Single-end input and dual-end output amplifier circuit and signal processing circuit

Abstract

The invention discloses a single-end input double-end output amplifier circuit and signal disposing circuit, which comprises the following parts: amplifier to amplify the input signal, input end to receive the input signal and first output end, single-end input double-end output conversion circuit to converse the amplified signal to differential signal, first transistor to receive the amplified signal, first grid to couple the first output end, first first pole to couple the second output end, first second pole to couple the first node, second transistor with second grid to couple the second first pole of third output end, second second pole to couple the first node, second capacitance coupled between the second output end and second grid, first resistance coupled between the second output end and power source, second resistance coupled between the third output end and voltage source, current source coupled between the first node and ground point.

Description

technical field [0001] The invention relates to a signal processing circuit, in particular to a low noise amplifier circuit with single-end input and double-end output. Background technique [0002] Most of the antennas currently used are single-ended antennas, but the Image-rejection Mixer (Image-rejection Mixer) used to down-frequency the signal usually uses a Double-Balanced Mixer (Double-Balanced Mixer) with double-ended input. Mixer) to achieve. Therefore, the single-ended input signal received by the antenna must be converted to a double-ended output signal before the image signal cancellation mixer can down-convert the signal from the antenna side for back-end processing. [0003] There are currently two methods for converting a single-ended input signal into a double-ended output signal. FIG. 1 shows one single-ended input and double-ended output amplifier circuit 100 , including a balancing circuit (Balun) 12 and a double-ended input and double-ended output amplif...

AI Technical Summary

Problems solved by technology

[0009] However, although the method of replacing the single-ended to double-ended conversion circuit 23 with the traditional differential amplifier pair circuit 33 with the negative input terminal grounded reduces the chip area, due to the bypass of the differential amplifier circuit 33 with the traditional negative input terminal grounded The (bypass) capacitor 306 will couple the noise on the chip to the input end of the differential amplifier pair circuit 33 whose negative input end is grounded, so the quality of the double-ended output signal at the output end of the amplifier circuit 300 will be affected by the noise.

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