CN210839562U

CN210839562U - Broadband rapid frequency hopping frequency source

Info

Publication number: CN210839562U
Application number: CN201922083610.3U
Authority: CN
Inventors: 罗武; 田殷; 孙敏; 宋烨曦; 朱中浩; 黄春燕
Original assignee: Sichuan Jiuzhou Electric Group Co Ltd
Current assignee: Sichuan Jiuzhou Electric Group Co Ltd
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-06-23
Anticipated expiration: 2029-11-27

Abstract

The utility model discloses a broadband rapid frequency hopping frequency source, which comprises a DDS circuit and a frequency conversion local oscillator circuit, wherein the frequency conversion local oscillator circuit comprises a clock circuit, a comb spectrum generator and a first amplification filter circuit which are electrically connected in sequence; harmonic signals generated by the comb spectrum generator are processed by the first amplification filter circuit and then are mixed with output signals of the DDS circuit to obtain required broadband signals. The utility model discloses improve on the basis of traditional broadband quick frequency hopping circuit, change former fixed mixing local oscillator into changeable mixing local oscillator, solve the not wide problem of traditional circuit bandwidth.

Description

Broadband rapid frequency hopping frequency source

Technical Field

The utility model relates to the field of communication technology, concretely relates to quick frequency hopping frequency source of broadband.

Background

The broadband rapid frequency hopping frequency source has wide application prospect in the fields of radar and communication. In radar applications, a broadband fast frequency hopping frequency source may provide a radar system with high range resolution. In communication applications, the broadband fast frequency hopping frequency source can provide strong anti-interference capability for a communication system. Therefore, it is a hot topic to research a broadband fast frequency hopping frequency source.

The conventional implementation of a wideband fast frequency hopping frequency source is generally implemented as shown in fig. 1. A Direct Digital Synthesizer (DDS) is used for generating a broadband frequency agile signal, and then the broadband frequency agile signal is mixed with a fixed local oscillator to realize a broadband fast frequency hopping frequency source. The disadvantages of this implementation are: the frequency bandwidth is not wide. Based on the Nyquist theorem, the frequency of the DDS output is generally less than 40% of the reference clock, the current DDS reference clock does not exceed 4GHz at most, and the bandwidth of the DDS output signal is less than or equal to 1.6 GHz.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: the frequency bandwidth that traditional broadband quick frequency hopping circuit obtained is narrower, the utility model provides a solve a broadband quick frequency hopping frequency source of above-mentioned problem, improve on traditional broadband quick frequency hopping circuit's basis, change former fixed mixing local oscillator into changeable mixing local oscillator, solve the not wide problem of traditional circuit bandwidth.

The utility model discloses a following technical scheme realizes:

a broadband rapid frequency hopping frequency source comprises a DDS circuit and a frequency conversion local oscillator circuit, wherein the frequency conversion local oscillator circuit comprises a clock circuit, a comb spectrum generator and a first amplification filter circuit which are electrically connected in sequence; harmonic signals generated by the comb spectrum generator are processed by the first amplification filter circuit and then are mixed with output signals of the DDS circuit to obtain required broadband signals.

And the required broadband signal is filtered by the first band-pass filter and amplified by the amplifier in sequence, and then a broadband fast frequency modulation signal is output.

Furthermore, the first band-pass filter adopts multi-stage switch filtering, so that the frequency bandwidth is greatly widened.

Furthermore, the output end of the DDS circuit is also connected with a second band-pass filter, and the output signal of the DDS circuit is filtered by the second band-pass filter and then mixed with the harmonic signal processed by the first amplifying and filtering circuit.

Furthermore, the harmonic signal obtained after the harmonic signal generated by the comb spectrum generator is processed by the first amplification filter circuit is also used for providing a reference clock for the DDS circuit.

Furthermore, a second amplification filter is further arranged at the reference clock input end of the DDS circuit.

The utility model discloses have following advantage and beneficial effect:

the utility model discloses a mode of pectination register for easy reference + switch filtering realizes that pectination register for easy reference generator is a pulse generation circuit and is the core, produces signal generator many times, high-efficient harmonic. By utilizing the characteristic of comb spectrum, multiple harmonics (2, 3 and 4) of fundamental frequency are obtained simultaneously at low cost, and required harmonic signals are obtained in a switch filtering mode. The advantages of the switch filtering are: the method can obtain clean useful signals, and can also utilize the characteristic of fast switching of the switch without influencing the jump time of the system frequency. And after the required harmonic signal is obtained, mixing the harmonic signal with the DDS frequency agile output signal to obtain the required broadband signal.

The utility model provides a broadband fast frequency hopping frequency source realizes variable mixing local oscillator, the broadband of the existing system signal is output, and the frequency bandwidth can reach 4 times of that of the traditional circuit; compared with the traditional scheme, the method saves one DDS reference clock source circuit by using the harmonic signal generated by the comb spectrum as the reference clock of the DDS circuit.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a conventional wideband fast frequency hopping circuit;

FIG. 2 is a broadband fast frequency hopping circuit of the present invention;

fig. 3 is the utility model discloses a frequency conversion local oscillator circuit.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following examples and drawings, and the exemplary embodiments and descriptions thereof of the present invention are only used for explaining the present invention, and are not intended as limitations of the present invention.

Example 1

The embodiment provides a broadband fast frequency hopping frequency source, as shown in fig. 2, which includes a DDS circuit and a frequency conversion local oscillator circuit, where the frequency conversion local oscillator circuit includes a clock circuit, a comb spectrum generator, and a first amplification filter circuit, which are electrically connected in sequence; firstly, harmonic signals generated by a comb spectrum generator are processed by a first amplification filter circuit to obtain required harmonic signals, and output signals of a DDS circuit are processed by a second band-pass filter and then mixed with the required harmonic signals to obtain required broadband signals; finally, the required broadband signal is filtered by a first band-pass filter and amplified by an amplifier in sequence, and then a broadband fast frequency modulation signal is output; the first band-pass filter adopts multi-stage switch filtering, and the frequency bandwidth is greatly widened.

In addition, the harmonic signal obtained after the harmonic signal generated by the comb spectrum generator is processed by the first amplification filter circuit is also used for providing a reference clock for the DDS circuit after being processed by the second amplification filter circuit.

Example 2

Based on the broadband fast frequency hopping frequency source provided by the embodiment 1, taking the DDS output signal frequency of 700MHz to 1200MHz as an example, the mixing local oscillator of the traditional circuit is fixed, and the output bandwidth of the whole circuit is 500 MHz. The improved circuit takes the comb spectrum of 500MHz as an example to obtain 4GHz, 4.5GHz, 5GHz and 5.5 GHz. After frequency mixing, the output frequency of the system is 4.7 GHz-6.7 GHz, and the frequency bandwidth is 2GHz, which is 4 times of the bandwidth of the traditional scheme. As shown in fig. 3, the obtained 4GHz amplified and filtered clock provides a reference clock for the DDS circuit, which saves one DDS reference clock source circuit compared with the conventional scheme.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above description is only the embodiments of the present invention, and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A broadband rapid frequency hopping frequency source is characterized by comprising a DDS circuit and a frequency conversion local oscillator circuit, wherein the frequency conversion local oscillator circuit comprises a clock circuit, a comb spectrum generator and a first amplification filter circuit which are electrically connected in sequence; harmonic signals generated by the comb spectrum generator are processed by the first amplification filter circuit and then are mixed with output signals of the DDS circuit to obtain required broadband signals.

2. The wideband fast frequency hopping source according to claim 1, further comprising a first band pass filter and an amplifier, wherein said desired wideband signal is filtered by the first band pass filter and amplified by the amplifier in sequence to output a wideband fast frequency modulated signal.

3. A wideband fast frequency hopping frequency source according to claim 2, wherein said first band pass filter employs multi-stage switching filtering.

4. The broadband fast frequency hopping frequency source according to claim 1, wherein a second band pass filter is further connected to the output end of the DDS circuit, and the output signal of the DDS circuit is filtered by the second band pass filter and then mixed with the harmonic signal processed by the first amplifying and filtering circuit.

5. The wideband fast frequency hopping frequency source according to any one of claims 1 to 4, wherein the harmonic signal obtained after the harmonic signal generated by the comb spectrum generator is processed by the first amplifying and filtering circuit is further used to provide a reference clock for the DDS circuit.

6. The wideband fast frequency hopping source according to claim 5, wherein a second amplification filter is further provided at the reference clock input of the DDS circuit.