CN213637722U

CN213637722U - Wide-band fast frequency synthesizer

Info

Publication number: CN213637722U
Application number: CN202023198216.3U
Authority: CN
Inventors: 陈德平; 曲燕霞
Original assignee: Nanjing Ruide Communication Technology Co ltd
Current assignee: Nanjing Ruide Communication Technology Co ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-07-06
Anticipated expiration: 2030-12-25

Abstract

The utility model discloses a broadband rapid frequency synthesis device, which comprises a signal generator, an S wave band point frequency source, an X wave band point frequency source, a radio frequency switch, a first frequency mixer, a second frequency mixer, a first single-pole multi-throw switch, a filter bank and a second single-pole multi-throw switch; the signal generator, the S-band point frequency source and the signal input end of the first frequency mixer are connected, a radio-frequency signal after frequency mixing is output by the first frequency mixer, the X-band point frequency source and the radio-frequency switch are connected and then select a specific frequency point signal output by the radio-frequency switch, the signal output ends of the first frequency mixer and the radio-frequency switch are connected with the signal input end of the second frequency mixer, the signal input end of the second frequency mixer is connected with the filter bank through the first single-pole multi-throw switch, and the filter bank is connected with the second single-pole multi-throw switch to output the filtered signal. The utility model discloses a broadband output, quick frequency hopping and simple structure, the debugging degree of difficulty are low.

Description

Wide-band fast frequency synthesizer

Technical Field

The utility model belongs to the technical field of wireless communication, the quick frequency of concretely relates to wide band synthesizes device.

Background

The frequency synthesizer is an important component of a modern electronic system, and is widely applied to various fields such as communication, radar, electronic countermeasure, remote control and remote measurement, instruments and meters and the like, particularly the field of satellite navigation communication. In wireless electronic communication systems, a frequency synthesizer is a core component of a radio frequency transceiver system. The technical progress targets of frequency synthesizer frequency synthesis are that the frequency hopping speed is fast, the frequency interval is small, and the phase noise is low. The existing synthesis method has the advantage of high speed, but has the defects of large stray and complex control.

Disclosure of Invention

The purpose of the invention is as follows: the utility model aims to provide a broadband fast frequency synthesis device to the not enough of prior art, realized that broadband output, quick frequency hopping and simple structure, the debugging degree of difficulty are low.

The technical scheme is as follows: the utility model discloses a broadband fast frequency synthesis device, which comprises a signal generator, an S wave band point frequency source, an X wave band point frequency source, a radio frequency switch, a first frequency mixer, a second frequency mixer, a first single-pole multi-throw switch, a filter bank and a second single-pole multi-throw switch; the signal generator, the S-band point frequency source and the signal input end of the first frequency mixer are connected, a radio-frequency signal after frequency mixing is output by the first frequency mixer, the X-band point frequency source and the radio-frequency switch are connected and then select a specific frequency point signal output by the radio-frequency switch, the signal output ends of the first frequency mixer and the radio-frequency switch are connected with the signal input end of the second frequency mixer, the signal input end of the second frequency mixer is connected with the filter bank through the first single-pole multi-throw switch, and the filter bank is connected with the second single-pole multi-throw switch to output the filtered signal.

Further perfecting the technical scheme, the signal generator outputs a signal of stepping 25M.

Further, the X-band dot frequency source is a phase-locked loop that generates 4X-band dot frequencies.

Further, the second mixer outputs radio frequency signals covering a 2-18G frequency band.

Further, the filter bank is a cavity filter. The cavity filter has good inhibiting effect on out-of-band stray.

Furthermore, the first single-pole multi-throw switch and the second single-pole multi-throw switch are both single-pole eight-throw switches.

Further, the signal generator is connected with a CPLD. The signal generator is controlled by the CPLD, and the requirement that the frequency hopping speed is less than 100ns is met.

Has the advantages that: compared with the prior art, the utility model has the advantages of: the utility model adopts the scheme that the radio frequency switch switches the local oscillation frequency and the signal generator DDS rapidly hops frequency, the frequency hopping speed of the output end is jointly determined by the radio frequency switch speed and the frequency hopping speed of the signal generator DDS, and the speed of the radio frequency switch can reach ns level and is far higher than the frequency hopping speed of the DDS; the signal generator DDS is controlled by the CPLD, and the requirement that the frequency hopping speed is less than 100ns is met. Through circuit design and debugging, test results show that the frequency synthesizer outputs 2-18G of frequency, steps 1M, has a frequency hopping speed of less than 100ns, has a stray of more than or equal to 70dBc, has a phase noise of-83 dBc/Hz @100Hz, -98dBc/Hz @1kHz, -112dBc/Hz @10kHz when the frequency synthesizer is at 13.4G, realizes rapid frequency hopping and broadband output, has a simple structure, is low in debugging difficulty, and is beneficial to design and production.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention;

fig. 2 is a schematic structural diagram of the present invention.

Detailed Description

The technical solution of the present invention is described in detail below with reference to the accompanying drawings, but the scope of the present invention is not limited to the embodiments.

As shown in fig. 1, the utility model provides a wide band fast frequency synthesizer divides 3 parts altogether: the first part is that after a stepping 25M signal output by a signal generator DDS and an S-waveband dot frequency pass through a first mixer, a radio frequency signal with lower output frequency and rapid frequency hopping is generated; in the second part, 4X-waveband point frequencies are generated by a phase-locked loop, and a radio frequency switch selects which frequency point is output; the third part is to combine the first two parts, the radio frequency signal generated after the mixing of the second mixer covers the 2-18G frequency band and is output by selective filtering through the filter bank. The whole output frequency is divided into 8 channels, the channels are switched by a first single-pole eight-throw switch SP8T-1 and a second single-pole eight-throw switch SP8T-2, and a filter group in each channel selects a cavity filter and has a good inhibiting effect on out-of-band stray.

The frequency hopping speed of the output end of the utility model is determined by the frequency hopping speed of the radio frequency switch and the frequency hopping speed of the signal generator DDS together, the speed of the radio frequency switch can reach ns level and is far higher than the frequency hopping speed of the signal generator DDS; the signal generator DDS is controlled by the CPLD, and the requirement that the frequency hopping speed is less than 100ns is met.

Fig. 2 is an outline diagram of a wideband fast frequency synthesizer module box, in which the output stray of the signal generator DDS is large and the point of the large stray should be avoided on the output frequency. The circuit board is installed on the box body by adopting screws or is brazed, so that the operation is simple and the implementation is easy.

As mentioned above, although the present invention has been shown and described with reference to certain preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. Broadband fast frequency synthesis device, its characterized in that: the system comprises a signal generator, an S-band point frequency source, an X-band point frequency source, a radio frequency switch, a first mixer, a second mixer, a first single-pole multi-throw switch, a filter bank and a second single-pole multi-throw switch; the signal generator, the S-band point frequency source and the signal input end of the first frequency mixer are connected, a radio-frequency signal after frequency mixing is output by the first frequency mixer, the X-band point frequency source and the radio-frequency switch are connected and then select a specific frequency point signal output by the radio-frequency switch, the signal output ends of the first frequency mixer and the radio-frequency switch are connected with the signal input end of the second frequency mixer, the signal input end of the second frequency mixer is connected with the filter bank through the first single-pole multi-throw switch, and the filter bank is connected with the second single-pole multi-throw switch to output the filtered signal.

2. The wideband fast frequency synthesizer of claim 1 further comprising: the signal generator outputs a signal that steps by 25M.

3. The wideband fast frequency synthesizer of claim 2 further comprising: the X wave band point frequency source is a phase-locked loop which generates 4X wave band point frequencies.

4. The wideband fast frequency synthesizer of claim 3 further comprising: the second mixer outputs a radio frequency signal covering a 2-18G frequency band.

5. The wideband fast frequency synthesizer of claim 4 further comprising: the filter bank is a cavity filter.

6. The wideband fast frequency synthesizer of claim 5 further comprising: the first single-pole multi-throw switch and the second single-pole multi-throw switch are both single-pole eight-throw switches.

7. The wideband fast frequency synthesizer of claim 5 further comprising: the signal generator is connected with a CPLD.