| 摘要 |
In an extended range amplifier, a simplified feedback system is provided to control a voltage control attenuator (or voltage control variable gain amplifier). The feedback loop may be embodied in analog or digital form. An input signal is applied to a variable gain or variable attenuating amplifier and, preferably, to a linear diode detector. The system logarithmic output is taken from the variable controlled device, and the linear diode detector supplies a linear output. The linear output from the diode detector is compared with a reference level. A resulting error signal is used to control the attenuation of the voltage control attenuator. In this matter, the simplified, reliable adjustment of extended dynamic range of amplification and power measurement are provided. The selection of reference level of the attenuator or amplifier will determine the gain of the amplifier.
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