CN201025712Y - A dual differential I/Q modulation device - Google Patents
A dual differential I/Q modulation device Download PDFInfo
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- CN201025712Y CN201025712Y CNU2006200152927U CN200620015292U CN201025712Y CN 201025712 Y CN201025712 Y CN 201025712Y CN U2006200152927 U CNU2006200152927 U CN U2006200152927U CN 200620015292 U CN200620015292 U CN 200620015292U CN 201025712 Y CN201025712 Y CN 201025712Y
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Abstract
The utility model discloses a double difference I/Q modulating device, comprising an I/Q signal modulator, a local oscillator circuit of differential output, an I differential signal transmission link, a Q differential signal transmission link and an RF output circuit wherein both the I differential signal transmission link transmitting the I differential signal and the Q differential signal transmission link transmitting the Q differential signal are connected with the I/Q signal modulator with the I differential signal transmission link and the Q differential signal transmission link in consistency with each other. The local oscillator circuit of differential output producing intrinsic signals of equal amplitudes and opposite phases is also connected with the I/Q signal modulator, resulting in a superior performance and stronger anti-interference ability of the double difference I/Q signal modulator.
Description
Technical field
The utility model relates to moving communicating field, relates in particular to two difference I/Q modulating device technology of mobile communication system.
Background technology
Modulator-demodulator (being Modem or Modulator-Demodulator) is the device that carries out conversion of signals between computer and the telephone wire, is made up of modulator and demodulator two parts.Modulator be the digital signal (as literal etc.) of computer being modulated into can be at the device of the defeated voice signal of phone line, at receiving terminal, demodulator converts voice signal to and calculates the digital signal that function receives.Just can realize data communication between the computer by modulator-demodulator and telephone wire.
Adapt to bandwidth according to Modem and divide, Modem has common dial modem, cable modem and ADSL Modem.Cable modem and ADSL Modem are mainly used in the broadband networks of transmission speed more than 1Mbps.Open grave is big gradually although present broadband networks uses, and considers that ISDN, ADLS, Cable Modem cost of access are higher, and common dial modem the present and the future's following period of time still can be the main product of personal user's first-selection.
The speed of dial modem has 14.4Kbps, 28.8Kbps, 33.6Kbps and 56KBbps several, mainly popular is the 56Kbps modulator-demodulator at present, it is the modulator-demodulator that per second can transmit 56 000 (56Kbps) data, its transmission range is 30 kilometers, up (promptly sending) speed reaches 33.6Kbps, and descending (promptly receiving) speed reaches 56Kbps.
Modulator-demodulator will be determined speed, modulation demodulation system, error correction compress mode etc. when connecting, this process is also named " shaking hands ".Require transmit leg must use identical transmission means, be called agreement, have only when transmit leg all uses identical agreement with the recipient and just can finish data exchange process with the recipient.In the time can realizing exchanges data between the modulator-demodulator, claim " shaking hands successfully ".For solving the communication protocol problem of modulator-demodulator, International Telegraph Consultative Committee has been formulated the standard of relevant agreement as all modulator-demodulators, and it is all made stipulations to each connection activity.Modulator-demodulator as 33.6kbps will be observed V.34-PLUS standard, and the modulator-demodulator of 56kbps will be observed V.90 standard agreement or V.92 standard agreement or the like.
Broadband networks mainly contains two kinds of Cable modulator-demodulator and ADSL Modem with modulator-demodulator.
Cable modulator-demodulator (Cable Modem) is in recent years along with the expansion that broadband network is used grows up.The Cable modulator-demodulator is the customer access equipment that designs for the communication service of coaxial cable net development data specially.Its employing standard " F " head links to each other with cable, link to each other with user personal computer with the standard ether interface, also can adopt the ATM signaling interface to link to each other with user personal computer, be responsible for finishing the downlink radio-frequency signal of network front end is converted to the ether bag signal that personal computer receives, the computer ether conversion of signals that personal computer is sent becomes up radiofrequency signal simultaneously, so that realize the two-way communication of user personal computer and network front end.
The communication that the Cable modulator-demodulator uses is the hybrid fiber coax that combines with optical fiber and coaxial cable, when message transmission when the user side, not only can insert TV but also can signal be converted into digital information and offered digitizers such as computer by the Cable modulator-demodulator.
ADSL (Asymmetric Digital Subscriber Line) Asymmetrical Digital Subscriber Line just constantly spreads out in China big and medium-sized cities as the bandwidth host technology that flows, and the ADSL access service has been opened in many cities.The ADSL technology has adopted senior Digital Signal Processing and new symmetrical packed data algorithm, has utilized the idle bandwidth of telephone wire, makes mass data be able to high-speed transfer.It is 1.088Mbps (being 640kbps at present) that ADSL provides the speed uplink of speed in theory, and downstream rate is 8Mbps, and transmission range reaches 3～5km.
For the performance design that satisfies wireless base station and cable infrastructure equipment the wide in range high linearity up-conversion of class and down-conversion active mixer, directly change i/q demodulator, digital programmable gain A DC driver/amplifier and modulator.
I/Q (inphase/quadrature phase) modulator is to carry out long-distance transmissions on the band-limited analog channel and design having for the digital signal of data communication, and it generally is made up of Base-Band Processing, modulation, signal amplification and several parts such as filtering, equilibrium.Modulation is with digital signal and sound carrier combination, produces to be suitable for the defeated audio signal (analog signal) of phone line, and demodulation is to recover digital signal from audio signal.
A radiofrequency signal can be represented with amplitude and phase place on polar coordinates, can represent with the value of X and Y on rectangular coordinate.But in digital communication system, general X replaces with I, the expression homophase, and Y replaces with Q, represents 90 ° of phase places.Therefore so-called I/Q modulator, i/q demodulator and QPSK (quadriphase keying) modulator/demodulator have been produced.
Traditional difference I/Q modulating device, noise level be-153dB/Hz; OIP3 is 15dBm; Its representative value of modulation loss is 7.5dB; In the channel power output be-during 11dBm, the ACPR value is-67dBc that sideband suppresses to be 33dBc that promptly the I/Q modulator performance is lower.
The utility model content
In view of this, the utility model provides a kind of pair of difference I/Q modulating device, makes this pair difference I/Q modulator have higher performance, and antijamming capability is strong.
A kind of pair of difference I/Q modulating device, comprise the i/q signal modulator, the local oscillation circuit of difference output, I differential signal transmission link, Q differential signal transmission link and RF output circuit, wherein, the I differential signal transmission link of transmission I differential signal, link to each other with the i/q signal modulator, the Q differential signal transmission link of transmission Q differential signal links to each other with the i/q signal modulator, I differential signal transmission link and Q differential signal transmission link have consistency, and the generation amplitude equates that the local oscillation circuit of the difference output of the local oscillation signal that phase place is opposite links to each other with the i/q signal modulator.
Described difference i/q signal modulator is i/q signal modulator TRF3703, and the local oscillation circuit of this difference output is local oscillation circuit TRF3761.
Described i/q signal modulator comprises 90 ° of distributors, first frequency mixer, second frequency mixer and 0 ° of distribution/synthesizer, receive 90 ° of distributors of difference local oscillation signal with receive the I differential signal and carry out frequency conversion first frequency mixer link to each other, receive 90 ° of distributors of difference local oscillation signal and link to each other, carry out signal allocation/0 ° of synthetic distribution/synthesizer and link to each other with first frequency mixer, second frequency mixer respectively with second frequency mixer that receives the Q differential signal and carry out frequency conversion.
Described I differential signal is BBIM and BBIP, and the Q differential signal is BBQM and BBQP, and the difference local oscillation signal is LOP and LOM.
During described pair of difference I/Q modulating device design pcb board, this pcb board wiring distinguishes i/q signal.
The pcb board of described pair of difference I/Q modulating device is placed in the metal case, and the cavity design of metal case satisfies the requirement of PCB to electromagnetic field.
Compared with prior art, a kind of pair of difference I/Q modulating device of the present utility model and a kind ofly place the metal case that two difference I/Q modulating device pcb boards are put, in this pair difference I/Q modulating device, the differential signal that is input to difference i/q signal modulator will pass through I differential signal transmission link earlier, Q differential signal transmission link, I differential signal transmission link and Q differential signal transmission link have consistency, the difference local oscillation signal that is input to difference i/q signal modulator is realized by the local oscillation circuit of difference output, the local oscillation circuit generation amplitude of difference output equates, the local oscillation signal that phase place is opposite is given the i/q signal modulator, make this pair difference I/Q modulator have higher performance, antijamming capability is strong.
Description of drawings
Fig. 1 is the electrical block diagram of the difference I/Q modulating device of the utility model better embodiment;
Fig. 2 is the particular circuit configurations schematic diagram of the i/q signal modulator 10 of the utility model better embodiment;
Fig. 3 is the metal case structural representation of the placement i/q signal modulator pcb board of the utility model better embodiment.
Embodiment
For the purpose, technical scheme, the advantage that make the utility model is clearer and more definite, clear, the technical scheme of the utility model is described in further detail below in conjunction with embodiment, accompanying drawing.
As shown in Figure 1, electrical block diagram for the difference I/Q modulating device of the utility model better embodiment, comprise i/q signal modulator 10, the local oscillation circuit 20 of difference output, I differential signal transmission link 30, Q differential signal transmission link 40 and RF output circuit 50, wherein, this difference i/q signal modulator 10 can be i/q signal modulator TRF3703, and the local oscillation circuit 20 of this difference output can be local oscillation circuit TRF3761.The differential signal that is input to difference i/q signal modulator 10 will pass through I differential signal transmission link 30 earlier, and it is strict one straightforward that Q differential signal transmission link 40, I differential signal transmission link 30 and Q differential signal transmission link 40 will have.The difference local oscillation signal that is input to difference i/q signal modulator 10 is realized by the local oscillation circuit 20 of difference output.The local oscillation circuit 20 of difference output produces strict amplitude and equates, the local oscillation signal that phase place is opposite is given i/q signal modulator 10.
As shown in Figure 2, particular circuit configurations schematic diagram for the i/q signal modulator 10 of the utility model better embodiment, this i/q signal modulator 10 (TRF3703) comprises what 90 ° of distributors 101, two 102,103 and 0 ° of distribution/synthesizers of frequency mixer 104 were formed, as modulator the time, the data stream separation of input is independently I differential signal and Q differential signal, wherein the I differential signal is BBIM and BBIP, the Q differential signal is BBQM and BBQP, upconvert in frequency mixer 102,103.Because 90 ° of the difference local oscillation signal phase phasic differences of two frequency mixers 102,103, wherein the difference local oscillation signal is LOP and LOM, so the output of frequency mixer 102,103 is quadratures, two orthogonal signalling vector in 0 ° of synthesizer 104 is synthetic, forms output.As demodulator the time, local oscillation signal is from the synthetic end input of 90 ° of distributors 101, and radiofrequency signal is from the synthetic end input of 0 ° of distributor 104, and to down-conversion, the output i/q signal is decoded in two frequency mixers 102,103.
Disturb for avoiding producing between the various signals, when carrying out the pcb board design, this PCB layout strictness distinguishes i/q signal.The PCB circuit that designs need be placed in the metal case, and the cavity design of metal case satisfies the requirement of PCB to electromagnetic field, can be shown in Figure 3.
This metal case comprises loam cake 301, press strip 302, box body 303, two parting beads 1, parting bead 2 305, parting bead 3 306, three feedthrough capacitors 307, earthing rod 308, six sub-miniature A connectors 309.Loam cake 301 is a rectangular plate body, empty cuboid in loam cake 301 and box body 303 can fasten mutually and form.In box body 303, parting bead 2 305 and parting bead 3 306 are connected to " T " font, the inside of box body 303 is divided into three parts, and parting bead 2 305 are vertical with the long limit of this cuboid, and parting bead 3 306 is parallel with the long limit of this cuboid.In the space that the minor face of parting bead 2 305 cuboid relative with it is formed, two parting beads 1 are divided into this space three parts again, and two parting beads 1 are all perpendicular to the minor face of this cuboid.In the cuboid minor face that joins with parting bead 3 306 and the outside of this cuboid, be provided with three feedthrough capacitors 307, earthing rod 308, six sub-miniature A connectors 309.
Empty cuboid in loam cake 301 and box body 303 can fasten mutually and form one in the time of then need being placed on the PCB circuit that designs in this metal case, the cavity design of metal case satisfies the requirement of PCB to electromagnetic field, can avoid interference.
In sum, transmission and processing procedure that difference I/Q modulating device of the present utility model has been realized differential signal, finally realized the normal balance modulator designing technique--two difference I/Q modulating devices have higher performance.Can be used for multiple moving communicating field, as can be used in the WCDMA system, to the modulation circuit of baseband signal and intermediate-freuqncy signal.Its advantage is that modulation loss is little: representative value is 4.5dB; Very low noise level :-164dB/Hz; Very high OIP3:25dBm; For single carrier WCDMA signal, in the channel power output be-11dBm the time, the ACPR value is-77dBc, sideband suppresses to be 40dBc.
Though the utility model is described with reference to current better embodiment; but those skilled in the art will be appreciated that; above-mentioned better embodiment only is used for illustrating the utility model; be not to be used for limiting protection range of the present utility model; any within spirit of the present utility model and principle scope; any modification of being done, equivalence replacement, improvement etc. all should be included within the rights protection scope of the present utility model.
Claims (6)
1. two difference I/Q modulating device, comprise the i/q signal modulator, the local oscillation circuit of difference output, I differential signal transmission link, Q differential signal transmission link and RF output circuit, it is characterized in that: the I differential signal transmission link of transmission I differential signal links to each other with the i/q signal modulator, the Q differential signal transmission link of transmission Q differential signal links to each other with the i/q signal modulator, I differential signal transmission link and Q differential signal transmission link have consistency, the generation amplitude equates that the local oscillation circuit of the difference output of the local oscillation signal that phase place is opposite links to each other with the i/q signal modulator.
2. a kind of pair of difference I/Q modulating device as claimed in claim 1 is characterized in that: described difference i/q signal modulator is i/q signal modulator TRF3703, and the local oscillation circuit of this difference output is local oscillation circuit TRF3761.
3. a kind of pair of difference I/Q modulating device as claimed in claim 1, it is characterized in that: described i/q signal modulator comprises 90 ° of distributors, first frequency mixer, second frequency mixer and 0 ° of distribution/synthesizer, receive 90 ° of distributors of difference local oscillation signal with receive the I differential signal and carry out frequency conversion first frequency mixer link to each other, receive 90 ° of distributors of difference local oscillation signal and link to each other, carry out signal allocation/0 ° of synthetic distribution/synthesizer and link to each other with first frequency mixer, second frequency mixer respectively with second frequency mixer that receives the Q differential signal and carry out frequency conversion.
4. a kind of pair of difference I/Q modulating device as claimed in claim 3, it is characterized in that: described I differential signal is BBIM and BBIP, and the Q differential signal is BBQM and BBQP, and the difference local oscillation signal is LOP and LOM.
5. a kind of pair of difference I/Q modulating device as claimed in claim 1 is characterized in that: during described pair of difference I/Q modulating device design pcb board, this pcb board wiring distinguishes i/q signal.
6. a kind of pair of difference I/Q modulating device as claimed in claim 1 is characterized in that: the pcb board of described pair of difference I/Q modulating device is placed in the metal case, and the cavity design of metal case satisfies the requirement of PCB to electromagnetic field.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2006200152927U CN201025712Y (en) | 2006-10-18 | 2006-10-18 | A dual differential I/Q modulation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2006200152927U CN201025712Y (en) | 2006-10-18 | 2006-10-18 | A dual differential I/Q modulation device |
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| CN201025712Y true CN201025712Y (en) | 2008-02-20 |
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| CNU2006200152927U Expired - Fee Related CN201025712Y (en) | 2006-10-18 | 2006-10-18 | A dual differential I/Q modulation device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023123970A1 (en) * | 2021-12-30 | 2023-07-06 | 中国石油天然气集团有限公司 | Global phase quadrature demodulation method and apparatus for optical fiber sensing data |
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2006
- 2006-10-18 CN CNU2006200152927U patent/CN201025712Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023123970A1 (en) * | 2021-12-30 | 2023-07-06 | 中国石油天然气集团有限公司 | Global phase quadrature demodulation method and apparatus for optical fiber sensing data |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080220 Termination date: 20091118 |