A signal transmission system includes: a first signal line and a second signal line each making up a differential line; a first capacitive load mechanism disposed in a first region connected to the first signal line, the first capacitive load mechanism having a first capacitance value; and a second capacitive load mechanism disposed in a second region connected to the second signal line and to the ground point line, the second capacitive load mechanism having a capacitance value asymmetric with the first capacitance value. This signal transmission system suppresses an increase in mode conversion loss caused by component characteristics variations.

A signal filter includes a notch filter and a wideband filter. The notch filter is configured to perform a band-rejection filtering operation according to a band-rejection filtering property. The wideband filter is coupled to the notch filter, and is configured to perform a wideband filtering operation according to a wideband filtering property. The band-rejection filtering property includes a first cutoff frequency, a frequency bandwidth, a relatively high quality factor and a relatively low coupling coefficient. The wideband filtering property includes a second cutoff frequency, a relatively low quality factor and a relatively high coupling coefficient. The first and the second cutoff frequencies have a frequency difference therebetween. A ratio of the frequency difference to the frequency bandwidth is within a preset ratio range being from 2.5% to 20%.

An LC filter includes a multilayer body including dielectric layers layered therein, plate electrodes, capacitor electrodes, inductor vias, and ground vias. The plate electrodes are provided on different layers of the multilayer body. The capacitor electrodes each define a capacitor between itself and the electrode. The inductor via is connected with the electrode and the capacitor electrode, while the inductor via is connected with the electrode and the capacitor electrode. The ground vias connect the plate electrodes to each other. The inductor via and the capacitor electrode define a resonance circuit that receives a signal from an input terminal. The inductor via and the capacitor electrode define a resonance circuit that transfers a signal to the output terminal.

An LC filter includes an input terminal, an output terminal, a multilayer body, plate electrodes, connection electrodes connecting the plate electrodes, capacitor electrodes, and a inductor vias. Each of the capacitor electrodes opposes the plate electrode. One end of an inductor via is connected with the input terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode. An inductor via is connected between the plate electrode and a capacitor electrode. An inductor via is connected between the plate electrode and a capacitor electrode. One end of an inductor via is connected with the output terminal with a capacitor electrode interposed therebetween. Another end of the inductor via is connected to an intermediate point of a connection electrode.

A communication device includes a first radio frequency circuit; a plurality of second radio frequency circuits; and a power division/combination network, including a signal combining port and a plurality of signal dividing ports, where the signal combining port is coupled to the first radio frequency circuit, and the plurality of signal dividing ports is coupled to the plurality of second radio frequency circuits. The power division/combination network includes a power divider/combiner. Two ends of a first signal transmission network in the power divider/combiner are coupled to a common port and a first dividing port respectively, two ends of a second signal transmission network are coupled to the common port and a second dividing port respectively, and a mode tuning circuit is coupled to the first signal transmission network.

A communication device includes a first radio frequency circuit; a plurality of second radio frequency circuits; and a power division/combination network, including a signal combining port and a plurality of signal dividing ports, where the signal combining port is coupled to the first radio frequency circuit, and the plurality of signal dividing ports is coupled to the plurality of second radio frequency circuits. The power division/combination network includes a power divider/combiner. Two ends of a first signal transmission network in the power divider/combiner are coupled to a common port and a first dividing port respectively, two ends of a second signal transmission network are coupled to the common port and a second dividing port respectively, and a mode tuning circuit is coupled to the first signal transmission network.

A technique relates to a microwave device. The microwave device includes a Josephson ring modulator, a first multimode resonator connected to the Josephson ring modulator, where the first multimode resonator is made of a first left-handed transmission line, and a second multimode resonator connected to the Josephson ring modulator, where the second multimode resonator is made of a second left-handed transmission line.

The present disclosure may include, for example, a tunable capacitor having a decoder for generating a plurality of control signals, and an array of tunable switched capacitors comprising a plurality of fixed capacitors coupled to a plurality of switches. The plurality of switches can be controlled by the plurality of control signals to manage a tunable range of reactance of the array of tunable switched capacitors. Additionally, the array of tunable switched capacitors is adapted to have non-uniform quality (Q) factors. Additional embodiments are disclosed.

A switched-capacitor circuit comprising a differential operational amplifier and a feedback circuit is described. In some embodiments, the feedback circuit may be configured to provide a reference voltage that is insensitive to temperature and/or process variations. In some embodiments, the feedback circuit may be configured to mitigate the time delay associated with one or more capacitors of the switched-capacitor circuit. The switched-capacitor circuit may be controlled by a pair of control signals. During a first phase, one or more capacitors may be charged, or discharged, through an input signal. During a second phase, the electric charge of the one or more capacitors may be retained.

A high frequency band pass filter with a coupled surface mount transition is provided, including a filter substrate, circuit connection elements defining input and an output elements provided on a surface of the filter substrate, electronic filter components provided on the first surface of the filter substrate, and impedance matching structures provided on the first surface of the filter substrate between the electronic filter components and the respective input and output elements. Signal connection structures are provided on an opposed surface of the filter substrate, in locations that positionally correspond to respective positions of the input and output elements. The respective signal connection elements are capacitively coupled, through a thickness direction of the filter substrate, to a respective one of the input and output elements on the opposed surface of the filter substrate without the presence of any vertical conductive structures within the filter substrate at the input and the output elements.