A Broadband Low Noise FM Signal Source

Abstract

The invention discloses a broadband low-noise frequency modulation signal source. A high-stability clock module has two clock signals as output, the first clock signal as output is directly connected with the reference clock end of a DDS module, and the second clock signal is connected with the input end of a power divider; the power divider divides the second clock signal into haves and respectively outputs the two haves through two output ends, wherein one half is output to a DDS configuration module; the DDS configuration module outputs a configuration signal to the DDS module, the DDS module, after receiving the configuration signal, generates a frequency modulation signal by use of a phase synthesis and table look-up method and outputs the frequency modulation signal through a waveform output end; the waveform output end is respectively connected with a first phase-locked loop circuit and a second phase-locked loop circuit through a low-noise amplifier; output of the first phase-locked loop circuit is taken as an emission local oscillator; and output of the second phase-locked loop circuit is taken as a receiving local oscillator. The signal source provided by the invention can meet the demands for high linearity and low phase noise of a broadband frequency modulation signal source.

Description

technical field [0001] The invention belongs to the technical field of radar systems and relates to an advanced technology specially used for generating high-performance broadband frequency modulation signal sources. Background technique [0002] Broadband low-noise FM signal sources are mainly used in communication, radar and other systems, and have broad application prospects. In the field of radar, a broadband low-noise FM signal source can provide radar with high range resolution, thereby enhancing the radar's target recognition capability. With the continuous development of radar and communication technology, higher and higher requirements are put forward for various indicators such as frequency modulation linearity and phase noise of the signal source. [0003] The technical research based on broadband signal generation has become a major research focus. At present, the domestic and foreign implementation methods are mainly based on the direct digital synthesis (DDS) ...

AI Technical Summary

Problems solved by technology

However, the signal obtained by this method needs to be multiplied and mixed multiple times before it can be used in the microwave and millimeter wave bands, which increases the complexity of the circuit and has a certain impact on the signal quality. Therefore, this method can only be used in the middle Only in the frequency band can better phase noise and spurious indicators be obtained

The advantage of phase-locked frequency synthesis technology is that it has a wide frequency band, low noise and high operating frequency, but its biggest disadvantages are long frequency conversion time and low frequency resolution.

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