A matching network is a matching network of a power amplifier circuit that outputs a signal obtained by a differential amplifier amplifying power of a high-frequency signal. The matching network includes an input-side winding connected between differential outputs of the differential amplifier; an output-side winding that is coupled to the input-side winding via an electromagnetic field and whose one end is connected to a reference potential; a first LC series resonant circuit including a capacitive element and an inductive element connected in series with each other, and being connected in parallel with the input-side winding; and a second LC series resonant circuit including a capacitive element and an inductive element connected in series with each other, and being connected in parallel with the output-side winding.

An improved transformer based switch for PALNA applications. The transformer based switch having an input single pole port and a circuit with at least one transformer and at least one switch configured to connect portions of the transformer to ground or to short the transformer. The primary side of the transformer being connected to the input port and the secondary side of the transformer being connected to an output port.

In accordance with an embodiment, a method for operating a millimeter-wave power amplifier including an input transistor having an output node coupled to a load path of a cascode transistor includes: receiving a millimeter-wave transmit signal at a control node of the input transistor; amplifying the millimeter-wave transmit signal to form an output signal; providing the output signal to a load coupled to an output node of the cascode transistor; and adjusting a first DC bias current of the input transistor to form a substantially constant second DC bias current of the cascode transistor.

A power amplifier arrangement comprises a power amplifier comprising at least one transistor having a first gate and a second gate. The first gate is configured to receive a radio frequency input signal superimposed with a first control signal, and the second gate is configured to receive a second control signal. The first control signal is a linearization signal varying in relation to an envelope of the input signal and the second control signal is a temperature compensation signal varying in relation to a temperature of the power amplifier, or vice versa.

An amplifier circuit according to the present invention includes a first block, a second block, a transformer, and a reference node and operates as a negative impedance converter circuit. A circuit configuration formed by a first transistor and at least one first passive component in the first block with respect to a first terminal of the transformer and a circuit configuration formed by a second transistor and at least one second passive component in the second block with respect to a second terminal of the transformer are the same as each other.

A transceiver or RF front end employing a transformer with a low loss transmit/receive (T/R) switch circuit in the ground path. In various embodiments, differential outputs of a power amplifier are coupled to the first winding of the transformer, while the input of a low noise amplifier is coupled to the second side of the transformer via a matching inductor. The T/R switch circuit, which may be a thin oxide CMOS transistor, is coupled between the second side of the transformer and ground. In operation, the T/R switch circuit may be enabled during transmit mode operations of the power amplifier, such that a low impedance path to ground is provided at the input of the low noise amplifier, thereby protecting it from high voltage swings generated by the power amplifier.

A transformer includes multiple differential ports and first and second transformer windings. The first transformer winding includes a first transformer half-winding coupled to a first differential port of the differential ports. The first transformer winding also includes a second transformer half-winding coupled to a second differential port of the differential ports. An amplifier system that has a transformer is also provided. The amplifier system includes a first and a second stage amplifier. The first stage amplifier includes a first and a second amplifier. The second stage amplifier includes a third and a fourth amplifier. The transformer is coupled between the first stage amplifier and the second stage amplifier, where the transformer has a primary loop and a secondary loop. The primary loop of the transformer may be configured to receive differential signals of the first amplifier. A method for fabricating a transformer is also provided.

A dual mode notch filter for use in a multi-band millimeter wave (mmW) transmitter includes a transmit filter circuit disposed between two amplifiers in a mmW transmit signal path, the transmit filter circuit formed by at least one switch, at least one capacitor, and a double-tuned transformer, the transmit filter circuit having at least two modes configured to selectively filter a spurious signal in at least a first communication band.

A bias circuit for a PA. A first transistor has its drain terminal and its gate terminal connected to a first circuit node and its source terminal connected to a first supply terminal, a first current source connected to the first circuit node, and a first resistor connected between the first and second circuit nodes. A second transistor receives a first component of a differential input signal to the PA at its gate terminal, has its drain terminal connected to the second circuit node and its source terminal connected to a second supply terminal, and a third transistor receives a second component of the differential input signal to the PA at its gate terminal, having its drain terminal connected to the second circuit node and its source terminal connected to a second supply terminal. The gates terminals of the second and the third transistors are biased by a first voltage.

An apparatus is disclosed for processing a signal with a divided amplifier. In example implementations, an apparatus includes a first portion of an amplifier, a first port interface, a second port interface, and a switch matrix. The first port interface includes a first transformer; a second portion of the amplifier, which is coupled to the first transformer; and a first switch component that is coupled to at least one of the first transformer or the second portion of the amplifier. The second port interface includes a second transformer and a second switch component that is coupled to the second transformer. The switch matrix is coupled between the first switch component and the first portion of the amplifier and between the second switch component and the first portion of the amplifier. The switch matrix is also coupled between the second portion of the amplifier and the first portion of the amplifier.