Abstract: A transmission device includes a frequency detector configured to detect a frequency of an input signal to generate frequency information; a signal generator configured to generate a modulation wave signal with a frequency equivalent to the frequency of the input signal based on the frequency information; and a single side band modulator configured to modulate a carrier wave by the modulation wave signal.

Abstract: The amplifier circuit comprises a low voltage input stage (1) connected via transformers (3) to a high voltage output stage (5). The transformers comprise a central transformer having one primary winding (30) and two oppositely-wound secondary windings (31, 32), and two end transformers each having a primary winding (33, 35) and a secondary winding (34, 36). The low voltage input stage comprises an input amplifier (10), a differentiator (12, 13) and two oscillators (23, 25). The amplifier output is fed via the differentiator to the primary winding of the central transformer and is connected to both oscillators in such a manner as to actuate one or other of them depending on its polarity. Each of the oscilators is connected to the primary winding of a respective one of the two end transformers.