The present invention is directed to communication systems and electrical circuits. According to an embodiment, the present invention provides a termination circuit that includes an inductor network. The inductor network is coupled to a termination resistor and a capacitor network, which includes a first capacitor and a second capacitor. The termination resistor, the first capacitor, and the second capacitor are adjustable, and they affect attenuation of the termination circuit. There are other embodiments as well.

A wireless transceiver circuit with an impedance matching network within an integrated circuit is disclosed. In some embodiments, the impedance matching network utilizes an inductor, having two portions, disposed on two different metal layers of the integrated circuit. The first end of the first portion of the inductor is in communication with an antenna. The second end of the second portion is in communication with a low noise amplifier for receiving signals and a power amplifier for transmitting RF signals. The second end of the first portion is connected to the first end of the second portion using a via. In another embodiment, the two portions are disposed on the same metal layer, wherein one portion is disposed within the other with a gap separating the two portions. These configurations require less space than using two separate inductors and also have a low coupling coefficient.

A matching circuit (100) according to the present disclosure is a matching circuit (100) that matches impedance of an antenna (200) used for communication in a plurality of frequency bands with that of a subsequent circuit (300) being subsequent to the antenna (200). The matching circuit (100) includes a selection circuit (110) and a bypass circuit (120). The selection circuit (110) includes a switch (SW) for making a selection from impedances corresponding to the respective frequency bands. A bypass circuit (120) establishes a bypass between the antenna (200) and the subsequent circuit (300).

An apparatus is disclosed for implementing an antenna tuner. In an example aspect, the apparatus includes a substrate, an antenna disposed on or in the substrate, a radio-frequency integrated circuit disposed on the substrate, and an antenna tuner. The radio-frequency integrated circuit includes an amplification circuit. The antenna tuner is coupled between the antenna and the amplification circuit. The antenna tuner includes an inductive component disposed on or in the substrate and a capacitive component implemented within the radio-frequency integrated circuit.

A switching module assembly is provided. The switching module assembly includes a plurality of transmit/receive terminals, an antenna terminal, a shunt indictor coupled to the antenna terminal, a plurality of duplexers coupled to the plurality of transmit/receive terminals, and a plurality of impedance rotation elements coupled to the plurality of duplexers. Each duplexer corresponds to a signal frequency of a plurality of signal frequencies, and the impedance rotation elements are configured to adjust the impedance of each duplexer in conjunction with the shunt inductor to provide a resonant frequency at the signal frequency of each duplexer. The switching module can be used in the front-end module of a communications device, such as a mobile phone.

A method improves antenna matching for a wireless node, preferably of a sensor wireless node and/or actuator wireless node. A radio signal, or at least a portion thereof, is coupled out of the antenna and/or out of the transmit path of the wireless node. The impedance and/or the resonant frequency of the antenna is determined therefrom in the wireless node, and the impedance and/or the resonant frequency of the antenna is adjusted according to the determined impedance and/or resonant frequency by a circuit acting on the antenna.

Technologies for impedance matching networks for qubits are disclosed. In one illustrative embodiment, an impedance matching network matches a 50 Ohm transmission line to a spin qubit with a state-dependent resistance of 100 kiloohms to 105 kiloohms. The illustrative impedance matching network is tunable, allowing the impedance transformation ratio to be changed without significantly changing the matching frequency of the impedance matching network. In some embodiments, the impedance matching network matches a 50 Ohm transmission line to a lower-resistance state of a qubit. In other embodiments, the impedance matching network matches a 50 Ohm transmission line to an impedance value in between a lower-resistance state and a higher-resistance state of a qubit.

A kHz to 100 GHz DC coupled circuit with an on-chip integrating capacitor includes an impedance matching structure, an input impedance, an input stage structure and an on-chip capacitor; the impedance matching structure comprises an matching inductor with one end connected to the input terminal and a first matching branch with one end connected to the input terminal, a second matching branch with one end connected to the other end of the matching inductor as well as the other end of the first matching branch, a third matching branch with one end connected to the matching inductor, in which the other ends of the second matching branch and the third matching branch are connected to the input impedance; the first, second and third matching branches are implemented as RLC circuits; or, one or two of the first, second, and third matching branches are break circuits, and the others are RLC circuits.

An impedance matching network for a radio frequency (RF) transmission system can include first port for coupling to a first transistor differential pair. The network can further include a second port for coupling to a second tansistor differential pair. The network can further incluede a matching network connected to the port and the second port, the matching network comprised of a pair of coupled lines. Other aspects are described.

An impedance tuning circuit includes a first node and a second node, and an inductance circuit including an inductor and a first switch connected in series such that the inductor is connected to the first node and the first switch is connected to the second node. The inductance circuit further includes a second switch implemented between ground and a third node between the inductor and the first switch, such that the inductance circuit is capable of providing a series inductance path between the first and second nodes or a shunt inductance path between the third node and the ground.