CN206114773U - High performance spectral analyser - Google Patents
High performance spectral analyser Download PDFInfo
- Publication number
- CN206114773U CN206114773U CN201620994424.9U CN201620994424U CN206114773U CN 206114773 U CN206114773 U CN 206114773U CN 201620994424 U CN201620994424 U CN 201620994424U CN 206114773 U CN206114773 U CN 206114773U
- Authority
- CN
- China
- Prior art keywords
- unit
- signals
- processor
- frequency
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 230000003595 spectral effect Effects 0.000 title abstract description 3
- 238000001514 detection method Methods 0.000 claims abstract description 35
- 238000001914 filtration Methods 0.000 claims abstract description 33
- 238000001228 spectrum Methods 0.000 claims description 33
- 230000010355 oscillation Effects 0.000 claims description 22
- 230000003321 amplification Effects 0.000 claims description 14
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 11
- 230000003139 buffering effect Effects 0.000 claims description 4
- 238000004458 analytical method Methods 0.000 abstract description 3
- 230000001568 sexual effect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 15
- 238000005070 sampling Methods 0.000 description 6
- 238000010183 spectrum analysis Methods 0.000 description 5
- 230000014509 gene expression Effects 0.000 description 4
- 238000010408 sweeping Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model provides a high performance spectral analyser relates to the data processing field, a serial communication port, the analysis appearance includes: a display uni. Display element signal connection is in the treater, the treater is signal connection in peak detection unit, oscillating unit and adc respectively, peak detection unit signal connection is in programme -controlled amplifying unit, oscillating unit signal connection is in low -pass filtering unit, adc signal connection in the detection unit, programme -controlled amplifying unit respectively signal connection in low -pass filtering unit and mixing unit, the mixing unit is signal connection in first amplifying unit and second amplifying unit respectively, second amplifying unit signal connection is in the band -pass filter unit. The utility model has the advantages of simple structure, with low costs, the operation is stable, the error is little and the sexual valence relative altitude.
Description
Technical Field
The invention relates to the field of spectrum analysis, in particular to a high-performance spectrum analyzer.
Background
The spectrum analyzer is an instrument for researching the spectrum structure of electric signals, is used for measuring signal parameters such as signal distortion degree, modulation degree, spectrum purity, frequency stability, intermodulation distortion and the like, can be used for measuring certain parameters of circuit systems such as amplifiers, filters and the like, and is a multipurpose electronic measuring instrument. It may also be referred to as a frequency domain oscilloscope, a tracking oscilloscope, an analysis oscilloscope, a harmonic analyzer, a frequency characteristic analyzer, or a fourier analyzer, etc. Modern spectrum analyzers can display the analysis results in an analog or digital manner and can analyze electrical signals of all radio frequency bands of very low frequencies below 1 hz to sub-millimeter wave bands.
The main function of the spectral analysis system is to display the spectral characteristics of the input signal in the frequency domain. The spectrum analyzer has two types according to different signal processing modes; namely, a Time-frequency Spectrum Analyzer (Real-Time Spectrum Analyzer) and a scan-Tuned Spectrum Analyzer (swept-Tuned Spectrum Analyzer), the function of the Real-Time frequency Analyzer is to display the signal amplitude of the frequency domain at the same instant, the working principle of the Real-Time frequency Analyzer is to have corresponding filters and detectors (detectors) for different frequency signals, and then to transmit the signals to a CRT or liquid crystal display instrument for display through a synchronous multiplex scanner, the Real-Time frequency Analyzer has the advantages of being capable of displaying the transient response of Periodic stray Waves (Periodic Random Waves), the disadvantage of being expensive and limited in performance by the frequency range, the number of filters and the maximum Switching Time (Switching multiplex Time), the most common Spectrum Analyzer is a scan-Tuned Spectrum Analyzer, the basic structure of which is similar to an ultra-heterodyne receiver, the working principle of the input signal being directly applied to a mixer through an attenuator, a variable local oscillator generates an oscillating frequency which varies linearly with Time through a scan generator synchronized with the CRT, the intermediate frequency signal (IF) after mixing and frequency reduction with the input signal by the mixer is amplified again, filtered and detected and transmitted to the vertical direction plate of the CRT, so that the corresponding relation between the amplitude and the frequency of the signal is displayed on the vertical axis of the CRT.
Disclosure of Invention
In view of this, the invention provides a high-performance spectrum analyzer, which has the advantages of simple structure, low cost, stable operation, small error, high cost performance and the like.
The technical scheme adopted by the invention is as follows:
a high performance spectrum analyzer, the analyzer comprising: a display unit for displaying a frequency spectrum; the display unit is in signal connection with a processor for controlling the analyzer to work; the processor is respectively connected with a peak detection unit for performing peak detection, an oscillation unit for generating an oscillation signal and an analog-to-digital converter for converting an analog signal into a digital signal; the peak detection unit is connected with the program-controlled amplification unit for program-controlled amplification through signals; the oscillation unit is connected with a low-pass filtering unit for low-pass filtering through signals; the analog-digital converter is connected with a detection unit for detecting the signals; the program-controlled amplifying unit is respectively connected with the low-pass filtering unit and the frequency mixing unit for frequency mixing through signals; the frequency mixing unit is respectively connected with a first amplifying unit and a second amplifying unit which are used for amplifying signals; the second amplifying unit is connected with a band-pass filtering unit for band-pass filtering through signals.
The detection unit includes: an active rectifier for rectification; the active rectifier is connected with a square/divider for square/division operation through signals; the squaring/dividing circuit signal is connected to a separate buffer amplifier for input buffering or filtering; the independent buffer amplifier is connected with the bias circuit through signals.
The frequency mixing unit is a down frequency mixing unit; the input differential voltage value of the frequency mixing unit is not lower than 2 Vpp; the frequency of the input differential voltage of the mixing unit is 250 MHz.
The display unit includes: a display and a keyboard; the display is connected with the processor through signals and used for displaying waveforms according to the signals sent by the processor; the keyboard is connected with a processor through signals and used for providing control commands for workers to control the operation of the analyzer.
The processor includes: the interface unit is used for providing a display unit and other units for connecting the processor, and is in signal connection with a digital-to-analog conversion unit used for converting digital signals into analog signals; the digital-to-analog conversion unit is connected with the display unit through an interface unit signal; the processor further comprises: and the judging unit is used for judging whether the voltage value meets the range requirement.
Technical scheme more than adopting, the utility model discloses following beneficial effect has been produced:
1. small volume and low cost: the utility model discloses an oscillating electric unit only needs a small amount of peripheral device can constitute complete signal source, and has that conversion rate is fast, and the resolution ratio is high, and it is fast to trade the frequency, and the frequency band is wide, and control is convenient, characteristics such as signal stability. In addition, the mixing unit only has a down-mixing unit, and only one intermediate frequency narrow-band filter is needed. Further reduces the cost
2. The structure is simple: the utility model has the advantages of simple structure, each part relation of connection is understood easily, and easy industrial production makes, further reduction manufacturing cost.
3. The measurement is accurate: the utility model discloses an oscillating unit inner structure includes active rectifier (being absolute value unit), square/divider, filter amplifier, independent buffer amplifier and bias circuit. The buffer amplifier can be used as an input buffer, and can also form an active filter for filtering, so that the measurement accuracy is improved.
Drawings
Fig. 1 is a schematic diagram of an analyzer structure of a high-performance spectrum analyzer according to the present invention.
Detailed Description
All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.
Any feature disclosed in this specification (including any accompanying claims, abstract) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.
The embodiment 1 of the invention provides a high-performance spectrum analyzer, and the structure of the analyzer is shown in figure 1:
a high performance spectrum analyzer, the analyzer comprising: a display unit for displaying a frequency spectrum; the display unit is in signal connection with a processor for controlling the analyzer to work; the processor is respectively connected with a peak detection unit for performing peak detection, an oscillation unit for generating an oscillation signal and an analog-to-digital converter for converting an analog signal into a digital signal; the peak detection unit is connected with the program-controlled amplification unit for program-controlled amplification through signals; the oscillation unit is connected with a low-pass filtering unit for low-pass filtering through signals; the analog-digital converter is connected with a detection unit for detecting the signals; the program-controlled amplifying unit is respectively connected with the low-pass filtering unit and the frequency mixing unit for frequency mixing through signals; the frequency mixing unit is respectively connected with a first amplifying unit and a second amplifying unit which are used for amplifying signals; the second amplifying unit is connected with a band-pass filtering unit for band-pass filtering through signals.
The detection unit includes: an active rectifier for rectification; the active rectifier is connected with a square/divider for square/division operation through signals; the squaring/dividing circuit signal is connected to a separate buffer amplifier for input buffering or filtering; the independent buffer amplifier is connected with the bias circuit through signals.
The frequency mixing unit is a down frequency mixing unit; the input differential voltage value of the frequency mixing unit is not lower than 2 Vpp; the frequency of the input differential voltage of the mixing unit is 250 MHz.
The display unit includes: a display and a keyboard; the display is connected with the processor through signals and used for displaying waveforms according to the signals sent by the processor; the keyboard is connected with a processor through signals and used for providing control commands for workers to control the operation of the analyzer.
The processor includes: the interface unit is used for providing a display unit and other units for connecting the processor, and is in signal connection with a digital-to-analog conversion unit used for converting digital signals into analog signals; the digital-to-analog conversion unit is connected with the display unit through an interface unit signal; the processor further comprises: and the judging unit is used for judging whether the voltage value meets the range requirement.
Embodiment 2 of the present invention provides a high performance spectrum analysis method:
a method for spectrum analysis based on a high performance spectrum analyzer, the method comprising the steps of:
step 1: initializing a system, and initializing each unit module;
step 2: after being amplified by the first amplifying unit, the signal is transmitted to a frequency mixing unit for frequency mixing processing;
and step 3: the frequency mixing unit sends the signals subjected to frequency mixing processing to the program control amplifying unit and the second amplifying unit respectively;
and 4, step 4: the program control amplification unit gains the signals by a certain magnitude and then sends the signals to the peak detection unit, and step 5 is executed; the second amplifying unit amplifies the signal and sends the amplified signal to the band-pass filtering unit; the single-pass filtering unit carries out band-pass filtering on the received signal and sends the filtered signal to the detection unit; the detection unit detects the received signal and sends the detected signal to the analog-to-digital converter, and step 7 is executed;
and 5: the processor controls the peak detection unit to carry out peak detection; according to the result of peak detection, the processor sends a control command to the digital-to-analog conversion unit to change the gain of the program-controlled amplification unit;
step 6: the processor sends a control command to the oscillation unit for frequency sweeping processing; the oscillation unit sends the frequency sweeping result to the processor;
and 7: the processor sends a control command to the analog-to-digital converter for signal sampling, and the analog-to-digital converter sends a sampling result to the processor;
and 8: and the processor sends the sampling result to the display unit for displaying.
The method for the oscillating unit to sweep frequency comprises the following steps: the processor sends a preset sweep frequency starting frequency to the oscillation unit; the oscillation unit adds the sweep frequency starting frequency and the preset frequency deviation to obtain a new sweep frequency, and the oscillation unit uses the frequency to sweep frequency.
The method for changing the gain of the program control amplification unit by the processor comprises the following steps: the processor compares the voltage value acquired by the analog-to-digital converter with a preset voltage value, and if the acquired voltage value is greater than the preset voltage value, the gain is controlled to be reduced; and if the acquired voltage value is smaller than the preset voltage value, controlling the gain to increase.
The method for selecting the center frequency by the band-pass filter comprises the following steps:
step 1: let the expression of the original input signal be:
wherein,is a modulation index;is the carrier amplitude;
step 2: calculating the frequency of the signal according to the expression of the signal(ii) a And maximum amplitude value；
And step 3: finding a second maximum in the frequency spectrum of the signalAnd corresponding frequencyThen, judgeIf the amplitude of the corresponding point is larger than a preset first threshold value, the amplitude is frequency modulation wave,i.e. its center frequency; if the amplitude is smaller than the preset first threshold value, the wave is amplitude modulated wave or constant amplitude wave,then it is the center frequency; because the bandwidth of amplitude modulated wave is 20kHz, only judgment is neededOrIf the value of the point is smaller than the preset second threshold value, the amplitude-modulated wave is obtained, and if the value of the point is larger than the preset second threshold value, the amplitude-modulated wave is obtained.
Embodiment 3 of the present invention provides a high performance spectrum analyzer, wherein the structure diagram of the analyzer is shown in fig. 1:
a high performance spectrum analyzer, the analyzer comprising: a display unit for displaying a frequency spectrum; the display unit is in signal connection with a processor for controlling the analyzer to work; the processor is respectively connected with a peak detection unit for performing peak detection, an oscillation unit for generating an oscillation signal and an analog-to-digital converter for converting an analog signal into a digital signal; the peak detection unit is connected with the program-controlled amplification unit for program-controlled amplification through signals; the oscillation unit is connected with a low-pass filtering unit for low-pass filtering through signals; the analog-digital converter is connected with a detection unit for detecting the signals; the program-controlled amplifying unit is respectively connected with the low-pass filtering unit and the frequency mixing unit for frequency mixing through signals; the frequency mixing unit is respectively connected with a first amplifying unit and a second amplifying unit which are used for amplifying signals; the second amplifying unit is connected with a band-pass filtering unit for band-pass filtering through signals.
The detection unit includes: an active rectifier for rectification; the active rectifier is connected with a square/divider for square/division operation through signals; the squaring/dividing circuit signal is connected to a separate buffer amplifier for input buffering or filtering; the independent buffer amplifier is connected with the bias circuit through signals.
The frequency mixing unit is a down frequency mixing unit; the input differential voltage value of the frequency mixing unit is not lower than 2 Vpp; the frequency of the input differential voltage of the mixing unit is 250 MHz.
The display unit includes: a display and a keyboard; the display is connected with the processor through signals and used for displaying waveforms according to the signals sent by the processor; the keyboard is connected with a processor through signals and used for providing control commands for workers to control the operation of the analyzer.
The processor includes: the interface unit is used for providing a display unit and other units for connecting the processor, and is in signal connection with a digital-to-analog conversion unit used for converting digital signals into analog signals; the digital-to-analog conversion unit is connected with the display unit through an interface unit signal; the processor further comprises: and the judging unit is used for judging whether the voltage value meets the range requirement.
A method for spectrum analysis based on a high performance spectrum analyzer, the method comprising the steps of:
step 1: initializing a system, and initializing each unit module;
step 2: after being amplified by the first amplifying unit, the signal is transmitted to a frequency mixing unit for frequency mixing processing;
and step 3: the frequency mixing unit sends the signals subjected to frequency mixing processing to the program control amplifying unit and the second amplifying unit respectively;
and 4, step 4: the program control amplification unit gains the signals by a certain magnitude and then sends the signals to the peak detection unit, and step 5 is executed; the second amplifying unit amplifies the signal and sends the amplified signal to the band-pass filtering unit; the single-pass filtering unit carries out band-pass filtering on the received signal and sends the filtered signal to the detection unit; the detection unit detects the received signal and sends the detected signal to the analog-to-digital converter, and step 7 is executed;
and 5: the processor controls the peak detection unit to carry out peak detection; according to the result of peak detection, the processor sends a control command to the digital-to-analog conversion unit to change the gain of the program-controlled amplification unit;
step 6: the processor sends a control command to the oscillation unit for frequency sweeping processing; the oscillation unit sends the frequency sweeping result to the processor;
and 7: the processor sends a control command to the analog-to-digital converter for signal sampling, and the analog-to-digital converter sends a sampling result to the processor;
and 8: and the processor sends the sampling result to the display unit for displaying.
The method for the oscillating unit to sweep frequency comprises the following steps: the processor sends a preset sweep frequency starting frequency to the oscillation unit; the oscillation unit adds the sweep frequency starting frequency and the preset frequency deviation to obtain a new sweep frequency, and the oscillation unit uses the frequency to sweep frequency.
The method for changing the gain of the program control amplification unit by the processor comprises the following steps: the processor compares the voltage value acquired by the analog-to-digital converter with a preset voltage value, and if the acquired voltage value is greater than the preset voltage value, the gain is controlled to be reduced; and if the acquired voltage value is smaller than the preset voltage value, controlling the gain to increase.
The method for selecting the center frequency by the band-pass filter comprises the following steps:
step 1: let the expression of the original input signal be:
wherein,is a modulation index;is the carrier amplitude;
step 2: according to expressions of the signalCalculating the frequency of the signal(ii) a And maximum amplitude value；
And step 3: finding a second maximum in the frequency spectrum of the signalAnd corresponding frequencyThen, judgeIf the amplitude of the corresponding point is larger than a preset first threshold value, the amplitude is frequency modulation wave,i.e. its center frequency; if the amplitude is smaller than the preset first threshold value, the wave is amplitude modulated wave or constant amplitude wave,then it is the center frequency; because the bandwidth of amplitude modulated wave is 20kHz, only judgment is neededOrIf the value of the point is smaller than the preset second threshold value, the amplitude-modulated wave is obtained, and if the value of the point is larger than the preset second threshold value, the amplitude-modulated wave is obtained.
The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.
Claims (5)
1. A high performance spectrum analyzer, the analyzer comprising: a display unit for displaying a frequency spectrum; the display unit is in signal connection with a processor for controlling the analyzer to work; the processor is respectively connected with a peak detection unit for performing peak detection, an oscillation unit for generating an oscillation signal and an analog-to-digital converter for converting an analog signal into a digital signal; the peak detection unit is connected with the program-controlled amplification unit for program-controlled amplification through signals; the oscillation unit is connected with a low-pass filtering unit for low-pass filtering through signals; the analog-digital converter is connected with a detection unit for detecting the signals; the program-controlled amplifying unit is respectively connected with the low-pass filtering unit and the frequency mixing unit for frequency mixing through signals; the frequency mixing unit is respectively connected with a first amplifying unit and a second amplifying unit which are used for amplifying signals; the second amplifying unit is connected with a band-pass filtering unit for band-pass filtering through signals.
2. The high performance spectrum analyzer of claim 1, wherein said detection unit comprises: an active rectifier for rectification; the active rectifier is connected with a square/divider for square/division operation through signals; the squaring/dividing circuit signal is connected to a separate buffer amplifier for input buffering or filtering; the independent buffer amplifier is connected with the bias circuit through signals.
3. The high performance spectrum analyzer of claim 2, wherein the mixing unit is a down-mixing unit; the input differential voltage value of the frequency mixing unit is not lower than 2 Vpp; the frequency of the input differential voltage of the mixing unit is 250 MHz.
4. The high performance spectrum analyzer of claim 3, wherein the display unit comprises: a display and a keyboard; the display is connected with the processor through signals and used for displaying waveforms according to the signals sent by the processor; the keyboard is connected with a processor through signals and used for providing control commands for workers to control the operation of the analyzer.
5. The high performance spectrum analyzer of claim 4, wherein the processor comprises: the interface unit is used for providing a display unit and other units for connecting the processor, and is in signal connection with a digital-to-analog conversion unit used for converting digital signals into analog signals; the digital-to-analog conversion unit is connected with the display unit through an interface unit signal; the processor further comprises: and the judging unit is used for judging whether the voltage value meets the range requirement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620994424.9U CN206114773U (en) | 2016-08-31 | 2016-08-31 | High performance spectral analyser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620994424.9U CN206114773U (en) | 2016-08-31 | 2016-08-31 | High performance spectral analyser |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206114773U true CN206114773U (en) | 2017-04-19 |
Family
ID=58515606
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620994424.9U Expired - Fee Related CN206114773U (en) | 2016-08-31 | 2016-08-31 | High performance spectral analyser |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206114773U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106353595A (en) * | 2016-08-31 | 2017-01-25 | 成都市和平科技有限责任公司 | High-performance spectrum analyzer and spectrum analysis method |
-
2016
- 2016-08-31 CN CN201620994424.9U patent/CN206114773U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106353595A (en) * | 2016-08-31 | 2017-01-25 | 成都市和平科技有限责任公司 | High-performance spectrum analyzer and spectrum analysis method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104122444B (en) | All-digital IF spectrum analyzer and frequency spectrum analysis method | |
| CN106772297B (en) | Radar emission power measurement and frequency automatic tracking system | |
| CN102780535B (en) | A kind of vector network analyzer Poewr control method based on intermediate frequency detection | |
| CN103630743B (en) | The method of a kind of heterodyne system spectrum analyzer frequency correction | |
| CN102879643A (en) | Novel spectrum analyzer and method | |
| CN106886002B (en) | Calibration method of spectrum analyzer | |
| WO2018032645A1 (en) | Wideband wide-frequency agile signal measurement instrument and measurement method | |
| CN100473996C (en) | Apparatus for detecting linear index of power amplifier | |
| CN104283625A (en) | Superheterodyne harmonic detector based on harmonic mixing | |
| CN102647241B (en) | Non-coherent detection system and method for short-wave broad-band channel | |
| US8805313B2 (en) | Magnitude and phase response calibration of receivers | |
| CN104270148A (en) | Broadband digital fixed-amplitude multi-system radio frequency signal source module | |
| CN114217279A (en) | Portable radar transponder tester and testing method | |
| CN203798907U (en) | Multi-channel broadband microwave radiometer with self-calibration function | |
| CN104635062A (en) | Environment electromagnetic radiation monitoring system | |
| CN111585927B (en) | Frequency modulation demodulation system and signal processing method | |
| CN202503522U (en) | Super heterodyne harmonic detection device | |
| US20170168097A1 (en) | Data Management with Spectrum Analyzers | |
| US7629795B2 (en) | Vector impedance measurement system and method of using same | |
| CN104950171A (en) | Multichannel broadband microwave radiometer with self-calibration function | |
| CN109412619A (en) | A kind of high neighboring trace inhibition radio-frequency transmitter | |
| CN106680788B (en) | A kind of intermediate-freuqncy signal generation system based on radar signal simulator | |
| CN110308463B (en) | Wind-finding radar system with data acquisition card and working method thereof | |
| CN206114773U (en) | High performance spectral analyser | |
| CN106353594B (en) | A kind of fast multiresolution frequency spectrum analysis system and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20170419 Termination date: 20180831 |