A power amplifier including a first transistor for amplifying and outputting a radio frequency signal, a second transistor, a third transistor for supplying a bias current, a first voltage supply circuit for supplying a lower voltage to a base of the third transistor as a temperature of a first diode is higher. The third transistor and the first transistor, or the third transistor and the second transistor, are disposed without another electronic element interposed therebetween. The third transistor is disposed such that a distance between the third transistor and the first transistor is smaller than a distance between the first voltage supply circuit and the first transistor, or a distance between the third transistor and the second transistor is smaller than a distance between the first voltage supply circuit and the second transistor.

A power amplifier including a first transistor for amplifying and outputting a radio frequency signal, a second transistor, a third transistor for supplying a bias current, a first voltage supply circuit for supplying a lower voltage to a base of the third transistor as a temperature of a first diode is higher. The third transistor and the first transistor, or the third transistor and the second transistor, are disposed without another electronic element interposed therebetween. The third transistor is disposed such that a distance between the third transistor and the first transistor is smaller than a distance between the first voltage supply circuit and the first transistor, or a distance between the third transistor and the second transistor is smaller than a distance between the first voltage supply circuit and the second transistor.

A power amplifying circuit includes a first amplifying unit that amplifies a first radio-frequency signal and a second amplifying unit that amplifies a second radio-frequency signal. The first amplifying unit includes a first matching circuit that performs impedance matching for a circuit in a preceding stage, and a first amplifying circuit that amplifies the first radio-frequency signal that has passed through the first matching circuit. The second amplifying unit includes a second matching circuit that performs impedance matching for the circuit in the preceding stage, a resistor including a first end and a second end, the first end being electrically connected to the second matching circuit, and a second amplifying circuit that is electrically connected to the second end of the resistor and that amplifies the second radio-frequency signal that has passed through the resistor.

A power amplifying circuit includes a first amplifying unit that amplifies a first radio-frequency signal and a second amplifying unit that amplifies a second radio-frequency signal. The first amplifying unit includes a first matching circuit that performs impedance matching for a circuit in a preceding stage, and a first amplifying circuit that amplifies the first radio-frequency signal that has passed through the first matching circuit. The second amplifying unit includes a second matching circuit that performs impedance matching for the circuit in the preceding stage, a resistor including a first end and a second end, the first end being electrically connected to the second matching circuit, and a second amplifying circuit that is electrically connected to the second end of the resistor and that amplifies the second radio-frequency signal that has passed through the resistor.

A driver for a transmitter includes an output stage comprising a first equalizer and a second equalizer, coupled to an output circuit of the transmitter, being operable for receiving a plurality of differential input data streams to generate an equalized differential output signals, wherein the first equalizer and the second equalizer being coupled and reconfigured to form a plurality of parallel driver segments, each driver segment having a calibration circuit, at least one of the calibration circuits been enabled to control the impedance of the output circuit, the plurality of differential input data streams are processed by the first and the second equalizer to shape the plurality of differential input data streams for compensating the channel loss.

Techniques for controlling a low-profile medium wave transmitting system are provided. An example of an antenna system according to the disclosure includes a first radiator operably coupled to a first amplifier, a first modulator operably coupled to the first amplifier and configured to provide a first radio frequency signal to the first amplifier, a second radiator operably coupled to a second amplifier, a second modulator operably coupled to the second amplifier and configured to provide a second radio frequency signal to the second amplifier, a control module operably coupled to the first modulator, first amplifier, the second modulator, and the second amplifier, the control module being configured to control a delta phase value based on the first radio frequency signal and the second radio frequency signal, and control the power output of the first amplifier and the second amplifier.

Techniques for controlling a low-profile medium wave transmitting system are provided. An example of an antenna system according to the disclosure includes a first radiator operably coupled to a first amplifier, a first modulator operably coupled to the first amplifier and configured to provide a first radio frequency signal to the first amplifier, a second radiator operably coupled to a second amplifier, a second modulator operably coupled to the second amplifier and configured to provide a second radio frequency signal to the second amplifier, a control module operably coupled to the first modulator, first amplifier, the second modulator, and the second amplifier, the control module being configured to control a delta phase value based on the first radio frequency signal and the second radio frequency signal, and control the power output of the first amplifier and the second amplifier.

A linear amplifier is provided to have higher efficiency for an envelope tracking modulator. In one embodiment, a first stage amplifier circuit can be simply operated in a high gain mode or a high bandwidth mode for different applications, without using large chip area. In another embodiment, an output stage has a cascode structure whose dynamic range is controlled according to a voltage level of a supply voltage, to make a core device within the output stage have better protection and suitable dynamic range.

A radio frequency low noise amplifier circuit with a receive signal input, a receive signal output, and a voltage source include a low noise amplifier and a coupled inductor circuit with a primary inductive chain connected to the output of the low noise amplifier and to the voltage source. The coupled inductor circuit further includes a secondary inductive chain with a first inductor electromagnetically coupled to the primary inductive chain, and a second inductor in series with the first inductor and magnetically coupled to the primary inductive chain. The second inductor is connected to a feedback node of the low noise amplifier. There is an output matching network connected to the first inductor of the secondary inductive chain and to the receive signal output.

A radio frequency low noise amplifier circuit with a receive signal input, a receive signal output, and a voltage source include a low noise amplifier and a coupled inductor circuit with a primary inductive chain connected to the output of the low noise amplifier and to the voltage source. The coupled inductor circuit further includes a secondary inductive chain with a first inductor electromagnetically coupled to the primary inductive chain, and a second inductor in series with the first inductor and magnetically coupled to the primary inductive chain. The second inductor is connected to a feedback node of the low noise amplifier. There is an output matching network connected to the first inductor of the secondary inductive chain and to the receive signal output.