A multiplexer (1) used in a communication device (5) includes an antenna (21) for a first frequency band group including 5GNR and an antenna (22) for a second frequency band group and includes a filter (12) for a first communication band and a filter (13) for a second communication band. The second frequency band group is higher than the first communication band, the second communication band is lower than the first communication band, the filter (12) includes a resonant circuit (31), an inductor (L1) connected to a node (n1) in a series arm path, and an inductor (L2) magnetically coupled with the inductor (L1).

A multiplexer includes: a common filter, a first filter connected to the common terminal and having a passband including a reception band of a first communication band; a second filter connected to the common terminal and having a passband including a transmission band of the first communication band; a third filter connected to the common terminal and having a passband including a transmission band of a second communication band; and a fourth filter connected to the common terminal and having a passband including a reception band of the second communication band. The transmission band of the first communication band and the transmission band of the second communication band are located between the reception band of the first communication band and the reception band of the second communication band, and at least one of the first communication band or the second communication band is a 5G-NR communication band.

In some embodiments, a front-end architecture can include a quadplexer configured to support uplink carrier aggregation with a first antenna. The quadplexer can include a low-band filter, a mid-band filter, a first high-band filter, and a second high-band filter, with each filter having a respective input node, and the quadplexer including a common output node associated with the first antenna. The front-end architecture can further include a triplexer configured to support uplink carrier aggregation with a second antenna. The triplexer can include a mid-band filter, a first high-band filter, and a second high-band filter, with each filter having a respective input node, and the triplexer including a common output node associated with the second antenna.

A communication system in which a constellation employing partially anti-symmetric amplitude labels is used to transmit probabilistically shaped amplitudes such that said amplitudes are also used to determine the signs applied thereto for transmission. In an example embodiment, a data transmitter is configured to use a suitable logic function (e.g., an XOR function) to place the parity generated by an FEC code into a selected amplitude bit while using the partially anti-symmetric amplitude labels to avoid placing the parity into the sign bits of the transmitted constellation symbols. In some embodiments, the FEC code can be a low-density parity-check code. Some embodiments are compatible with layered FEC coding, e.g., employing an outer FEC code and an inner FEC code. In some embodiments, FEC coding may be optional. Some embodiments can advantageously be used in communication systems relying on DMT modulation, such as the systems providing DSL access over copper wiring.

A filter includes two series arm resonators electrically connected in series between two input/output terminals, a parallel arm resonator electrically connected between a ground and a series arm between the two series arm resonators, an inductor electrically connected in parallel to the two series arm resonators, and a matching circuit electrically connected between one of the two series arm resonators and one of the input/output terminals, wherein the two series arm resonators and the parallel arm resonator define a pass band of a bandpass filter, the two series arm resonators and the inductor define an LC resonant circuit, respective anti-resonant frequencies of each of the two series arm resonators and a resonant frequency of the parallel arm resonator are located in a pass band of the LC resonant circuit, and a resonant frequency of the LC resonant circuit is lower than the resonant frequency of the parallel arm resonator.

A filter circuit includes a first switch circuit that exclusively connects a first common terminal to either of a first selection terminal and a second selection terminal; a first signal terminal that is connected to the first selection terminal and that is for communicating a first communication signal belonging to a first frequency range, which is a frequency range of a first communication band; a second signal terminal that is connected to the second selection terminal and that is for communicating a second communication signal belonging to a second frequency range, which is the frequency range of a second communication band and which is at least partially overlapped with the first frequency range; and a first band pass filter one end of which is connected to the first common terminal and which uses both the first frequency range and the second frequency range as pass bands.

A transmitting and receiving circuit that transmits and receives signals using coaxial cables includes an input/output terminal that delivers and receives signals, a first port, a second port, a switch, and a ceramic-based electro-static discharge protector. The first port transfers a transmitted signal in a first transmission frequency band width and a received signal in a first reception frequency band width. The second port transfers a transmitted signal in a second transmission frequency band width and a received signal in a second reception frequency band width. The switch connects a common port to one of the first port and the second port. The common port is connected to the input/output terminal on one end of the common port and to the switch on the other end. The electro-static discharge protector is connected between the common port and the ground potential.

A frequency-selective system that may be used as, or as part of, an add/drop multiplexer. An input signal is fed to a Mach-Zehnder interferometer configured to drop, or suppress, by destructive interference, a signal component in a first frequency band from among a plurality of frequency bands. One or more bandpass filters in one arm of the Mach-Zehnder interferometer suppress other frequencies, outside of the first frequency band, so that signals at these other frequencies are not suppressed by destructive interference and are present at the output of the Mach-Zehnder interferometer. A coupler connected after the output of the Mach-Zehnder interferometer adds, into the signal path, a replacement for the dropped signal.

Front-end architecture having split triplexers for carrier aggregation and MIMO support. In some embodiments, a multiplexing architecture can include an assembly of filters configured to support carrier aggregation with one or more antennas. The assembly of filters can include a first triplexer configured to support a low-band, a mid-band, and a first high-band. The assembly of filters can further include a second triplexer configured to support the low-band, the mid-band, and a second high-band. The multiplexing architecture can further include a switch assembly implemented between the assembly of filters and respective one or more nodes associated with the one or more antennas.

Front-end architecture having split diplexers for carrier aggregation and MIMO support. In some embodiments, a multiplexing architecture can include an assembly of filters configured to support carrier aggregation with one or more antennas. The assembly of filters can include a first diplexer configured to support a mid-band and a first high-band. The assembly of filters can further include a second diplexer configured to support the mid-band and a second high-band. The multiplexing architecture can further include a switch assembly implemented between the assembly of filters and respective one or more nodes associated with the one or more antennas.