Nortel Networks Corporation

Apple Inc.

Rockstar Bidco, LP

Chun-Yun Jian

Steve Andre Beaudin

Somsack Sychaleun

Eric Gagnon

Lan Hu

Yuxing Zhang

Conrad F Gratton

The present application describes a radio frequency band reject filter including an input port, an output port, a plurality of acoustic resonators and an inductor for matching the impedance of the plurality of acoustic resonators. The inductor is positioned within the band reject filter in respect of the plurality of acoustic resonators such that a static capacitance between the input port and the inductor is substantially equivalent to a static capacitance between the output port and the inductor. The plurality of acoustic resonators may be a plurality of parallel resonators, a plurality of series resonators or a combination of series and parallel resonators. The radio frequency band reject filter is fabricated using any of surface acoustic wave (SAW) technology, thin film bulk acoustic resonator (FBAR) technology, and bulk acoustic wave (BAW) technology.

Self-matched band reject filter

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.

Filter having impedance matching circuits

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 cascaded filter has a new third set of filter parameters that are a function of both the first material and the second material.

Device and method for cascading filters of different materials

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.

Duplexer/multiplexer having filters that include at least one band reject filter

The present invention provides combining and separation circuitry, which allows multiple signals in different frequency bands to travel in either direction over a single cable and be combined and separated as desired. In one embodiment, the combining and separation circuitry includes first, second, third, and fourth ports. The first port is configured to send or receive signals in a first frequency band, the second port is configured to send or receive signals in a second frequency band, and the third port is configured to send or receive DC signals, baseband signals, or a combination thereof. The fourth port is configured to be coupled to a cable in which the signals in the first and second frequency bands, as well as the DC and/or baseband signals, can be sent in either direction.

Cable reduction

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.

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&#xb0; to 135&#xb0;. 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.

Band reject filters

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.

Distributed band reject filters are disclosed. A first radio frequency band reject filter is disclosed having a splitter having a first input port, a first output port and a second output port, the splitter being operable on an input signal applied to the first input port to provide a respective output signal proportional to the input signal at each of the first and second output ports, the output signals having a phase shift between 45 degrees and 135 degree with respect to the input signal, as well as first, second and third acoustic resonators coupled respectively to the first input port, the first output port and the second output port. A second radio frequency band reject filter is disclosed having a combiner having a first input port, a second input port and a first output port, the combiner being operable on an input signals applied to the first input port and the second input port to provide a respective output signal proportional to the input signals at the first output port, the output signal having a phase shift between 45 degrees and 135 degree with respect to the input signals, as well as first, second and third acoustic resonators coupled respectively to the first input port, the second input port and the first output port. Also disclosed are amplifiers that comprise such radio frequency band reject filters.

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&#xb0; to 135&#xb0;. 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.

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.

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Ottawa, Canada

Chun-Yun Jian