CN1190295A - The common receiver for light signal - Google Patents
The common receiver for light signal Download PDFInfo
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- CN1190295A CN1190295A CN97100003A CN97100003A CN1190295A CN 1190295 A CN1190295 A CN 1190295A CN 97100003 A CN97100003 A CN 97100003A CN 97100003 A CN97100003 A CN 97100003A CN 1190295 A CN1190295 A CN 1190295A
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Abstract
The light signal receiver for optical fibre communication system changes the light signal modulated by analog or digital waveform into radio signal. The light signal receiver includes a automatic level controlling circuit which regulates electronic signal gain across wide frequency band; two impedance matching circuits which increase the receiving frequency to 1GHz by means of wide frequency band matching technology expanding frequency band; a RLC impedance matching circuit which forms a resonant circuit maintaining one +/-1 dB fluctuation between lower and higher frequency limits; and one 75 ohm impedance matching circuit which produces one 180 deg phase shift between output and input segnals to reduce reflection loss.
Description
The present invention is about a kind of optical fiber telecommunications system; Particularly about using the common receiver for light signal that a kind of light signal is transformed into analog or digital video (RF) signal.
Under the situation that the traffic (traffic) on information super-highway today (information superhighway) grows with each passing day, optical fiber telecommunications system is for some areas and long provide a kind of important medium apart from video, audio frequency and message transmission.Information is carried on the fiber optic cables according to all multi-frequencies in the wide frequency-band spectrum.When more information " was dumped " (dumped) on coaxial or fiber optic cables, the signal volume in wide frequency-band spectrum will be nervous, thereby cause channel communication congested (traffic congestion).
Typical optical fiber telecommunications system comprises: a transmitter, a receiver and a plurality of fiber optic cables.Transmitter is a modulated light signal with a RF signal transition, and is transferred to the receiver that it is subordinate to via fiber optic cables.Receiver then transforms back into light signal original RF signal.
The traditional type optical receiver comprises impedance matching circuit, this impedance matching circuit frequency range from 50MHz (megahertz) to the narrow frequency range that can use for cable TV (CATV) channel the 550MHz, be used for matched impedance.In than the low frequency spectrum frequency range, these optical receiver restricted information rates of transform (transfer rate).In addition, these receivers all are subject to input power, and are subject to export the influence of radio frequency (RF) jitter.On the receiver output, generally be provided with the protecting against shock voltage protector (surge protectors) and the bias voltage T shape circuit (bias tess) of the combination institute construction that utilizes parasitic capacitance and inductance.The combination of these two kinds of assemblies can cause " loss of turning back " (returnloss).
The object of the present invention is to provide a kind of optical receiver, to utilize relatively large information processing with broad frequency band frequency spectrum.
The present invention includes an optical receiver that an analog or digital light signal is transformed into a rf signal.Optical receiver comprises photodetector, amplifier, impedance matching circuit and automatic control of Electric potentials (ALC) circuit, is used for light signal is changed into the signal of telecommunication, adjusts the signal of telecommunication through changing and the signal receiving velocity is increased to about 1GHz (10
9Conspicuous).
There is the circuit impedance of two impedance matching circuits and this signal band to be complementary, loss so that acquisition evenness (flatness) and maximum are turned back.An outlet side that is coupled to optical receiver in two impedance matching circuits, and comprise 75 Ω (ohm) transmission line of a length-specific, turning back with increase is lost at utmost.And second impedance matching circuit, then in addition construction of the mode of forming with resistor, inductor, capacitor (RLC); And be placed in the optical receiver, to form the resonant circuit that can obtain high smooth performance.
In addition, automatically control of Electric potentials (ALC) circuit adopts a kind of feedback loop, so that during via receiver system, be used for adjusting the gain of this signal at the signal of telecommunication.Monitored decay by the signal of pair amplifier output, can be maintained the stability of receiver output radiofrequency signal with automatic adjustment alc circuit.
And optical receiver of the present invention all promotes its conversion of signals for two kinds of general windows in optical fiber telecommunications system that is second window and the 3rd window.Second window is the light wave about 1310nm (millimicron).Optical attenuation in this scope relatively low (about 0.4dB/Km) is generally used for the provincialism dispensing of cable TV signal, shown in Fig. 4 A.The 3rd window is 1550nm (millimicron) left and right sides light wave.Optical attenuation in this window extremely low (about 0.25dB/Km) is applicable to that the long distance of cable TV signal transmits.Shown in Fig. 4 B, this light signal directly amplifies, and makes cable TV transmit longer distance and more saves cost.
The accompanying drawing simple declaration:
Fig. 1: a general calcspar of an optical fiber telecommunications system of the present invention.
Fig. 2: the calcspar of optical receiver of the present invention.
Fig. 3: at the bandwidth spectrum of multiple fiber optic applications.
Fig. 4 A: the calcspar that is 1310 millimicrons of optical receivers in the system.
Fig. 4 B: the calcspar that is 1550 millimicrons of optical receivers in the system.
Fig. 5 A: the circuit diagram of a kind of impedance matching circuit of RLC mode of the present invention.
Fig. 5 B: the circuit diagram of a kind of impedance matching circuit in the 75 Ω transmission lines of the present invention.
Fig. 6: the circuit diagram of a kind of automatic potential control circuit of the present invention.
Fig. 7 A is for having and do not adding evenness characteristic under the RLC impedance matching circuit of the present invention with graphical display.
Fig. 7 B is in the loss characteristic of turning back that does not add under the 75 Ω transmission line impedance match circuits of the present invention with graphical display.
Fig. 7 C is in the loss characteristic of turning back that has under the 75 Ω transmission line impedance match circuits of the present invention with graphical display.
Reaching preferred embodiment in conjunction with the accompanying drawings is described as follows receiver of the present invention:
With reference now to Fig. 1,, emission and reception comprise video (video), audio frequency (voice), and the calcspar of an optical fiber telecommunications system of the multiple signal of data signal.From wired TV (CATV) transmitter 130 collect from such as-satellite 110 ,-telecommunications tandem office (telcom switching office) 120, and a plurality of signals of telecommunication of a microwave (communication) link (microwave link) 100, and via some fiber optic cables X with many optical signal transmission to an optical receiver 150.Usually and the remote optical receiver 150 of transmitter 130 distances, the light signal that is received is transformed into waits to be dispensed into the signal of telecommunication of selecting such as warps such as government bodies, company or households of being interrogated target.In addition, optical receiver 150 comprises a up link (up-link) transmitter (path of turning back) 160, in order to will be from the signal of receiver, via retrace signal receiver 140, send to the transmitter 130 of cable TV starting point, make the cable TV starting point with such as " personal communication networking " (PCN), radio networking 180 and multiple news between the target such as many households 171,172 and 173 can communicate by letter in talk mode (interactive).
With reference now to Fig. 2,, it is the calcspar of optical receiver 150 of the present invention.Photodetector 210 receiving optical signals, and light signal is transformed into a signal of telecommunication.One signal processing circuit 215 comprises: a preamplifier 220, an automatic potentiometric controller (ALC) 240 and gradient (tilt) circuit 250.It is used for receiving the signal of telecommunication from photodetector 210, and the signal of telecommunication of correspondence is transferred to an impedance matching circuit 230.Preamplifier 220 amplifies a signal of telecommunication, and this signal of telecommunication is too faint because of amplitude usually, so that can't further transmit or be distributed to the customers' place at follow-up coaxial system.For in response to because different for link loss value due to the influence of connector of transmission range, cable quality and temperature fluctuation and environment change, an ALC240 circuit that is coupled to the output of preamplifier 220 promptly produces as the function as the automatic tuning formula attenuator, to keep the stability of receiver 150 output signals.The decay of ALC240 is according to the feedback signal from post amplifier 270 outputs.Gradient circuit 250 will be adjusted from the signal (amplitude is to frequency) of optical receiver 150, so that compensate on follow-up coaxial cable, and the relative signal loss under high frequency.
In optical receiver 150, be provided with two impedance matching circuits 230 and 260, so that the broadband frequency response is increased to 1GHz.Impedance matching circuit 230 is by resistor, inductor, capacitor (RLC) combination, and matched impedance resonates to form along with the frequency shift of the signal of telecommunication, and adjusts shaking together of low-frequency spectra and then the frequency response evenness of acquisition ± 1dB (decibel).Impedance matching circuit 230 then comprises one section 75 Ω transmission line through designated length, be used for absorbing retrace signal and get back in the output of optical receiver 150 to avoid its propagation, using in the future, injection (injected) the noise distortion of coaxial cable T drops to minimum level.Fig. 5 A further illustrates the operational scenario of impedance matching circuit 230, the then detailed effect of showing 75 Ω transmission lines of Fig. 5 B.A post amplifier 270 that is similar to preamplifier 220 is connected to after the impedance matching circuit 230, in order to improve the amplitude of (boost) signal of telecommunication.A/B switch 280 is an alternative multiplexer, is used for selecting: receive the signal of telecommunication of being propagated via photodetector 210; Perhaps, by being connected directly to A/B switch 280 and bypass (bypassing) photodetector 210 from a coaxial cable input Y.
To supply to impedance matching circuit 230 at the signal of telecommunication of the output of A/B switch 280, impedance matching circuit 230 is mated the signal of telecommunication that receives, so that reach the best loss performance of turning back, its method is to absorb to be folded back signal in order to avoid make the distortion noise enter optical receiver 150." loss of turning back " is defined as: 10log (Pi/Pr), and wherein Pr is the RF power that is folded back from receiver; Pi is then for being incident to the incident RF power of receiver.In other words, the loss of turning back is: the incident RF power that is incident to receiver is measured compared to of RF power of being folded back from receiver.Output potential watch-dog 290 is coupled between the input of the output of post amplifier 270 and ALC driver 295, increases or reduce the amplitude of the signal of telecommunication to look the output signal current potential whether be below or above a predetermined better signal current potential.Output potential watch-dog 290 more is used to control A/B switch 280.If be higher than the prearranged signals current potential from the output signal of post amplifier 270, yet from the output signal of post amplifier 270, if output signal is lower than the prearranged signals current potential, this means optical receiver 150 is inoperable; Then alternative A/B switch 280 joins with standby coaxial cable Y, in order to receiving alternative signal input, and then bypass the light input of photodetector 210.
The overall performance of optical receiver 150 mainly is to depend on three parameters, that is: evenness, light turn back loss and optical dynamic range.Frequency response evenness and stability determine by resistor in impedance matching circuit 230 530 and capacitor 520.The numerical value of the evenness and the loss parameter that turns back all most depends on to be the peak frequency response that two impedance matching circuits 260 and 230 are allowed.And the 3rd parameter that is optical dynamic range, then conduct is for a limiting factor of the input power current potential of optical receiver.On the one hand, high input optical power may make circuit overloads, and causes the significantly distortion of synthetic output radiofrequency signal.And on the other hand, low input optical power then produces the low signal current potential, thereby can reduce " signal-noise " ratio.
With reference now to Fig. 3,, is presented on the part of frequency spectrum, at some bandwidth of various signal communications application.The analog catv channel takies the bandwidth between 55MHz and 550MHz.Optical receiver 150 more provides the upper limit of the frequency range from about 550MHz to 1GHz, receives the light signal that is the analog or digital form so that allow.5MHz then keeps to the retrace signal path to the bandwidth of 30MHz and uses.
Fig. 4 A and 4B show: two kinds of alternate embodiments of optical receiver 150; They are designed to receive respectively some light signals in 1310 millimicrons and 1550 millimicrons of wavelength are finished drilling the communication system of doing.In some optical fiber telecommunications systems, some audio frequency and vision signal can be used as is light signal, regards it as the optical wavelength of 1310 millimicrons or 1550 millimicrons, and is carried in optical fiber with differential declines speed.Because lower, so with regard to local information dispensing, be to select 1310 millimicrons of light signals usually 1550 millimicrons decay; And, then select 1550 millimicrons of light signals to long distance communication.And can utilize image intensifer for amplifying optical signals.
In Fig. 4 A, transmitter 410 is distributed to optical receiver 440 with light signal by a fiber optic cables Z.Optical receiver 440 converts light signal to the signal of telecommunication, and signal is amplified so that dispensing (shown in Fig. 4 A).The preferred embodiment of light signal is 1310 millimicrons of wavelength, the light signal of this wavelength usually can be in 30Km transmission signals.Yet, for surpassing the long Distance Transmission of 30Km, can use an image intensifer 420 to increase the amplitude of light signal, general purpose receiver 440 subsequently can be arranged at from transmitter part far away, and preferable operative wavelength is 1550 millimicrons.The general purpose receiver of optical receiver 440 for can on two wavelength of 1310 millimicrons and 1550 millimicrons light signals, operating.
With reference now to Fig. 5 A,, it is an embodiment of impedance matching circuit 230.Impedance matching circuit 230 is selected at a series connection RLC combinational circuit of about 300MHz frequency low-resonance.By impedance matching circuit 230, the evenness of crossing over the frequency response of whole frequency band can be adjusted in 2 decibels, or ± 1 decibel.2 decibels the deviation of signal that is produced between low frequency and high frequency can make that the whole channels in frequency spectrum are all kept certain signal potential.Have the RLC combination of a grounding resistor, can improve the low frequency signal amplitude excursion, lower signal amplitude, but keep high frequency response deviation is remained in 2 decibels the acceptable fluctuation range in low-frequency range.Otherwise,, thereby on display screen, can produce bunch yarn (snowy lines) if the signal amplitude deviation surpasses 2 decibels.
With reference now to Fig. 5 B,, it is an embodiment of impedance matching circuit 260.Impedance matching circuit 260 reductions are turned back to the signal of receiver 150 so that the jamming incoherent signal of induction reaches minimum.The quality of impedance matching is normally with the loss metric that turns back.The loss of turning back is bigger, and then retrace signal is littler, and produces to be smaller than and disturb.Impedance matching circuit 260 comprises one 75 Ω (ohm) transmission line 571, and an inductor 560 and two capacitors 570 and 580 combine, and makes the system impedance coupling reach 75 Ω, and obtains the maximum loss (being better than 16 decibels) of turning back.The length of transmission line 571 cut into by precision the 750MHz signal wavelength 1/4th.Look at coaxial that 180 ° phase change can take place the 750MHz signal of round-trip transmission in the line.Now check a return signal, observe impedance matching circuit 260.The capacitor 580 of little capacitance is open for low frequency signal with the capacitor 570 of high capacitance.Impedance matching circuit 260 effects as a simple transmission line do not exert an influence for low-frequency transmission.When signal frequency was higher, inductor 560 produced parasitic capacitance.Because 180 ° of phase change parasitic capacitances at transmission line 571 change inductance into.Stray inductance and capacitor 580 form a resonance circuit, and shown in Fig. 7 C, fall into the retrace signal in about 900MHz.Clean effect helps frequency range and improves integral body and turn back loss to being better than-16 decibels.
Fig. 6 shows a schematic diagram of automatic control of Electric potentials of the present invention (ALC) circuit 240.Basically, this circuit is one to have the π type attenuator (Piattenuator) of 75 Ω impedances.With three groups of back-to-back diode pair A, B and C assembly and form a kind of π type padding device (Pipad) in addition.The resistance of each diode pair changes along with the electric current of each diode of flowing through.SHUNT_VOL is in order to the bias of control flows through the electric current of diode pair A and C, and SERIES_VOL is in order to the bias of control flows through the electric current of diode pair B.Inductor but stops radio frequency (RF) signal to leak to greatly with so that the DC bias current passes through.In order to weaken to 20dB by 1, but for still keeping the impedance of 75 Ω, each diode pair A, B, and the resistance of C list in the table 1.Wherein, ATTN, Z, Ra, Ra and Rc are respectively diode pair A, the B of alc circuit, the resistance of C.
Table 1: π type padding device with 75 Ω impedances
| ??ATTN | ?????Z | ?????Rb | ??Ra，Rc |
| ??(dB) | ???(ohm) | ????(ohm) | ???(ohm) |
| ????1 | ????75 | ????1305.0 | ????8.7 |
| ????2 | ????75 | ????654.3 | ???17.4 |
| ????3 | ????75 | ????438.6 | ???26.4 |
| ????4 | ????75 | ????331.5 | ???35.8 |
| ????5 | ????75 | ????267.8 | ???45.6 |
| ????6 | ????75 | ????225.8 | ???56.0 |
| ????7 | ????75 | ????196.1 | ???67.2 |
| ????8 | ????75 | ????174.2 | ???79.3 |
| ????9 | ????75 | ????157.5 | ???92.4 |
| ????10 | ????75 | ????144.4 | ??106.7 |
| ????12 | ????75 | ????125.3 | ??138.4 |
| ????14 | ????75 | ????112.4 | ??180.5 |
| ????16 | ????75 | ????103.2 | ??230.7 |
| ????18 | ????75 | ?????96.6 | ??293.1 |
| ????20 | ????75 | ?????91.7 | ??371.3 |
Wherein, SHUNT_VOL and SERIES_VOL be for drawing from radio-frequency potential, is used for automatic gain stablizing radiofrequency signal in same level value, do not influence and be not subjected to the operating temperature of the change of input optical power and optical receiver 150 to change institute.
With reference now to Fig. 7 A, 7B and 7C,, be presented under the situation that comprises and do not comprise impedance matching circuit 260 and impedance matching circuit 230 performance diagram of the evenness and the loss of turning back among the figure.In Fig. 7 A, curve chart is presented under the compensation that has and do not have RLC impedance matching circuit 230, the evenness characteristic of the frequency response of radiofrequency signal.The x axle represents that from 0 to 1GHz frequency spectrum, the y axle is then represented the signal amplitude by 1 decibel of increment.Upper curve figure is presented at the evenness characteristic of the optical receiver that does not have under the impedance matching circuit 230.In wherein, the curve between low frequency 50MHz and high frequency 750MHz (mark) comprises the amplitude excursion greater than 2 decibels.The lower curve figure of Fig. 7 a is presented at the transmission characteristic that comprises under the impedance matching circuit 230.Because the effect of impedance matching circuit 230 will drag down than the amplitude of low frequency signal, with acquisition in the more consistent performance that has less deviation of signal (that is: in ± 1 decibel) between low frequency and the high frequency.Similarly, curve chart in Fig. 7 B and 7C shows the loss characteristic of turning back, and is added on signal under the compensation situation on the receiver outlet side in order to the 75 Ω transmission lines of explanation in having (Fig. 7 C) and shortcoming (Fig. 7 B) impedance matching circuit 260.
To sum up state institute, the present invention has following effect:
The present invention is owing to added impedance matching circuit, and automatic potential control circuit, can obtain the signal frequency response of high-flatness, can obtain stable radiofrequency signal, among the present invention owing to take the wavelength transmission signal grown with the increasing of transmission range, with the decay of further reduction optical signal, corresponding saving cost.
Claims (18)
1, a kind of common receiver for light signal is characterized in that, comprising:
-photodetector is in order to be received in the input optical signal that has most channels through selected frequency band place, input optical signal is transformed into the corresponding signal of telecommunication;
-the first impedance matching circuit is coupled to photodetector, is used for the compensating signal evenness, so that make the power potential of crossing over most channels keep unanimity; And
-the second impedance matching circuit is coupled to first impedance matching circuit, is used for transmission of electric signals to a coaxial cable.
2, optical signal receiver according to claim 1, it is characterized in that, also comprise a signal processing circuit that is coupled between described photodetector and described first impedance matching circuit, it comprises a preamplifier circuit, and it has an input of an output that is coupled to described photodetector.
3, optical signal receiver according to claim 2, it is characterized in that, described signal processing circuit more comprises one automatic electric control circuit, it has an input of an output that is coupled to described preamplifier, in order in the dynamic range for 1310 millimicrons and 1550 millimicrons optical wavelength, mat is adjusted the amplitude of the signal of telecommunication and is kept the stability of the signal of telecommunication.
4, optical signal receiver according to claim 3, it is characterized in that, described signal processing circuit also comprises a gradient circuit, has an input that is coupled to from an output of the accurate control circuit of electrokinetic potential, is used for adjusting the amplitude that the frequency with the signal of telecommunication changes.
5, optical signal receiver according to claim 4 is characterized in that, comprises that more one is used for amplifying the post amplifier of the gain of this signal of telecommunication, has an input that is coupled to described first impedance matching circuit.
6, optical signal receiver according to claim 5 is characterized in that, more comprises a switch, and it has: one first input interface, be coupled to an output of described post amplifier; One second input interface is coupled to the input from a coaxial cable; Reach an output interface, be coupled to an input of described second impedance matching circuit; To be used for the signal of selective reception from described first input interface or second input interface.
7, optical signal receiver according to claim 6 is characterized in that, more comprises an automatic control of Electric potentials drive circuit, and it has: an input, be coupled to described output potential monitoring system circuit; And an output, be coupled to described automatic meta control circuit.
8, optical signal receiver according to claim 7 is characterized in that, more comprises an output potential monitor circuit, and it has; One input interface is coupled to the output interface of described post amplifier, is used for receiving the signal of telecommunication from the output interface of post amplifier; Whether just suitably one first output interface is coupled to described switch, be used for notifying the running of switch optical receiver; And one second output interface, be coupled to described automatic control of Electric potentials drive circuit, be used for controlling the amplitude of the signal of telecommunication.
9, according to the desirable 1 described optical signal receiver that requires, it is characterized in that described second impedance matching circuit comprises one 75 Ω transmission lines, be used for absorbing a retrace signal that is reflected, in order to avoid the noise distortion is injected the output of described second impedance matching circuit.
10, optical signal receiver according to claim 9 is characterized in that, described first impedance matching circuit comprises resistor, inductor, the capacitor of a series connection.
11, optical signal receiver according to claim 10, it is characterized in that, comprise that also one is coupled in the signal processing circuit between described photodetector and described first impedance matching circuit, it comprises a preamplifier circuit, the input that it has an output that is coupled to described photodetector is used for increasing the amplitude of the signal of telecommunication.
12, optical signal receiver according to claim 11, it is characterized in that, described signal processing circuit more comprises an automatic potential control circuit, it has an input of an output that is coupled to described preamplifier, in order to being in the dynamic range of transmissive for 1310 millimicrons and 1550 millimicrons of optical wavelength, mat is adjusted the amplitude of the described signal of telecommunication and is kept the stability of the signal of telecommunication.
13, optical signal receiver according to claim 12, it is characterized in that, described signal processing circuit also comprises a gradient circuit, has an input of an output that is coupled to described automatic potential control circuit, is used for adjusting the amplitude that the frequency with the signal of telecommunication changes.
14, optical signal receiver according to claim 13 is characterized in that, described signal processing circuit more comprises a post amplifier, has an input that is coupled to described first impedance matching circuit, the gain that is used for amplifying this signal of telecommunication.
15, optical signal receiver according to claim 14 is characterized in that, described signal processing circuit more comprises a switch, and it has: one first input interface, be coupled to an output of described post amplifier; One second input interface is coupled to the input from a coaxial cable; Reach an output interface, be coupled to the input of described second impedance matching circuit; To be used for selecting so that receive signal from described first input interface or second input interface.
16, optical signal receiver according to claim 15 is characterized in that, described signal processing circuit more comprises an automatic control of Electric potentials drive circuit, and it has: an input, be coupled to described output potential monitor circuit; And an output, be coupled to described automatic potential control circuit, be used for supplying with the described signal of telecommunication to automatic potential control circuit.
17, optical signal receiver according to claim 16, it is characterized in that, described signal processing circuit more comprises output potential monitoring system circuit, it has: an input interface, be coupled to the output interface of described post amplifier, be used for receiving the signal of telecommunication from the post amplifier output interface; Whether just suitably one first output interface is coupled to switch, be used for notifying the running of switch optical receiver; And one second output interface, be coupled to described automatic control of Electric potentials drive circuit, be used for controlling the amplitude of the signal of telecommunication.
18, having under first impedance matching circuit and the second impedance matching circuit situation, in a wide frequency-band spectrum, be used for light signal is transformed into a kind of method of radiofrequency signal, may further comprise the steps:
Receive a light signal, use described light signal is transformed into radiofrequency signal;
Have under first impedance matching circuit, crossing over wide frequency-band spectrum, the frequency departure of described radiofrequency signal is maintained ± 1 decibel in; And
Have under second impedance matching circuit, absorbing a signal that is reflected, in order to avoid described radiofrequency signal is injected in the noise distortion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN97100003A CN1190295A (en) | 1997-02-05 | 1997-02-05 | The common receiver for light signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN97100003A CN1190295A (en) | 1997-02-05 | 1997-02-05 | The common receiver for light signal |
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| Publication Number | Publication Date |
|---|---|
| CN1190295A true CN1190295A (en) | 1998-08-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97100003A Pending CN1190295A (en) | 1997-02-05 | 1997-02-05 | The common receiver for light signal |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007068145A1 (en) * | 2005-12-16 | 2007-06-21 | Allen Ho | Module with both analog and digital receiving-transmitting |
| CN101136660B (en) * | 2006-08-29 | 2012-04-18 | 中国电信股份有限公司 | Matching absorber for reducing damage of bridge tap to cable transmission performance |
| CN103644926A (en) * | 2013-12-16 | 2014-03-19 | 上海华魏光纤传感技术有限公司 | Optical signal collection system |
| CN107072162A (en) * | 2014-10-16 | 2017-08-18 | 纽海姆有限公司 | Yield QTL in cucumber plant |
| CN107404855A (en) * | 2014-10-16 | 2017-11-28 | 纽海姆有限公司 | Yield QTL in cucumber plant |
-
1997
- 1997-02-05 CN CN97100003A patent/CN1190295A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007068145A1 (en) * | 2005-12-16 | 2007-06-21 | Allen Ho | Module with both analog and digital receiving-transmitting |
| CN101136660B (en) * | 2006-08-29 | 2012-04-18 | 中国电信股份有限公司 | Matching absorber for reducing damage of bridge tap to cable transmission performance |
| CN103644926A (en) * | 2013-12-16 | 2014-03-19 | 上海华魏光纤传感技术有限公司 | Optical signal collection system |
| CN107072162A (en) * | 2014-10-16 | 2017-08-18 | 纽海姆有限公司 | Yield QTL in cucumber plant |
| CN107404855A (en) * | 2014-10-16 | 2017-11-28 | 纽海姆有限公司 | Yield QTL in cucumber plant |
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