Micro-stepping ultra-wideband frequency agile frequency synthesizer with low spur and low phase noise

Abstract

The invention relates to a micro-stepping ultra-wideband frequency agile frequency synthesizer with low spur and low phase noise. As shown in the drawings, the technologies of direct digital frequency synthesis and precise graded frequency synthesis and the real-time computing control of an FPGA (Field Programmable Gate Array) are adopted. A micro-stepping frequency agile control is implemented through the high performance computing of the FPGA and the function of a self-check table without the remote computing control of a radar system so that the computation of a control unit of the radar system and the control data transmission time and the transmission amount of the whole system are simplified and the frequency hopping speed and the real-time response capability of the frequency synthesizer are greatly increased and improved; through the technology of direct digital frequency synthesis, the frequency synthesizer has high frequency resolution so that the function of the frequency synthesizer for generating micro-stepping base band signals is achieved; and through the technology of precise partition frequency synthesis, which is implemented based on a great number of tests and precise computation, a narrow-band base frequency is divided for multiple times for frequency mixing so as to implement full coverage of ultra-wide frequency bands, so that spur and phase noise are effectively restrained from being worsen and the performances of high-speed frequency switching and high-frequency resolution of a DDS (Direct Digital Synthesis) technology for generating base frequencies are effectively retained. In the whole radar system, a universal frequency synthesizer platform capable of greatly shortening the frequency hopping time of the whole radar system and capable of being used as a radar is adopted; the control mode is simple and fast; and the index can fully meet the requirement of various new systems.

Description

technical field [0001] The invention relates to a fine-step ultra-broadband-agile frequency synthesizer with low spurious and low phase noise and related technology. The present invention is based on FPGA plus direct digital frequency synthesis (DDS) technology, realizes the function of arbitrary high-speed operation through FPGA programming, thus can no longer need DSP or CPU and other slow-speed auxiliary chips to perform operation to obtain the control word, and the control unit directly sends the actual The frequency value and power value can simplify the control unit of the radar system, make the control word simple and intuitive to send quickly, and greatly shorten the system frequency hopping time, so as to realize the flexible, real-time calculation and high-speed control of the fine-step ultra-wideband agile frequency synthesizer , realize various complex and flexible working modes of the frequency synthesizer, complete the generation of fine-step and agile frequency ...

AI Technical Summary

Problems solved by technology

The traditional direct synthesis analog frequency synthesizer and narrowband direct digital frequency synthesis technology require the radar system to perform table lookup operations through the DSP chip or CPU chip and send the results (control words and various control codes) to the frequency synthesizer to achieve frequency synthesis The signal generation of the device and the control of various mixing units, this method is slow in operation speed, requires multiple control units, and the control method is complicated, resulting in slow frequency hopping time of the entire radar system

Moreover, due to the limitation of the control unit and the frequency mixing section of the traditional frequency synthesizer, it is generally difficult to span multiple octave ranges from the low frequency 1Hz to the high frequency 10GHz, and at the same time meet the requirements of fast frequency hopping, Low spurious, low phase noise index

Therefore, the traditional direct synthesis analog frequency synthesizer and narrowband direct digital frequency synthesis technology are difficult to meet the needs of the new radar system, and there is an urgent need for a simple control method with fine step ultra-wideband agile frequency and low spurious and low phase noise. New Frequency Synthesizer

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