A Broadband Low Offset Active Balun Circuit

Abstract

The invention belongs to the technical field of integrated circuits, and particularly relates to an active Balun circuit applied to broadband low detuning. The active Balun circuit is composed of a common-source amplifier and a source follower. The common-source amplifier is composed of a transistor M1, a resistor Rp and a resistor Rd, inputs a signal VIN to be coupled to a grid electrode of the common-source amplifier through a capacitor Cc, and outputs an inversion signal VOUT minus; the source follower is composed of a transistor M2, a transistor M3, a resistor Rp1 and a capacitor Cf, the signal VIN is inputted to the source follower, and the in-phase signal VOUT plus is outputted; in this way, the basic active Balun circuit is obtained. According to the active Balun circuit of the structure, the capacitor Cf is introduced to the source follower to serve as a freedom degree factor for adjusting phase balance and is matched with the resistor Rd, for adjusting amplitude balance, in the common-source amplifier, and therefore small phase detuning and amplitude detuning can be simultaneously achieved for the active Balun circuit within the wide frequency band range. The active Balun circuit can be obtained through the CMOS process, the BiMOS process and the like.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and specifically relates to an active Balun circuit applied to broadband, low amplitude offset and phase offset, which can be used in analog integrated circuits requiring low offset single-ended input and differential output, such as the front end of a radio frequency microwave receiver. . Background technique [0002] With the development of communication and semiconductor technology, all kinds of mobile communication and wireless data transmission are developing rapidly. At the same time, people's requirements for high speed and large bandwidth of wireless communication technology are becoming stronger and stronger, which prompts people to continuously develop and utilize higher frequency Wireless communication technology with resources and research on UHF. At the same time, wireless communication integrated circuits are developing towards a highly integrated system-on-a-chip. Ther...

AI Technical Summary

Problems solved by technology

For the radio frequency microwave Balun circuit, if the passive Marchand Balun circuit is used, not only will there be a loss of signal gain, but it will also occupy a large area; and if the traditional capacitive cross-coupling (CCC: Capacitor Cross Coupled) mode active Balun circuit is used , although the circuit occupies a small area, due to the influence of parasitic capacitance effects, it is difficult for the differential signal generated by it to achieve a small amplitude offset and phase offset within a wide frequency range at the same time due to the effect of parasitic capacitance

Therefore, it becomes a big design challenge to realize an active balun circuit with high frequency, wide bandwidth, low phase offset and amplitude offset

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