Signal polarity detection device and associated method

Abstract

A sign detection device including a first comparing device for comparing a first input signal with a first threshold signal in a first period and a second period to generate a first output signal; a second comparing device for comparing a second input signal with a second threshold signal to generate a second output signal; a converter for optionally changing the polarity of the second output signal to obtain a third output signal; and an operator coupled to the first comparing device and the converter for performing a logic operation of the first output signal and the third output signal to obtain polarity information of the product of the first input signal and the second input signal.

Description

technical field [0001] The invention relates to a signal polarity detection device and method, especially a detection device and method for detecting the multiplicative polarity of two input signals. Background technique [0002] Quadrature Signals (Quadrature Signals) I / Q generation has been widely used in various wireless signal transmissions, and can be implemented with a quadrature down-conversion mixer or a polyphase filter. In non-zero-IF receiver architectures, quadrature signal I / Q is important for post-frequency conversion image signal cancellation; in zero-IF receiver architectures, quadrature signal I / Q can be used in noncoherent demodulation (noncoherent demodulation). like figure 1 As shown in the block diagram of the wireless signal receiving end, after the radio frequency wireless signal RF is received by the antenna 10, it is multiplied by the sinusoidal signal Sinωt and the Cosωt signal respectively, and then demodulated to generate the in-phase (In-phase)...

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Problems solved by technology

[0007] However, the image signal rejection ratio (IRR) of 30dB to 35dB can no longer meet the application of today's wireless radio frequency signal receivers (radio receiver). For example, the image signal rejection ratio (IRR) requirements of terrestrial TV receivers have been reduced. Up to 60dB

And from figure 2 It can be seen that in order to achieve an image signal rejection ratio (IRR) of 60dB, ΔA / A and θ need to be kept under a gain mismatch of 0.01dB and a phase mismatch of 0.1 degrees, respectively, and without any correction circuit case, the above conditions are difficult to achieve in the field of analog signals

[0008] Therefore, some correction techniques such as the following [1] to [6] reference data have been developed to compensate the imbalance between the analog signal I and the signal Q, but the offset of the components themselves will affect the result of the correction, so it is necessary to develop A Solution for Accurately Detecting Gain Imbalance and Phase Imbalance with Improved Rejection Ratio

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