CN1200628A - Linearization circuits and methods - Google Patents
Linearization circuits and methods Download PDFInfo
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- CN1200628A CN1200628A CN 97112140 CN97112140A CN1200628A CN 1200628 A CN1200628 A CN 1200628A CN 97112140 CN97112140 CN 97112140 CN 97112140 A CN97112140 A CN 97112140A CN 1200628 A CN1200628 A CN 1200628A
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Abstract
The invention relates to a method for linearizing circuit switching function and its circuit. Said method includes the following steps: receiving original signal to be provided for a circuit system, producing a preset distortion signal for regulating amplitude and phase curve, and combining the preset signal with original signal. Said invented circuit includes a preset distortion circuit, said circuit includes a signal divider, first and second backward diodes and curve regulating circuit, and said signal divider is used for dividing inputted radio-frequency signal into two radio-frequency signals, it possesses two output ends, and two backward diodes are respectively coupled with output ends of the signal divider, and the curve-matching circuit output end is connected with two output ends of the signal divider.
Description
The present invention is relevant for a kind of linearizing method of circuit conversion function and circuit of making, relevant especially multichannel radio RF conversion of signals is laser diode translation function (transfer function) the linearizing method and the circuit of light signal, it is to utilize to preset distorted signal, and the method for the expection distortion in the compensation laser diode output signal improves the linear transformation function of circuit.
In the cable television system of today, need the television channel of larger amt.Typical cable television system comprises the television channel of 60 analog signals, but extends to 80 or more channel.
In an information superhighway system, a cable television system may need 132 or more digital signal channel, info-channel and telephone signal channel.Digital video, data and telephone signal all are modulated on the radio frequency carrier wave.Digital Video System then can be answered demand service (demandservices) and vision signal is provided.
Fiber optic transmission system is being used cause one cable TV transmitting terminal center (headend center) or at present by a call center, with information bearing to a fiber optic service site near the user.Fibre system must rely on the media of optical fiber as transmission.Among this type systematic, can use laser that radio frequency rf signal is converted into light signal, so that in optical fiber, transmit.
For the high fidelity that will guarantee information transmits, the translation function that the RF conversion of signals is become the Laser Devices of light signal must be linear.As if translation function is not linear, will produce harmonic distortion, intermodulation (inter-modulation) distortion between the then parallel channel, and multiple beat frequency phenomenons such as (multiple-beating), just can reduce the video quality of cable TV significantly.Unfortunately, the common neither problem that is enough to avoid distortion of the linear characteristic of the translation function of Laser Devices.
The linearization technique of laser translation function has been the problem that is studied for many years.These methods are usually all very complicated and to carry out cost quite high.The existing people's research of particularly linearizing optical fiber feed-forward technique (feedforward technique).A large portion reason of distortion is owing to work under saturation condition.In saturation condition following operating period, when the current potential of laser signal was higher, the light signal that comes from Laser Devices was lower than corresponding radio frequency rf signal.According to known method, adopt second Laser Devices to produce one according to a kind of known feed-forward technique and preset distortion (pre-distortion) light signal.This presets that the distortion light signal is added in the main light signal again so that compensate for laser part saturated.This kind compensation practice can play a role, but there are three major defects in this kind practice.At first, the wavelength of two laser signals need mate in advance.For example, if,, limited the linearisation effect in optical fiber just then two signals can be advanced with different speed owing to the cause of optical fiber scattering does not match two optical fiber.Secondly, preset in time and the independently change of output meeting of distorted signal and main laser signal, cause the non-linearization of not expecting.The 3rd, the use of multiple device is quite expensive, and the circuit of execution light feedforward is also quite expensive.Therefore, just having to provide a kind of simple in structure, low cost and the solution that presets distortion that is easy to implement.
Fig. 1 is based on one piece of paper of having delivered, wherein show the improvement of the translation function of a microwave amplifier, this piece paper is entitled as that " microwave SSB-AM system presets distortion non-linearities compensator (" Pre-distortion Nonlinear Compensator for Microwave SSB-AM System "); be published in NEC and communication (Electronics and COmmunications in Japan) by people such as Toshio Nojima; Vol.67-B; No.5, in 1984.As shown in Figure 1, the reduction amount of its expression distortion depends on the distorted signal that presets a distorted signal and an amplifier translation function, the amplitude between the two and the matching degree of phase place.Wherein must add amplitude adjustment and phase place and adjust circuit, minimize so that will preset the amplitude error and the phase error of the distorted signal of a distorted signal and an amplifier translation function.Paper according to narrow-band is used can adopt the accent of amplitude and the accent of phase place.
In broadband system, by the present invention, its frequency range is between 50Mhz to 750MHz, even up to 1000MHz.Such frequency extending range letter has covered 4 to 6 octaves.As well-known in the art, distortion is related with frequency.Can utilize one to preset distorted signal, amplitude adjustment relevant with frequency and phase place adjustment guarantee can make in the whole frequency range scope the enough significant reduction of distortion.
The object of the present invention is to provide a kind of utilization to preset method and circuit that the distortion compensation mode improves circuit linearisation translation function.
For achieving the above object, the present invention takes following measure:
The present invention adopts a kind of distortion circuit that presets, and revising the non-linear of laser or other electrical systems or device, it can produce and can compensate one of pending systematic distortion and preset distorted signal.According to the present invention, based on the signal compensation principle, this presets distorted signal, and the amplitude that its amplitude comes down to the distorted signal that produced with pending system equates, but phase place is opposite.According to the present invention, preset distorted signal and combine with primary signal, form and preset distorted signal.In one embodiment, presetting distorted signal is to be used to modulate a laser diode or an electrical system.Distorted signal has compensated because laser diode or the caused distortion of other Circuits System have stayed the signal such as the good quality of cable TV CATV image.
According to the present invention, the distortion in the laser signal be eliminated be since added one in selected frequency range scope its amplitude equal the amplitude of expecting distortion, phase place is opposite presets distorted signal.According to the present invention, lower the effect of distortion, depend on and preset distorted signal amplitude error and the phase error between the two that is produced in distorted signal and the system's conversion.Amplitude error is all relevant with frequency with phase error.According to the present invention, in order to produce the light signal that does not have error, as the amplitude curve that presets the distortion frequency function, cooperating phase place to adjust curve provides.
Convert the electrical signal to Laser Devices, can preset distorted signal according to the invention provides input for light signal.In a kind of application of CATV, Laser Devices utilize a direct current DC current offset to obtain a constant luminous power output.The CATV signal of RF frequency range is used for the modulated laser power output.With regard to linear transformation, the deviation of optical output power (P) is to form linear scale with CATV RF electric current (I).Translation function can be expressed as P=A
1I.If translation function is not linear, then translation function just can be expressed as a kind of Taylor series: P=A
1I+A
2I
2+ A
3I
3+ A
4I
4, A wherein
2I
2Be second-order distortion, and A
3I
3It then is third order distortion.
According to the present invention, be to combine with the frequency curve phase-adjusting circuit as the frequency and amplitude curve adjustment of presetting distortion.The secondary that inserts by secondary that laser or other system produced and third order distortion utilization and preset distortion three times and offset.Secondary with preset distortion three times and equate with the amplitude of answering distortion that laser or other system are produced respectively, but phase place is opposite.According to the present invention, be input to a RF signal that presets distortion circuit and be split up into through the main flow signal of a delay line and be used to produce the son stream RF signal that presets distorted signal.This son stream signal is divided into two stream signals again: one supplies the generation secondary to preset distorted signal, and another then presets distorted signal three times for producing.
According to the present invention, preset in the distortion path at a secondary, a variable decay device and an amplifier are used to adjust the amplitude of less important stream signal, thereby have promptly adjusted secondary and preset distorted signal.Secondary signal is cut apart through a dispenser again, to produce two signals of mutual tool 180 degree phase differences.This two signal is by in first and second diode of a difference feed-in phase basis.Each diode respectively has independently biasing control with the third order distortion of balance diode.The signal that comes from two diodes is used to produce a secondary again and presets distortion, and suppresses linear signal and third order distortion signal.Change an amplitude curve presetting the distorted signal amplitude and adjust circuit, be used to produce relevant with a frequency distorted signal that presets, it can be complementary on amplitude with the distortion that system is produced.Can cooperate circuit be used to produce relevant with frequency one with phase curve of frequency variation and preset distorted signal, it can be complementary on phase place with the distortion of laser system.Phase deviation device is used to finely tune the phase place between main delay line and the distortion generation system.
According to the present invention, preset in the distortion path for three times at one, a variable decay device and an amplifier are used to adjust the amplitude of less important stream signal, and then are used to adjust three times again and preset distorted signal.Input signal utilizes a dispenser again and is cut apart to produce two signals.This two signal has identical phase place mutually.At last, these two signals are more respectively by in the separate diode of two couplings of feed-in.Each diode respectively has the control of independently setovering with the amplitude of balance from the second-order distortion of each diode.The signal that comes from two diodes is used to produce one and presets distorted signal and suppress second-order distortion for three times.One can change with the amplitude curve that presets the distorted signal amplitude of frequency change and adjusts circuit, is used to produce a frequency that depends on predetermined distortion, and the distortion of itself and Laser Devices is complementary on amplitude.Adjust circuit with a phase curve of frequency variation and then be used to produce a frequency that depends on predetermined distortion, itself and a laser match each other on phase place.One phase deviation device is used to finely tune the phase difference between main delay line and the distortion generation system.
According to the present invention, secondary and preset distorted signal three times and be combined, and be added in the main signal in the main stream RF signal.The final distorted signal that presets is used to modulated laser device output signal, or the output signal of another electrical system.The RF signal that presets distortion can be promoted the linear characteristic of Laser Devices translation function.
A kind of linearizing method of circuit conversion function that makes of the present invention is characterized in that, comprises the steps:
Reception will be supplied to a primary signal with Circuits System of non-linear conversion characteristic;
Produce the distorted signal that presets of an adjustable amplitude and phase curve, to compensate the non-linear of described Circuits System;
To preset distorted signal combines with primary signal to produce a binding signal;
Described binding signal is provided for described Circuits System.
A kind of linearizing circuit of circuit conversion function that makes of the present invention is characterized in that, comprising:
One first signal splitter, the radiofrequency signal of one input can be divided into first and second radiofrequency signal, first signal splitter has main and less important first signal splitter output, main first signal splitter output provides a main signal, and less important first signal splitter provides a less important signal;
One secondary signal dispenser, has the secondary signal dispenser input that is connected to less important first signal splitter output, the secondary signal dispenser has main and less important secondary signal dispenser output, main secondary signal dispenser output produces a secondary and presets the distortion output signal, and less important secondary signal dispenser output then produces one and presets the distortion output signal three times;
One the 3rd signal splitter, has one the 3rd signal splitter input that is connected to main secondary signal dispenser output, the 3rd signal segmentation has main and less important the 3rd signal splitter output, main the 3rd signal splitter output applies a selected phase deviation to the received signal of the 3rd signal splitter input, and less important the 3rd signal splitter output then applies a phase deviation of spending with described selected phase deviation 180 to the received signal of the 3rd signal splitter input;
Be connected to first and second reversal connection diode of described main and less important the 3rd signal splitter output respectively, first and second reversal connection diode is connected and presets distorted signal to produce a secondary;
One the 4th signal splitter, has one the 4th signal splitter input that is connected to less important secondary signal dispenser output, the 4th signal segmentation has main and less important the 4th signal splitter output, and main and less important the 4th signal splitter output produces the signal that forms same phase mutually;
Be connected to first and second non-reversal connection diode of described main and less important the 4th demultiplexer output respectively, first and second non-reversal connection diode is connected and presets distorted signal three times to produce one; With
Be connected to one first signal combiner of described first and second reversal connection and non-reversal connection diode, with in conjunction with secondary and preset distorted signal three times.
Brief Description Of Drawings
The attenuating value of display distortion among Fig. 1 is as a figure that presets the function of distorted signal and amplitude between the distorted signal that Laser Devices conversions is produced and phase error;
Fig. 2: one of one embodiment of the invention presets the distortion circuit calcspar;
Fig. 3: one embodiment of the invention, can adjust the circuit diagram of the amplitude curve that presets distorted signal;
Fig. 4: the present invention, with respect to the curve synoptic diagram of a kind of amplitude fading characteristic of Fig. 3 circuit;
Fig. 5: one embodiment of the invention, the circuit diagram of the phase curve of adjustment preset signal;
Fig. 6: the phase-delay characteristic curve synoptic diagram of circuit among Fig. 5 of the present invention.
Reaching embodiment in conjunction with the accompanying drawings is described in detail as follows main points of the present invention:
Shown in Figure 2: it is a kind of circuit design that presets distortion circuit 9 of the present invention.Preset distortion circuit 9 and comprise a dispenser 20, a linear radio-frequency (RF) signal delay line 21, colligator 22,23, a dispenser 24 and first and second twice level circuit 24a and 24b.The first secondary circuit 24a produces a secondary and presets distorted signal, and second subprime circuit 24b then produces one and presets distorted signal three times.Dispenser 20 comprises an input 20a, one first output 20b and one second output 20c.A radio frequency (RF) input signal is provided for input terminal 20a (dispenser 20).Dispenser 20 will be imported analog signal and be divided into first and second signal stream output at the output 20b and the 20c of correspondence.The respective signal position standard of the output signal flow on output 20b and 20c, its ratio was 98: 2 to 80: 20 scope.First signal flow is driving laser device 22b ' and optical fiber cable 22b " main signal.Linear RF signal delay line 21 among Fig. 2 comprises an input terminal 21a and a lead-out terminal 21b.The output 20b of dispenser 20 is connected on the input 21a of linear RF signal delay line 21.Colligator 22 comprises first and second input 22a and 22a ', and an output 22b.The output 21b of linear RF signal delay line 21 is connected to the first input 22a of colligator device 22.Dispenser 24 comprises an input 24a ' and first and second output 24b ' and 24b ".Colligator device 23 first and second input 23a and 23a ', and an output 23b. Secondary circuit 24a and 24b respectively comprise input interface 24i and 24i ', and output interface 24o and 24o '.The output 24b ' of dispenser 24 is connected to the input interface 24i of secondary circuit 24a, the output 24b of dispenser 24 " then be connected to the input interface 24i ' of secondary circuit 24b.The output interface 24o of secondary circuit 24a is connected to the input 23a of dispenser 23, and the output interface 24o ' of secondary circuit 24b then is connected to the input 23a ' of colligator 23.Secondary circuit 24a comprises variable decay device 25, amplifier 26, and divider means 27, diode 28 and 29, variable decay device 30 and 31, amplitude curve is adjusted circuit 32, and phase curve is adjusted circuit 33, and phase deviation device 34. Variable decay device 30 and 31 is set during operation, is contributed partly and cancels each other to guarantee to preset for three times distortion and primary signal.Secondary circuit 24b comprises variable decay device 25 ', amplifier 26 ', and dispenser 27 ', diode 28 ' and 29 ', variable decay device 30 ' and 31 ', amplitude curve is adjusted circuit 32 ', and phase curve is adjusted circuit 33 ', and phase deviation device 34 '.
Amplitude curve is adjusted circuit 32 and 32 ' and is shown among Fig. 3.Situation as shown in Figure 4 can be by selected every group of R
1, R
2, L
1, L
2, C
1With C
2Numerical value, can form specific circuit 32 and 32 ' secondary and three translation function measured values that obtain to meet real test and error adjustment in factory or other places.
Variable decay device 25 ' is connected to the input interface 24i ' of secondary circuit 24b and the input of amplifier 26 '.Dispenser 27 ' comprises an input terminal 27 ' a, and first and second lead-out terminal 27b ' and 27b ".Variable decay device 30 ' is connected between the input of a selected reference voltage (REF) and diode 28 '.Variable decay device 31 ' then is connected between the input of a selected reference voltage (REF) and diode 29 '.Variable decay device 30 ' and 31 ' is set during operation, presets the counteracting of distortion to guarantee secondary.
Amplitude curve cooperates circuit 32 ' to comprise input and lead-out terminal 32i ' and 32o '.Amplitude curve cooperates the input terminal 32i ' of circuit 32 ' to be connected on diode 28 ' and 29 ', the latter is connected to each other again, so that by the output 27 ' b and the 27 ' b ' of dispenser 27 ', flow to amplitude curve by two diodes 28 ' and 29 ' and adjust circuit 32 '.Amplitude curve is adjusted circuit 32 ' and is connected on the phase curve adjustment circuit 33 '.Phase curve is adjusted circuit 33 ' and is connected to phase deviation device 34 ' again.Phase deviation device 34 ' is connected to secondary circuit output interface 24o '.
The analog RF input signal is partitioned into two streams by dispenser 20 according to certain ratio.Preferable ratio is between 98: 2 to 80: 20 scope.In an embodiment, the ration of division is 90: 10.But, the present invention still can operate under other ratio.Main stream comprises coaxial delay line 21, and it can compensate by the caused delay of signal path lengths, and the secondary that is produced by each corresponding secondary circuit 24a and 24b and preset the electronic delay of distortion three times.In one embodiment, the path of main line is approximately 14 inches.Less important stream is again by 24 isometric cutting apart of dispenser.The generation that the path of secondary circuit 24a can provide secondary to preset distortion, the path of secondary circuit 24b then can provide the generation of presetting distortion for three times.
Preset in the distortion at the secondary by secondary circuit 24a, secondary presets the amplitude of distorted signal and is controlled with amplifier 26 by variable decay device 25.Variable decay device 25 can comprise a resistor network.Decay amount according to an embodiment can reach 5dB.The input of RF signal is exaggerated the device 26 needed signal level that is amplified to.Its result's signal is then cut apart by dispenser 27 again.The output 27b of dispenser 27 provides the phase deviation of one 180 degree with respect to the signal of input 27a.The output 27b ' of dispenser 27 does not then provide phase deviation with respect to input signal.Two output signals that come from dispenser 27 are given the diode 28 and 29 of two couplings reversal connection by coupling capacitively again. Diode 28 and 29 input signal preferably depart from mutually with the phase places of 180 degree, but the present invention all can go in the phase deviation scopes of about 180 ± 30 degree.Each diode 28 and 29 respectively has its control of independently setovering.Except that transmitting separately the linear input signal, each diode 28 and 29 produces secondary separately, three times and the more distortion of high order.The amount distortion that comes from diode 28 and 29 can be utilized biasing networks 30 and 31 and adjusted respectively.Linear signal is adjusted to the amplitude of the signal that comes from diode 29 with the odd distortion that is produced by diode 28 and equates, but its phase phasic difference 180 degree, and at this moment, comes from diode 28 and presets distortion with 29 even and then be set the identical phase place of tool.Variable capacitance is used to finely tune the phase difference between signals that comes from diode 28 and 29.Variable decay device then is used to produce the difference of vibration between the signal that the characteristic that presets distortion and fine setting come from diode 28 and 29.Two signals are combined on the tie point between diode 28 and 29, preset distorted signal so that only produce an even.The amplitude curve adjustment circuit 32 of frequency is used for adjusting an amplitude that presets distorted signal as the function of frequency, so that compensation laser is with the amplitude distortion of frequency change.33 in circuit of phase curve adjustment is used for adjusting a phase place that presets distorted signal as the function of frequency, so that the distortion of compensation laser signal on phase place.Amplitude curve adjusts circuit and phase curve is adjusted the series combination tolerable correction frequency of circuit according to the distortion that becomes.One electric capacity is used as a phase deviation device, so that adjust the phase difference between main delay line and the secondary circuit 24a.The phase curve of frequency is adjusted circuit 33 and be illustrated the frequency plot coupling that can be used to make laser in Fig. 5.
Preset in the distortion path at three times by secondary circuit 24b, the amplitude that presets distorted signal for three times is to be controlled with amplifier 26 ' by variable decay device 25 '.Variable decay device 25 ' can comprise a resistor network.Decay reaches 5dB in the present embodiment.The input of RF signal is exaggerated device 26 ' and is amplified to needed signal level.Its output signal is then cut apart by dispenser 27 ' again.Two outputs of dispenser 27 ' all do not have the skew of phase place.Two output signals that come from dispenser 27 ' are then capacitively coupled and are presented the reversal connection diode 28 ' and 29 ' to two couplings again.Each diode 28 ' and 29 ' respectively has its control of independently setovering.Each diode 28 ' and 29 ' produces secondary separately, three times and the distorted signal of high order more, and carry linear input signal separately.The amount distortion that comes from diode 28 ' and 29 ' can be utilized respectively and comprise, for example, fixing and variable decay device is adjusted with the suitable biasing networks of+5 volts reference voltage.The even distortion that diode 28 ' and 29 ' is produced is adjusted to has identical amplitude, but its phase phasic difference 180 degree, and its odd presets then identical or deviation+or-30 degree in phase place of distorted signal.Variable capacitance is used to the phase difference between signals that fine setting comes from diode 28 ' and 29 '.Variable decay device then is used to finely tune the difference of vibration between the signal that comes from diode 28 ' and 29 '.Two signals are combined on the tie point between diode 28 ' and 29 ', preset distorted signal so that produce an odd.The adjustment of this deviation can utilize fixing or conditioned circuit is finished.For example, an inductance can be used for producing a fixing deviation, when each adjustable curve filter element of adjustment as shown in Figure 3 can produce an aberration curve.Corresponding phase curve is adjusted circuit 32 ' and is adjusted the distortion that circuit 33 ' tolerable is proofreaied and correct associated frequencies with amplitude curve.An electric capacity can be used as a phase deviation device, so that adjust the phase difference between main delay line and the secondary circuit 24b.The phase curve of associated frequencies is adjusted circuit 33 ' is illustrated the associated frequencies that is used for compensating laser in Fig. 5 the distortion of Laser Devices on phase place.
Secondary with preset the combined device 23 of distorted signal three times and combined, and add among the main signal, so that produce output RF signal with the distortion of presetting at output 22b.Electric capacity is used for finely tuning the phase relation between the distorted signal of presetting of the main signal at input 22a place of colligator 22 and input 22a ' part.The distorted signal that presets that comes from secondary circuit 24a and 24b is adjusted to amplitude and equates, but to produce the phase place of the distortion that system will produce opposite with a laser or other distortions.The distorted signal that presets distortion and reality that is produced is because the adjustment effect of amplitude curve and the phase curve adjustment of being set up have been cancelled each other in the scope of whole selected frequency range.Preset the RF signal of distortion and therefore just can in a broad frequency range of RF signal input, set up the full linearization that laser or other distortions produce the translation function of system.
Fig. 3 shows that according to one embodiment of the invention one amplitude curve is adjusted a circuit diagram of circuit 39.Amplitude curve circuit 39 is included in a common node 40 ' and goes up interconnected first and second resistance 40 and 41.Amplitude curve circuit 39 more comprises an inductance 42 (L
1) and a variable capacitance 43 (C
1), both are connected in series mutually.Inductance 42 is connected in parallel with variable capacitance 43 and resistance 40 and 41.Circuit 39 more comprises an electricity group 44 (R
1), according to one embodiment of the invention, it can be 162 ohm resistance.Electricity group 44 is connected in parallel with resistance 40 and 41.Circuit 39 more includes the resistance 45 (R that are connected in series
2) and variable capacitance 46 (C
2), be connected between node 40 ' and the earth point.Circuit 39 more includes inductance 47 (L
2).Resistance 45 is connected on the common node 45 ' with electric capacity 46.Inductance 47 is connected between node 45 ' and the earth point.It has set the input and the output impedance of circuit 39.Resistance R
1With R
2Set the maximum decay of circuit 39.For example, work as R
1=162 ohm and R
2In the time of=34.7 ohm, maximum decay is to be 10 (+) dB.Inductance L
1, L
2With capacitor C
1, C
2Set the shape of decay curve.With regard to laser preset distortion, the amplitude curve adjustment decay according to the present invention one presets distorted signal preferably was set to frequency from high to low, exported to obtain the higher distortion of presetting in higher frequency.This true distortion that can be a laser affords redress, and this kind compensation reaches maximum in the high-frequency range of its operation frequency range.R
1, R
2, L
1, L
2, C
1With C
2The embodiment of the curve of numerical value is shown among Fig. 4.In Fig. 4, numerical value R is the resistance of representing with ohm, and C is an electric capacity, and L is an inductance.Preset distortion and be adjustable to just that the distortion curve on inverse ratio ground and Laser Devices or other instruments is complementary according to of the present invention, and offset the interior distortion of scope of whole selected frequency range.
Fig. 5 is the line map that a phase curve of the present invention is adjusted circuit 49, presets the distorted signal phase curve for adjusting one.Phase curve of the present invention is adjusted circuit 49 and is comprised first and second terminal 50 and 51; The first, the second with for the third time the level circuit 52,52 ', with 53, first and second electric capacity 54 and 55; One inductance 56, and a common node 57.First secondary circuit 52 comprises a variable capacitance 52a, and first and second inductance 52b and 52b ' in parallel with variable capacitance 52a and that connect mutually.Inductance 52b and 52b ' are public with node 52 one " on be connected to each other.The first terminal 50 of phase curve circuit 49 is connected to the first inductance 52b of the variable capacitance 52a and first secondary circuit 52.Second subprime circuit 52 ' comprises a variable capacitance 52a ', and with variable capacitance 52a ' parallel connection and first and second inductance 52 ' b and the 52 ' b ' that connect mutually.Inductance 52 ' b and 52 ' b ' are at common node a 52 ' b " on be connected to each other.Variable capacitance 52a ' and first and second inductance 52 ' b and 52 ' b parallel connection of polyphone mutually.Level circuit 53 comprises a variable capacitance 53a for the third time, and an inductance 53c in parallel with variable capacitance 53a.Level circuit 53 more comprises mutual series connection and first and second electric capacity 53b and the 53b ' that are connected in parallel with electric capacity 53a again for the third time.Variable capacitance 53a, inductance 53c, and the second electric capacity 53b ' is connected to output interface 51.Electric capacity 54 is connected to common node 52b " and common node 57 between; Electric capacity 55 is connected to common node 52 ' b " and between the node 57; 56 of inductance are connected to common node 56b " and between the common node 57.Utilize to adjust the value of electric capacity, the phase delay that changes with frequency just can be adjusted to such an extent that accord with the phase deviation of the distorted signal that Laser Devices produce.
Fig. 6 shows the single selected phase-delay characteristic that presets distortion circuit 91.Utilization is adjusted variable capacitance 52a in factory or other places, 52a ' and 53a, and time delay curve (TX TIME DELAY) just can be corrected to such an extent that can compensate characteristic of laser.
Claims (20)
1. one kind makes the linearizing method of circuit conversion function, it is characterized in that, comprises the steps:
Reception will be supplied to a primary signal with Circuits System of non-linear conversion characteristic;
Produce the distorted signal that presets of an adjustable amplitude and phase curve, to compensate the non-linear of described Circuits System;
To preset distorted signal combines with primary signal to produce a binding signal;
Described binding signal is provided for described Circuits System.
2. one kind makes the linearizing circuit of circuit conversion function, it is characterized in that, comprising:
One first signal splitter, the radiofrequency signal of one input can be divided into first and second radiofrequency signal, first signal splitter has main and less important first signal splitter output, main first signal splitter output provides a main signal, and less important first signal splitter provides a less important signal;
One secondary signal dispenser, has the secondary signal dispenser input that is connected to less important first signal splitter output, the secondary signal dispenser has main and less important secondary signal dispenser output, main secondary signal dispenser output produces a secondary and presets the distortion output signal, and less important secondary signal dispenser output then produces one and presets the distortion output signal three times;
One the 3rd signal splitter, has one the 3rd signal splitter input that is connected to main secondary signal dispenser output, the 3rd signal segmentation has main and less important the 3rd signal splitter output, main the 3rd signal splitter output applies a selected phase deviation to the received signal of the 3rd signal splitter input, and less important the 3rd signal splitter output then applies a phase deviation of spending with described selected phase deviation 180 to the received signal of the 3rd signal splitter input;
Be connected to first and second reversal connection diode of described main and less important the 3rd signal splitter output respectively, first and second reversal connection diode is connected and presets distorted signal to produce a secondary;
One the 4th signal splitter, has one the 4th signal splitter input that is connected to less important secondary signal dispenser output, the 4th signal segmentation has main and less important the 4th signal splitter output, and main and less important the 4th signal splitter output produces the signal that forms same phase mutually;
Be connected to first and second non-reversal connection diode of described main and less important the 4th demultiplexer output respectively, first and second non-reversal connection diode is connected and presets distorted signal three times to produce one; With
Be connected to one first signal combiner of described first and second reversal connection and non-reversal connection diode, with in conjunction with secondary and preset distorted signal three times.
3. circuit according to claim 2 is characterized in that, more comprises a secondary signal colligator that is coupled to described first signal combiner and the main first signal splitter output.
4. circuit according to claim 2 is characterized in that, more comprises a delay line that is connected to the described main first signal splitter output.
5. circuit according to claim 2 is characterized in that, more comprises the signal level adjusting device, can be for the signal amplitude in first and second reversal connection of control and the non-reversal connection diode.
6. circuit according to claim 2 is characterized in that, more includes the control device of diode.
7. circuit according to claim 2 is characterized in that, more includes the amplitude curve adjusting device.
8. circuit according to claim 2 is characterized in that, more includes the phase curve adjusting device.
9. circuit according to claim 2 is characterized in that, more includes the phase deviation device that is connected to described first signal combiner.
10. the distortion circuit that presets that will be supplied to radiofrequency signal with known distortion characteristic circuit system is characterized in that, comprising:
One first signal splitter is divided into first and second radiofrequency signal with a radiofrequency signal of importing, and first signal splitter has first and second output;
Be coupled to first and second reversal connection diode of one first output node and first and second output respectively; With
One curve is adjusted circuit, and its component that has with the selected Circuits System of known distortion characteristic is the frequency characteristic of reciprocal relation, and has an output that is connected to first and second output node, presets distorted signal for producing one first output.
11. circuit according to claim 10 is characterized in that, more includes a secondary signal dispenser, and an input radio frequency signal segmentation is become the 3rd and the 4th radiofrequency signal, the secondary signal dispenser has the 3rd and the 4th output; Be coupled to the 3rd and the 4th non-reversal connection diode of one second output node, it also is coupled to the 3rd and the 4th output respectively; Adjust circuit with second curve, preset distorted signal for producing one second output with output binding that is connected to the 3rd and the 4th node.
12. the distortion circuit that presets according to claim 10 is characterized in that, the described first curve fitting circuit comprises amplitude and phase curve adjustment circuit.
13. the distortion circuit that presets according to claim 10 is characterized in that, described first output signal produces a signal that departs from 180 degree with respect to described second output signal.
14. the distortion circuit that presets according to claim 11 is characterized in that, described the 3rd phase of output signal is identical with described the 4th phase of output signal.
15. the distortion circuit that presets according to claim 11 is characterized in that, it more comprises one the 3rd dispenser, and it has the 5th and the 6th output that is connected to described first and second dispenser respectively.
16. the distortion circuit that presets according to claim 11 is characterized in that it more comprises a colligator, it is connected to described first and second curve and adjusts circuit, with in conjunction with first and second output distortion signal.
17. by producing an a kind of method that presets distorted signal in the input radio frequency signal, it is characterized in that, comprise the steps:
One input radio frequency signal segmentation is become first and second signal;
Set up first and second separate signal path that respectively has strange and even signal component;
Adjust described odd signal component according to one first kind of selected figure and adjust curve, adjust signal so that produce one first curve;
Adjust described even signal component according to one second kind of selected figure and adjust curve, adjust signal so that produce one second curve; With
Adjust signal in conjunction with described first and second curve, produce a compound distorted signal that presets.
18. method according to claim 17 is characterized in that, first and second that comprises that foundation can offset with known signal distortion figure presets the step of distortion figure.
19. method according to claim 17 is characterized in that, more comprises utilizing the distorted signal that presets with scheduled transmission frequency range, and at its secondary three times and the step of more offsetting a known distortion figure on the amplitude of the associated frequencies of high order.
20. method according to claim 17 is characterized in that, more comprises utilizing the distorted signal that presets with scheduled transmission frequency range, and at its secondary three times and the step of more offsetting a known distortion figure on the phase place of the associated frequencies of high order.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW085108888A TW335579B (en) | 1997-05-26 | 1996-07-22 | Linearization circuits and methods the invention relates to linearization circuits and methods |
| CN 97112140 CN1200628A (en) | 1997-05-26 | 1997-05-26 | Linearization circuits and methods |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 97112140 CN1200628A (en) | 1997-05-26 | 1997-05-26 | Linearization circuits and methods |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1200628A true CN1200628A (en) | 1998-12-02 |
Family
ID=5172107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 97112140 Pending CN1200628A (en) | 1997-05-26 | 1997-05-26 | Linearization circuits and methods |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN1200628A (en) |
| TW (1) | TW335579B (en) |
-
1996
- 1996-07-22 TW TW085108888A patent/TW335579B/en active
-
1997
- 1997-05-26 CN CN 97112140 patent/CN1200628A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| TW335579B (en) | 1998-07-01 |
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