Up-conversion mixer

Abstract

The present invention discloses a up-conversion mixer, including mixer baseband amplifying circuit, high frequency switch module, comparator and compensation current circuit. The baseband amplifying circuit connects with the high frequency switch module, the feedback end of the compensation current circuit connects with the baseband amplifying circuit, the baseband amplifying circuit is arranged with baseband signal input end, the high frequency switch module is arranged with radio carrier frequency signal input end, the positive phase output end and the reverse phase output end of the baseband amplifying circuit connect with the high frequency switch module as well as a pre-amplifying circuit, which output end connects to the input end of the comparator, the output end of the comparator connects to the compensation current circuit after a positive and negative complementary corrective digital control circuit. The correction of the present invention divides into positive complementary process and negative complementary process, the final compensative current is the average of the two corrective results, thus to avoid the mismatch error brought by the corrective circuit, so as to improve local oscillator rejection ratio of the mixer.

Description

technical field [0001] The invention relates to an analog circuit, in particular to an up-conversion mixer. Background technique [0002] In modern wireless communication transceiver integrated circuits, the up-conversion mixer is an important module circuit to realize the wireless transmission of baseband signals. The main function of the up-conversion mixer, as the name implies, is to change the carrier frequency of the baseband data signal to a higher frequency that can be transmitted wirelessly, while the data signal is still intact; therefore, the circuit requires at least the input terminal of the baseband signal and The local oscillator is the input end of the wireless carrier frequency signal, and the two signals are actually multiplied mathematically. It can be seen that the equivalent DC mismatch error at the input end of the up-conversion mixer will introduce unnecessary local oscillator leakage at the output end, which will deteriorate the signal-to-noise ratio ...

AI Technical Summary

Problems solved by technology

[0007] However, this structure requires the gain of the amplifier circuit to be very large, and the comparator itself does not introduce mismatch, otherwise the accuracy of the compensation will be affected

Moreover, if the comparator directly compares the signal that has been up-converted by the mixer, the design and implementation of the comparator for high-frequency signals is very complicated and difficult.

In addition, the gain of the mixer itself must consider the linearity of the signal, so the gain cannot be infinitely large; the comparator itself must also have a mismatch error

Therefore, using the existing method, the dynamic range of the signal output power is still limited by the non-ideal mismatch voltage error of the circuit, and the leakage of the local oscillator is relatively large

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