Quadrature mismatch calibration system and method, and radio frequency front-end chip

Abstract

The present invention provides a calibration system and method for quadrature mismatch and a radio frequency front-end chip. The system includes: SGCAL, which is used to generate a first DC test signal and a second DC test signal; a signal strength detector whose output The terminal is connected to the SHC input terminal, which is used to detect the first signal strength of the first RF signal after the frequency conversion of the first DC test signal by the transmitting front-end chip, and the second RF signal after the frequency conversion of the second DC test signal by the transmitting front-end chip. The second signal strength; the SHC, whose output is connected to the CALCC, is used to compare the first signal strength and the second signal strength, and sends the comparison result to the CALCC; The comparison result is used to control the adjustment circuit to calibrate the circuit to be calibrated. The above-mentioned technical solution solves the problems of high circuit complexity and high power consumption in the related art, without the assistance of an off-chip circuit or a digital baseband chip.

Description

technical field [0001] The present invention relates to the communication field, and more specifically relates to a quadrature mismatch calibration system and method, and a radio frequency front-end chip. Background technique [0002] Modern communication systems usually use phase or quadrature amplitude modulation, such as quadrature phase shift keying (QuadraturePhase Shift Keying, referred to as QPSK), Gaussian minimum shift keying (Gaussian Minimum ShiftKeying, referred to as GMSK), quadrature amplitude modulation (Quadrature Amplitude Modulation, referred to as QAM) and so on. In these modulation systems, the upper and lower sidebands of the signal spectrum contain different information. Therefore, the RF front-end must adopt an orthogonal transformation method to distinguish the information of the two sidebands. [0003] Quadrature mismatch means that the amplitude of the in-phase branch (I) and the quadrature-phase branch (Q) are not equal or the phase difference de...

AI Technical Summary

Problems solved by technology

[0007] First, it needs the assistance of a digital baseband chip or an off-chip circuit, and the interface is complicated, which reduces the range of two-way selection;

[0008] Second, the band-pass filter is used, the circuit complexity is high, and the power consumption and chip area are large

[0009] Aiming at the complex interface, high circuit complexity and high power consumption caused by the need to add redundant devices (digital baseband core, or off-chip circuit, pass filter) in related technologies, no effective solution has been proposed yet

Images