CN203942514U - Synthetic local oscillation device in TD-LTE-Advanced comprehensive test instrument - Google Patents
Synthetic local oscillation device in TD-LTE-Advanced comprehensive test instrument Download PDFInfo
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Abstract
The utility model discloses synthetic local oscillation device in a kind of TD-LTE-Advanced comprehensive test instrument.Comprising: sampling ring, sampler module, Direct Digital synthesis module, local oscillator generation module, with reference to distributor circuit; Wherein, sampling ring, is used to sampler that the sampling local oscillation signal of 207MHz～236MHz is provided, and input radio frequency frequency is sampled; Sampler module, for the middle junction compound module of sampling ring and local oscillator generation module, for carrying out frequency sample, frequency spectrum shift; Direct Digital synthesis module, for realizing the frequency resolution of whole local oscillator, carries out fractional frequency division; Local oscillator generation module, selects economical broadband VCO, covers 5.0GHz～10.0GHz frequency range; With reference to distributor circuit, for by various frequency divisions and frequency multiplier circuit, frequency reference is provided to the modules of frequency synthesis.Solve frequency range, resolution and the lower problem of frequency synthesis output frequency of comprehensive test instrument in correlation technique.
Description
Technical Field
The utility model relates to a TD-LTE-Advanced terminal radio frequency conformance testing application especially relates to a synthesize local oscillator device in TD-LTE-Advanced integrated tester.
Background
TD-LTE-A (Time Division-Long Term Evolution Advanced) with independent intellectual property has become one of IMT-A (International Mobile telecommunications) international standards, and compared with TD-LTE, the TD-LTE-A has more technical advantages. In various detections and verifications of mobile communication terminal products, radio frequency and radio frequency consistency tests of terminals are a key ring to check whether the terminal products meet the requirements of radio frequency test specifications.
3GPP TS36.521 defines all test cases of TD-LTE-A terminals, compared with TD-LTE, TD-LTE-A requires the terminal radio frequency conformance test equipment to output frequency resolution of 1Hz, output EVM is less than 3%, the frequency range is expanded to 4GHz, and the radio frequency is expanded to 100MHz until the intermediate frequency bandwidth. From the superheterodyne theory, the medium frequency and the large bandwidth require a high medium frequency scheme for mixing, that is, the highest frequency of the local oscillator output is still higher than the radio frequency after subtracting the radio frequency, which requires that the synthesized local oscillator device needs to expand the upper limit frequency while ensuring the high resolution of 1 Hz.
The phase noise of the local oscillator is a key index for restricting a TD-LTE-A transmitter and a receiver, and in the TD-LTE-A comprehensive tester, the phase noise index of the local oscillator directly influences the test results such as EVM (error rate) and the like. The resolution of the local oscillator determines the frequency resolution of the signal reception and transmission.
Aiming at the problem that the frequency band, resolution and frequency synthesis output frequency of the comprehensive tester in the related technology are low, no effective solution is provided at present.
SUMMERY OF THE UTILITY MODEL
Frequency channel, resolution ratio and the lower problem of frequency synthesis output frequency to the comprehensive tester among the correlation technique, the utility model provides a synthesize local oscillator device among TD-LTE-Advanced comprehensive tester for solve above-mentioned technical problem.
According to an aspect of the utility model provides a synthetic local oscillator device in TD-LTE-Advanced synthesizes tester, the device includes: the device comprises a sampling ring, a sampler module, a direct digital synthesis module, a local oscillator generation module and a reference distribution circuit; the sampling ring is connected with the reference distribution circuit at a signal input end and connected with the sampler module at a signal output end, and is used for providing a sampling local oscillator signal of 207 MHz-236 MHz for a sampler in the sampler module and sampling input radio frequency; the sampler module is a middle combination module of the sampling ring and the local oscillator generation module, and comprises a sampler, an amplifier, a radio frequency switch, a frequency divider, a filter and a radio frequency switch, and is used for executing frequency sampling and frequency spectrum shifting; the signal of the local oscillator generation module is input to the amplifier, and after passing through the radio frequency switch, the signal is divided into two paths, one path is transmitted to the other radio frequency switch through the frequency divider, the other path is combined with the signal output by the sampling ring at the sampler, and the combined signal is output to the other amplifier and is transmitted to the other radio frequency switch through the filter; the direct digital synthesis module is connected with the reference distribution circuit at a signal input end and connected with the local oscillator generation module at a signal output end, and is used for realizing the frequency resolution of the whole local oscillator and executing fractional frequency division; the signal input end of the local oscillator generation module is respectively connected with the sampler module and the direct digital synthesis module, the signal output end of the local oscillator generation module is connected with the sampler module, and a broadband VCO is selected to cover a frequency band of 5.0 GHz-10.0 GHz; the reference distribution circuit is connected with the sampling ring and the direct digital synthesis module and is used for providing frequency reference for each module of frequency synthesis through various frequency division and frequency multiplication circuits.
Preferably, the local oscillator generating module includes: the phase discriminator is used for receiving two paths of signals of a sampling intermediate frequency and Direct Digital Synthesis (DDS) circuit to compare phases, and utilizes the optimized fitting and bandwidth selection of multi-order loop parameters to control the broadband VCO and debug the performance of output spurious and phase noise indexes.
Preferably, the above apparatus further comprises: and the FPGA control circuit is used for executing the logic control of each module in the device.
Preferably, the bandwidth of the sampling loop is 100-300 Hz.
Preferably, the local oscillation generating module executes a debugging operation of a main phase-locked loop, wherein the output of the main phase-locked loop is the output frequency of the device, the range is 5.0 GHz-10.5 GHz, the VCO output amplitude is-6 dBm, the post-coupler output amplitude is-12 dBm, and the post-amplifier output amplitude is 5 dBm.
Preferably, the reference distribution circuit is formed by combining different frequency dividers and frequency multipliers to provide required reference signals for the frequency synthesis units of the device.
Preferably, during the scanning process, the frequency of the sampling oscillator is not changed, and the frequency scanning operation is completed by the direct digital synthesis module; the integral of the main VCO loop remains in a uniform direction over all frequency bins.
Through the utility model provides a synthesize local oscillator device in TD-LTE-Advanced comprehensive tester, the device includes: sample ring, sampler module, direct digital synthesis module, local oscillator generation module, refer to the distributing circuit, through the collaborative operation of above each module, the lower problem of frequency channel, resolution ratio and the synthetic output frequency of comprehensive tester among the correlation technique has been solved, the technical scheme of the utility model adopt the VCO of economic type to replace expensive YTO, replace expensive microwave sampler with the paster sampler of economic type, design economy and be suitable for and have high-frequency channel, high-purity polycyclic local oscillator device, the frequency channel reaches 5 ~ 10GHz, frequency resolution reaches 1Hz, is arranged in TD-LTE-A comprehensive tester, makes the frequency channel, EVM and the bit error rate of receiving and transmitting device itself far above 3GPP requirement.
The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the present invention is given.
Drawings
Fig. 1 is a block diagram of a synthesized local oscillator device in a TD-LTE-Advanced integrated tester according to an embodiment of the present invention;
fig. 2 is a schematic diagram of an operation principle of a synthesized local oscillation device in the TD-LTE-Advanced comprehensive tester according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a phase noise measurement result of a synthesized local oscillator device in a TD-LTE-Advanced integrated tester at 10GHz carrier and 1kHz offset carrier according to the embodiment of the present invention;
fig. 4 is a schematic diagram of a phase noise measurement result of a synthesized local oscillator device in a TD-LTE-Advanced integrated tester at 10GHz carrier and 10kHz offset carrier according to the embodiment of the present invention;
fig. 5 is a schematic diagram of a phase noise measurement result of a synthesized local oscillator device in a TD-LTE-Advanced integrated tester at 10GHz carrier and 100kHz offset carrier according to the embodiment of the present invention.
Detailed Description
In order to solve the lower problem of frequency channel, resolution ratio and the frequency synthesis output frequency of the comprehensive tester among the correlation technique, the utility model provides a synthesize local oscillator device among TD-LTE-Advanced comprehensive tester, it is right that below combines attached drawing and embodiment the utility model discloses further detailed description proceeds. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
This embodiment provides a synthesize local oscillator device in TD-LTE-Advanced integrated tester, and fig. 1 is the basis the utility model discloses a synthesize local oscillator device's block diagram in TD-LTE-Advanced integrated tester, as shown in fig. 1, the device includes: a sampling loop 10, a sampler module 20, a direct digital synthesis module 30, a local oscillator generation module 40 and a reference distribution circuit 50. This structure will be described in detail below.
The sampling ring 10 is used for providing a sampling local oscillator signal of 207 MHz-236 MHz for the sampler and sampling the input radio frequency;
a sampler module 20, which is a middle combination module of the sampling ring and the local oscillation generation module, and is used for performing frequency sampling and frequency spectrum shifting;
a direct digital synthesis module 30, configured to implement frequency resolution of the entire local oscillator and perform fractional frequency division;
the local oscillation generating module 40 selects an economical broadband VCO to cover a frequency band of 5.0 GHz-10.0 GHz; the index of the output frequency of the local oscillation generation module is established on the basis of multi-ring fitting, the phase noise index between 100Hz and 1kHz is ensured by a reference crystal, the phase noise index between 1kHz and 3kHz is ensured by a direct digital synthesis module, the phase noise index between 3kHz and 10kHz is ensured by a sampling ring, and the phase noise index which is far away from 100kHz is ensured by the far end of a VCO;
and a reference distribution circuit 50 for providing frequency references to the respective modules of the frequency synthesis through various frequency dividing and multiplying circuits.
Through above-mentioned device, provide a synthesis local oscillator device in TD-LTE-Advanced integrated tester, the device includes: sample ring, sampler module, direct digital synthesis module, local oscillator generation module, refer to the distributing circuit, through the collaborative operation of above each module, the lower problem of frequency channel, resolution ratio and the synthetic output frequency of synthesizing the tester among the correlation technique has been solved, the technical scheme of the utility model design economy be suitable for and have high frequency channel, high-purity polycyclic local oscillator device, produced high frequency channel, high resolution ratio, high-purity local oscillator synthetic signal, the frequency channel reaches 5 ~ 10GHz, frequency resolution ratio reaches 1Hz, is arranged in TD-LTE-A synthesizes the tester, makes the frequency channel, EVM and the bit error rate of receiving and transmitting device itself far be higher than the 3GPP requirement.
The following describes a synthesized local oscillation device in the TD-LTE-Advanced integrated tester in detail.
A local oscillation module designed by a synthesized local oscillation device in the TD-LTE-Advanced comprehensive tester generates local oscillation signals of 5.0 GHz-10.0 GHz and 0dBm and outputs the local oscillation signals, and the local oscillation module is a core module in the TD-LTE-A comprehensive tester and comprises the following functional blocks: the device comprises a sampling ring, a sampler module, a Direct Digital Synthesis (DDS) module, a local oscillator generation module, a reference distribution circuit and the like. The specific functions are described as follows:
(1) the sampling ring provides 207 MHz-236 MHz sampling local oscillation signals for the sampler, samples the input radio frequency, and plays a vital role in improving the phase noise of the whole local oscillation. The indexes of the sampling loop are ensured by depending on three factors of high reference, integer frequency division, high-performance narrow-band VCO and the like.
(2) The sampler module is the joint point of the local oscillator generation module and the sampling ring, realizes frequency sampling and completes frequency spectrum shifting, and the phase noise index of the sampling ring is extremely high, so that the phase noise caused by general frequency multiplication is prevented from being greatly deteriorated. The intermediate frequency amplifying and filtering circuit amplifies the intermediate frequency signal and filters out the radio frequency and the local oscillation frequency leaked at the front end.
(3) The Direct Digital Synthesis (DDS) circuit realizes the fine frequency resolution of the whole local oscillator, plays a role of fractional frequency division and ensures the realization of higher frequency resolution (1 Hz). The FPGA control circuit completes the logic control of the whole module.
(4) The local oscillation generating module selects an economical broadband VCO (voltage controlled oscillator) to cover a frequency band of 5.0 GHz-10.0 GHz, the index of the output frequency of the local oscillation generating module is established on the basis of multi-loop fitting, the phase noise index between 100Hz and 1kHz is ensured by a reference crystal, the phase noise index between 1kHz and 3kHz is ensured by a Direct Digital Synthesis (DDS) circuit, the phase noise index between 3kHz and 10kHz is ensured by a sampling ring, and the phase noise index beyond 100kHz is ensured by the remote end of the VCO.
A phase discriminator in the local oscillator generation module receives two paths of signals of a sampling intermediate frequency and a Direct Digital Synthesis (DDS) circuit to compare phases, and the ideal output stray and phase noise index performance is debugged by utilizing the optimized fitting and bandwidth selection of multi-order loop parameters to control the broadband VCO.
(5) The reference distribution circuit provides a high-stability frequency reference for each module of frequency synthesis through various frequency dividing and frequency multiplying circuits.
The frequency synthesis technology is always one of key technologies in the aspect of radio frequency design, and the frequency synthesis with high frequency band, high resolution and high purity is the key for realizing the development of the TD-LTE-A terminal comprehensive tester to a higher band and a higher bandwidth. The embodiment of the utility model provides a according to the requirement of TD-LTE-A terminal radio frequency conformance testing equipment, utilize the local oscillator device in the high-band, high resolution, high-purity TD-LTE-A signal generation and the receiver of multi-ring structural design. The input/output frequency range and the radio frequency bandwidth index of the TD-LTE-A comprehensive tester are guaranteed to meet the requirements of 3GPP, and similarly, the device can also be used in other frequency synthesis occasions and has strong universality.
The present invention will be described in detail with reference to the accompanying drawings and examples. Fig. 2 is a schematic diagram of an operation principle of a synthesized local oscillator device in the TD-LTE-Advanced comprehensive tester according to the embodiment of the present invention, as shown in fig. 2, specifically performed according to the following steps:
(1) a sampling loop circuit unit: the sampling ring provides 207 MHz-236 MHz sampling local oscillator signals for the sampler, the sampling ring is a frequency bolster structure controlled by the integrated phase discriminator, according to the debugging method of the phase-locked loop, under the premise of ensuring the reference of 200MHz and 400MHz, the FPGA is used for controlling the number of the integrated phase discriminator by a debugging program (the number is sent and is referred to the truth table of ADF 4002), the radio frequency point measuring cable is combined with the frequency spectrograph to measure the output of the sampling ring, and the frequency value of the sampling ring is in accordance with the corresponding frequency division ratio: fVCO200MHz + (400 MHz/N). And changing the frequency dividing ratio, and verifying the sampling ring in the range of 207MHz to 236MHz, thereby deducing that the value of N is between 11 and 57. Locking is only possible over the entire frequency range. And completing debugging of the sampling ring. The bandwidth of the sampling loop is designed to be very narrow (100-300 Hz) so as to ensure the stray and noise indexes of the loop.
Based on the above description, this embodiment provides a preferred embodiment, that is, the sampling ring includes: the sampling ring circuit unit is used for carrying out transmission control on the integrated phase discriminator by using the FPGA through a debugging program on the premise of ensuring the existence of 200MHz and 400MHz according to the debugging method of the phase-locked loop, and measuring the output of the sampling ring by using a radio frequency point measuring cable in combination with a frequency spectrograph; wherein, the frequency value should accord with the corresponding frequency dividing ratio: fVCO200MHz + (400 MHz/N); and changing the frequency dividing ratio, verifying the sampling ring in the range of 207MHz to 236MHz, locking in the whole frequency range, and executing the debugging operation of the sampling ring. The bandwidth of the sampling ring is 100-300 Hz.
(2) A sampler circuit unit: after the sampling ring is debugged, the sampler circuit can be debugged in cooperation with an additional signal source, the radio frequency end of the sampler is connected with the signal source input, the amplitude of the signal source is set to be 0dBm, the amplitude of a sampling local oscillator signal from the sampling ring is higher than 17dBm, and the intermediate frequency output of the sampler is observed by combining a point measurement cable with a frequency spectrograph.
Based on the above description, this embodiment provides a preferred embodiment, that is, the sampler module includes: and the sampler circuit unit is used for matching with an additional signal source to debug the sampler circuit after the debugging operation of the sampling ring is completed, connecting the signal source input to the radio frequency end of the sampler, setting the amplitude of the signal source to be 0dBm, setting the amplitude of the sampling local oscillation signal from the sampling ring to be higher than 17dBm, and observing the intermediate frequency output of the sampler by using a point measurement cable in combination with a frequency spectrograph.
The following first discusses the selection method of the sampling frequency and the frequency of the sampled output intermediate frequency (also the output of the direct digital synthesis circuit DDS): under the condition of the appointed output frequency of the main VCO, the sampling local oscillator and the sampling intermediate frequency (namely the DDS output frequency) need to be properly selected so as to obtain the optimal output performance of the main VCO. Different design schemes, different selection criteria and methods. In this scheme, the following principles need to be considered:
1) when a plurality of sampling local oscillators are available for selection, a low sampling frequency is selected, and good phase noise performance can be obtained. (phase noise of the sampling oscillator is deteriorated due to the frequency division effect in the sampling ring, and reducing the frequency division ratio M reduces the phase noise).
2) When the sampling intermediate frequency is selected, a frequency point with large output stray of the direct digital synthesis circuit DDS is avoided, which needs to do more experiments on the output of the direct digital synthesis circuit DDS.
3) Since the scheme is only applied to the condition that the sweep width is less than 10MHz, the frequency of the sampling oscillator is not changed as much as possible in the scanning process, and the frequency scanning is completed by a direct digital synthesis circuit.
4) The integration of the main VCO loop should be as uniform as possible over all frequency points, e.g. selecting FLO-N*FSAMP＝FIF. Of course, in some frequency points, it may not be able to completely cover, and then it is necessary to select N x FSAMP-FLO＝FIFBut it is necessary to consider whether there is a possibility of a false lock.
The specific steps of selecting a sampling local oscillator and sampling an intermediate frequency are as follows:
1) first, the VCO output frequency is determined to be FLODetermining all possible sampling multiples according to the following formula
Examples are: 2500; 5250
N1＝INT[(2500-50)]/236＝10，N2＝INT[(2500+50)]/207+1＝13
N1＝INT[(5250-50)]/236＝22，N2＝INT[(2500+50)]/207+1＝26
2) Searching all possible sampling frequencies from N1 to N2, stepping the sampling frequency from 207-236 by 5MHz for each sampling multiple, and finding and listing N and fs of sampling intermediate frequency within a selected range. Selecting proper sampling local frequency Fs, sampling multiple N and sampling intermediate frequency F from the table according to the principleIFAt a sampling intermediate frequency FIFAlso a Direct Digital Synthesis (DDS) circuit (equivalent to a conventional fractional loop) requires the frequency of the output.
The intermediate frequency signal amplification circuit amplifies the sampled intermediate frequency to an amplitude range suitable for phase discrimination, the amplitude of which should reach 0 dBm.
The other path in the sampler circuit is integer frequency division, sampling is not needed, the circuit is used for the condition of local oscillation large bandwidth scanning (the bandwidth is more than 10MHz), and the scanning is finished by a Direct Digital Synthesis (DDS) circuit without the work of a sampling ring during large bandwidth scanning.
(3) Direct Digital Synthesis (DDS) unit: combining a DDS output formula: fout ═ N/232)*frefAnd the DDS is fed with the number N through debugging software, and the output frequency of the DDS is measured by combining a radio frequency point measuring cable with a frequency spectrograph. The range of the frequency control word N is changed, so that the frequency coverage of the DDS is from 18MHz to 50MHz, and the output power is required to be uniformly changed by 0 dBm.
The quality of the direct digital synthesis output signal index is directly related to the quality of the main signal, and the phase noise transfer relationship of the direct digital synthesis output signal index and the main signal is a translation relationship. It is noted that the center ground point of the DDS chip is reliably and well grounded, and the digital ground and the analog ground are reasonably distributed.
(4) The local oscillation generation module: after the debugging of each module unit is finished, the local oscillator generation module is entered, namely, the debugging of the main phase-locked loop is carried out, the output of the main phase-locked loop is the output frequency of the device, the range is 5.0 GHz-10.5 GHz, the output amplitude of the VCO is-6 dBm, the output amplitude after the coupler is-12 dBm, and the output amplitude after the amplifier is 5 dBm.
The output frequencies of the sampling loop and the Direct Digital Synthesis (DDS) unit are respectively controlled by debugging program to determine the sampling times N, and then the frequency F of the main VCO loop can be determinedVCO，
I.e. FVCO＝N*FSAMP+FIF
After each set of frequency values is set, the output frequency of the VCO is verified by using a radio frequency point measurement cable in combination with a frequency spectrograph to measure. Meanwhile, the radio frequency point measurement cable can be combined with a frequency spectrograph to measure and verify the output frequency of the sampling ring and the output frequency of a Direct Digital Synthesis (DDS) unit. And the requirements of the setting are met.
And verifying the main phase-locked loop in the range of 5 GHz-10.5 GHz, and only locking in the whole frequency range. And completing debugging of the main phase-locked loop.
Based on the above description, this embodiment provides a preferred embodiment, that is, the local oscillation generating module executes a main phase-locked loop debugging operation, where the output of the main phase-locked loop is the output frequency of the apparatus, the range is 5.0GHz to 10.5GHz, the VCO output amplitude is-6 dBm, the post-coupler output amplitude is-12 dBm, and the post-amplifier output amplitude is 5 dBm.
(5) The reference distribution circuit is formed by combining different frequency dividers and frequency multipliers and provides required reference signals for all frequency synthesis units of the device.
Based on the above description, this embodiment provides a preferred implementation manner, that is, the reference distribution circuit is formed by combining different frequency dividers and frequency multipliers to provide the required reference signals for the frequency synthesis units of the apparatus.
In the scanning process of the embodiment, the frequency of the sampling oscillator is not changed, and the frequency scanning operation is completed by the direct digital synthesis module; the integral of the main VCO loop remains in a uniform direction over all frequency bins.
Preferably, the local oscillation generating module includes: the phase discriminator is used for receiving two paths of signals of a sampling intermediate frequency and Direct Digital Synthesis (DDS) circuit to compare phases, and utilizes the optimized fitting and bandwidth selection of multi-order loop parameters to control the broadband VCO and debug the performance of output spurious and phase noise indexes. The device still includes: and the FPGA control circuit is used for executing the logic control of each module in the device.
The technical solution of the present invention will be described in detail by the preferred embodiments.
The most measurable metric for a frequency synthesizer level is single sideband phase noise. The output frequency of the device is tested by utilizing the high-performance spectrum analyzer to carry out single-sideband phase noise test, the output frequency of the device is selected to be 10GHz, the point is the highest end of the device, the output index is the worst index of the device and represents the design level of the device, and if the output frequency point of the low end is selected, the test index can be better.
Fig. 3 is according to the utility model discloses a carrier 10GHz, the schematic diagram of phase noise measurement result when deviating carrier 1kHz, as shown in fig. 3, the phase of measuring when deviating 10GHz carrier 1kHz makes an uproar, sets up the scanning SPAN of spectrometer to 5kHz, selects the phase of spectrometer direct reading when deviating carrier 1kHz to make an uproar the value, sees that the measuring value that the upper right corner of spectrometer shows is deviating carrier (X)1kHz, and phase makes an uproar measuring value (Y) and is-107.34 dBc/Hz.
Fig. 4 is a carrier 10GHz according to the embodiment of the present invention, and the schematic diagram of phase noise measurement result when deviating from carrier 10kHz, as shown in fig. 4, measures the phase noise when deviating from 10GHz carrier 10kHz, sets the scanning SPAN of the spectrometer to 50kHz, selects the phase noise value when the spectrometer directly reads deviating from carrier 10kHz, and sees that the measured value displayed in the upper right corner of the spectrometer is deviating from carrier (X)10kHz, and the measured value (Y) of phase noise is-104.53 dBc/Hz.
Fig. 5 is a schematic diagram of phase noise measurement results when the carrier wave 10GHz deviates from the carrier wave 100kHz according to the embodiment of the present invention, as shown in fig. 5, the phase noise when the measurement deviates from the carrier wave 10GHz by 100kHz is measured, the scanning SPAN of the spectrometer is set to 500kHz, the phase noise value when the spectrometer directly reads the deviation carrier wave 100kHz is selected, the measurement value displayed at the upper right corner of the spectrometer is seen to be the deviation carrier wave (X)100kHz, and the measurement value (Y) of the phase noise is-110.57 dBc/Hz. As can be seen from the test results shown in FIGS. 3, 4 and 5, the device meets the index requirements of the local oscillator of the TD-LTE-Advanced tester.
From the above description, the present invention relates to a radio frequency local oscillation loop and device with high frequency band, high resolution and high purity for use in TD-LTE-Advanced tester. The technical scheme of the utility model design economy and be suitable for and have high frequency channel, high-purity polycyclic local oscillator device, produced high frequency channel, high resolution, high-purity local oscillator synthetic signal, the frequency channel reaches 5 ~ 10GHz, frequency resolution reaches 1Hz for in the TD-LTE-A synthesizes the tester, make frequency channel, EVM and the bit error rate of receiving and transmitting equipment itself far above the 3GPP requirement.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, and that the scope of the present invention is not limited to the embodiments disclosed.
Claims (6)
1. The utility model provides a synthesize local oscillator device in TD-LTE-Advanced integrated tester, its characterized in that, the device includes: the device comprises a sampling ring, a sampler module, a direct digital synthesis module, a local oscillator generation module and a reference distribution circuit; wherein,
the signal input end of the sampling ring is connected with the reference distribution circuit, and the signal output end of the sampling ring is connected with the sampler module and used for providing a sampling local oscillator signal of 207 MHz-236 MHz for a sampler in the sampler module and sampling input radio frequency;
the sampler module is a middle combination module of the sampling ring and the local oscillator generation module, and comprises a sampler, an amplifier, a radio frequency switch, a frequency divider, a filter and a radio frequency switch, and is used for executing frequency sampling and frequency spectrum shifting; the signal of the local oscillator generation module is input to the amplifier, and after passing through the radio frequency switch, the signal is divided into two paths, one path is transmitted to the other radio frequency switch through the frequency divider, the other path is combined with the signal output by the sampling ring at the sampler, and the combined signal is output to the other amplifier and is transmitted to the other radio frequency switch through the filter;
the direct digital synthesis module is connected with the reference distribution circuit at a signal input end and connected with the local oscillator generation module at a signal output end, and is used for realizing the frequency resolution of the whole local oscillator and executing fractional frequency division;
the signal input end of the local oscillator generation module is respectively connected with the sampler module and the direct digital synthesis module, the signal output end of the local oscillator generation module is connected with the sampler module, and a broadband VCO is selected to cover a frequency band of 5.0 GHz-10.0 GHz;
the reference distribution circuit is connected with the sampling ring and the direct digital synthesis module and is used for providing frequency reference for each module of frequency synthesis through various frequency division and frequency multiplication circuits.
2. The apparatus of claim 1, wherein the local oscillation generating module comprises:
the phase discriminator is used for receiving two paths of signals of a sampling intermediate frequency and Direct Digital Synthesis (DDS) circuit to compare phases, and utilizes the optimized fitting and bandwidth selection of multi-order loop parameters to control the broadband VCO and debug the performance of output spurious and phase noise indexes.
3. The apparatus of claim 1, wherein the apparatus further comprises:
and the FPGA control circuit is used for executing the logic control of each module in the device.
4. The method of claim 1, wherein the sampling loop has a bandwidth of 100 to 300 Hz.
5. The apparatus of claim 1,
the local oscillator generation module executes debugging operation of a main phase-locked loop, the output of the main phase-locked loop is the output frequency of the device, the range is 5.0 GHz-10.5 GHz, the VCO output amplitude is-6 dBm, the post-coupler output amplitude is-12 dBm, and the post-amplifier output amplitude is 5 dBm.
6. The apparatus of claim 1, wherein the reference distribution circuit is formed by a combination of different frequency dividers and frequency multipliers to provide the required reference signals for the respective frequency synthesis units of the apparatus.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103633997A (en) * | 2013-11-18 | 2014-03-12 | 中国电子科技集团公司第四十一研究所 | Synchronizing and local oscillating device in TD-LTE-A (time-division long term evolution advanced) integrated tester |
| CN105577184A (en) * | 2015-12-17 | 2016-05-11 | 中国电子科技集团公司第四十一研究所 | Frequency synthesis device for LTE-Advanced signal analyzer |
| EP3206301A3 (en) * | 2016-02-10 | 2017-10-18 | Rohm Co., Ltd. | Oscillation circuit |
| CN110537351A (en) * | 2017-04-28 | 2019-12-03 | 松下电器（美国）知识产权公司 | Measuring device and measurement method |
-
2013
- 2013-11-18 CN CN201320733279.5U patent/CN203942514U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103633997A (en) * | 2013-11-18 | 2014-03-12 | 中国电子科技集团公司第四十一研究所 | Synchronizing and local oscillating device in TD-LTE-A (time-division long term evolution advanced) integrated tester |
| CN103633997B (en) * | 2013-11-18 | 2016-08-17 | 中国电子科技集团公司第四十一研究所 | TD-LTE-Advanced comprehensive test instrument synthesizes local oscillation device |
| CN105577184A (en) * | 2015-12-17 | 2016-05-11 | 中国电子科技集团公司第四十一研究所 | Frequency synthesis device for LTE-Advanced signal analyzer |
| EP3206301A3 (en) * | 2016-02-10 | 2017-10-18 | Rohm Co., Ltd. | Oscillation circuit |
| CN110537351A (en) * | 2017-04-28 | 2019-12-03 | 松下电器（美国）知识产权公司 | Measuring device and measurement method |
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