A Broadband RF Mixer Based on Current Mode Active Devices

Abstract

The present invention discloses a current mirror and DOCCII (dual-output current conveyor)-based wideband radio mixer. The wideband radio mixer provided by the invention is composed of a dual-NMOS-PMOS current mirror mixing unit and a current output stage; four dual-NMOS-PMOS current mirrors embedded with local oscillation signals vLO+ / - are combined together so as to form the dual-NMOS-PMOS current mirror mixing unit; the dual-NMOS-PMOS current mirror mixing unit is used for executing the input stage and passive switch core of the mixer and is equivalent to the double-balance topological structure of a traditional active Gilbert mixer; the in-phase current output ends and anti-phase current output ends of two dual-output current conveyors are in cross coupled connection with each other, so that the current output stage can be formed; and the current output stage is adopted as the transimpedance amplifier of a conventional passive mixer; and the current output stage has very low input impedance and high output impedance and is used for achieving the amplification of output current signals which have been subjected to pre-frequency conversion and effectively driving a next-stage circuit. According to the wideband radio mixer provided by the invention, inductive passive components are not required. The wideband radio mixer can simultaneously have the advantages of the active Gilbert mixer and the passive mixer.

Description

technical field [0001] The invention relates to a wideband radio frequency mixer based on a current mode active device, which is realized by a current mirror and a dual-output current transmitter, and belongs to the field of radio frequency integrated circuits. Background technique [0002] At present, the design of miniaturized radio frequency integrated circuits has very important theoretical and practical significance for the realization of implantable biomedical devices (such as wireless capsule endoscopes) or emerging wearable devices working in the human body. [0003] In the design of miniaturized radio frequency integrated circuits, broadband mixers are mainly used to realize frequency conversion. At present, inductive passive components are widely used in impedance matching networks, bandwidth expansion and resonant load circuits of broadband mixers. Although the size of MOS transistors is shrinking with the development of CMOS technology, the passive components of...

AI Technical Summary

Problems solved by technology

The active Gilbert mixer is composed of an input transconductance stage, a switch stage and an output load stage. It uses a MOS transistor stack structure for vertical commutation to complete the frequency conversion. It has a large conversion gain and good port isolation characteristics; but it does not Supports process generation reduction, requires passive inductance to complete impedance transformation, and it will generate serious flicker (1 / f) noise at the switch level

A passive mixer consists of an input transconductance stage, a switching stage, and a transimpedance amplifier, such as figure 1 As shown, the frequency conversion is completed by using the capacitive direct coupling structure horizontal commutation, which can reduce the number of stacked layers of MOS tubes, and its switching stage has no DC current, which can reduce 1 / f noise and improve linearity; but it requires a strong local vibration driving power, while the large parasitic impedance of the transimpedance amplifier limits the frequency bandwidth

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