Abstract: Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having parallel front and back surfaces, the back surface attached to the substrate. An interdigital transducer (IDT) is formed on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are disposed on a portion of the piezoelectric plate suspended over a cavity formed in the substrate.

Abstract: Communications receivers and devices are disclosed. A communications receiver includes a low noise amplifier; a multi-band transmit blocking filter having a first port connected to an output of the low noise amplifier, and an RF analog-to-digital converter having an input connected to a second port of the multi-band transmit blocking filter. The multi-band transmit filter passes the receive frequencies of a group of two or more LTE bands, where a first receive frequency range of a first band in the group and a second receive frequency range of a second band in the group are disjoint and not subsets of a receive frequency range of a third band in the group, and attenuates the transmit frequencies of at least some bands in the group by at least twenty dB.

Abstract: A method for designing a narrowband acoustic wave microwave filter including: generating a modeled filter circuit design having circuit elements including an acoustic resonant element defined by an electrical circuit model that includes a parallel static branch, a parallel motional branch, and one or both of a parallel Bragg Band branch that models an upper Bragg Band discontinuity and a parallel bulk mode function that models an acoustic bulk mode loss; and generating a final circuit design. Generating the final circuit design includes optimizing the modeled filter circuit design to generate an optimized filter circuit design; comparing a frequency response of the optimized filter circuit design to requirements; selecting the optimized filter circuit design for construction into the actual acoustic microwave filter based on the comparison; and transforming the optimized filter circuit design to a design description file for input to a construction process.

Abstract: A method of designing a microwave filter using a computerized filter optimizer, comprises generating a filter circuit design in process (DIP) comprising a plurality of circuit elements having a plurality of resonant elements and one or more non-resonant elements, optimizing the DIP by inputting the DIP into the computerized filter optimizer, determining that one of the plurality of circuit elements in the DIP is insignificant, removing the one insignificant circuit element from the DIP, deriving a final filter circuit design from the DIP, and manufacturing the microwave filter based on the final filter circuit design.

Abstract: Non-transitory computer-readable media to perform a method for designing a multiband filter. The method includes generating an initial circuit structure comprising a desired number and type of circuit elements; generating an initial circuit design by mapping the frequency response requirements of the initial circuit structure into normalized space; generating an acoustic filter circuit design by transferring the initial filter circuit design; generating a pre-optimized circuit design by unmapping one or more circuit elements of the acoustic filter circuit design into real space and introducing parasitic effects; and communicating the pre-optimized circuit design to a filter optimizer that generates a final circuit design comprising a plurality of resonators, wherein a first resonator exhibits a high resonant frequency, a second resonator demonstrates a low resonant frequency and the difference between the low resonant frequency and the high resonant frequency is at least 1.

Abstract: A method of designing a microwave filter using a computerized filter optimizer, comprises generating a filter circuit design in process (DIP) comprising a plurality of circuit elements having a plurality of resonant elements and one or more non-resonant elements, optimizing the DIP by inputting the DIP into the computerized filter optimizer, determining that one of the plurality of circuit elements in the DIP is insignificant, removing the one insignificant circuit element from the DIP, deriving a final filter circuit design from the DIP, and manufacturing the microwave filter based on the final filter circuit design.

Abstract: Methods to design band-pass acoustic wave microwave filters are disclosed. A performance metric related to an input impedance of a baseline filter design is calculated, the baseline filter design including a plurality of series surface acoustic wave resonators and a plurality of shunt surface acoustic wave resonators, each surface acoustic wave resonator having a respective resonant frequency. One or more alternative filter designs is established, each alternative filter design derived from the baseline filter design by reordering the resonant frequencies of two or more of the plurality of series surface acoustic wave resonators and/or two or more of the plurality of shunt surface acoustic wave resonators. A respective performance metric related to an input impedance of each alternative filter designs is calculated. A final filter design is selected from among the baseline filter design and the alternative filter designs based on the respective performance metrics.

Abstract: A transmit filter for a communications device includes a surface acoustic wave (SAW) band-pass filter configured to pass a transmit frequency band and a tunable transmitter impedance matching network in series. The tunable transmitter impedance matching network matches an input impedance of the SAW band-pass filter to the output impedance of a power amplifier over a portion of the transmit frequency band in response to a tuning input.

Abstract: Bandpass filters and methods of designing bandpass filters are disclosed. A bandpass filter includes a plurality of series acoustic resonators connected in series between an input and an output, and a plurality of\ shunt acoustic resonators, each shunt acoustic resonator connected between a ground and one of the input, the output, and a junction between two of the plurality of series acoustic resonators. A first shunt resonator of the plurality of shunt resonators has a motional resonance frequency higher than and adjacent to an upper edge of a passband of the bandpass filter.

Abstract: A multi-band acoustic wave microwave filter, including a signal transmission path having an input and an output; a plurality of nodes disposed along the signal transmission path; a plurality of non-resonant branches respectively coupling one or more nodes to ground, wherein each non-resonant branch comprises at least one non-resonant element; and a plurality of resonant branches that couple one or more nodes to ground and include a plurality of resonators on said branches, wherein the plurality of resonators define a first band and at least one additional band and further wherein the difference between the lowest resonant frequency and the highest resonant frequency of the first band is at least 1.25 times the average separation of the resonators.

Abstract: Multi-band filters, communications devices, and methods of designing multi-band filters are disclosed. A multi-band filter has a lower pass-band and an upper pass-band separated by an intervening stop-band. The multi-band filter includes a first ladder network and a second ladder network coupled in series. The first ladder network provides transmission zeros at frequencies below a lower edge of the lower pass-band and transmission zeros at frequencies above an upper edge of the upper pass-band. The second ladder network provides transmission zeros at frequencies within the intervening stop-band.

Abstract: Surface acoustic wave (SAW) filters and methods of fabricating SAW filters are disclosed. A filter includes a piezoelectric wafer having a thickness within one of a plurality of noncontiguous thickness ranges that define piezoelectric wafers upon which filter circuits meeting predetermined requirements can be fabricated according to a predetermined design using a predetermined fabrication process, and a filter circuit fabricated on the piezoelectric substrate according to the predetermined design using the predetermined fabrication process.

Abstract: Communications receivers and devices are disclosed. A communications receiver includes a low noise amplifier; a multi-band transmit blocking filter having a first port connected to an output of the low noise amplifier, and an RF analog-to-digital converter having an input connected to a second port of the multi-band transmit blocking filter. The multi-band transmit filter passes the receive frequencies of a group of two or more LTE bands, where a first receive frequency range of a first band in the group and a second receive frequency range of a second band in the group are disjoint and not subsets of a receive frequency range of a third band in the group, and attenuates the transmit frequencies of at least some bands in the group by at least twenty dB.

Abstract: Communications devices, triplexers, high-pass filters, and low-pass filters are disclosed. A communications device includes a triplexer having a common port and first, second, and third branch ports. A hybrid LC/SAW high-pass filter is connected between the common port and the third branch port, a hybrid LC/SAW low-pass filter is connected between the common port and an internal node, an LC high-pass filter is connected between the internal node and the second branch port, and an LC low-pass filter is connected between the internal node and the first branch port.

Abstract: Methods of designing band-pass filters are disclosed. A baseline filter design is established, the baseline filter design including a plurality of surface acoustic wave resonators having respective resonant frequencies, the surface acoustic wave resonators organized by resonant frequency into two or more groups. One or more alternative filter designs are established, each alternative filter design derived from the baseline filter design by reordering the resonant frequencies of two or more surface acoustic wave resonators within at least one of the two or more groups. A respective performance metric related to input impedance over a pass band is calculated for each of the baseline filter design and the alternative filter designs. A final filter design is selected from the baseline filter design and the alternative filter designs based on the respective performance metrics.

Abstract: A method of designing an acoustic microwave filter in accordance with frequency response requirements.

Abstract: Communications receivers and devices are disclosed. A communications receiver includes a low noise amplifier; a multi-band transmit blocking filter having a first port connected to an output of the low noise amplifier, and an RF analog-to-digital converter having an input connected to a second port of the multi-band transmit blocking filter. The multi-band transmit filter passes the receive frequencies of a group of two or more LTE bands, where a first receive frequency range of a first band in the group and a second receive frequency range of a second band in the group are disjoint and not subsets of a receive frequency range of a third band in the group, and stops the transmit frequencies of at least some bands in the group.

Abstract: Multi-band filters and communications devices are disclosed. A multi-band filter has a lower pass-band and an upper pass-band separated by an intervening stop-band. The multi-band filter includes a first ladder network and a second ladder network coupled in series. The first ladder network is configured to provide transmission zeros at frequencies below a lower edge of the lower pass-band and transmission zeros at frequencies above an upper edge of the upper pass-band. The second ladder network is configured to provide transmission zeros at frequencies within the intervening stop-band.

Abstract: Methods of designing band-pass filters and filters are disclosed. A baseline filter design meeting first design criteria may be established, the baseline filter design including a plurality of series surface acoustic wave resonators and a plurality of shunt surface acoustic wave resonators, each surface acoustic wave resonator having a respective resonant frequency. A performance metric based on an input impedance of the baseline filter design over a pass band may be determined. One or more alternate filter designs may be established and respective performance metrics determined, each alternative filter design established by reordering the resonant frequencies of two or more of the plurality of series surface acoustic wave resonators and/or two or more of the plurality of shunt surface acoustic wave resonators. A final filter design may be selected from the baseline design and the one or more alternate filter designs based on the respective performance metrics.

Abstract: An NMR (nuclear magnetic resonance) detection module (such as an NMR probe) mounted in a vacuum vessel permits a transmit/receive coil to be cooled efficiently and to be placed closer to a sample container. The NMR detection module includes a core module (detection module) (54) consisting of a refrigerant block (118) and a transmit/receive coil formed on the inner surface of a detection hole (130). A sleeve (cylindrical partition wall) (122) forming a part of the vacuum vessel is inserted in the detection hole (130). A sample tube (56) is inserted in the sleeve (122). The refrigerant block (118) is connected to a heat exchanger via a support member (82). Since it is not necessary to form a bobbin inside the transmit/receive coil, the distance between the coil and the sample can be set small. The coil is entirely surrounded by the refrigerant block.