Designing an RF modular variable-gain amplifier

摘要

A flexible modular VGA design for use in modern communications devices. The RF variable-gain amplifier (VGA) is a major building block in modern high-frequency communications devices. It is used in the transmitter (Tx) and the receiver (Rx) stages for a number of functions. Different applications put different requirements on the VGA, and an integrated VGA is often either under-designed or over-designed for a variety of applications. It is difficult to find one VGA that will fit all the applications. This is why modular design is popular. The modular VGA design approach has a trade-off, as shown in the example below.