Abstract: A filter package is provided with a support structure, a filter device having terminals, impedance matching circuits formed on the support structure and electrically connected to at least some of the terminals of the filter device, and at least one electrical ground structure electrically connected to the impedance matching circuits. Moreover, the filter package has an outer housing to contain the support structure, filter device, impedance matching circuits, and at least one ground structure.

Abstract: Distributed band reject filters are disclosed. A band reject filter includes a first acoustic resonator and a second acoustic resonator, each of which has either shunt resonators adapted to resonate substantially at respective resonance frequencies defining a rejection frequency band or series resonators adapted to anti-resonate substantially at respective anti-resonance frequencies defining the rejection frequency band. These resonators are connected through a phase shifter which imparts an impedance phase shift of approximately 45° to 135°. Exemplary applications of the band reject filters disclosed herein include implementation as an inter-stage band reject filter for a base station power amplifier for a wireless communication system, as a radio frequency band reject filter in a duplexer for a wireless communication terminal, and in a low noise amplifier input stage.

Abstract: Some embodiments of the invention provide a filter having at least one first filter, each first filter being a band-reject type filter having a first set of filter parameters that are a function of a first material used to fabricate the at least one first filter, and at least one second filter, each second filter having a second set of filter parameters that are a function of a second material used to fabricate the at least one second filter, each second filter being one of a band-reject type filter and a band pass type filter. The at least one first filter and the at least one second filter are then cascaded together to form the filter. The first material and the second material are different materials. The cascaded filter has a new third set of filter parameters that are a function of both the first material and the second material. Other embodiments of the invention include a method for fabricating the filter and a method of filtering using such a cascaded filter.

Abstract: Band reject filters are disclosed. A band reject filter includes a first acoustic resonator and a second acoustic resonator, each of which has either shunt resonators adapted to resonate substantially at respective resonance frequencies defining a rejection frequency band or series resonators adapted to anti-resonate substantially at respective anti-resonance frequencies defining the rejection frequency band. These resonators are connected through a phase shifter which imparts an impedance phase shift of approximately 45° to 135°. Exemplary applications of the band reject filters disclosed herein include implementation as an inter-stage band reject filter for a base station power amplifier for a wireless communication system, as a radio frequency band reject filter in a duplexer for a wireless communication terminal, and in a low noise amplifier input stage.

Abstract: A wireless communications device includes an antenna, a multi-port path selection structure having an antenna port connected to the antenna, and plural ports connected to respective one or more receive and transmit paths of the wireless communications device. The multi-port path selection structure has a transmit band reject filter connected to the transmit path and a second filter connected to the receive path.

Abstract: Band reject filters are disclosed. A band reject filter includes a first acoustic resonator and a second acoustic resonator, each of which has either shunt resonators adapted to resonate substantially at respective resonance frequencies defining a rejection frequency band or series resonators adapted to anti-resonate substantially at respective anti-resonance frequencies defining the rejection frequency band. These resonators are connected through a phase shifter which imparts an impedance phase shift of approximately 45° to 135°. Exemplary applications of the band reject filters disclosed herein include implementation as an inter-stage band reject filter for a base station power amplifier for a wireless communication system, as a radio frequency band reject filter in a duplexer for a wireless communication terminal, and in a low noise amplifier input stage.

Abstract: A filter package is provided with a support structure, a filter device having terminals, impedance matching circuits formed on the support structure and electrically connected to at least some of the terminals of the filter device, and at least one electrical ground structure electrically connected to the impedance matching circuits. Moreover, the filter package has an outer housing to contain the support structure, filter device, impedance matching circuits, and at least one ground structure.

Abstract: Very low passband ripple is provided in a wide bandwidth high frequency SAW FIR filter using slanted finger IDTs by one or more of three techniques: cancelling regenerated SAWs at parallel-connected input IDTs of two SAW filters which are similar except for a quarter-wavelength difference in spacing of the input and output IDTs, this difference varying with wavelength across the IDT aperture; shaping edges of shield electrodes to provide quarter-wavelength differences in, and hence cancellation of, SAWs reflected at the edges, the differences varying with wavelength across the IDT aperture; and making pairs of slanted shield electrodes symmetrical to compensate for refraction of SAWS by the shield electrodes.

Abstract: Acoustic resonators such as surface acoustic wave (SAW) devices and thin film bulk acoustic resonators (FBAR) can be configured to produce a band reject filter. Such a filter overcomes the insertion loss and power handling limitations of conventional band pass configurations and as such can be used in power amplifier and duplexer applications.

Abstract: Very low passband ripple is provided in a wide bandwidth high frequency SAW FIR filter using slanted finger IDTs by one or more of three techniques: cancelling regenerated SAWs at parallel-connected input IDTs of two SAW filters which are similar except for a quarter-wavelength difference in spacing of the input and output IDTs, this difference varying with wavelength across the IDT aperture; shaping edges of shield electrodes to provide quarter-wavelength differences in, and hence cancellation of, SAWs reflected at the edges, the differences varying with wavelength across the IDT aperture; and making pairs of slanted shield electrodes symmetrical to compensate for refraction of SAWS by the shield electrodes.

Abstract: Very low passband ripple is provided in a wide bandwidth high frequency SAW FIR filter using slanted finger IDTs by one or more of three techniques: cancelling regenerated SAWs at parallel-connected input IDTs of two SAW filters which are similar except for a quarter-wavelength difference in spacing of the input and output IDTs, this difference varying with wavelength across the IDT aperture; shaping edges of shield electrodes to provide quarter-wavelength differences in, and hence cancellation of, SAWs reflected at the edges, the differences varying with wavelength across the IDT aperture; and making pairs of slanted shield electrodes symmetrical to compensate for refraction of SAWs by the shield electrodes.

Abstract: A SAW device has a weighted IDT (inter-digital transducer) which is divided along its length into two or more sections with different relative weights of the weighting function, the IDT sections being coupled to a gain arrangement having different relative gains to compensate for the different relative weights of the IDT sections. The IDT can be amplitude weighted with an apodization pattern having lobes corresponding to the IDT sections, each section having a relative weight so that its maximum finger overlap corresponds to the aperture of the SAW device.

Abstract: Acoustic resonators such as surface acoustic wave (SAW) devices and thin film bulk acoustic resonators (FBAR) can be configured to produce a band reject filter. Such a filter overcomes the insertion loss and power handling limitations of conventional band pass configurations and as such can be used in power amplifier and duplexer applications.

Abstract: Very low passband ripple is provided in a wide bandwidth high frequency SAW FIR filter using slanted finger IDTs by one or more of three techniques: cancelling regenerated SAWs at parallel-connected input IDTs of two SAW filters which are similar except for a quarter-wavelength difference in spacing of the input and output IDTs, this difference varying with wavelength across the IDT aperture; shaping edges of shield electrodes to provide quarter-wavelength differences in, and hence cancellation of, SAWs reflected at the edges, the differences varying with wavelength across the IDT aperture; and making pairs of slanted shield electrodes symmetrical to compensate for refraction of SAWs by the shield electrodes.

Abstract: Acoustic resonators such as surface acoustic wave (SAW) devices and thin film bulk acoustic resonators (FBAR) can be configured to produce a band reject filter. Such a filter overcomes the insertion loss and power handling limitations of conventional band pass configurations and as such can be used in power amplifier and duplexer applications.

Abstract: Acoustic resonators such as surface acoustic wave (SAW) devices and thin film bulk acoustic resonators (FBAR) can be configured to produce a band reject filter. Such a filter overcomes the insertion loss and power handling limitations of conventional band pass configurations and as such can be used in power amplifier and duplexer applications.

Abstract: A spatial harmonic transducer of a SAW device is made directional for SAWs at a spatial harmonic signal frequency of the transducer by a reflector for reflecting SAWs at that frequency. The transducer comprises repeated groups of consecutive electrodes having a predetermined polarity sequence, positioned to operate coherently for SAWs at the signal frequency. The reflector comprises reflector electrodes for producing constructive and destructive interference in opposite SAW directions, with electrode widths and spacings of at least a quarter wavelength at the signal frequency. A SAW device with two such spatial harmonic SPUDTs using different polarity sequences can provide desirable characteristics for filters and delay lines at frequencies of about 2 GHz.

Abstract: A spatial harmonic transducer of a SAW device is made directional for SAWs at a spatial harmonic signal frequency of the transducer by a reflector for reflecting SAWs at that frequency. The transducer comprises repeated groups of consecutive electrodes having a predetermined polarity sequence, positioned to operate coherently for SAWs at the signal frequency. The reflector comprises reflector electrodes for producing constructive and destructive interference in opposite SAW directions, with electrode widths and spacings of at least a quarter wavelength at the signal frequency. A SAW device with two such spatial harmonic SPUDTs using different polarity sequences can provide desirable characteristics for filters and delay lines at frequencies of about 2 GHz.