An amplifier operates to provide a high output impedance at an output through a push stage having a first transistor of a first transistor type and a pull stage having a second transistor of a second transistor type that is different from the first transistor type. The first transistor and the second transistor are coupled in a common-gate configuration. The first transistor and the second transistor are shorted together via a capacitor coupled to an input and share a common current path as a push-pull current-reusing common-gate low noise amplifier with a broadband input matching.

The present description concerns an amplifier. A first transistor couples a first input node to a first output node. A second transistor couples a second input node to a second output node. The control terminals of the first and second transistors are connected. A third transistor has a control terminal connected to the first input node and a conduction terminal connected to the second output node. A fourth transistor has a control terminal connected to the second input node and a conduction terminal connected to the first output node. A circuit controls a current through the first and second transistors. A circuit delivers a control signal to the control terminals of the first and second transistors.

A current feedback amplifier (CFA). The CFA includes a common-gate input stage, a biasing circuitry, and a differential pair coupled in parallel between the supply voltage node and the reference voltage node. The common-gate input stage amplifies an input signal received at an input node and supplies it to a gate of the complementary transistors of the differential pair. The biasing circuitry supplies a bias voltage to a gate of the transistors of the common-gate input stage. The input node of the common-gate input stage and a node between the complementary transistors in the first path of the differential pair are shorted.