Analog switch circuit based on radio frequency switch chip

Abstract

The invention discloses an analog switch circuit based on a radio frequency switch chip. The circuit comprises a radio switch chip, a linear voltage stabilizing module, an operation amplification module and an optocoupling module, wherein the radio frequency switch chip is separately connected with the linear voltage stabilizing module, the operation amplification module and the optocoupling module. A public output terminal of the radio frequency switch chip is connected with a low pass filter, and a direct current component in a signal is directly fed back to the radio frequency switch chip and the linear voltage stabilizer under the effect of the operation amplifier, so that voltage of an earth terminal is changed along with the change of direct current voltage, a power output terminal of the linear voltage stabilizer is also changed along with the change of voltage, and thus the condition that a voltage difference between the power output terminal and a reference ground is a fixed value is ensured, no direct current voltage difference exists between the public output terminal and the earth terminal of the radio frequency switch chip, a condition that direct current biasing is zero is matched, stability and reliability of the radio frequency switch chip are significantly improved, and a better switch characteristic is acquired. The analog switch circuit provided by the invention also has the advantages of simple structure, low production cost and small size.

Description

technical field [0001] The invention relates to the field of analog switches, in particular to an analog switch circuit based on a radio frequency switch chip with a switching frequency from direct current (0 Hz) to 4G (4 gigahertz). Background technique [0002] Among the existing switches, there are reed relays, photoelectric relays, radio frequency switches, MEMS switches and the like. Among them, the photorelay can pass DC signals, but due to the influence of its mechanical structure, its high-frequency performance is not good. The general dry reed relay has better high frequency performance than the photorelay, but it is also within 1G. Some RF relays have higher high-frequency characteristics, but they are bulky and very expensive. MEMS switches are small, but also very expensive. The RF switch is cheap, small in size, and its frequency band can be infinitely close to DC. However, due to its internal structure limitations, the signal must pass through a DC blocking ...

AI Technical Summary

Problems solved by technology

[0006] An analog switch circuit based on a radio frequency switch chip, the analog switch circuit is an application circuit of the radio frequency switch chip, which is mainly used to solve the problem that the radio frequency switch chip cannot carry DC level, and realize the switching frequency from DC (0 Hz) to 4G Hz control, the circuit structure mainly includes a radio frequency switch chip, a linear voltage regulator module that provides a stable voltage for the radio frequency switch chip, an operational amplifier module that extracts the DC component of the signal input terminal, and an optocoupler module that drives the radio frequency switch to work stably

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