CN217467859U

CN217467859U - Signal generating device for communication principle teaching and communication principle teaching system

Info

Publication number: CN217467859U
Application number: CN202220880336.1U
Authority: CN
Inventors: 肖学美; 陈雨莺
Original assignee: Changsha Changke Technology Co ltd
Current assignee: Changsha Changke Technology Co ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2022-09-20
Anticipated expiration: 2032-04-15

Abstract

The utility model discloses a signal generating device and a communication principle teaching system for communication principle teaching, wherein the signal generating device comprises a clock unit, and the clock unit is used for providing a reference clock; the clock unit is connected with a clock signal input end of the PLL, and the PLL is provided with an intermediate frequency output terminal and a radio frequency output terminal; the CPU is connected with the control end of the PLL and used for controlling the frequency of the output signal; the power supply unit is respectively connected with power supply ends of the PLL and the CPU for supplying power; and the control interface is connected with the control end of the CPU and used for receiving an external control command. The satellite navigation communication principle teaching experimental device is simple in structure, low in cost and adjustable in output signal frequency, and meets experimental requirements of satellite navigation communication principle teaching.

Description

Signal generating device for communication principle teaching and communication principle teaching system

Technical Field

The utility model relates to a signal generation equipment field, specificly relate to a signal generation device and communication principle teaching system for communication principle teaching.

Background

The wide application and popularization of the Beidou satellite navigation technology enable enterprises to increasingly demand various aspects of position services related to navigation, and accordingly application technologies such as Beidou position services, Beidou navigation speed measurement, Beidou time service and Beidou communication become research hotspots of scientific research institutions. In order to cultivate more communication navigation talents and well make teaching popularization work, the design of teaching equipment is becoming more important, a signal generating device is common equipment used in communication principle teaching, the existing signal generating device is complex in structure, high in cost and nonadjustable in output signal frequency, the output of all L-band navigation signal frequency points cannot be realized, and the experimental requirements of satellite navigation communication principle teaching cannot be met.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model provides a signal generation device and communication principle teaching system for communication principle teaching can solve the complicated, with high costs and the nonadjustable problem of output signal frequency of structure that current signal generation device exists.

According to the utility model discloses a signal generation device for communication principle teaching, include: a clock unit for providing a reference clock; the clock unit is connected with a clock signal input end of the PLL, and the PLL is provided with an intermediate frequency output terminal and a radio frequency output terminal; the CPU is connected with the control end of the PLL and used for controlling the frequency of the output signal; the power supply unit is respectively connected with power supply ends of the PLL and the CPU for supplying power; and the control interface is connected with the control end of the CPU and used for receiving an external control command.

According to the utility model discloses a signal generation device for communication principle teaching of first aspect embodiment has following technological effect at least: the utility model discloses embodiment provides the reference clock for the PLL through the clock unit, CPU receives the control command back through external interface, control PLL output frequency's signal, CPU realizes the switching of PLL output signal frequency through changing PLL internal control register, the PLL passes through the signal of intermediate frequency output terminal and the different frequencies of radio frequency output terminal output, can realize the output at all L frequency channel navigation signal frequency points, this application simple structure, with low costs and output signal frequency is adjustable, satisfy the experiment demand of satellite navigation communication principle teaching.

According to the utility model discloses a some embodiments, the clock unit includes inside crystal oscillator, change over switch and external reference clock input, change over switch's an input is connected respectively to inside crystal oscillator and external reference clock input, change over switch's output is connected the input of PLL, CPU connects change over switch's control end.

According to the utility model discloses a some embodiments, the radio frequency output terminal with be provided with the combiner between the PLL, the radio frequency output pin of the different output frequency range of PLL is connected respectively to the input of combiner, the output of combiner is connected the radio frequency output terminal.

According to some embodiments of the utility model, power supply unit includes power source, power protection module, DC/DC module, power filter, first LDO and second LDO, power source connects power protection module's input is in order to be used for inputing external power, power protection module's output is connected the input of DC/DC module, the output of DC/DC module is connected power filter's input, power filter's an output is connected the input of first LDO, another output of power filter is connected the input of second LDO, CPU's feed end is connected to first LDO, PLL's feed end is connected to the second LDO, CPU connects DC/DC module's control end.

According to the utility model discloses a some embodiments still include the current-voltage acquisition unit, the current-voltage acquisition unit is including gathering ADC module and current detection circuit, the current detection circuit sets up power protection module with between the DC/DC module, the feedback end of current detection circuit is connected gather an input of ADC module in order to be used for gathering supply current, power filter's feedback end is connected gather another input of ADC module in order to be used for gathering mains voltage, the output of gathering the ADC module is connected CPU's feedback end.

According to some embodiments of the utility model, still include the display interface, the display interface is connected CPU's output.

According to some embodiments of the present invention, further comprising a sensor interface, the sensor interface is connected to the CPU for receiving feedback data of an external sensor.

According to some embodiments of the invention, the CPU has a model of Atmage 64/128.

According to some embodiments of the invention, the PLL is of type Si 4133.

According to the utility model discloses communication principle teaching system of second aspect embodiment includes: the computer controls the signal generating device to generate and output signals with different frequencies.

According to the utility model discloses communication principle teaching system of second aspect embodiment has following technological effect at least: the utility model discloses embodiment provides the reference clock for the PLL through the clock unit, CPU receives the control command back through external interface, and control PLL outputs the signal of assigned frequency, and CPU realizes the switching of PLL output signal frequency through changing PLL internal control register, and the PLL passes through the signal of intermediate frequency output terminal and the different frequencies of radio frequency output terminal output, and simple structure, with low costs and output signal frequency are adjustable, satisfy the experiment demand of communication principle teaching.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram of a signal generating device according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.

Referring to fig. 1, a signal generating apparatus for teaching of communication principles, comprising: clock unit, PLL (phase locked loop), CPU, power supply unit and control interface. The clock unit is connected with a clock signal input end of the PLL to provide a reference clock, and the PLL is provided with an intermediate frequency output terminal and a radio frequency output terminal; the CPU is connected with the control end of the PLL, realizes the adjustment of the frequency of the output signal by changing the internal control register of the PLL, and is respectively connected with the PLL and the power supply end of the CPU to provide a power supply; the control interface is connected with the control end of the CPU, and the computer is connected with the CPU through the control interface and sends a control command to control the output of the signal.

The conventional clock unit all adopts single internal crystal oscillator, but is only suitable for general conditions, the internal crystal oscillator can not meet the requirement when a high-stability reference clock is needed, in the embodiment, the clock unit adopts an internal and external switching mode, the internal crystal oscillator comprises an internal crystal oscillator, a switch and an external reference clock input end, the external reference clock input end can be connected with an external reference clock of 10Mhz, the internal crystal oscillator and the external reference clock are respectively connected with one input end of the switch, the output end of the switch is connected with the input end of a PLL, and a CPU is connected with the control end of the switch. The change-over switch adopts detection automatic switching control to realize PLL frequency source supply under internal and external reference input, the internal crystal oscillator is used as internal reference under default condition, and external reference can be accessed through an external reference clock input end when a high-stability reference clock is needed. In this embodiment, the model of the internal crystal oscillator is TG271331, and the model of the switch is HMC284A, although other models of crystal oscillators and switches may also be used.

In this embodiment, the PLL is in a type of Si4133, the Si4133 includes one intermediate frequency output port and 2 rf output ports, an intermediate frequency output pin of the Si4133 is connected to the intermediate frequency output terminal through an AD8353, and two rf output pins of the Si4133 are connected to the rf output terminal through a combiner and the AD 8353. The output signal frequencies of the radio frequency output terminal and the intermediate frequency output terminal can be realized by changing a PLL internal control register, the output frequency range of one radio frequency output port of the Si4133 is 900MHz-1800MHz, the output frequency range of the other radio frequency output port is 750MHz to 1.5GHz, and the two radio frequency output ports are combined in the embodiment, so that the radio frequency output terminals are ensured to output signals under the condition of control change, and the full-range output of 750MHz-1800MHz signals is realized. The type of the combiner in this embodiment is GP251+, and other types of combiners may be adopted.

The power supply unit comprises a power supply interface, a power supply protection module, a DC/DC module, a power filter, a first LDO and a second LDO, the power supply interface is connected with the input end of the power supply protection module, and an external power supply is input, the power supply protection module in the embodiment adopts a power supply circuit with the model of MAX17613C, and the power supply unit has the functions of overvoltage protection, overcurrent protection, undervoltage protection and reverse connection protection under the input voltage of 5-12V, the output end of the power supply protection module is connected with the input end of the DC/DC module, the output end of the DC/DC module is connected with the input end of the power filter, one output end of the power filter is connected with the input end of the first LDO, the other output end of the power filter is connected with the input end of the second LDO, the first LDO supplies power to a CPU, the second LDO is connected with the power supply end of a PLL, and the CPU is connected with the control end of the DC/DC module. In the embodiment, the model of the first LDO is adp150aujz-3.3-R7, the model of the second LDO is adp150aujz-3.0-R7, the model of the power supply filter is NFM31HK103R1H3L, and the model of the DC/DC module is TPS 54540. Of course, the models of the above components can be adjusted and replaced according to actual requirements.

In order to realize state identification and judgment, the device further comprises a current and voltage acquisition unit and a sensor interface, wherein the current and voltage acquisition unit comprises an acquisition ADC module and a current detection circuit, the current detection circuit is arranged between the power protection module and the DC/DC module, the feedback end of the current detection circuit is connected with one input end of the acquisition ADC module and acquires power current, the feedback end of the power filter is connected with the other input end of the acquisition ADC module, the voltage of the current point is acquired as power voltage, and the output end of the acquisition ADC module is connected with the feedback end of the CPU. The sensor interface is connected to the CPU for receiving feedback data from an external sensor, such as a temperature sensor. The type of the acquisition ADC module in this embodiment is AD7888, but other types of acquisition ADC modules may also be used.

In this embodiment, the control interface adopts a serial port module with a TRS3122 model, the computer is connected with the CPU through the control interface to send a control command, the display interface is connected with the output end of the CPU, the display interface adopts the serial port module with the TRS3122 model, and certainly, the display interface and the control interface with other models can also be adopted. The model of the CPU in this embodiment is Atmage64/128, but other models of CPU may be adopted.

The utility model discloses still relate to a communication principle teaching system, include: the computer controls the signal generating device to generate and output signals with different frequencies. The student can gather each sensor and relevant characteristic parameter according to sensor interface and collection ADC module and export, and the output protocol is for agreeing the protocol, obtains output operating condition information (for example operating voltage, operating current, temperature, whether key characteristic parameter such as locking) through the display screen at the in-process of signal generation device work. The control can also be carried out by the computer sending relevant instructions such as frequency control and the like.

To sum up, the embodiment of the utility model discloses embodiment provides the reference clock for PLL through the clock unit, and CPU receives the control command back through external interface, and the signal of the appointed frequency of control PLL output, CPU realize PLL output signal frequency's switching through changing PLL internal control register, and PLL passes through the signal of intermediate frequency output terminal and the different frequencies of radio frequency output terminal output, and simple structure, with low costs and output signal frequency are adjustable, satisfy the experiment demand of communication principle teaching. Besides outputting a sampling clock and a radio frequency signal required by a communication principle experiment through fixed configuration, the working principle of a radio frequency phase-locked loop can be carried out; a phase-locked loop register configuration method; SPI communication control mechanism and realization; the frequency of a phase-locked loop VCO is related to the working frequency; and carrying out related development experiments on the relationship between the signal phase noise and the external environment and the like.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims

1. A signal generating device for teaching communication principles, comprising:

a clock unit for providing a reference clock;

the clock unit is connected with a clock signal input end of the PLL, and the PLL is provided with an intermediate frequency output terminal and a radio frequency output terminal;

the CPU is connected with the control end of the PLL and used for controlling the frequency of the output signal;

the power supply unit is respectively connected with power supply ends of the PLL and the CPU for supplying power;

and the control interface is connected with the control end of the CPU and used for receiving an external control command.

2. The signal generating apparatus for teaching communication principles of claim 1, wherein: the clock unit comprises an internal crystal oscillator, a change-over switch and an external reference clock input end, the internal crystal oscillator and the external reference clock input end are respectively connected with one input end of the change-over switch, the output end of the change-over switch is connected with the input end of the PLL, and the CPU is connected with the control end of the change-over switch.

3. The signal generating apparatus for teaching communication principles of claim 1, wherein: a combiner is arranged between the radio frequency output terminal and the PLL, the input end of the combiner is respectively connected with the radio frequency output ports of the PLL with different output frequency ranges, and the output end of the combiner is connected with the radio frequency output terminal.

4. The signal generating apparatus for teaching of the principles of communication of claim 1 wherein: the power supply unit comprises a power interface, a power protection module, a DC/DC module, a power filter, a first LDO and a second LDO, wherein the power interface is connected with an input end of the power protection module to input an external power supply, an output end of the power protection module is connected with an input end of the DC/DC module, an output end of the DC/DC module is connected with an input end of the power filter, an output end of the power filter is connected with an input end of the first LDO, another output end of the power filter is connected with an input end of the second LDO, the first LDO is connected with a power supply end of the CPU, the second LDO is connected with a power supply end of the PLL, and the CPU is connected with a control end of the DC/DC module.

5. The signal generating apparatus for teaching of the principles of communication of claim 4 wherein: still include the current-voltage acquisition unit, the current-voltage acquisition unit is including gathering ADC module and current detection circuit, current detection circuit sets up power protection module with between the DC/DC module, current detection circuit's feedback end is connected gather an input of ADC module in order to be used for gathering supply current, power filter's feedback end is connected gather another input of ADC module in order to be used for gathering mains voltage, the output of gathering the ADC module is connected CPU's feedback end.

6. The signal generating apparatus for teaching of the principles of communication of claim 1 wherein: the display device also comprises a display interface, and the display interface is connected with the output end of the CPU.

7. The signal generating apparatus for teaching of the principles of communication of claim 1 wherein: the sensor interface is connected with the CPU and used for receiving feedback data of an external sensor.

8. The signal generating apparatus for teaching of the principles of communication of claim 1 wherein: the model of the CPU is Atmage 64/128.

9. The signal generating apparatus for teaching of the principles of communication of claim 1 wherein: the PLL model is Si 4133.

10. A communication principle teaching system, comprising: a computer and a signal generating device as claimed in any one of claims 1 to 9, the computer controlling the signal generating device to generate and output signals of different frequencies.