A distributed antenna system of an aircraft includes first and second antennas and corresponding first and second remote transceiver units (RTUs). Each RTU receives a radio signal from the corresponding antenna and includes a field-programmable gate array (FPGA)/digital signal processor (DSP). The FPGA/DSP of a second RTU receives a second signal corresponding to the radio signal from the second antenna and receives a first signal from the first RTU corresponding to the radio signal from the first antenna. The FPGA/DSP of a second RTU determines which of the first and second antennae will transmit a reply to an interrogation included in the radio signals from the first and second antennae, based on a comparison of the first signal and the second signal.

An apparatus comprises an RF receiver for receiving an RF signal. The RF receiver includes front-end circuitry to generate a first down-converted signal, and a plurality of signal detectors to generate a corresponding plurality of detection signals from signals derived from the down-converted signal. The RF receiver further includes a controller to provide at least one control signal to the front-end circuitry based on the plurality of detection signals.

A digital up-converter (DUC) includes conjugate-mixer-combiner. The conjugate-mixer-combiner includes a pre-combiner configured to generate combinations of a first in-phase (I) value to be transmitted at a first frequency of a first frequency band, a first quadrature (Q) value to be transmitted at the first frequency of a first frequency band, a second I value for to be transmitted at a second frequency of a second frequency band, and a second Q value to be transmitted at the second frequency of a second frequency band. The conjugate-mixer-combiner further includes a plurality of multipliers collectively configured to shift the combinations based on an average difference between the first frequency and the second frequency.

The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures.

We disclose multiband receivers for millimeter-wave devices, which may have reduced size and/or reduced power consumption. One multiband receiver comprises a first band path comprising a first passive mixer configured to receive a first input RF signal having a first frequency and to be driven by a first local oscillator signal having a frequency about the first frequency; a second band path comprising a second passive mixer configured to receive a second input RF signal having a second frequency and to be driven by a second local oscillator signal having a frequency about the second frequency; and a base band path comprising a third passive mixer configured to receive intermediate RF signals during a duty cycle and to be driven by a third local oscillator signal having a frequency about the first frequency or about the second frequency during the duty cycle.

One general aspect of the present disclosure includes a device configured to perform communication. The device including: at least one transceiver; at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:

transmitting an uplink signal via two bands among a plurality of E-UTRA operating bands; and receiving a downlink signal via three bands among the plurality of E-UTRA operating bands, wherein pre-configured MSD value is applied to a reference sensitivity for receiving the downlink signal based on the E-UTRA operating band 66.

Methods, systems, and devices for channelizing a wideband waveform for transmission on a spectral band comprising unavailable channel segments are described. Generally, the described techniques provide for transmitting and receiving wideband waveforms when channels of a system bandwidth are unavailable for transmission. A transmitter may separate a first wideband signal into segments, with each segment a bandwidth corresponding to a channel of the system bandwidth, and may map the segments to the available channels. The transmitter may combine the mapped segments into a second wideband waveform and transmit the second wideband waveform using the available channels. A receiver may receive a first wideband signal waveform and may separate the first wideband signal waveform into segments, de-map the segments and combine the de-mapped segments into a second wideband waveform for demodulation. The techniques may be used to transmit and receive wideband waveforms over tactical data links.

Embodiments may relate to a radio frequency (RF) front-end module (FEM) with a first filter and a second filter. The RF FEM may include a termination inductor coupled to ground, and a switch that is to selectively couple the first filter and the second filter to the termination inductor. Other embodiments may be described or claimed.

A filter, apparatus, system and method are provided for implementing a band select filter, for example a frequency agile band select filter. In an implementation, the filter includes two separate signal generators configured to provide different local oscillator signals to an input mixer and to an output mixer, resulting in the filter output frequency being different from the filter input frequency. This is in contrast to known approaches which use the same signal generator to drive both input and output mixers. The filter may include two bandpass filters, three mixers, and three signal generators, each signal generator uniquely associated with one of the mixers, and configured to provide bandwidth control. A system of filters may include a set of bandpass filters, a plurality of sets of mixers, and a plurality of sets of signal generators, each set of signal generators being associated with a different set of mixers.

A radio-frequency front-end circuit includes first and second filters, and first and second band elimination filters. The first filter is connected between an antenna common terminal and a first input-output terminal, and has a first frequency band as a pass band. The second filter is connected between the antenna common terminal and a second input-output terminal, and has a second frequency band as a pass band. The first band elimination filter is connected between the antenna common terminal and a third input-output terminal, and has the first frequency band as a stop band. The second band elimination filter is connected in series with the first band elimination filter between the antenna common terminal and the third input-output terminal, and has the second frequency band as a stop band.