Frequency continuously adjustable trap circuit based on phase cancellation

Abstract

The invention discloses a continuously adjustable frequency trap circuit based on phase cancellation, which comprises a signal input end and a signal output end. A high-pass phase-shifting network and a resonant circuit connected in parallel with the high-pass phase-shifting network are arranged between the signal input end and the signal output end; when the signal frequency is far away from the resonance point, the signal only passes through the high-pass phase-shifting network, and when the signal frequency is located at the resonance point, the signal passes through the high-pass phase-shifting network and the resonance loop at the same time; the high-pass phase shift network enables the signals to generate phase shift when the signals pass, and the resonance circuit enables the signals to generate phase shift opposite to the phase shift generated when the signals pass through the high-pass phase shift network when the signals pass through. According to the invention, the continuously adjustable frequency trap circuit based on phase cancellation has good frequency selectivity and trap depth not less than 60dB, and is an ideal in-site interference suppression circuit.

Description

technical field [0001] The invention belongs to the field of anti-interference circuits, and in particular relates to a frequency continuously adjustable trap circuit based on phase cancellation. Background technique [0002] At present, shortwave / ultrashortwave has been widely used in the field of communications. Shortwave / ultrashortwave radio stations mainly transmit analog AM signals, including voice signals and short-term data communications. With the development of informatization, the demand for communication is also increasing. Sometimes there are multiple shortwave / ultrashortwave high-power transmitters and receivers working at the same time on large carriers. The amplitude of the channel interference wave from the radio transmitter is higher than The amplitude of the signal is much larger. Moreover, the waveform of the interference wave is complex, and the fundamental frequency of the interference wave is not fixed. Although many optimization measures have been ta...

AI Technical Summary

Problems solved by technology

However, this signal cancellation technology has problems such as high technical difficulty, precise and sensitive control, large equipment size, and high cost, making it difficult to realize

In addition, the interference suppression in the digital domain is suitable for occasions where the interference signal can enter the digital domain without distortion. When the interference signal causes distortion in the RF front end, the digital domain processing will be powerless

[0004] At present, there is a lack of a notch technology based on lumped parameter elements for countering co-site interference of HF / UHF stations

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