Zero-intermediate-frequency/low-intermediate-frequency configurable variable gain amplifier

Abstract

The invention discloses a Zero-intermediate-frequency / low-intermediate-frequency (ZIF / LIF) configurable variable gain amplifier (VGA), which belongs to the technical field of radio-frequency communication. The Zero-intermediate-frequency / low-intermediate-frequency (ZIF / LIF) configurable variable gain amplifier (VGA) comprises a basic VGA circuit and a mode switching control circuit, wherein the mode switching control circuit mainly consists of two parts which are respectively positioned on a signal positive direction path and a feedback loop, and the two parts are mutually matched for realizing the configurable features of modules. The mode switching control circuit arranged on the signal positive direction path respectively adopts direct coupling and resistance-capacitance coupling modesto realize the zero-intermediate-frequency / low-intermediate-frequency work mode, and the mode switching control circuit arranged on the feedback switching control circuit is a direct-current imbalance eliminating switching control circuit used for controlling the work state of a direct-current imbalance eliminating circuit. The zero-intermediate-frequency / low-intermediate-frequency configurable variable gain amplifier of the invention can easily meet the requirements of miniaturization and high integration degree, and is particularly suitable for the system environment requiring multi-mode multi-band frequency and multi-standard work.

Description

technical field [0001] The invention belongs to the technical field of radio frequency communication, and relates to a variable gain amplifier, in particular to a zero-IF / low-IF configurable variable gain amplifier. A mode switching control circuit switches the working state of the circuit between zero-IF and low-IF modes. In between, circuits at all levels are connected through different coupling methods, so as to realize the multiplexing of hardware resources. Background technique [0002] At present, the level of science and technology in the field of communication and radio frequency in the world is constantly improving, and the development of various system chips with a single function is becoming more and more mature, such as system chips using Bluetooth for short-distance wireless transmission, and broadband Internet interconnection using UMTS / WCDMA Connected technology system chip and so on. In recent years, the rapid development of technology has led to a leap in t...

AI Technical Summary

Problems solved by technology

This parallel structure method has the following defects: First, the signal paths in two different modes have mutual influence and mutual interference, which will seriously affect the performance of the module and the entire chip

Second, the isolation of different signal paths is achieved through a complex circuit structure, which not only increases the complexity of the system, but also increases the chip area, hardware resource overhead and power consumption

Third, in the parallel structure, when one mode is working, the entire part of the other mode is in a non-working state, thus causing waste of hardware resources and electric energy

Fourth, the module adopts a parallel structure, and the chip area is at least doubled, which not only increases the cost but also fails to meet the miniaturization requirements of modern communication devices

Fifth, when it is necessary to switch the working mode, the two channels need to be activated and closed separately, involving the entire part of the two channels, which will increase additional power consumption and increase the power consumption of the entire system

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