Telecommunications – Transmitter – With feedback of modulated output signal
Patent
1992-07-20
1994-06-07
Eisenzopf, Reinhard J.
Telecommunications
Transmitter
With feedback of modulated output signal
455 89, 455127, 330129, 330279, H04B 104, H03G 320
Patent
active
053198042
ABSTRACT:
In a feedback loop, a modulation carrier signal is amplified or attenuated by a variable gain amplifier (2). A part of a transmission signal amplified by a power amplifier (3) is extracted by a monitor circuit (4) , and is detected by an envelope detector (6). This transmission envelope signal and a distortion-free standard envelope signal produced from a standard envelope generator (7) are compared in an error detector (8). An error signal obtained by amplifying the error of the two signals and a DC voltage are added in an adder (9). A gain control terminal (11) of the variable gain amplifier (2) is controlled by using this adder output signal as the control signal. The envelope detector (6) is capable of varying the attenuation quantity of the variable high frequency attenuator (61) and the load resistance value of the variable load circuit (63). Therefore, the dynamic range of the transmission monitor circuit monitor output corresponding to the output voltage of the envelope detector in a predetermined range can be expanded.
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Kosugi Hiroaki
Matsumoto Takayuki
Eisenzopf Reinhard J.
Matsushita Electric - Industrial Co., Ltd.
Vo Nguyen
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