CN216490451U

CN216490451U - Ka wave band frequency synthesizer based on multi-ring phase locking

Info

Publication number: CN216490451U
Application number: CN202120828343.2U
Authority: CN
Inventors: 孙科; 张兴友; 张冰; 杨秀强; 张意; 廖志雄; 冯术成; 韩娜
Original assignee: Chengdu Seekcon Microwave Communication Co ltd
Current assignee: Chengdu Seekcon Microwave Communication Co ltd
Priority date: 2021-04-21
Filing date: 2021-04-21
Publication date: 2022-05-10
Anticipated expiration: 2031-04-21

Abstract

The utility model discloses a Ka-band frequency synthesizer based on multi-loop phase locking, which comprises a first phase-locked loop, a second phase-locked loop, a frequency mixing module, a filtering module, a frequency dividing module, a third phase-locked loop and a frequency doubling module, wherein the first phase-locked loop is connected with the second phase-locked loop; the input end of the first phase-locked loop and the input end of the second phase-locked loop are both connected with the input end of a Ka-band frequency synthesizer, the output end of the first phase-locked loop and the output end of the second phase-locked loop are both connected with the input end of the frequency mixing module, the output end of the frequency mixing module is connected with the input end of the frequency doubling module through the filtering module, the frequency dividing module and the third phase-locked loop, and the output end of the frequency doubling module is the output end of the Ka-band frequency synthesizer. The utility model has the advantages of miniaturization, fine stepping, small stray, wide output frequency band and the like, and has good stability in the working frequency band, wide working temperature range and wide application prospect.

Description

Ka wave band frequency synthesizer based on multi-ring phase locking

Technical Field

The utility model belongs to the technical field of radars and electronic countermeasure electronic devices, and particularly relates to a Ka-band frequency synthesizer based on multi-ring phase locking.

Background

The frequency synthesizer is the heart of a modern electronic system, and the technical indexes of the frequency synthesizer directly determine the overall performance indexes of the electronic systems such as radars, electronic countermeasures, communication, instruments and meters and the like.

The frequency synthesis technology is an advanced circuit technology with high difficulty, has a very wide application range, and comprises a communication system, a navigation system, a radar, a space electronic technology, instruments, meters and the like which all need to apply a frequency source technology, and the performance index of the frequency source directly influences the performance index of the whole machine. The synthesis mode of the microwave frequency source can be divided into two main types of direct synthesis and indirect synthesis. The indirect synthesis, i.e. the phase-locked frequency synthesizer, has a high working frequency, a wide working frequency band and a good spectral purity, but the locking time is long, and in addition, the spectral resolution of the indirect frequency synthesis source is low. The direct frequency synthesis has extremely high frequency resolution and extremely short frequency conversion time, but the working frequency band is limited, the direct output frequency of the current DDS (direct digital frequency synthesizer) is below 1GHz, if the DDS needs to work in a higher frequency band, frequency multiplication and other modes are adopted, a large number of filters are used, and the volume and the complexity of the system are increased.

With the development requirements of ultra-wideband radar and electronic countermeasure systems, a high-frequency wideband frequency synthesizer has become one of the important fields and directions for the development of frequency synthesis technology, and with the requirements of electronic system miniaturization and higher performance, higher requirements are also provided for the design of frequency synthesizer miniaturization, frequency agility, fine stepping, low stray and low phase noise. The various criteria of the frequency synthesizer often conflict and are not compatible. In order to realize fine stepping, the stray indexes are correspondingly deteriorated; in order to realize the optimization of each index, the requirement of miniaturization is worsened; in the field of traditional broadband fine stepping technology, when the spurious index requirement is high, the traditional PLL (phase-locked loop) is difficult to realize, the DDS is introduced into the phase-locked loop in an industrial general method, the traditional method comprises the steps of exciting the PLL by the DDS, interpolating the DDS by the PLL, mixing in the PLL + DDS loop and the like, but the introduction of the DDS can greatly increase the complexity of the scheme and cannot meet the requirement of miniaturization, and the spurious of the DDS is deteriorated along with the frequency dividing ratio N of the PLL being 20 log N and special treatment needs to be carried out on the spurious of the DDS. In order to realize the same index and meet the miniaturization requirement, the method in the industry is based on double-loop phase-locked to generate fine stepping, and when the method is used for fine stepping, a main loop still needs to adopt a fractional frequency division mode, and the problem of spurious emission cannot be effectively solved.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects in the prior art, the utility model provides a Ka-band frequency synthesizer based on multi-ring phase locking, and the frequency synthesizer component has the advantages of miniaturization, fine stepping, small stray, wide output frequency band and the like, and has good stability in a working frequency band, wide working temperature range and wide application prospect.

In order to achieve the purpose of the utility model, the utility model adopts the technical scheme that: a Ka-band frequency synthesizer based on multi-loop phase locking comprises a first phase-locked loop, a second phase-locked loop, a frequency mixing module, a filtering module, a frequency dividing module, a third phase-locked loop and a frequency doubling module;

the input end of the first phase-locked loop and the input end of the second phase-locked loop are both connected with the input end of a Ka-band frequency synthesizer, the output end of the first phase-locked loop and the output end of the second phase-locked loop are both connected with the input end of the frequency mixing module, the output end of the frequency mixing module is connected with the input end of the frequency doubling module through the filtering module, the frequency dividing module and the third phase-locked loop, and the output end of the frequency doubling module is the output end of the Ka-band frequency synthesizer.

Furthermore, the first phase-locked loop, the second phase-locked loop, the frequency mixing module, the filtering module, the frequency dividing module, the third phase-locked loop and the frequency doubling module are all produced and assembled by adopting a micro-assembly process.

Further, the first phase-locked loop, the second phase-locked loop, the frequency mixing module, the filtering module, the frequency dividing module, the third phase-locked loop and the frequency doubling module are standardized modules with input and output impedances of 50 ohms.

The utility model has the beneficial effects that:

(1) the utility model adopts the frequency synthesis mode of multi-loop phase-locked, the frequency division is carried out after the signals of the first phase-locked loop 1 and the second phase-locked loop 2 are mixed to be used as the reference frequency of the third phase-locked loop 6, the fine stepping is realized through the operations of frequency division, frequency mixing and frequency division of the former two-stage phase-locked loops, the signal replaces the fixed reference signal of the traditional phase-locked loop, can realize fine stepping at the reference signal, compared with the traditional phase-locked loop, can realize fine stepping output of the phase-locked loop by utilizing various fine stepping changes of the reference frequency, meanwhile, the phase noise index of the output signal is ensured by using higher phase discrimination frequency, the low stray index of the phase-locked loop is realized by various changes of the reference signal, meanwhile, the band-pass characteristic of the PLL loop can well inhibit partial spurious in the output frequency spectrum of the variable reference signal, so that the frequency synthesizer component has the characteristics of fine stepping and low spurious.

(2) The utility model adopts a method of combining multiple frequency division and frequency mixing to realize small stepping, can realize finer stepping compared with the traditional single frequency division, and can not introduce decimal frequency division stray under the condition that the phase-locked loop adopts an integer module, so that the signal provided for the final phase-locked loop is a high-quality and fine stepping signal.

(3) All parts and circuits of the utility model are produced and assembled by adopting an advanced micro-assembly process, thereby greatly reducing the circuit size, having the characteristics of small volume, stable performance, high index consistency and the like, simultaneously having good input and output matching, being suitable for batch production, greatly reducing the production cost, and being suitable for various microwave systems such as radar, electronic countermeasure, satellite communication and the like.

Drawings

Fig. 1 is a schematic diagram of a Ka-band frequency synthesizer based on multi-loop phase locking according to the present invention.

Wherein: the frequency-division-based phase-locked loop comprises a 1-first phase-locked loop, a 2-second phase-locked loop, a 3-frequency mixing module, a 4-filtering module, a 5-frequency division module, a 6-third phase-locked loop and a 7-frequency multiplication module.

Detailed Description

The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the utility model as defined and defined in the appended claims, and all matters produced by the utility model using the inventive concept are protected.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, a Ka-band frequency synthesizer based on multi-loop phase locking includes a first phase-locked loop 1, a second phase-locked loop 2, a frequency mixing module 3, a filtering module 4, a frequency dividing module 5, a third phase-locked loop 6, and a frequency doubling module 7;

the input of first phase-locked loop 1 and the input of second phase-locked loop 2 all are connected with Ka wave band frequency synthesizer's input, the output of first phase-locked loop 1 and the output of second phase-locked loop 2 all are connected with frequency mixing module 3's input, frequency mixing module 3's output passes through filtering module 4, frequency division module 5 and third phase-locked loop 6 and is connected with frequency doubling module 7's input, frequency doubling module 7's output is Ka wave band frequency synthesizer's output.

The first phase-locked loop 1, the second phase-locked loop 2, the frequency mixing module 3, the filtering module 4, the frequency dividing module 5, the third phase-locked loop 6 and the frequency doubling module 7 are all produced and assembled by adopting a micro-assembly process.

The first phase-locked loop 1, the second phase-locked loop 2, the frequency mixing module 3, the filtering module 4, the frequency dividing module 5, the third phase-locked loop 6 and the frequency doubling module 7 are standardized modules with input and output impedances of 50 ohms.

The first phase-locked loop 1 is a high-performance frequency-mixing local oscillator and has the characteristics of ultra-low phase noise and high phase discrimination frequency; the second phase-locked loop 2 is a low-frequency and fine-step phase-locked loop, is used for generating intermediate-frequency signals required by frequency mixing, and has the characteristics of fine stepping and low stray; the third phase-locked loop 6 is a high-frequency phase-locked loop, is formed by a digital phase-locked loop controlled by a parallel port, has the characteristics of low phase noise and high frequency, and is used for generating a Ku wave band phase-locked signal; the high-performance mixer of the frequency mixing module is used for mixing the signals of the first phase-locked loop 1 and the second phase-locked loop 2 and providing the signals to the filtering module; the filtering module is a high-performance band-pass filter and is used for mixing the frequency of the output signal of the frequency mixing module and filtering out intermodulation stray of the frequency mixer; the frequency division module is a high-performance frequency divider and is used for dividing the frequency of the output signal of the filtering module and providing the frequency to the third phase-locked loop 6 as a reference; the frequency doubling module is a Ka-band frequency doubling chip and is used for doubling the frequency of the Ku-band signal generated by the third phase-locked loop 6 and generating the Ka-band signal.

The first phase-locked loop 1 is used for generating an S-waveband point frequency signal and has the characteristics of ultra-low phase noise, high stability and high frequency accuracy, and a frequency code of the first phase-locked loop 1 is generated by an internal single chip microcomputer; the second phase-locked loop 2 is used for generating narrow-band fine stepping signals of a low frequency band, and the frequency switching of the second phase-locked loop 2 is realized through an external SPI control code; the third phase-locked loop 6 is formed by a digital phase-locked loop controlled by a parallel port, and has the characteristics of low phase noise and high frequency.

The working principle of the utility model is as follows: the first phase-locked loop 1 generates an ultra-low phase noise local oscillator signal of a fixed frequency point, the second phase-locked loop 2 generates a low-frequency band fine step signal in an integer mode, the first phase-locked loop and the second phase-locked loop carry out frequency mixing through the frequency mixing module 3 and then carry out band-pass filtering through the filter module 4 to filter out intermodulation stray, the frequency-divided signal is divided by the frequency dividing module 5 and then enters the third phase-locked loop 6 to serve as a variable reference of the third phase-locked loop 6, and the third phase-locked loop 6 generates a Ku wave band signal and then generates a Ka wave band fine step and low stray signal through the frequency doubling module 7.

Claims

1. A Ka-band frequency synthesizer based on multi-ring phase locking is characterized by comprising a first phase-locked loop (1), a second phase-locked loop (2), a frequency mixing module (3), a filtering module (4), a frequency dividing module (5), a third phase-locked loop (6) and a frequency doubling module (7);

the input of first phase-locked loop (1) and the input of second phase-locked loop (2) all are connected with Ka wave band frequency synthesizer's input, the output of first phase-locked loop (1) and the output of second phase-locked loop (2) all are connected with the input of mixing module (3), the output of mixing module (3) passes through filtering module (4), frequency division module (5) and third phase-locked loop (6) and is connected with the input of doubling of frequency module (7), the output of doubling of frequency module (7) is Ka wave band frequency synthesizer's output.

2. The Ka-band frequency synthesizer based on multi-loop phase locking is characterized in that the first phase-locked loop (1), the second phase-locked loop (2), the frequency mixing module (3), the filtering module (4), the frequency dividing module (5), the third phase-locked loop (6) and the frequency doubling module (7) are all produced and assembled by adopting a micro-assembly process.

3. The Ka-band frequency synthesizer based on multi-loop phase locking according to claim 1, wherein the first phase-locked loop (1), the second phase-locked loop (2), the frequency mixing module (3), the filtering module (4), the frequency dividing module (5), the third phase-locked loop (6) and the frequency multiplying module (7) are standardized modules with input and output impedances of 50 ohms.