Local oscillator signal leakage suppression method

Abstract

The invention discloses a local oscillator signal leakage suppression method which comprises the following steps: a direct-current voltage input step: an input radio-frequency signal is output as a group of radio-frequency orthogonal signals through a broadband 3dB bridge, a pair of adjustable direct-current voltage is connected with an output port of the broadband 3dB bridge through a choke inductor, and the two are superposed to obtain a group of superposed orthogonal radio-frequency signals; a frequency mixing step: a local oscillator signal source generates a local oscillator signal, the local oscillator signal is output as a group of local oscillator orthogonal signals through a local oscillator 3dB bridge, the superposed orthogonal radio frequency signal and the local oscillator orthogonal signals are input into a frequency mixing unit, and the frequency mixing unit outputs an intermediate frequency signal and a local oscillator leakage signal; and a direct-current voltage adjustment step: obtaining an adjustment parameter according to the local oscillator leakage signal, adjusting the direct-current voltage according to the adjustment parameter to obtain a new direct-current voltage, and sequentially repeating the steps until the suppression value of the local oscillator leakage signal reaches a preset suppression reference value. According to the method, the local oscillation signal can be effectively filtered out and is irrelevant to the frequency of the local oscillation signal.

Description

technical field [0001] The invention relates to the technical field of microwave radio frequency communication, in particular to a method for suppressing local oscillator signal leakage. Background technique [0002] With the development of technology in the field of wireless communication, the wireless signal transmitted on the air interface carries higher and higher data information capacity, and the radio frequency has also increased from tens of MHz to tens of GHz, or even THz. These changes have great impact on the RF front-end The design also made new demands. In the signal receiving system, the higher carrier frequency needs to be frequency-converted to the baseband signal for processing. Similarly, at the transmitter end, the baseband signal also needs to be up-converted to the carrier signal in the microwave and millimeter wave bands. In the process of frequency conversion, in addition to meeting the wider operating bandwidth, spurious suppression efficiency, and n...

AI Technical Summary

Problems solved by technology

However, due to factors such as device technology level, filter design difficulty, and cost, the filter cannot achieve the desired effect.

For example, when the local oscillator signal is very close to the output carrier signal frequency or when the local oscillator is a variable frequency signal, the local oscillator leakage signal cannot be effectively filtered

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