Enhancement of class C operation of bipolar junction transistor
AssigneeRockwell International Corporation
InventorRobert J. Weber
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Abstract
Pulsed RF operation of a class C biased BJT is enhanced using a three element system to control the BJT emitter current. The three element system includes a transformer having a secondary connected in the emitter current path. Connected to the transformer primary are the other two elements, namely, an impedance and a pulse source. The three elements cooperate to cause the emitter current to substantially conform to a desired or predetermined pulse waveform.
Claims15
A circuit comprising a class C biased BJT which is for outputting RF bursts, and means for controlling the shape of the envelope of said RF burst, said shape controlling means comprising:
- first means comprising a transformer having a primary winding with M.sub.p turns and a secondary winding with M.sub.S turns where M.sub.p :M.sub.S >1, said secondary winding being connected in the BJT emitter current path,
- pulse source second means, connected to the primary winding, for providing pulses having predetermined parameters,
- impedance third means connected to the primary winding,
- said first, second, and third means cooperating to control the BJT emitter current and cause the BJT emitter current envelope to substantially conform to a predetermined function of time I.sub.e (t), where I.sub.e (t) is a pulse waveform.
Apparatus comprising:
- a class C biased BJT for outputting RF bursts,
- a transformer having (i) a primary winding with a first number of turns and (ii) a secondary winding with a second number of turns, said first number being greater than said second number, and said secondary winding being connected in the BJT emitter current path,
- means for providing pulses having predetermined parameters, and being connected to said primary winding for delivering pulses thereto,
- whereby, said pulses cause the BJT emitter current envelope to substantially conform to a predetermined function of time where said predetermined function of time is a pulse waveform.
Dependencies are inferred from the claim text.