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.

A voltage gain control circuit comprising: a current-to-current conversion circuit comprising; a first current mirror transistor; a second current mirror transistor; and a current mirror transistor, the voltage gain control circuit further comprising and a current-to-voltage conversion circuit, wherein an input of the current-to-voltage conversion circuit is coupled to an output of the current-to-current conversion circuit and wherein the current-to-voltage conversion circuit is configured to provide an output voltage signal which varies proportionately to a signal received at the input of the current-to-voltage conversion circuit, and wherein the configuration of the current-to-current conversion circuit is such that a linear current variation in the received linear control current results in an exponential current variation in an output current of the current-to-current conversion circuit provided to the current-to-voltage circuit via the second CMT input terminal.

Circuits, semiconductor devices, and systems are provided. An illustrative circuit includes a first pair of transistors cross-coupled with a second pair of transistors. The circuit may further include a gain control circuit coupled with the first pair of transistors and the second pair of transistors, where the gain control circuit provides an error compensation for a beta variation effect in at least one of the first pair of transistors and the second pair of transistors.

In accordance with an embodiment, a variable gain amplifier includes: a first differential transistor pair coupled to a signal input; a first current source configured to provide a first bias current to the first differential transistor pair; a pair of diodes coupled to an output of the first differential transistor pair; a second differential transistor pair having an input coupled to the pair of diodes; a second current source configured to provide a second bias current to the second differential transistor pair; and a current control circuit coupled to the first current source and the second current source.

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.