Self-calibrating device and method for reducing local oscillation leakage of broadband frequency mixer

Abstract

The invention discloses a self-calibrating device and method for reducing local oscillation leakage of a broadband frequency mixer. The device comprises an RF switch (1), the broadband frequency mixer (2), a broadband combiner (3), a broadband coupler (4), a broadband detector (5), a controller (6), a broadband phase shifter (7), an analog attenuator (8) and a broadband local-oscillation coupler (9). According to the invention, a feedforward technology is used, from the aspect of local oscillation, local oscillation signals same in the amplitude and opposite in phases are introduced intentionally in the output end of the frequency mixer, and local oscillation leakage is reduced; the device and method are suitable for any frequency conversion systems including frequency conversion related reception and emission systems, and application is wide; and the device and method also have the advantages including wide working frequency, high local oscillation inhibition performance, automatic calibration, small debugging amount of high productibility. On the original basis, local oscillation inhibition can be improved by more than 30dB, and the isolation performance of the broadband frequency mixer is improved.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a self-calibration device and method for improving the leakage of a local oscillator of a broadband mixer. Background technique [0002] Broadband monitoring receivers / transmitters often use multiple frequency conversion schemes. The spurs caused by multiple frequency conversions due to local oscillator leakage are usually easy to fall into the IF filter band and are difficult to filter out. An important indicator of the transmitter, the quality of this performance will directly determine whether the receiver can correctly capture useful signals. In the traditional solution, after frequency conversion, the intermediate frequency filter is mainly used to filter out clutter signals such as local oscillator leakage. However, the wideband mixer used in the wideband receiver / transmitter has very wide RF frequency and IF frequency bandwidth. The traditional IF filter For exampl...

AI Technical Summary

Problems solved by technology

However, this invention patent is only applicable to the field of transmission, and does not involve broadband, and the invention patent starts from the baseband, and improves the local oscillator leakage of the transmission system by adjusting the baseband IQ signal matching. It is only applicable to IQ mixers, with narrow frequency bands and narrow applications.

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