Infineon Technologies Ag

Finisar Corporation

Günter Donig

Krzysztof Kitlinski

Winfried Bakalski

Hans-Dieter Wohlmuth

Boris Kapfelsperger

Alfons Schmid

A subtractor circuit which provides, at an output, a signal that is proportional to the difference, which is applied to the input, between two signal levels is specified. Formed at the output of an operational amplifier of the subtractor circuit are two synchronous signal sources, one of which is used for feedback from one of the two identical outputs to an input of the operational amplifier. In accordance with the proposed principle, a feedback resistor which is normally present in analog subtractor circuits is avoided. The altered voltage swing at the output of the operational amplifier makes it possible to operate the latter without a negative supply voltage. The subtractor circuit described is particularly suited to power detection using an input-side power detector.

Subtractor circuit and power detector arrangement having that subtractor circuit

A power amplifier arrangement comprises a power amplifier in a semiconductor body. At least one first input terminal on the surface of the semiconductor body is provided for feeding in a signal to be amplified. A first output tap of the arrangement is designed for outputting a signal with a first center frequency; a second and a third output tap are designed for outputting a second signal with a second center frequency. A line wire is respectively connected to the second and third output taps on the surface of the semiconductor body. According to the invention, a charge store is provided, which is coupled to the third output tap and is designed for forming a series resonant circuit with the line wire connected to the third output tap.

Power amplifier arrangement and method for processing a radiofrequency signal

An integrated power amplifier arrangement with multistage construction is provided, in which a matching filter with integrated capacitance and inductance for impedance transformation is provided between an input transistor and an output transistor. In one example, the inductance of the matching filter is formed as a microstrip conductor, resulting in a significantly higher quality factor of the inductance and hence an improved linearity and an improved efficiency of the integrated power amplifier. The invention can advantageously be employed in particular in integrated transmitting arrangements.

Growing community of inventors

Poing, Germany

Günter Donig