A multibeam-inductive-output-tube amplifier comprises an output cavity and a plurality of electron guns each intended to emit an electron beam through the output cavity, each electron gun comprising a cathode intended to emit the electron beam and a gate allowing the density of the electron beam to be modulated. The amplifier comprises, associated with each gun, a DC voltage supply, each of the supplies connected to the gate of the corresponding electron gun so as to bias the gate. The voltage of at least one of the supplies is adjustable so as to balance the density of the various electron beams.

A transmission system includes a first transponder including a first I/Q modulator, and a second transponder including a second I/Q modulator, and configured to communicate with the first transponder using a frequency modulation scheme, wherein the first transponder is configured to set a first phase rotation mode in a first state for first light signal output from the first I/Q modulator, and transmit, to the second transponder, a first command to specify a second phase rotation mode for second light signal output from the second I/Q modulator, and the second transponder is configured to set, in response to the first command, the second phase rotation mode in a state specified by the first command.

A transmission system includes a first transponder including a first I/Q modulator, and a second transponder including a second I/Q modulator, and configured to communicate with the first transponder using a frequency modulation scheme, wherein the first transponder is configured to set a first phase rotation mode in a first state for first light signal output from the first I/Q modulator, and transmit, to the second transponder, a first command to specify a second phase rotation mode for second light signal output from the second I/Q modulator, and the second transponder is configured to set, in response to the first command, the second phase rotation mode in a state specified by the first command.

High-frequency amplifier apparatuses suitable for producing output powers of at least 1 kW at frequencies of at least 2 MHz for plasma excitation are disclosed. These high-frequency amplifiers include two transistors, the source or emitter connections of which are each connected to a ground connection point. The transistors can have an identical design and are arranged on a multilayer printed circuit board. The apparatus also includes a power transformer, the primary winding of which is connected to the drain or collector connections of the transistors. The primary winding and the secondary winding of the power transformer are each in the form of planar conductor tracks which are arranged in different upper layers of the multilayer printed circuit board.

Circuitry, which includes a PA power supply and RF PA circuitry, is disclosed. The RF PA circuitry includes a group of RF PAs and a group of PA decoupling circuits. The group of RF PAs includes a first RF PA and a second RF PA. The group of PA decoupling circuits includes a first PA decoupling circuit and a second PA decoupling circuit. The PA power supply provides a first PA power supply output signal to at least one of the group of RF PAs and to at least one of the group of PA decoupling circuits. The first PA decoupling circuit is coupled across the first RF PA, is programmable, and at least partially decouples the first RF PA from other circuitry. The second PA decoupling circuit is coupled across the second RF PA and at least partially decouples the second RF PA from other circuitry.

In high data rate receivers, comprising a photodetector (PD) and a transimpedance amplifier (TIA), a transmitted optical signal typically has poor extinction ratio, which translates into a small modulated current with a large DC current at the output of the PD. The large DC current saturates the TIA, which significantly degrades the gain and bandwidth performance. Accordingly, cancelling photo diode DC current in high data rate receivers is important for proper receiver operation. A DC current cancellation loop, comprising a low pass filter section and a trans-conductance cell (GM) are connected to the input of the TIA. PD DC current I.sub.DC is drawn from the input node of the TIA in the GM cell, such that the cancellation loop maintains the DC voltage value of the TIA input node to be the same as a reference voltage (V.sub.REF).

A hybrid planar combiner for use in broadband high power multi-component power amplifier architectures in planar solid-state power amplifiers, which does not comprise impedance converters in the power amplifier layer, is suitable for hermetic construction, supports effective cooling infrastructure and enables easy in-circuit applications.

A hybrid planar combiner for use in broadband high power multi-component power amplifier architectures in planar solid-state power amplifiers, which does not comprise impedance converters in the power amplifier layer, is suitable for hermetic construction, supports effective cooling infrastructure and enables easy in-circuit applications.

There is disclosed a communication cable module including: a conductive cable; a linear amplifier connected to the conductive cable; a detector for detecting presence or absence of an input signal of the conductive cable; a first circuit having a variable-current function; and a second circuit having a common-mode voltage regulating function, wherein when the input signal is not present, the variable-current function of the first circuit reduces an output current of the linear amplifier and the common-mode voltage regulating function of the second circuit regulates an output common-mode voltage of the linear amplifier.

There is disclosed a communication cable module including: a conductive cable; a linear amplifier connected to the conductive cable; a detector for detecting presence or absence of an input signal of the conductive cable; a first circuit having a variable-current function; and a second circuit having a common-mode voltage regulating function, wherein when the input signal is not present, the variable-current function of the first circuit reduces an output current of the linear amplifier and the common-mode voltage regulating function of the second circuit regulates an output common-mode voltage of the linear amplifier.