CN203519823U - High-power shortwave broadband transmit-receive switch - Google Patents
High-power shortwave broadband transmit-receive switch Download PDFInfo
- Publication number
- CN203519823U CN203519823U CN201320668814.3U CN201320668814U CN203519823U CN 203519823 U CN203519823 U CN 203519823U CN 201320668814 U CN201320668814 U CN 201320668814U CN 203519823 U CN203519823 U CN 203519823U
- Authority
- CN
- China
- Prior art keywords
- circuit
- input end
- circuits
- transmit
- output terminal
- 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
Images
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The utility model provides a high-power shortwave broadband transmit-receive switch, which comprises a switching circuit, a protection circuit and a single-polarity pulse circuit, wherein the switching circuit is divided into two parts: a transmitting circuit from a transmitter to an antenna, and a receiving circuit from the antenna to a receiver; the protection circuit is used for overcurrent protection; and the single-polarity pulse circuit provides gating big pulses for transmit-receive sharing. The high-power shortwave broadband transmit-receive switch is mainly used for high-frequency radar systems and shortwave communication systems, and provides a reliable and stable platform for achieving the transmit-receive sharing. When the system operates in the transmitting period, the transmit-receive switch can connect the antenna and the transmitter as well as disconnect the antenna and the receiver quickly and rapidly; and in the receiving period, the transmit-receive switch can connect the antenna and the receiver as well as disconnect the antenna and the transmitter quickly and rapidly. The high-power shortwave broadband transmit-receive switch not only protects the receiver of a shortwave system against being damaged, but also greatly reduces the occupied space of the antenna, and is one of the key components of the high-frequency radar systems and the shortwave communication systems.
Description
Technical field
The utility model belongs to shortwave technical field, particularly a kind of high-power short wave bandwidth transmit-receive switch.
Background technology
High-frequency ground wave radar is operated in short-wave band, and it utilizes vertically polarized wave, at the seawater surface diffraction propagation of high conductivity, can detect the sighting distance mobile ships in sea, low flyer and large-area ocean dynamics state parameter in addition.For surveying ocean surface dynamic factors, remote high-frequency ground wave radar generally adopts phased array antenna or monopole crossed loops antenna, in order to obtain high sensitivity and high precision, the antenna aperture of phased array antenna is very large, may reach hundreds of rice to thousands of rice, find by the sea and can provide the area of this radar station of construction by no means easy, in portable high frequency groundwave radar, also need a quarter-wave monopole antenna as emitting antenna and a monopole crossed loops antenna as accepting antenna, two antennas will inevitably make portable radar system become complicated, also can make the difficulty of setting up of antenna increase, and need the area that area occupied is larger.Short wave communication is a kind of of wireless communication, be operated in short-wave band, mainly contain the propagation of ground wave, the modes such as sky wave propagation and direct wave propagation, in Shortwave Communication System, in order to reduce system cost, reduce volume and the weight of machine system, a lot of Shortwave Communication System all use one pair of antenna to realize transmit-receive sharing function, fast development along with modern military technology, electronic warfare, the development level of information war is more and more higher, for the status of having the advantage in the electronic countermeasure in modern war, hold the initiative of information war, the emissive power of Shortwave Communication System is also increasing, this will can transmit larger emissive power with regard to transmit-receive switch, simultaneously in order to meet the needs of group-net communication, each communication system needs to accept, process and send a large amount of information, therefore also more and more higher to the requirement of transmit-receive switch, particularly at electronic countermeasure, in electronic interferences, want effectively to suppress opponent, just must on transmit signal power, have overwhelming superiority, the requirement that all these are new, all need transmit-receive switch to have by power large simultaneously, each interport isolation is high, the switch speed of switch is fast, there is the features such as highly reliable: in the application of communication countermeasure simultaneously, for adapting to frequency hopping, follow the tracks of the needs that disturb, scout jamming equipment and must possess the ability that has quick conversion between transmitting-receiving, and can not exert an influence to reconnaissance equipment while requiring broadband interference, this just requires the slewing rate of transmit-receive switch to want fast, it is large that want in broadband, loss is little, and can bear certain power, in HF Communication Systems of Naval Vessel, naval vessel is very important with short wave communication on the bank, for saving resource is simultaneously also in order to make communication system more succinct, utilizes transmit-receive switch that one pair of antenna receiving-sending is shared very necessary.Also there is in recent years the development of transmit-receive switch, be mainly used in microwave radar and microwave communication and power little, as TR assembly, be applicable to that the research of high-power transmit-receive switch of short-wave band is fewer and technology is also immature: the interim Wide-Band T/R Switch for HF Ground Wave Radar of Wuhan University Journal (Edition) the 47th volume the 5th for example, this transmit-receive switch is mainly used in high-frequency ground wave radar OSMAR2000, it has been realized preferably one pair of antenna receiving-sending and has shared, on-off circuit is succinct, performance has also reached required index, but the bipolar pulse circuit that its gating pulse circuit adopts triode to form, circuit structure more complicated, unstable and easily burn when working long hours, and because adopting single PIN diode structure isolation, on-off circuit can only reach 81dB left and right, the interim high-power transmit-receive switch of broadband through type of radio engineering the 28th volume the 5th and for example, this transmit-receive switch is applied to the frequency hopping interference equipment in system in communication countermeasure, solved better a difficult problem for transmit-receive sharing in frequency hopping interference equipment, but be about as 40us the switching time of its transmit-receive switch.Therefore their major defect is: hardware system is unstable, can not work long hours, and systematic comparison is complicated, and the switching time of transmit-receive switch is longer, and the noise power of being introduced receiver by transmit-receive switch is larger, and power attenuation is also larger.
Utility model content
The problem existing for background technology, the utility model provides a kind of high-power short wave bandwidth transmit-receive switch.
For solving the problems of the technologies described above, the utility model adopts following technical scheme:
A high-power short wave bandwidth transmit-receive switch, comprises on-off circuit, holding circuit, unipolar pulse circuit; On-off circuit comprises radiating circuit, receiving circuit, the output terminal of radiating circuit is connected with the input end of holding circuit, the output terminal of holding circuit is connected with the input end of receiving circuit, and unipolar pulse circuit San road output terminal is connected with the power input of on-off circuit; Holding circuit is current foldback circuit.
Described unipolar pulse circuit comprises shaping circuit, driving circuit, IGBT half-bridge circuit; The output terminal of shaping circuit is connected with the input end of driving circuit, and the two-way output terminal of driving circuit is connected with the two-way input end of IGBT half-bridge circuit.
Described radiating circuit comprises two PIN diode symmetric circuits, filtering circuit, two biasing circuits, two bypass circuits, block isolating circuit; The output terminal of filtering circuit is connected with the input end of two PIN diode symmetric circuits, the input end of two biasing circuits is connected with output terminal with the input end of two PIN diode symmetric circuits respectively, the input end of two bypass circuits be connected with the input end of two biasing circuits respectively, the output terminal of two PIN diode symmetric circuits is connected with the input end of block isolating circuit.
Described receiving circuit comprises two PIN diode symmetric circuits, single PIN pipe circuit, filtering circuit, two biasing circuits, two bypass circuits, block isolating circuit, coupled circuit; The output terminal of filtering circuit is connected with the input end of two PIN diode symmetric circuits, the input end of two biasing circuits is connected with the input end of two PIN diode symmetric circuits, the output terminal of two PIN diode symmetric circuits respectively, the input end of two bypass circuits be connected with the input end of two biasing circuits respectively, the output terminal of two PIN diode symmetric circuits is connected with the input end of block isolating circuit.
Described filtering circuit is T-shaped high-pass filtering circuit.
Described filtering circuit is high-pass filtering circuit.
The utility model is mainly used in HF radar system and high-power Shortwave Communication System.The utility model is used an antenna to realize transmit-receive sharing: the transmitting phase, make to the utility model fast and reliable antenna and transmitter connect and disconnect with receiver, high-power transmitting gone out through antenna transmission with very little insertion loss, and enter receiver with high high-power the transmitting of isolation blocking-up; In the take over period, make to the utility model fast and reliable antenna and receiver connect and disconnect with transmitter, now miniwatt echoed signal enters receiver with very little loss through antenna, and by radiating circuit, blocks echoed signal and be transferred to transmitter.
Compared with prior art, the utility model adopts new hardware system, unipolar pulse circuit adopts supper-fast IGBT pipe, according to small voltage, control the principle of large voltage, designed and can stablize the switching pulse generative circuit of work fast, make the utility model hardware system stable, reliably, can work long hours, isolation reaches 93dB, insertion loss and loss all reach below 0.4dB, shorter the reaching below 1.5us switching time of transmit-receive switch, and the noise power of introducing receiver is less, power attenuation is also less, systematic comparison is simple, both protected receiver not to be damaged, make again the floor area of antenna greatly reduce, it is one of critical component of HF radar system and Shortwave Communication System.
Accompanying drawing explanation
Fig. 1 is the circuit block diagram of the utility model integral body;
Fig. 2 is that the transmitter of on-off circuit in the utility model is to the radiating circuit schematic diagram of antenna;
Fig. 3 is that the antenna of on-off circuit in the utility model is to the receiving circuit schematic diagram of receiver;
Fig. 4 is the circuit block diagram of unipolar pulse circuit in the utility model;
Fig. 5 is the shaping circuit schematic diagram of unipolar pulse circuit in the utility model;
Fig. 6 is the driving circuit of unipolar pulse circuit in the utility model and the schematic diagram of IGBT half-bridge circuit;
Fig. 7 is the input and output pulse voltage sequential chart of unipolar pulse circuit in the utility model;
Fig. 8 is the two-dimensional distance Doppler spectrogram that the utility model field experiment obtains;
Fig. 9 is Doppler's spectrogram that the utility model field experiment obtains;
Figure 10 is the distance spectrogram that the utility model field experiment obtains.
Wherein, 1-radiating circuit, 2-holding circuit, 3-receiving circuit, 4-unipolar pulse circuit, 4-1
-shaping circuit, 4-2-driving circuit and IGBT half-bridge circuit, 4-3-power module.
Embodiment
Below in conjunction with accompanying drawing and test findings, the utility model is described in further detail.
As shown in Figure 1, the utility model comprises that transmitter in on-off circuit is to the radiating circuit 1 of antenna, holding circuit 2, and the antenna in on-off circuit is to the receiving circuit 3 of receiver, unipolar pulse circuit 4.The output terminal of radiating circuit 1 is connected with the input end of holding circuit 2, and the output terminal of holding circuit 2 is connected with the input end of receiving circuit 3, and unipolar pulse circuit 4 San road output terminals are connected with the power input of on-off circuit; Holding circuit is current foldback circuit.
Radiating circuit comprises two PIN diode symmetric circuits, filtering circuit, two biasing circuits, two bypass circuits, block isolating circuit; The output terminal of filtering circuit is connected with the input end of two PIN diode symmetric circuits, the input end of two biasing circuits is connected with output terminal with the input end of two PIN diode symmetric circuits respectively, the input end of two bypass circuits be connected with the input end of two biasing circuits respectively, the output terminal of two PIN diode symmetric circuits is connected with the input end of block isolating circuit.Fig. 2 is that the transmitter of on-off circuit in the utility model is to the radiating circuit part of antenna, wherein C1, C2, L1 form T-shaped Hi-pass filter, high-power transmitting to transmitter input carried out filtering, and L2 and L3 also can block and make it deliver to smoothly antenna high-frequency signal simultaneously; D11 and D12 are high-power PIN diode, and they form symmetrical structure in circuit, and its side is biasing circuit, and PIN diode presents a very little pure resistance R when positively biased
s(0.5 Ω left and right), its value increases and reduces with forward current, presents a very little capacitor C when anti-inclined to one side
t(1pF left and right), its value is the function of reverse biased.
Receiving circuit comprises two PIN diode symmetric circuits, single PIN pipe circuit, filtering circuit, two biasing circuits, two bypass circuits, block isolating circuit, coupled circuit; The output terminal of filtering circuit is connected with the input end of two PIN diode symmetric circuits, the input end of two biasing circuits is connected with the input end of two PIN diode symmetric circuits, the output terminal of two PIN diode symmetric circuits respectively, the input end of two bypass circuits be connected with the input end of two biasing circuits respectively, the output terminal of two PIN diode symmetric circuits is connected with the input end of block isolating circuit.Fig. 3 is that the antenna of on-off circuit in the utility model is to the receiving circuit of receiver, wherein D21 and D22 are high back-pressure PIN diode, they form symmetrical structure in circuit, its side is biasing circuit, D3, D4, D5, D6, D7 are the low back-pressure PIN diode of miniwatt, its side is biasing circuit, filtering circuit and block isolating circuit, and Fig. 2 and Fig. 3 form on-off circuit jointly.
Unipolar pulse circuit comprises shaping circuit 4-1, driving circuit and IGBT half-bridge circuit 4-2, power module 4-3; The output terminal of shaping circuit is connected with the input end of driving circuit, and the two-way output terminal of driving circuit is connected with the two-way input end of IGBT half-bridge circuit.In the transmitting phase: the VCC1 that unipolar pulse circuit produces is as shown in Figure 4 0V, and VCC2 is 240V, and VCC3 is 24V, and now, the equal positively biased of D11 and D12, presents resistance characteristic, and high-power transmitting enters antenna with very little insertion loss; D21 and D22 are all anti-presents capacitance characteristic partially, and due to reversed bias voltage very large (228V), the very little 0.62pF that is about of capacitance, therefore presents a very large impedance to high-frequency signal, thereby high-power transmitting is blocked at receiving branch, has protected receiver; D3 is anti-inclined to one side; D4, D5, the equal positively biased of D6, D7; they are to entering into the further decay that transmits of receiving branch; the insertion loss of transmitting branch reaches below 0.5dB; whole receiving branch reaches 91dB to the isolation transmitting; thereby make the loss transmitting with very little enter antenna, and protected receiver.In the take over period, the VCC1 that unipolar pulse circuit produces is as shown in Figure 4 12V, VCC2 is 0V, VCC3 is 0V, and now, D11 and D12 are all partially anti-, present capacitance characteristic, the very little 2pF that is about of capacitance, presents a larger impedance to the echoed signal by antenna reception, thereby miniwatt clawback signal is blocked at transmitting branch; D21, D22, the equal positively biased of D3, present resistance characteristic, and forward current is 60mA, and resistance is about 0.7 Ω, thereby make miniwatt echoed signal through receiving branch, enter receiver with very little loss; D4, D5, D6, D7 are all partially anti-, present capacitance characteristic, the very little 2pF that is about of capacitance, useful miniwatt echoed signal is presented to a larger impedance, thereby echoed signal can be attenuated, and whole receiving branch reaches below 0.5dB the decay of echoed signal, and site test proves, echoed signal can be detected preferably, and signal to noise ratio (S/N ratio) is that 30dB is to 40dB.
Fig. 5 is the shaping circuit of unipolar pulse circuit in the utility model, emission control pulse TPIN exports TPOUTH and the TPOUTL two-way gating pulse that edge is precipitous after the shaping of schmidt trigger phase inverter, equally, press earthwave gating pulse TBIN after schmidt trigger phase inverter, export edge precipitous TBOUTH and TBOUTL two-way gating pulse, after shaping, the front and back of the Si road gating pulse of exporting are along all having reached below 1.2us, and shaping effect is better.
Fig. 6 is driving circuit and the IGBT half-bridge circuit of unipolar pulse circuit in the utility model, the utility model adopts IRS2304 as IGBT half-bridge electric drive chip, utilize IRGB4064 to set up IGBT half-bridge circuit: the IRS2304 minimal internal dead space time is 100ns, high-end bias voltage is up to 600V, and the precipitous transmission delay in driving pulse edge generating is short, be therefore the first-selection that drives chip in driving circuit; IRGB4064 is supper-fast IGBT pipe, V
cESup to 600V, to open time delay and be low to moderate 27ns, turn off delay time is low to moderate 79ns, and the half-bridge of composition can stably be exported the high-voltage pulse with precipitous edge.Whole pulsing circuit is exported three tunnel pulse voltages, and VCC1 is 0V and 24V, and VCC2 is 0V and 240V, VCC3 is 0V and 24V, the front and rear side edge of three tunnel pulses is very precipitous reaching below 1.5us all, and unipolar pulse circuit is core of the present utility model, and its performance has directly affected performance of the present utility model.
Fig. 7 is the input and output pulse voltage sequential chart of unipolar pulse circuit in the utility model, and wherein emission control pulse TPIN and pressure earthwave gating pulse TBIN are same same period, and the forward position of TBIN shifts to an earlier date ▽ t compared with TPIN
1, rear edge is compared with TPIN hysteresis ▽ t
2, ▽ t
1with ▽ t
2according to the edge of production burst, determine, doing is like this that receiving branch was turn-offed in advance in the transmitting phase, delays reception, thereby protected receiver in the take over period.The corresponding sequential relationship of VCC1, VCC2 and VCC3 and TPIN, TBIN as shown in Figure 7, when TPIN is high level, VCC1 is low level, VCC1 high level when TPIN is low level, when TBIN is high level, VCC2, VCC3 are high level, and when TBIN is low level, VCC2, VCC3 are low level.
Fig. 8, Fig. 9, Figure 10 are that the utility model is applied in the data plot that in portable high frequency groundwave radar, field experiment obtains, in portable high frequency groundwave radar, its antenna is monopole crossed loops antenna, the utility model makes a monopole in monopole crossed loops antenna as transmit-receive sharing passage, make crossed loops wherein as two receiving cables, a monopole crossed loops antenna relies on transmit-receive switch to realize one three and receives transmit-receive sharing: the transmitting phase, make to transmit-receive switch fast and reliable antenna and transmitter connect and disconnect with receiver; In the take over period, make to transmit-receive switch fast and reliable antenna and receiver connect and disconnect with transmitter.The data plot obtaining from field experiment, can find out, the utility model effect is better, has abundant wind, wave, stream information and target information in data, the signal to noise ratio (S/N ratio) of signal be 30dB to 40dB, can extract better wind, wave, stream and target information.
Claims (6)
1. a high-power short wave bandwidth transmit-receive switch, is characterized in that: comprise on-off circuit, holding circuit, unipolar pulse circuit; On-off circuit comprises radiating circuit, receiving circuit, the output terminal of radiating circuit is connected with the input end of holding circuit, the output terminal of holding circuit is connected with the input end of receiving circuit, and unipolar pulse circuit San road output terminal is connected with the power input of on-off circuit; Holding circuit is current foldback circuit.
2. a kind of high-power short wave bandwidth transmit-receive switch according to claim 1, is characterized in that: described unipolar pulse circuit comprises shaping circuit, driving circuit, IGBT half-bridge circuit; The output terminal of shaping circuit is connected with the input end of driving circuit, and the two-way output terminal of driving circuit is connected with the two-way input end of IGBT half-bridge circuit.
3. a kind of high-power short wave bandwidth transmit-receive switch according to claim 1 and 2, is characterized in that: described radiating circuit comprises two PIN diode symmetric circuits, filtering circuit, two biasing circuits, two bypass circuits, block isolating circuit; The output terminal of filtering circuit is connected with the input end of two PIN diode symmetric circuits, the input end of two biasing circuits is connected with output terminal with the input end of two PIN diode symmetric circuits respectively, the input end of two bypass circuits be connected with the input end of two biasing circuits respectively, the output terminal of two PIN diode symmetric circuits is connected with the input end of block isolating circuit.
4. a kind of high-power short wave bandwidth transmit-receive switch according to claim 1 and 2, is characterized in that: described receiving circuit comprises two PIN diode symmetric circuits, single PIN pipe circuit, filtering circuit, two biasing circuits, two bypass circuits, block isolating circuit, coupled circuit; The output terminal of filtering circuit is connected with the input end of two PIN diode symmetric circuits, the input end of two biasing circuits is connected with the input end of two PIN diode symmetric circuits, the output terminal of two PIN diode symmetric circuits respectively, the input end of two bypass circuits be connected with the input end of two biasing circuits respectively, the output terminal of two PIN diode symmetric circuits is connected with the input end of block isolating circuit.
5. a kind of high-power short wave bandwidth transmit-receive switch according to claim 3, is characterized in that: described filtering circuit is T-shaped high-pass filtering circuit.
6. a kind of high-power short wave bandwidth transmit-receive switch according to claim 4, is characterized in that: described filtering
Circuit is high-pass filtering circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320668814.3U CN203519823U (en) | 2013-10-28 | 2013-10-28 | High-power shortwave broadband transmit-receive switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320668814.3U CN203519823U (en) | 2013-10-28 | 2013-10-28 | High-power shortwave broadband transmit-receive switch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203519823U true CN203519823U (en) | 2014-04-02 |
Family
ID=50378735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320668814.3U Expired - Fee Related CN203519823U (en) | 2013-10-28 | 2013-10-28 | High-power shortwave broadband transmit-receive switch |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203519823U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106405505A (en) * | 2016-09-28 | 2017-02-15 | 武汉大学 | Dual-frequency vector sensor used for HF/VHF radar |
| CN110109082A (en) * | 2019-04-17 | 2019-08-09 | 天津大学 | A kind of Terahertz Active Radar imaging array of shared antenna |
| CN114584119A (en) * | 2022-03-04 | 2022-06-03 | 扬州万方科技股份有限公司 | Wireless communication system receiving and transmitting switch circuit with power-off protection |
-
2013
- 2013-10-28 CN CN201320668814.3U patent/CN203519823U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106405505A (en) * | 2016-09-28 | 2017-02-15 | 武汉大学 | Dual-frequency vector sensor used for HF/VHF radar |
| CN110109082A (en) * | 2019-04-17 | 2019-08-09 | 天津大学 | A kind of Terahertz Active Radar imaging array of shared antenna |
| CN114584119A (en) * | 2022-03-04 | 2022-06-03 | 扬州万方科技股份有限公司 | Wireless communication system receiving and transmitting switch circuit with power-off protection |
| CN114584119B (en) * | 2022-03-04 | 2022-10-11 | 扬州万方科技股份有限公司 | Wireless communication system receiving and transmitting switch circuit with power-off protection |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104954052B (en) | Multi-input/output antenna transmission circuit | |
| CN204031163U (en) | High-power millimeter wave transceiving assembly | |
| CN102412917B (en) | Multiple-antenna measurement system and method based on network analyzer and RF (radio frequency) switch | |
| CN202424728U (en) | Multi-antenna measuring system based on network analysis instrument and radio-frequency switch | |
| CN104090269B (en) | Dual-polarization multifunctional ultra wide band T/R module | |
| CN103941296A (en) | Double-frequency double-antenna ground penetrating radar | |
| CN203519823U (en) | High-power shortwave broadband transmit-receive switch | |
| CN104577332B (en) | Improve spuious isolation closed-loop Tuning Control device and method between antenna | |
| CN204947087U (en) | A kind of anti-interference antenna | |
| CN102891665B (en) | The spectrum control method of all solid-state transmitter pulse modulation waveform | |
| CN106680846A (en) | Anti-interference satellite receiving equipment antenna switching apparatus under shielding condition | |
| CN106027077B (en) | The radio frequency front-end device that integrated carrier wave polymerize and the mobile terminal comprising it | |
| CN105158757B (en) | A kind of radar Multichannel combination control box and its method of work | |
| CN203457154U (en) | Antenna-feed system access device and antenna feed system | |
| CN203289416U (en) | A signal frequency range processing system and a terminal | |
| CN206041951U (en) | Big dynamic decay ware of S wave band | |
| CN114520670B (en) | Ultra-wideband communication system and electronic equipment | |
| CN204634050U (en) | Light signal access type LTE quorum sensing inhibitor system | |
| CN202513878U (en) | Millimeter wave active frequency multiplier integrated circuit | |
| CN110336571B (en) | High-power microwave protection device with self-adaptive frequency selection broadband | |
| CN103607235B (en) | Antenna-feedback system access device and antenna-feedback system | |
| CN203630354U (en) | Radar communication system based on DDS | |
| CN204967795U (en) | Hypophase high L to general frequency synthesizer of C wave band of isolation that makes an uproar | |
| CN206725750U (en) | A kind of VHF ionospheric irregularities detection system transmit-receive switch | |
| CN104597429B (en) | A kind of multi-operation mode transmitting-receiving subassembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140402 Termination date: 20141028 |
|
| EXPY | Termination of patent right or utility model |