FR2856153A1 - Electric signal/high frequency component measuring/analyzing method, involves sending digitized electrical signals via broadband communication interface to computer, and implementing signal processing algorithm to process signals - Google Patents

Abstract

The method involves transposing and digitizing electrical signals (2) using transposition and digitalization parameters (4) supplied by a user. The digitized signals (7) are sent via a broadband communication interface (15) to a computer (10). The parameters are configured by a user interface (5). A signal processing algorithm is implemented for processing the signals (7) to provide measurement results (8) to the user. An independent claim is also included for a measuring device permitting a user to measure and/or analyze the electric signals and/or to characterize the high frequency components by the electric signals.

Description

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  METHOD AND APPARATUS FOR MEASURING AND / OR ANALYZING SIGNALS AND / OR HIGH-FREQUENCY DIFFERENT SUBJECTS Field concerned, The field concerned by the present invention is that of methods and apparatuses for measuring and / or analyzing signals and / or high frequency components.

  Problem posed The development of telecommunications, but also the new requirements linked to electromagnetic compatibility standards, have generated a very significant increase in the need for measuring devices specialized in high frequency signals (of the order of 500 MHz to several GHz) : Spectrum analyzers, vector network analyzers, modulation analyzers, vector generators, microwave frequency meters, etc. In particular, many small and medium-sized enterprises now have such needs and are penalized by the very high cost of this kind of equipment.

  Furthermore, the increasing complexity of the data transmission protocols used implies a growing need for functionalities and processing power in these 20 measuring devices, further widening the gap between the cost of this equipment and the means of the users.

  PRIOR ART There are currently two types of high frequency measuring devices, and in B11057 in particular spectrum analyzers: One can distinguish, on the one hand, entry level devices, mainly based on analog architectures. These devices are less and less usable for modern applications and are moreover of complex maintenance (it is necessary to carry out repeated calibrations).

  We can distinguish, on the other hand, high-end devices using digital signal processing technologies, and very high cost.

  Solution The invention is based on a combination of the following technological advances: - IT equipment (in particular of the PC type) now has very high processing power, making it possible to directly perform signal processing functions previously requiring processors specialized.

  - IT equipment (in particular of the PC type) has a cheap and commonplace high-speed interface: the USB / USB2 bus, allowing a transfer of a large quantity of raw data between a measurement equipment and a PC computer .

  - The needs of telecommunications have prompted the development of very high performance components allowing the digitization of broadband signals (analog / digital broadband converters, digital mixers, digital filters, decimators, etc.).

  - The needs of telecommunications have made it possible to develop, in the field of digital modulation / demodulation, algorithms which make it possible to magnify the intrinsic performance of a measuring device, and this again thanks to the flexibility brought by the use of a computer system.

  The combination of these technological advances, according to the technical features explained below, makes it possible to develop measuring devices specialized in high frequencies which are particularly economical and flexible. The invention relates to a method allowing a user to measure and / or analyze electrical signals and / or characterize high frequency components through the electrical signals they generate or modify. The method according to the invention is particularly economical and flexible. Within the meaning of the present invention, the term “electrical signals” also designates radioelectric or electromagnetic signals. The method comprises the step of transposing into baseband and digitizing the electrical signals, by implementing transposition and digitization parameters supplied by the user.

  Within the meaning of the present invention, by transposition of the electrical signals into baseband is meant a transposition between the native frequencies of the signals, relatively high (greater than a few hundred MHz), and a signal of suitable frequency to allow its digitization. This transposition can for example be a frequency shift or the measurement of one or more characteristic quantities of the signal, quantities with slower evolution (amplitude, frequency, etc.).

  The method further comprises the following steps: - the step of transferring the electrical signals thus digitized, via a high speed communication interface of the USB or USB2 type, to a computer equipment, - the step, for the computer equipment, * configure the transposition and digitization parameters supplied by the user using a man-machine interface or a programming interface (API).

  * to process the digital electrical signals, using computer processing means, in particular a signal processing algorithm, so as to extract measurement results therefrom, * to transmit the measurement results to the user, in particular to using the man-machine interface or programming interface.

  Preferably according to the invention, the method is such that the step of transposition into baseband and digitization of the electrical signals further comprises a filtering step.

  Preferably, according to the invention, the filtering step 10 is carried out on the electrical signals after digitization.

  Preferably according to the invention, the method further comprises the following steps: the step, for the computer equipment, to characterize in particular automatically, by means of calibration parameters, the step having the object of transposing into baseband and digitize the electrical signals, - the step, for the IT equipment, to correct the measurement results by implementing the calibration parameters.

  In the case of an alternative embodiment of the invention, the method is more particularly intended for characterizing a high frequency component by means of the electrical signals which it modifies. Preferably according to the invention, in the case of this alternative embodiment, the method comprises the following steps: - the step of automatically generating, via the computer equipment, a signal suitable for the characteristics to be measured, - the step to excite the high frequency component by the appropriate signal.

  Also in the case of this alternative embodiment, preferably according to the invention, the signal suitable for the characteristics to be measured is defined by generation parameters. The step of generating the signal appropriate to the characteristics to be measured comprises the following steps: the step, for the computer equipment, of determining the parameters for generating the appropriate signal - the step of transferring the parameters for generating the signal suitable, via a high speed communication interface of USB or USB2 type, to a generator, - the step, for the generator, of generating the appropriate signal by carrying out a digital to analog conversion followed if necessary by a frequency transposition.

  Measuring device The invention also relates to a measuring device enabling a user to measure and / or analyze electrical signals and / or to characterize high frequency components by means of the electrical signals which they generate or which they modify. The measuring device according to the invention is particularly economical and flexible.

  The measuring device according to the invention comprises: transposition and digitization means for transposing into baseband and for digitizing the electrical signals, by implementing transposition and digitization parameters supplied by the user, transfer means for transferring the electrical signals thus digitized, via a high speed communication interface of the USB or USB2 type, to a computer equipment.

  The computer equipment comprises, - a man-machine interface and / or a programming interface (API) for configuring the transposition and digitization parameters supplied by the user, via a configuration software module, - computer processing means , in particular a signal processing algorithm, for processing the digital electrical signals, so as to extract measurement results therefrom, - transmission means for transmitting the measurement results to the user, in particular by means of the human interface -machine or programming interface.

  Preferably according to the invention, the measuring device is such that the means for transposing into baseband and for digitizing the electrical signals also comprise filtering means.

  Preferably according to the invention, the filtering means operate on the electrical signals after digitization.

  Preferably according to the invention, the computer equipment further comprises: - means for automatic characterization, by calibration parameters, means for transposition and digitization, - correction means for correcting the measurement results by implementing the calibration parameters.

  In the case of an alternative embodiment of the invention, the measuring apparatus is more particularly intended for characterizing a high frequency component by means of the electrical signals which it modifies. Preferably according to the invention, in the case of this alternative embodiment, the measuring device comprises: - a generator controlled by the computer equipment and automatically generating a signal suitable for the characteristics to be measured, - an excitation circuit for excite the high frequency component by the appropriate signal.

  Also in the case of this alternative embodiment, the signal suitable for the characteristics to be measured is defined by generation parameters. According to the invention, the computer processing means of the computer equipment make it possible: - to determine the parameters for generating the appropriate signal, - to transfer the parameters for generating the appropriate signal via a high speed communication interface of the USB or USB2 type , to a generator.

  The generator generates the appropriate signal by carrying out a digital analog conversion followed if necessary by a frequency transposition.

  This innovative technological approach makes it possible to develop particularly inexpensive but also very efficient equipment. As an example, the prototype of a vector network analyzer covering the range from 0 to 1 GHz was developed using this approach and using less than 250 EUR of components. No nearby device is currently available for less than 10,000 EUR on the market! This invention is applicable to a large number of high frequency measuring devices, whether they are signal analyzers (spectrum analyzers, modulation analyzers, microwave frequency meters, time analyzers, power analyzers, etc.), signals (modulated generators, vector generators, etc.) or mixed (vector network analyzers, etc.).

detailed description

  Other characteristics and advantages of the invention will appear on reading the description of alternative embodiments of the invention given below by way of indicative and non-limiting example, and of FIG. 1 which represents the overall architecture of the measuring device according to the invention.

  This measuring device 17 is operated by a user 1. Externally it receives electrical signals 2 and provides measurement results 8. In the case of measurement of high frequency component (s) 3 it provides also a signal appropriate to the characteristics to be measured 13 30 in order to excite it.

  Internally, this measuring device comprises transposition and digitization means 18 for transposing into baseband and for digitizing the electrical signals 2, by implementing transposition and digitization parameters 4 supplied by the user. This sub-assembly supplies at its output the electrical signals in digitized form 7. Preferably according to the invention this sub-assembly includes filtering means 22, which preferably operate according to the invention after digitization.

  Internally, this measuring device further comprises transfer means 19 for transferring the electrical signals thus digitized 7, via a high speed communication interface of the USB or USB2 type 15, to a computer equipment 10. In the case where the generation an excitation signal 13 is necessary this transfer means 19 is also used to transmit the generation parameters 14 from the computer equipment 10 to the generator 16.

  The computer equipment 10 comprises: a man-machine interface 5 and / or a programming interface (API) for configuring the transposition and digitization parameters 4 supplied by the user 1, via a configuration software module 20, computer processing means 6, in particular a signal processing algorithm, for processing the digitized electrical signals 7, so as to extract measurement results 8 therefrom, transmission means 21 for transmitting the measurement results 8 to user 1, in particular by means of the man-machine interface 5 or the programming interface. Preferably according to the invention, the computer equipment 10 further comprises: - automatic characterization means 23, by calibration parameters 11, transposition and digitization means 18, - correction means 24 for correcting the measurement results 8 by implementing the calibration parameters 11.

  In the case of an alternative embodiment of the invention, the measuring device is more particularly intended for characterizing a high frequency component 3 by means of the electrical signals 2 which it modifies. Preferably according to the invention, in the case of this alternative embodiment, the measuring device comprises: - a generator 16 controlled by the computer equipment 10 and automatically generating a signal suitable for the characteristics to be measured 13, - a circuit excitation 25 to excite the high frequency component 3 by the appropriate signal 13.

  Also in the case of this alternative embodiment, the signal suitable for the characteristics to be measured 13 is defined by generation parameters 14. According to the invention, the computer processing means 6 of the computer equipment 10 make it possible: - to determine the generation parameters 14 of the appropriate signal 13, - transferring the generation parameters of the appropriate signal 14 via a high speed communication interface of the USB or USB2 type 15, to a generator 16.

  The generator 16 generates the appropriate signal 13 by carrying out a digital analog conversion followed if necessary by a frequency transposition.

  Example of an alternative embodiment 1: Measuring device 17 of the spectrum analyzer type One of the most direct applications of this invention is the production of a very economical and very efficient microwave spectrum analyzer. Such an analyzer will comprise for example the following elements: Means of transposition and digitization 18: One or more steps of frequency transposition, analog filtering and amplification will make it possible to select and amplify a relatively narrow frequency band ( a few tens of MHz in width) placed anywhere in the measuring range of the analyzer, under the control of a microcontroller itself controlled by computer equipment 35 10. This signal will then be digitized by an analog converter / high performance digital, then if necessary can be processed by a programmable digital filter 22 (improvement of the effective sensitivity, reduction of the bandwidth by decimation, etc.) before being transferred to a microcontroller via a memory of FIFO type Means 19: The same microcontroller can then transfer this data flow to the IT equipment via an interface USB or USB2 15, either as raw data or by extracting useful information from the signal beforehand (amplitude detection for example) Computer equipment: Computer equipment 10, a PC type computer in general, will configure the 15 frequency converters and digital filters 18, and will control via the USB / USB2 bus 15 and in real time the measurement sequence on the basis of parameters 4 defined by an ergonomic human-machine interface 5. It will then ensure the data repatriation 7, their processing 6 and their display. Two operating modes can be used: either a sequential measurement (narrow filtering and direct measurement of the amplitude of the signals at different frequencies), or a broadband measurement (wider filtering, measurement of the time signal and calculation of its spectrum by Fourier transform). For automated applications, the man-machine interface 5 can be replaced by an open programming interface (API of the DLL type for example).

  Example of alternative embodiment 2: Measuring device of the modulation analyzer type The same hardware base as that used for the above spectrum analyzer can easily be heard to make a complete modulation analyzer. This illustrates the great flexibility provided by this invention. In this case, it will suffice to replace the processing means 6 of the computer system 10 with software also including demodulation algorithms (FM or I / Q demodulation for example), as well as a suitable human-machine interface 5. In order to increase performance, it will also be possible to provide, at the digital filters 22 integrated in the device, an I / Q demodulation function carried out in a wired and digital manner.

  Example of an alternative embodiment 3: Measuring device of the vector network analyzer type Such a measuring device makes it possible to measure the gain and the phase shift provided by any component 3 subjected to an excitation signal 13. This invention makes it possible to carry out this type of device in a simple, efficient and economical way. Such an analyzer will include for example the following elements: Means of transposition and digitization 18: A sinusoidal signal generator 16, controlled by the computer equipment 10 via the USB or USB2 interface 15, will generate an excitation signal 13. One or more receivers 18 will measure the gain and the phase of the signal 2 transmitted by the ports of the component tested. These signals will then be digitized 7 20 and transmitted to a microcontroller Transfer means 19: The same microcontroller will then be able to transfer this data flow to the computer equipment 10 via a USB or USB2 interface 15. The same interface 15 will be used to control the generator 16 in real time.

  - Computer equipment 10: Computer equipment 10, a PC type computer in general, will control 14 generator 16 on the basis of parameters supplied by user 1, as well as measurement 30 in real time of gains and phases associates. This information will then be corrected 24 on the basis of information obtained during a prior automatic calibration phase 23 and will then be displayed 5 or transmitted to the user 1.

  NC4E4NCLATURE Measuring device Nominal group Ref. User number 1 Electrical signals 2 High frequency component (s) 3 Transposition and digitization parameters 4 Human-machine interface 5 Computer processing means 6 Digitized electrical signals 7 Results of 8 Computer equipment 10 Calibration parameters 11 Signal suitable for the characteristics to be measured 13 Generation parameters 14 USB or USB2 type broadband communication interface 15 Generator 16 Measuring device 17 Means of transposition and digitization 18 Means of transfer 19 Module configuration software 20 Transmission means 21 Filtering means 22 Characterization means 23 Correction means 24 Excitation circuit 25

Claims (12)

  1. Method allowing a user (1) to measure and / or analyze electrical signals (2) and / or to characterize high frequency components (3) by means of the electrical signals (2) which they generate or 5 that they modify; said process being particularly economical and flexible; said method comprising the following steps: the step of transposing into baseband and digitizing said electrical signals (2), by implementing 10 transposition and digitization parameters (4) supplied by said user (1), - the step of transferring the electrical signals (2) thus digitized, via a high speed communication interface of the USB or USB2 type (15), to a computer equipment (10), 15 - the step, for said computer equipment (10 ), * configure the transposition and digitization parameters (4) supplied by said user (1) by means of a man-machine interface (5) or a programming interface (API), * process the signals electrical devices (7), using computer processing means (6), in particular a signal processing algorithm, so as to extract measurement results (8), * to transmit said measurement results (8) audit 25 user (1), notably ment by means of said human machine interface (5) or a programming interface (API).   2. Method according to claim 1; said method being such that the step of transposing into baseband and digitizing said electrical signals (2) further comprises a filtering step.   3. Method according to claim 2; said filtering step being carried out on the electrical signals (2) after digitization.   4. Method according to any one of claims 1 to 3; said method further comprising the following steps: - the step, for said computer equipment (10), of characterizing in particular automatically, by calibration parameters (11) the step having the object of transposing into a strip of base and digitize said electrical signals (2), the step, for said computer equipment (10), to correct the measurement results (8) by implementing said calibration parameters (11).   5. Method according to any one of claims 1 to 4; said method being more particularly intended for characterizing a high frequency component (3) by means of the electrical signals (2) which it modifies; said method comprising the following steps: - the step of automatically generating, via said computer equipment (10), a signal suitable for the characteristics to be measured (13), - the step of exciting said high frequency component (3) by said signal suitable for the characteristics to be measured 20 (13).   6. Method according to claim 5; said signal suitable for the characteristics to be measured (13) being defined by generation parameters (14); the step of generating said signal suitable for the characteristics to be measured (13) comprising the following steps: the step, for said computer equipment (10), of determining said generation parameters (14) of said signal suitable for the characteristics to be measured (13), the step of transferring said generation parameters (14) of said signal suitable for the characteristics to be measured (13), via a high speed communication interface of USB or USB2 type (15), to a generator ( 16), - the step, for said generator (16), of generating said signal suitable for the characteristics to be measured (13) by carrying out a digital to analog conversion followed if necessary by a frequency transposition.   7. Measuring device (17) allowing a user (1) to measure and / or analyze electrical signals (2) and / or to characterize high frequency components (3) by means of electrical signals ( 2) that they generate or modify; said measuring device (17) being particularly economical and flexible; said measuring device (17) comprising: - transposition and digitization means (18) for transposing into baseband and for digitizing said electrical signals (2), by implementing transposition and digitization parameters (4) provided by said user (1), transfer means (19) for transferring the electrical signals (2) thus digitized, via a high speed communication interface of USB or USB2 type (15), to computer equipment (10); said computer equipment (10) comprising, - a man-machine interface (5) for configuring the transposition and digitization parameters (4) supplied by said user (1), via a configuration software module (20), means for computer processing (6), in particular a signal processing algorithm, for processing the digital electrical signals (7), so as to extract therefrom measurement results (8), - transmission means (21) for transmitting said results measurement (8) to said user (1), in particular by means of said man-machine interface (5).   8. Measuring device (17) according to claim 7; said measuring device (17) being such that said means for digitizing transposition (18) of said electrical signals (2) further comprises filtering means (22).   9. Measuring device (17) according to claim 8; said filtering means (22) operating on the electrical signals (2) after digitization.   10. Measuring device (17) according to any one of claims 7 to 9; said computer equipment (10) further comprising: - automatic characterization means (23), by calibration parameters (11), of said transposition and digitization means (18), - correction means (24) for correct the 10 measurement results (8) by implementing said calibration parameters (11).   11. Measuring device (17) according to any one of claims 7 to 10; said measuring device (17) being more particularly intended for characterizing a high frequency component (3) by means of the electrical signals (2) which it modifies; said measuring device (17) comprising: - a generator (16) controlled by said computer equipment (10) and automatically generating a signal suitable for the characteristics to be measured (13), - an excitation circuit (25) for exciting said component high frequency (3) by said signal suitable for the characteristics to be measured (13).   12. Measuring device (17) according to claim 11; said signal suitable for the characteristics to be measured (13) being defined by generation parameters (14); said computer processing means (6) of said computer equipment (10) allowing: - to determine said generation parameters (14) of said signal suitable for the characteristics to be measured (13), - to transfer said generation parameters (14) of said appropriate signal to the characteristics to be measured (13), via a high speed communication interface of the USB or USB2 type (15), to a generator (16); said generator (16) generating said signal suitable for the characteristics to be measured (13) by carrying out a digital to analog conversion followed by a frequency transposition.