Basic concept of RF power amplifier (RF PA), circuit composition and linearization technology of RF PA

Basic concepts Radio frequency power amplifier (RF PA) is the main part of transmission system, and its importance is self-evident. In the transmitter’s forward circuit, the RF signal generated by the modulation oscillating circuit is very small. After a series of amplification (buffer stage, intermediate amplification stage, and last stage power amplification stage), enough RF […]

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Application design of new buffer based on variable voltage control current source and comparator

Authors: Seyyed Hossein pishgar1, alihossein sepahvand1, Omid hashemipour2 This paper introduces a new buffer based on comparator using variable voltage controlled current source (vvccs). The application of traceable current source provides high-precision performance, which can not only reduce the overshoot error of output node, but also reduce the change of overshoot error relative to output […]

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Design and application of active bias control

In order to make a high-frequency amplifier, the bipolar transistor used in the common emitter configuration is sometimes defined by its small signal characteristics assuming that the collector emitter voltage (VCE) and collector current (IC) of the gain transistor are specific values. Therefore, it is necessary to produce these two conditions at the same time […]

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What is negative feedback and what is its role in circuit applications

About 86 years ago, Harold black proposed this milestone concept when trying to reduce amplifier distortion. At that time, he wanted to realize a circuit that accepts the input VI and generates the output VO, which is expressed as: Aideal is the desired circuit gain (not necessarily large, just meet the application needs). In the […]

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