A radio-frequency (RF) apparatus includes a wideband receive (RX) impedance matching circuit to provide a received differential RF signal to RF receive circuitry. The wideband RX impedance matching circuit includes first and second inductors to receive the differential RF signal. The wideband RX impedance matching circuit further includes a third inductor coupled across an input o the RF receive circuitry. The third inductor performs the functionality of a capacitor having a negative capacitance value.

A variable circuit includes a switch including a plurality of input terminals and a plurality of output terminals and an external wiring line. The multiple input terminals include a first input terminal to which a first input signal is inputted and a second input terminal to which a second input signal is inputted. The multiple output terminals include a first output terminal from which a first output signal is outputted and a second output terminal from which a second output signal is outputted. The switch is capable of forming at least one internal connection path electrically connecting any one of the multiple input terminals and any one of the multiple output terminals. The external wiring line is disposed outside the switch and is configured to electrically connect the second output terminal to the second input terminal.

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.

Embodiments relate to a transformer-based impedance matching network that may dynamically change its characteristic impedance by engaging different inductor branches on a primary side and optionally, on the secondary side. A primary side transformer circuit includes a primary inductor (311) and secondary inductor (321) configured to provide impedance matching over a first frequency band. One or more additional inductor branches (314A, 314B, are switchably coupled to either or both of the primary and secondary inductors to modify the impedance matching characteristics over additional operating frequencies. One or more LC filter branches (321, 322, 326, 327, 336, 330) can be included at the output of the secondary side to filter harmonic frequencies in each of the operating frequency bands.

A radio-frequency impedance tuner can include first and second nodes, a bypass path, first and second series capacitance paths, and an inductance path, with each path being implemented between the first and second nodes and including a switch configured to allow the path to couple or uncouple the first and second nodes. The tuner can further include first and second shunt paths, with each shunt path being implemented between the second node and ground and including a switch configured to allow the shunt path to couple or uncouple the second node and the ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

A radio-frequency module includes a multilayer substrate, an input switch, an output switch, and filters. A switch IC is disposed on a main surface of the multilayer substrate. The input switch is disposed in the switch IC and includes a first input terminal and first output terminals. The output switch is disposed in the switch IC and includes second input terminals and a second output terminal. The filters are disposed outside the switch IC and are connected to the first output terminals and the second input terminals. In a plan view of the multilayer substrate, the first input terminal and the first output terminals are disposed close to a first side of an exterior of the switch IC, and the second input terminals and the second output terminal are disposed close to a second side different from the first side of the exterior of the switch IC.

Provided are an output matching circuit and a power amplifier comprised thereof. The output matching circuit comprises an impedance transformation component and a first matching component connected to the input end of the impedance transformation component to establish matching. The first matching circuit comprises an impedance element and a controllable switch element whose on/off is controlled by an external control signal to form different impedances. The output matching circuit realizes the reconstruction of the output stage matching circuit and the switching of the output operating frequency band. It can be used for high frequency/medium frequency/low frequency, which reduces the cost, the number of components, and the design difficulty, and is easy to be integrated. It can be used for multi-band multiplexing power amplifiers. The wide-band amplifier is realized, the number of components and material cost are reduced, and the system integration degree of the power amplifier is increased.

In an embodiment, an electronic device may include a housing having an inner space, a first printed circuit board including a wireless communication circuit, an antenna structure connected to the wireless communication circuit through a first electrical path, and a tunable circuit having a first resistance value and disposed on a second electrical path. The electronic device may further include a low-resistance circuit disposed on a third electrical path branched from the second electrical path, and including a resistor and an inductor, the resistor having a second resistance value determined based on the first resistance value, and the inductor having a constant inductance value and disposed between the resistor and the ground. The electronic device may also include at least one processor configured to control the tunable circuit.

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 method of adjusting an impedance of a power amplifier of a radio frequency system for matching with an antenna switch die is disclosed. In one aspect, the method includes connecting the power amplifier to the antenna switch die via an impedance adjustment circuit, the impedance adjustment circuit including an input node, an output node, a plurality of electrical components arranged between the input node and the output node, and at least one switch configured to selectively electrically connect at least one of the electrical components to the input node and the output node. The method further includes determining an Error Vector Magnitude of the radio frequency system for each of a plurality of states of the at least one switch, and controlling the at least one switch to enter the state of the plurality of states that minimizes the Error Vector Magnitude of the radio frequency system.