CN102932020A - Beidou multimode time service receiving device - Google Patents
Beidou multimode time service receiving device Download PDFInfo
- Publication number
- CN102932020A CN102932020A CN 201210195134 CN201210195134A CN102932020A CN 102932020 A CN102932020 A CN 102932020A CN 201210195134 CN201210195134 CN 201210195134 CN 201210195134 A CN201210195134 A CN 201210195134A CN 102932020 A CN102932020 A CN 102932020A
- Authority
- CN
- China
- Prior art keywords
- frequency
- filter
- band
- time service
- multimode
- 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.)
- Pending
Links
Images
Landscapes
- Circuits Of Receivers In General (AREA)
- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Abstract
The invention discloses a Beidou multimode time service receiving device which is composed of a broadband time service active antenna and a multimode radio-frequency receiver module. According to the technical scheme of the invention, a plurality of special frequency-band time service antennas are not required to be set according to navigation satellites and frequency bands, the radio-frequency receiver module does not frequently switch local frequencies and intermediate-frequency filtering frequency points by using a time-division multiplexing technology, and frequency bands and multi-channel demodulation modes are not switched by using a tunable mode, but a programmable intermediate-frequency filter is controlled to automatically select main and standby time service signals through a storage control processor by using a software technology, so that the transmission and demodulation qualities can be ensured. According to the invention, because the time service active antenna and the multimode radio-frequency receiver module are subjected to an integrated design, a provided latest circuit design and a provided structure not only improve the flexibility and reliability of multimode time service conversion, but also extremely facilitate the reduction of renovation costs consumed for converting single-mode time services into multimode time services implemented by the existing domestic CDMA (code division multiple access) and TD-SCDMA (time division-synchronization code division multiple access) mobile communication base stations.
Description
The application is dividing an application of the original bill number of patent application is 200910073942.1, denomination of invention is on March 17th, 2009 application for a patent for invention for " big dipper multi-mode time service receiving device ", the applying date.
Technical field
The present invention relates to a kind of satellite positioning navigation multi-mode time service receiving device, it is synchronous to be specially adapted to the mobile communication apparatus station time services such as CDMA, CDMA2000, TD-SCDMA, belongs to mobile communication and satellite positioning navigation field.
Background technology
CDMA especially in Modern Mobile Communications Systems, in CDMA2000 and the TD-SCDMA mobile communication system, require the wave point of whole cellular system all to be synchronized with same etalon time, generally Position Fixing Navigation System or wire cable provide this etalon time via satellite, because NAVSTAR time service accuracy is high, time delay is little, therefore in these mobile communications devices, adopt satellite time transfers more, but, foundation along with a plurality of international satellite navigation system, except the gps satellite navigation system of the U.S., other the Galileo such as European Union, in " two generations of the Big Dipper " that Muscovite GLONASS and China will soon set up, are the global location navigation system (COMPASS-M1), all incite somebody to action or entered practical stage, therefore require satellite positioning navigation or the time service service receiver of a new generation, compatible and different satellite navigation time service signals of reception simultaneously, for the user provides more stable, reliably, it is inevitable that accurate service, multisystem compatible receiver replace the triangular web receiver to become.But, the enterprise that present domestic most designs and production base station produce the radio-frequency transmitter chip with time-service active antenna and design is respectively independently, the special China that works as encourages exploitation take the Big Dipper two generations satellite navigation system as main, when having simultaneously multi-system compatible type time service radio-frequency transmitter, just should take the method for time-service active antenna and radio-frequency transmitter integrated design, select best multimode to receive design." a kind of double-mode time service active antenna " patent of the previous application of applicant owing to the design of radio-frequency transmitter module is not considered as a whole interior, therefore is difficult to realize applicant's technical goal.For further improving reliability and the manufacturability of satellite time transfer, guarantee that domestic CDMA and TD-SCDMA mobile communication system carry out the Big Dipper two generations time service conversion and transform in the situation of normal operation, reduction system conversion cost, just be necessary time-service active antenna and radio-frequency transmitter module are carried out overall planning, adopt the technology path of simplifying most, realize that above-mentioned multimode receives and compatible target.
Summary of the invention
Problem to be solved by this invention be overall planning with the Big Dipper two on behalf of the master, multi-system compatible type time-service active antenna and radio-frequency transmitter module, adopt radio frequency reception integrated design scheme, guarantee that existing mobile communication base station can receive different satellite navigation time service signals simultaneously, strive breaking away from the dependence to single satellite navigation system, improve fail safe, reliability and the independence of China's mobile communication system network.
Big dipper multi-mode time service receiving device of the present invention is by the broadband time-service active antenna, the multi-mode radio frequency receiver module forms, the principal character of broadband time-service active antenna is: described broadband time-service active antenna is by broadband ceramic dielectric reception antenna, band-pass filter, the low noise field-effect amplifier, broadband band-pass filter, Low Noise Amplifier MMIC, lightening surge preventing impacts circuit, the power supply voltage stabilizing circuit, contain the double-sided printing copper-clad plate of microstrip circuit, the N-type needle electric coupler forms, this ceramic medium antenna is arranged at the one side of printing copper-clad plate, and is connected to the band-pass filter input by lead-in wire; Band-pass filter, low noise field-effect amplifier, broadband band-pass filter, one chip amplifier and lightening surge preventing impact circuit and the power supply voltage stabilizing circuit is positioned at the another side of printing copper-clad plate, and splits in two metallic enclosures; Band-pass filter and low noise field-effect amplifier place in the metallic enclosure, and remaining circuit places in another shielding cavity.This time-service active antenna is the application of inventor's patent 200520023991.1,200620024687.3 and 200720304839,200820228116.0,200820228123.0 in this patent.
Above-mentioned ceramic medium antenna is broad-band reception antenna, can accept simultaneously " two generations of the Big Dipper " and GPS, Galileo, or GLONASS satellite time transfer carrier signal, receive frequency is respectively 1561.098MHz and the 1575.42MHz of GPS, Galileo, the 1602.56MHz of GLONASS in " two generations of the Big Dipper ".
Above-mentioned broadband band-pass filter adopts Ceramic Dielectric Filter part or SAW (Surface Acoustic Wave) device, and the frequency response bandwidth is 1550 to 1620MHz; Or adopt staggered tuning band pass filter, wherein f
01Be the 1561.098MHz in " two generations of the Big Dipper ", f
021575.42MHz for GPS and Galileo; f
031602.56MHz for GLONASS.
Described broadband time-service active antenna important technological parameters is as follows:
(1) frequency range [MHz]: 1550-1620
(2) gain [dBi]:＞20
(3) noise factor [dB]:＜2.5@+25 ℃,＜3.0@+80 ℃
(4) Out-of-band rejection [dB]: fo=1585MHz
fo±30MHz ＞5
fo±50MHz ＞20
fo±100MHz ＞50
(5) input and output voltage standing-wave ratio :≤2.0
(6) Anti-surging (impact) immunity to interference performance meets GB/T17626.5-1999idt IEC61000-4-5:1995 standard
Surge waveform: CWG composite wave, 1.2/50 μ s, 8/20 μ s
Voltage peak [V]: 〉=2000
Number of pulses: 10
(7) signal time delay is less than 5ns.
The broadband time-service active antenna transfers to the multi-mode radio frequency receiver module via N-type needle electric coupler connecting coaxial cable, lightning arrester behind broadband filter and low noise amplification.
Above-mentioned multi-mode radio frequency receiver module is by the multimode narrow band filter, frequency mixer, a shared frequency comprehensive generator, the intermediate frequency integrated filter, the AGC automatic gain amplifier, the A/D analog to digital converter, access control processor, network interface, the multimode signal selector, signal level detecter, wideband low noise amplifier, intermediate-frequency filter able to programme, digital demodulator forms, it is characterized in that: described multi-mode radio frequency receiver module adopts the method for integrated circuit to be produced on one or two chip, wherein, frequency mixer, comprehensive frequency generator, the intermediate frequency integrated filter, the AGC automatic gain amplifier, the A/D analog to digital converter is integrated on the chip, and access control processor is integrated on another chip; Or all be integrated on the chip; Or frequency mixer, comprehensive frequency generator, multimode signal selector, signal level monitor, LNA wideband low noise amplifier, A/D analog to digital converter be integrated on the chip, intermediate-frequency filter able to programme, digital demodulator, access control processor are integrated on another chip; The multi-mode radio frequency receiver module is installed and is mounted on one and covers on the copper printed circuit board.
Described narrow band filter adopts Ceramic Dielectric Filter part or SAW (Surface Acoustic Wave) device to arrange respectively, and the intermediate-frequency bandwidth of GPS is 2.046MHz; The intermediate-frequency bandwidth of two generations of the Big Dipper and Galileo is 4.092MHz, and GLONASS intermediate-frequency bandwidth is 10MHz.
Described intermediate frequency integrated filter adopts the discrete devices such as Ceramic Dielectric Filter or surface acoustic wave to arrange outward, and its centre frequency depends on the selection of local frequency, is arranged on 1 to 30MHz.
The electric principle of described broadband time-service active antenna and multi-mode radio frequency receiver module is: the broadband time-service active antenna receives the satellite time transfer carrier signal from " two generations of the Big Dipper " and GPS, Galileo and GLONASS simultaneously, transfers to the multi-mode radio frequency receiver module via coaxial cable, lightning arrester.For containing existing four kinds of satellite navigation system time service carrier signals, the multi-mode radio frequency receiver module adopts the software engineering demodulation, a multimode signal selector was set before frequency mixer, the major function of this selector is that the high-frequency signal incoming level to the input radio frequency receiver detects and compares, and signal is strong to select, pulse code distortion smaller is as the time service main signal; The multimode signal selector is responsible for monitoring by the signal level detecter that independently arranges or be arranged in the access control processor, corresponding is that intermediate frequency integrated filter able to programme is made corresponding intermediate frequency filtering frequency and frequency band change action according to the control command of signal level detecter or access control processor simultaneously, to guarantee the accurate demodulation of digital demodulator; Frequency mixer can arrange one, or the mode by synchronous switching local frequency prevents adjacently frequently to disturb, enter the AGC automatic gain amplifier through filtered intermediate-freuqncy signal, then entering A/D analog-digital demodulation device finishes analog-to-digital conversion and conciliates spread spectrum and resolve, digit time signal after access control processor will resolve passes through network interface, according to and the base station time synchronism machine between communication protocol and technical specification transmission time synchronizing signal, guarantee that mobile communication system is synchronized with a fiducial time.
Because the present invention has carried out integrated design to time-service active antenna and radio-frequency transmitter module, the up-to-date circuit design that provides and structure take full advantage of existing integrated chip technology and software radio-frequency technique, not only improve flexibility, the reliability of multimode time service conversion, and extremely be conducive to reduce cost.The particularly operating CDMA of China, CDMA2000 and TD-SCDMA mobile communication system, be converted to the multimode time service by the time service of GPS single mode, only need to change time-service active antenna and the radio-frequency transmitter module of base station, other hardware facility can use in complete reservation, and do not increase new equipment, when guaranteeing the normal operation of whole mobile communication system network, can significantly reduce improvement expenses.This technical scheme can also extend to the civilian or military frequency range of other satellite, also can be applicable on the multimode positioning navigation device simultaneously.
Description of drawings
Fig. 1 is big dipper multi-mode time service receiving device schematic diagram of the present invention
Fig. 2 is multi-mode radio frequency receiver module principle figure of the present invention
Embodiment
Broadband time-service active antenna circuit is by broadband ceramic medium antenna 101, prefilter 102, low noise field-effect amplifier 103, broadband filter 104, Low Noise Amplifier MMIC 105, lightening surge preventing impacts circuit 106, power supply voltage stabilizing circuit 107, contain the double-sided printing copper-clad plate of microstrip circuit, the formations such as N-type needle electric coupler, operation principle is: broadband ceramic medium antenna 101 receives from GPS, Galileo, " two generations of the Big Dipper ", GLONASS satellite time transfer carrier signal, guarantee 1550 to 1620MHz Out-of-band rejections through prefilter 102 filtering, then send low noise field-effect amplifier 103 to amplify, broadband signal through amplifying enters broadband filter 104, the formation center frequency point is 1585MHz, cover simultaneously 1561.098MHz, 1575.42MHz and the carrier signal of 1602.56MHz, or adopt staggered tuning one-tenth multifrequency point wideband filtered, amplify through Low Noise Amplifier MMIC 105 again, guarantee that entire gain is more than 20db, noise is below 2.5db, then by N-type needle electric coupler and the coaxial cable that is connected the base station, lightning arrester connects, and transmits signals to the multi-mode radio frequency receiver module.
This technical scheme is to adopt software engineering that the multimode time signal is carried out demodulation, for containing existing four kinds of satellite navigation system time services, the broadband time-service active antenna is received bandwidth be extended to 1620MHz, increase GLONASS narrow band filter 201 in the multi-mode radio frequency receiver module, its centre frequency is 1602.56MHz bandwidth 10MHz; A multimode signal selector 209 was set before frequency mixer 202, the major function of this selector 209 is that the high-frequency signal incoming level to the input radio frequency receiver detects, or carrying out demodulation by the time signal of acquiescence, time signal is strong through relatively judge selecting, pulse code distortion smaller is as the time service main signal; Multimode signal selector 209 is responsible for monitoring by the signal level detecter 210 that independently arranges or be arranged on access control processor 207, corresponding is that intermediate frequency integrated filter 211 able to programme is made corresponding IF spot and frequency band change action according to the control command of signal level detecter 210 or access control processor 207 simultaneously, to guarantee digital demodulator 212 accurate demodulation; Frequency mixer 202 can arrange one, or switches synchronously local frequency; LNA wideband low noise amplifier 205, A/D analog to digital converter 206 are arranged on after the frequency mixer, to guarantee intermediate-frequency filter 211 needed number intermediate-freuqncy signal and gain amplifiers able to programme.Other is the same.As shown in Figure 2.
In view of whether GLONASS satellite carrier frequency changes frequently and how to change frequently, all will affect the enforcement of the present invention's another kind technical scheme, so the present invention only is explained as an example of the downlink carrier frequency parameter of current transmission example; In addition because software programmable intermediate frequency filtering and digital demodulation techniques are ripe; programmable filter software also can have different pattern and the versions write with time service digital demodulation software; even change can not change with the Big Dipper two on behalf of the compatible receiving mode of main multimode yet; therefore; all identical with principle with the present technique implementation or equivalents; its essence all falls into the row of the present invention's protection, be engaged in these those skilled in the art should with understanding.
Claims (8)
1. big dipper multi-mode time service receiving device comprises broadband time-service active antenna and multi-mode radio frequency receiver module two parts, wherein the broadband time-service active antenna is by broadband ceramic dielectric reception antenna, band-pass filter, the low noise field-effect amplifier, broadband band-pass filter, Low Noise Amplifier MMIC, lightening surge preventing impacts circuit, the power supply voltage stabilizing circuit, contain the double-sided printing copper-clad plate of microstrip circuit, the N-type needle electric coupler forms, it is characterized in that: described broadband ceramic medium antenna is arranged at the one side of printing copper-clad plate, and is connected to the band-pass filter input by lead-in wire; Band-pass filter, low noise field-effect amplifier, broadband band-pass filter, one chip amplifier and lightening surge preventing impact circuit and the power supply voltage stabilizing circuit is positioned at the another side of printing copper-clad plate, split in two metallic enclosures, band-pass filter and low noise field-effect amplifier place in the metallic enclosure, and remaining circuit places in another shielding cavity.
2. big dipper multi-mode time service receiving device according to claim 1, it is characterized in that: described ceramic medium antenna is broad-band reception antenna, and the receive frequency of this ceramic medium antenna is respectively 1561.098MHz and the 1575.42MHz of GPS, Galileo, the 1602.56MHz of GLONASS in " two generations of the Big Dipper ".
3. big dipper multi-mode time service receiving device according to claim 1 is characterized in that: described broadband band-pass filter adopts Ceramic Dielectric Filter part or SAW (Surface Acoustic Wave) device, and the frequency response bandwidth is 1550 to 1580MHz, or extends to 1620MHz; Or adopt staggered tuning band pass filter, wherein f
01Be the 1561.098MHz in " two generations of the Big Dipper ", f
021575.42MHz for GPS and Galileo; f
031602.56MHz for GLONASS.
4. big dipper multi-mode time service receiving device according to claim 1, it is characterized in that: described broadband time-service active antenna basic mechanical design feature index is:
(1) frequency range [MHz]: 1550-1620
(2) gain [dBi]:＞20
(3) noise factor [dB]:＜2.5@+25 ℃,＜3.0@+80 ℃
(4) Out-of-band rejection [dB]: fo=1585MHz
fo±30MHz ＞5
fo±50MHz ＞20
fo±100MHz ＞50
(5) input and output voltage standing-wave ratio :≤2.0
(6) Anti-surging (impact) immunity to interference performance meets
GB/T17626.5-1999 idt IEC 61000-4-5:1995 standard
Surge waveform: CWG composite wave, 1.2/50 μ s, 8/20 μ s
Voltage peak [V]: 〉=2000
Number of pulses: 10
(7) signal time delay is less than 5ns.
According to claim 1 described multi-mode radio frequency receiver module by multimode narrow band filter, frequency mixer; Shared frequency comprehensive generator, intermediate frequency integrated filter, AGC automatic gain amplifier, A/D analog to digital converter and an access control processor, network interface; Multimode signal selector, signal level detecter, intermediate-frequency filter able to programme, digital demodulator form, it is characterized in that: adopt the method for integrated circuit to be produced on one or two chip, wherein, frequency mixer, comprehensive frequency generator, intermediate frequency integrated filter, AGC automatic gain amplifier, A/D analog to digital converter are integrated on the chip, and access control processor is integrated on another chip; Or all be integrated on the chip; Adopt the software engineering demodulation, frequency mixer, comprehensive frequency generator, multimode signal selector, signal level monitor, LNA wideband low noise amplifier, A/D analog to digital converter are integrated on the chip, and intermediate-frequency filter able to programme, digital demodulator, access control processor are integrated on another chip; The multi-mode radio frequency receiver module is installed and is mounted on one and prints in the copper-clad plate.
6. according to claim 1,5 described multi-mode radio frequency receiver modules, it is characterized in that: described multimode narrow band filter adopts Ceramic Dielectric Filter part or SAW (Surface Acoustic Wave) device, and the intermediate-frequency bandwidth of GPS is 2.046MHz; The intermediate-frequency bandwidth of two generations of the Big Dipper and Galileo is 4.092MHz, and GLONASS intermediate-frequency bandwidth is 10MHz.
7. according to claim 1,5 described multi-mode radio frequency receiver modules, it is characterized in that: described intermediate frequency integrated filter is for can write intermediate-frequency filter; Or adopting the discrete device settings such as Ceramic Dielectric Filter or surface acoustic wave, its centre frequency depends on the selection of local frequency, is arranged on 1 to 30MHz.
8. according to claim 1,5 described big dipper multi-mode time service receiving devices, it is characterized in that: a multimode signal selector was set before frequency mixer, the major function of this selector is that the high-frequency signal incoming level to input multi-mode radio frequency receiver module detects and compare, and signal is strong to select, pulse code distorts smaller is as the time service main signal; The multimode signal selector is responsible for monitoring by the signal level detecter that independently arranges or be arranged in the access control processor, corresponding is that intermediate-frequency filter able to programme is made corresponding IF spot and frequency band change action according to the control command of signal level detecter or access control processor simultaneously, LNA wideband low noise amplifier, A/D digital to analog converter are arranged on after the frequency mixer, to guarantee the required digital intermediate frequency signal of intermediate-frequency filter able to programme and gain amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210195134 CN102932020A (en) | 2012-06-14 | 2012-06-14 | Beidou multimode time service receiving device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210195134 CN102932020A (en) | 2012-06-14 | 2012-06-14 | Beidou multimode time service receiving device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102932020A true CN102932020A (en) | 2013-02-13 |
Family
ID=47646744
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201210195134 Pending CN102932020A (en) | 2012-06-14 | 2012-06-14 | Beidou multimode time service receiving device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102932020A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106291623A (en) * | 2015-05-25 | 2017-01-04 | 张建城 | Big dipper multi-mode timing and navigation radio-frequency front-end Antenna Assemblies |
| CN111077762A (en) * | 2018-10-22 | 2020-04-28 | 张建城 | Beidou multimode time service receiving device |
| CN111279283A (en) * | 2018-12-27 | 2020-06-12 | 深圳市大疆创新科技有限公司 | Control method and device, unmanned aerial vehicle and storage medium |
| CN111279282A (en) * | 2018-12-27 | 2020-06-12 | 深圳市大疆创新科技有限公司 | Time service method, switching method, device, control system and unmanned aerial vehicle |
| CN111279671A (en) * | 2018-12-27 | 2020-06-12 | 深圳市大疆创新科技有限公司 | Control method and device, unmanned aerial vehicle and storage medium |
| CN113541731A (en) * | 2021-09-08 | 2021-10-22 | 中国商用飞机有限责任公司 | Method, system, and medium for automatically switching to a backup tuning system |
| CN114051276A (en) * | 2021-11-18 | 2022-02-15 | 许昌许继软件技术有限公司 | Serial time code time service method, system and electronic equipment |
-
2012
- 2012-06-14 CN CN 201210195134 patent/CN102932020A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106291623A (en) * | 2015-05-25 | 2017-01-04 | 张建城 | Big dipper multi-mode timing and navigation radio-frequency front-end Antenna Assemblies |
| CN111077762A (en) * | 2018-10-22 | 2020-04-28 | 张建城 | Beidou multimode time service receiving device |
| CN111279283A (en) * | 2018-12-27 | 2020-06-12 | 深圳市大疆创新科技有限公司 | Control method and device, unmanned aerial vehicle and storage medium |
| CN111279282A (en) * | 2018-12-27 | 2020-06-12 | 深圳市大疆创新科技有限公司 | Time service method, switching method, device, control system and unmanned aerial vehicle |
| CN111279671A (en) * | 2018-12-27 | 2020-06-12 | 深圳市大疆创新科技有限公司 | Control method and device, unmanned aerial vehicle and storage medium |
| WO2020133105A1 (en) * | 2018-12-27 | 2020-07-02 | 深圳市大疆创新科技有限公司 | Timing method, switching method, apparatus, control system, and unmanned aerial vehicle |
| WO2020133104A1 (en) * | 2018-12-27 | 2020-07-02 | 深圳市大疆创新科技有限公司 | Control method and apparatus, and unmanned aerial vehicle and storage medium |
| CN113541731A (en) * | 2021-09-08 | 2021-10-22 | 中国商用飞机有限责任公司 | Method, system, and medium for automatically switching to a backup tuning system |
| CN113541731B (en) * | 2021-09-08 | 2021-12-17 | 中国商用飞机有限责任公司 | Method, system, and medium for automatically switching to a backup tuning system |
| CN114051276A (en) * | 2021-11-18 | 2022-02-15 | 许昌许继软件技术有限公司 | Serial time code time service method, system and electronic equipment |
| CN114051276B (en) * | 2021-11-18 | 2024-04-12 | 许昌许继软件技术有限公司 | Serial time code time service method, system and electronic equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101841341B (en) | Big dipper multi-mode time service receiving device | |
| CN102932020A (en) | Beidou multimode time service receiving device | |
| CN101800363A (en) | Integrated double-mode time-service active antenna and double-mode analog-digital demodulation module | |
| CN101027892B (en) | Multi-mode radio with interference cancellation circuit | |
| CN101453228B (en) | Common station address interference elimination system and method | |
| CN203522718U (en) | Short-wave wide-band receiver with large dynamic range | |
| CN102928855A (en) | Beidou multimode time service receiving device | |
| CN201388192Y (en) | Big Dipper multi-mode time service receiving device | |
| CN107888276B (en) | Multi-frequency band multi-mode modulation and demodulation device | |
| CN103781085A (en) | Multi-frequency range TETRA digital cluster detection method and apparatus | |
| CN109975772B (en) | Multi-system radar interference performance detection system | |
| CN102291157B (en) | Multi-system channel multiplex circuit | |
| CN102377027A (en) | Active antenna and method for calibrating active antenna | |
| CN102761382A (en) | Method, system and correlated device for determining isolation between antennae | |
| CN201374694Y (en) | Integrated dual-mode timing active antenna and dual-mode analog/digital demodulation module | |
| US20140308892A1 (en) | Smart upconverter for broadband satellite communication | |
| US20080137561A1 (en) | Rf repeater used for time division duplexing and method thereof | |
| CN212413151U (en) | Under-sampling device for high-speed frequency hopping communication | |
| CN104253628A (en) | Short-wave pre-and-post-selector | |
| CN213879818U (en) | Support MIMO's 5G room and divide device | |
| CN111077762A (en) | Beidou multimode time service receiving device | |
| CN204465876U (en) | The cladding system of multi-service compartment system | |
| CN101752653A (en) | Double-mode time service active antenna | |
| CN102624438B (en) | Satellite data collecting and receiving machine | |
| CN201118558Y (en) | Short wave digital broadband transmission network device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130213 |