摘要 |
A current balanced linear amplifier which does not contain a transformer. A differential transistor pair (22, 32) forms the amplifying element, with at least one transistor (22 or 32) having an input signal (71, 72) applied to its base. A current sink (52) sinking a fixed value of current (I) is coupled to the commonly-coupled emitters of the transistor pair (22, 32). Coupled to the collector of each amplifying transistor (22, 32) is a self-biasing constant current source (2, 12) which produces a fixed amount of current (I/2) equal to one half the current (I) sunk by the current sink (52). Each self-biasing constant current source (2, 12) comprises a field effect transistor (2, 12) having a capacitor (6, 16) connected between the gate G and source S of the FET (2, 12) in a positive feedback arrangement. The balanced current output (61, 62) is taken from the collectors of each of the two amplifying transistors (22, 32).
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