Fusion circuit of front-end amplifier and mixer

Abstract

The invention belongs to the field of wireless communication chips, and relates to a front-end amplifier and mixer fused circuit which is composed of a signal receiving circuit and an inverting amplification circuit connected with the signal receiving circuit, the signal receiving circuit comprises an inverter and a switch S0, the first end of the switch S0 is connected with the inverter, the second end of the switch S0 is grounded, and the third end of the switch S0 is connected with the inverting amplification circuit; the inverting amplifying circuit is composed of N (N is an integer greater than or equal to 1) stages of inverting amplifiers, coupling capacitors corresponding to the stages of inverting amplifiers and switches, and the inverters receive the square wave signals, perform negation operation, output control signals to the switch S0 and the switches corresponding to the stages of inverting amplifiers and control the switches to be switched on or switched off. The front-end amplifier and the mixer are ingeniously combined, a direct current point can be determined without a feedback resistor, the gain of the amplifier can be increased, and the area and power consumption of a chip are remarkably reduced.

Description

technical field [0001] The invention belongs to the field of wireless communication chips, and relates to a circuit integrating a front-end amplifier and a mixer. Background technique [0002] Usually, in the receiving circuit of the wireless communication chip, it is necessary to perform front-end amplification on the received weak signal and then use a mixer for down-conversion operation. For human body channel communication, in order not to require a large input impedance of the amplifier, a capacitive coupling method is adopted. This requires that the front-end amplifier has high gain, high sensitivity, and low input equivalent noise, but the linearity is not high, so the amplifier with the inverter structure can achieve a large gain. An amplifier with a traditional inverter structure needs a feedback resistor to determine the DC point, and the larger the feedback resistor, the greater the gain of the amplifier, but at the cost of chip area. Contents of the invention ...

AI Technical Summary

Problems solved by technology

The amplifier of the traditional inverter structure needs a feedback resistor to determine the DC point, and the larger the feedback resistor, the greater the gain of the amplifier, but there will be a cost of chip area

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