Nortel Networks Corporation

Apple Inc.

Rockstar Bidco, LP

Somsack Sychaleun

Steve Andre Beaudin

Chun-Yun Jian

Gregory Carleton

Mark N Willetts

Darcy Poulin

Yuxing Zhang

Gord G Rabjohn

The present invention facilitates the reduction of cabling required in a base station environment. When receive diversity is employed, main and diversity antennas are used to receive common signals at different locations. The signals received at the main and diversity antennas are combined with one another in the masthead and transmitted over a single feeder cable to a base housing for further processing. Thus, signals that were normally sent over separate feeder cables and combined in the base housing are combined in the masthead and sent over a single feeder cable. The technique can be replicated for each sector provided by the base station environment.

Feeder cable reduction

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

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

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.

A communications tower, or other structure is provided with at least one waveguide defined in a structural support. The waveguide can be used to transmit signals up and down the communications tower thereby eliminating at least some cabling.

Structural waveguide formed in a leg of an antenna tower and method of use

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.

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.

Surface wave devices with low passband ripple

A low noise amplifier (LNA) in a LNA arrangement is selectively bypassed, without detracting from the performance of the LNA arrangement when it is not bypassed, by selecting components of an input signal which are reflected at the input of the LNA. These reflected signal components can be increased, when the LNA is bypassed, by interrupting a supply voltage to the LNA and/or shunting the input of the LNA to ground. The arrangement can be a balanced LNA arrangement, using two LNAs and two quadrature couplers, or it can be an unbalanced LNA arrangement.

Amplifier switching

The present invention relates to a bias circuit for biasing a depletion mode power transistor. The bias circuit includes a voltage offset circuit and a transistor, where the voltage offset circuit is serially coupled between the gate terminal of the depletion mode power transistor and the drain terminal of the transistor. The bias circuit generates a bias voltage that, when applied to the gate terminal of the depletion mode power transistor, maintains a substantially constant drain current through the power transistor over a range of threshold voltages caused by process and temperature variations.

Growing community of inventors

Kanata, Canada

Somsack Sychaleun