. In that case the length of the first and second group electric bus lines does not increase with increase in the number of channels and the central frequency of the input and output filters on surface acoustic waves.

EFFECT: design of a multi-channel filter on surface acoustic waves, providing for lowering distortions of the amplitude-frequency response.

4 dwg

FIELD: physics; electricity.

SUBSTANCE: surface acoustic wave filter consists of a piezoelectric acoustic line, on the working surface of which there is, in one acoustic channel, a central interdigital transducer - sectional, connected to the input terminal, and two identical lateral interdigital transducers, arranged symmetrically relative the centre and connected to the output terminal. The filter is characterised by that, the electrodes of the central and lateral interdigital transducers with width of λ/4, where λ is the wave length, and height 0.12÷0.15 mcm, are "buried" in the groove of the acoustic line, made with depth of 0.1÷0.12 mcm. The lateral interdigital transducers are uniform, and the central interdigital transducer is made in form of a set of 1+2N sections - middle, and 2N lateral, and symmetrical to it. The length Mo of the middle section and the length Mn of each lateral section in wave length λ, are chosen from the relationship: Σ2Mn≤Mo, where: fo - is the central frequency of the amplitude-frequency response; Δf' - is the given passband of the filter; the number n, determining the phase of each lateral section relative the middle section in the central interdigital transducer, is chosen from the expression: n≥2Mo. The expression from which the envelope curve of the amplitude-frequency response of the central interdigital transducer is determined is given.

EFFECT: improved filter selectivity and reduced distortions of the amplitude-frequency response without increase in losses.

4 dwg

FIELD: physics; radio.

SUBSTANCE: present invention pertains to acouto-electronics and can be used as a high-frequency (10 MHz - 1GHz) frequency-tunable surface acoustic wave filter, made using a wireless communication and signal processing device. The filter has a piezoelectric acoustic line, on the surface of which there are broadband converters, between which there is a photo-induced periodic structure, in the near-surface layer of the acoustic line. This structure has resonance properties, defined by the period of the structure.

EFFECT: possibility of tuning the resonant frequency of the filter.

1 dwg

FIELD: physics.

SUBSTANCE: surface acoustic wave (SAW) filter has a piezoelectric acoustic line on whose surface there are input and output wideband transducers and a periodic structure in between in form of a system of ferroelectric domains with opposite polarisation, made using a laser-electrical technique and having the required resonance frequency.

EFFECT: increase in Q-factor to 104 and possibility of adjusting resonance frequency of the SAW filter.

2 dwg

FIELD: electricity.

SUBSTANCE: magnitoelectric resonator consists of composite magnitoelectric material representing multilayer structure of piezoelectric layer, ferromagnetic layer and bias system, at that lay-out of interdigital transducer is applied to piezoelectric layer from side of ferromagnetic layer.

EFFECT: improvement of resonator quality factor, possibility of quality-factor control by magnetic field.

2 dwg

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