Systems and methods are related to a distributed amplification. An amplification device can include cells including a first cell and a second cell and transmission lines including a first line and a second line. The first cell is coupled to the first line, and the second cell is coupled to the second line. The first line is configured to provide a first delay related to a delay between the first cell and the second cell. The device also includes a summer including a first input coupled to the first line and second input coupled to the second line. The summer is configured to provide an output signal.

A capacitive load, an inductive load, or a transmission line coupled to an output of a closed-loop amplifier circuit can cause undesirable oscillations in a feedback signal of the amplifier circuit. The oscillations in the feedback signal can cause the amplifier circuit to exhibit instability and unpredictable behavior. Techniques are described that allow an amplifier circuit to provide a stable response while driving a capacitive load.

An amplifier circuit includes a first divider dividing an input signal into first and second signals, a control amplifier outputting a third signal, a second divider dividing the second signal into fourth and fifth signals, a first auxiliary amplifier outputting a sixth signal, a second auxiliary amplifier outputting a seventh signal, and a branch line coupler including first to fourth ends and first to fourth transmission lines. A first characteristic impedance at the center frequency of the first transmission line and the third transmission line is higher than a reference impedance, and a second characteristic impedance at the center frequency of the second transmission line and the fourth transmission line is lower than the first characteristic impedances/2. An amplitude of a power of the seventh signal is larger than an amplitude of a power of the sixth signal.

A power amplifier arrangement (100) for amplifying an input signal (Pin) to produce an output signal (Pout) is disclosed. The amplifier arrangement (100) comprise an input port (IN) for receiving the input signal; an output transmission line (110) having a first terminal (111) and a second terminal (112); an output port (OUT) coupled to the second terminal (112) of the output transmission line (110) for providing the output signal; and a plurality N of amplifying devices (121, 122, . . . 12N) distributed along the output transmission line (110). The power amplifier arrangement (100) is configured such that the plurality N of amplifying devices are active sequentially for amplifying the input signal with increasing amplitude of the input signal.

An amplifier system with high gain, compact size, and extended bandwidth is disclosed. The amplifier system includes one or more inputs configured to receive one or more input signals and a pre-driver configured to receive the one or more input signals. The pre-driver may comprise source connected FETs which create a virtual ground and may include inductors which cancel or counter parasitic capacitance of the FETs. The pre-driver amplifies the one or more input signals to create one or more pre-amplified signals, which are provided to a voltage divider network configured to reduce a DC bias voltage of the one or more pre-amplified signals, while maintaining a wide bandwidth range. An amplifier receives and amplifies the output of the voltage divider network to create amplified signals. The amplifier may comprise mirrored FET pairs in a common source configuration and a common gate arrangement.

A distributed amplifier system comprising an impedance matching network configured to match an input impedance to an output impedance of the signal source, and a DC block configured to block DC components in the input signal. A variable gain amplifier adjusts the gain applied to the input signal based on a gain control signal to generate a gain adjusted signal. An emitter follower circuit receives and processes the gain adjusted signal to introduce gain peaking to create a modified signal. A distributed amplifier receives and amplifies the modified signal from the emitter follower circuit, to create an amplified signal. The distributed amplifier includes a termination network and one or more impedance matching elements configured for gain shaping the amplified signal. The gain peaking introduced by the emitter follower circuit is controlled by a variable current source. The distributed amplifier may be an open collector distributed amplifier.

An example amplifier includes a first transconductance circuit, which includes a first output coupled to a first current source, a first input, a first network, and a cascode circuit; and a second transconductance circuit, which includes a second output coupled to a second input and a second current source; wherein the first current source is coupled to a supply voltage and the second current source is coupled to an electrical ground; and wherein the first output is coupled to the second output.