High-linearity upper frequency mixer with controllable output voltage and frequency mixing method

Abstract

The invention discloses a high-linearity upper frequency mixer with controllable output voltage, which comprises a voltage / current conversion circuit, a frequency mixing circuit, an amplitude detector and a comparison module, wherein the voltage / current conversion circuit is used for converting analog baseband signals into current signals; the frequency mixing circuit is used for mixing the current signals output by the voltage / current conversion circuit with LO signals, and outputting high-linearity frequency mixing signals; the amplitude detector is used for detecting the amplitude of the high-linearity frequency mixing signals, and outputting detection signals; and the comparison module is used for comparing the detection signals with reference voltage signals, and outputting control signals to control the current output by the voltage / current conversion circuit. Due to the adoption of a negative feedback control loop, the high-linearity upper frequency mixer ensures that the output voltage amplitude is accurate, has a simple circuit structure and is favorable for CMOS integration.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and relates to a highly linear up-mixer with controllable output voltage and a mixing method. Background technique [0002] With the rapid development of integrated circuit technology, it is possible to highly integrate the wireless transceiver system. At the same time, the development of communication system technology and the demands of the consumer market are focused on communication at high data rates. This requires the use of 64QAM (Quadrature Amplitude Modulation, quadrature amplitude modulation), 256QAM or even 1024QAM modulation. These modulation techniques all require high linearity in the transceiver for RF signal transmission. At present, in the integrated transmitter circuit, the mixer structure of the Gilbert (Gilbert) structure is usually used, such as figure 1 shown. But using this mixer structure, it is difficult to obtain high linearity, because figure 1 The M...

AI Technical Summary

Problems solved by technology

But using this mixer structure, it is difficult to obtain high linearity, because figure 1 The MOS transistor device in the circuit is a nonlinear device, which can work linearly only when the signal is small, and will produce distortion and nonlinearity if the signal increases

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