WO2013083839A1

WO2013083839A1 - Method for self-testing of a pulsed transceiver device having a unique emitting/receiving terminal

Info

Publication number: WO2013083839A1
Application number: PCT/EP2012/074953
Authority: WO
Inventors: Serigne DIA; Cédric MAYOR
Original assignee: Presto Engineering Europe
Priority date: 2011-12-09
Filing date: 2012-12-10
Publication date: 2013-06-13

Abstract

The invention relates to a method for self-testing of a pulsed transceiver device (100) having a unique emitting and receiving terminal, said method comprising: - generating digital reference data stream, - converting by the pulsed transceiver device itself the digital reference data stream into a pulsed signal, - emitting said pulsed signal by the terminal of the transceiver device in transmission mode, - delaying the emitted signal along a terminated transmission line (200) presenting an impedance discontinuity wherein the impedance at the terminating end (300) of the transmission line is different from the characteristic impedance of the transmission line, - reflecting at least a part of the delayed emitted signal at the terminating end of the transmission line (200), the length of said terminated transmission line being selected so as to avoid any temporal overlap of the reflected pulsed signal with the emitted pulsed signal, - delaying the reflected signal along the terminated transmission line (200), - stimulating with the delayed reflected pulsed signal the same terminal of the transceiver device in receiving mode, - converting by the transceiver device the received reflected signal into a received digital data stream, -comparing said received digital data stream to said reference generated digital data stream.

Description

METHOD FOR SELF-TESTING OF A PULSED TRANSCEIVER DEVICE

HAVING A UNIQUE EMITTING/RECEIVING TERMINAL

FIELD OF THE INVENTION

The invention relates to a method for self-testing of a pulsed transceiver device having a unique terminal acting as input and output for the reception and transmission of a pulsed signal, such as a radiofrequency (RF) or optoelectronic signal.

BACKGROUND OF THE INVENTION

Semiconductor technology performances is in a constant evolution boosted by mass market demand onto high speed communication devices such as wired or wireless systems or optical/optoelectronic data communication network infrastructure.

Nowadays, advanced communications systems, transmitters (TX) & receivers (RX) are implemented in the same die or module and a switch mechanism enables to select TX or RX communication mode.

A pulsed transceiver device is a device which can emit or receive pulsed signal during a determined time and can switch from transmit (TX) mode to receive (RX) mode.

Such pulsed signal is defined as the juxtaposition of a symbol interval coding information and a guard interval, carrying no signal and separating two successive symbols.

Figure 1 illustrates an example of physical pulsed signal generated by such a pulsed transceiver device.

The upper part of the figure presents the configuration mode, which is alternatively transmission (TX) and reception (RX). The time period for transmission is noted Ttx, the time period for reception is noted Trx, with a transition period Tsw corresponding to the switching between one mode and the other one.

The middle part of the figure shows a pulsed signal transmitted (within transmission period Ttx) and received (within reception period Trx) by a transceiver device. It can be noted that the amplitude of the received signal Arx is smaller than the amplitude of the transmitted signal Atx due to attenuation.

The lower part of the figure shows the OFDM modulation of the above-mentioned pulsed signal.

The transmitted signal is emitted during duration Tw and the received signal is delayed by duration Tdel.

Those transceivers implementation complexity is directly a consequence of frequency band transmission, data rate and range. Indeed, on the one hand, in order to increase data rate, radiofrequency standards have driven a consistently increase of the communication channel bandwidth introducing both Ultra Wide Band (UWB) as well as millimeter wave based radiofrequency technologies.

Those technologies enable from 528 MHz to above 2 GHz bandwidth in the channels. On the other hand, compelling need of the networking infrastructure led to successive normalization of copper or fiber based Ethernet communication standards from 100 Mbits/s to 100 Gbits/s.

The test of such communication systems becomes more challenging and the cost of test becomes more and more detrimental for final products cost.

Indeed, with regard to test carried out during production of transceiver devices, the cost of test of a transceiver device is mainly determined by three parameters: ATE (Automated Test Equipment) cost, test interface cost and test time.

An optimal test solution should realize the best tradeoff between these three parameters.

Required ATE performances and test interface hardware features are determined by transceiver complexity.

In particular, standards ATE are limited to 6GHz narrow band for RF tests.

On the one hand, testing high frequency or wide band RF transceiver devices can be achieved by developing a new ATE platform.

On the other hand, a less expensive approach would be to insert a specific test capability either in the chip itself or on the test interface connected to an existing standard ATE.

In such approach, test interface hardware should be as simple as possible in order to guarantee robustness, reliable and cost-effective solution.

Test time could be minimized by combination of functional and structural test and by adopting multi-site solution.

For a device, a functional test is a test which enables to validate the overall function of the device whereas a structural test is intended to measure one or more physical parameters or characteristics of the components constituting the device under test.

By stating function, we include for instance the ability to emit and receive a modulated physical signal and interpret it as digital piece of information.

The functional test enables to take a PASS or FAIL decision by comparing measurement result to a targeted value or reference value which is fixed by specifications upfront and known. When the functional test is combined to appropriate structural test, if the functional test is FAILED, the structural test enables to locate the cause of the failure.

The optimal test flow is the combination of functional and structural test which enables to minimize test time while achieving correct device component content coverage.

A transceiver device has two functionalities which are "emitting" and "receiving" functionalities.

Usually, the emitting and receiving functions are embodied by two separate physical components inside the transceiver device, as illustrated by FIG. 2.

The emitter 98 and the receiver 99 can share common resources. In a production test these two functionalities must be guaranteed.

Thus, for a transceiver device, the most pertinent functional test is the loopback test since it enables to verify the functionality of the whole device in a single test.

A loopback test means here a test consisting in connecting the TX terminal to the RX terminal with an appropriate circuitry, thus forming a physical loop between the TX terminal and the RX terminal, emitting a signal by the TX terminal and receiving this signal at the RX terminal.

FIG. 2 illustrates a testing device (represented by a dashed perimeter) implementing such a loop.

The transceiver device 100 to be tested comprises an emitter 98 with an emitting terminal TX_OUT and a receiver 99 with a receiving terminal RXJN.

The testing device comprises a transmission line 1 and an attenuator 2.

The transceiver device 100 is connected to two ports of the testing device, such that the transmission line 1 and the attenuator 2 form a physical loop that connects the emitting terminal to the receiving terminal of the transceiver device 100.

As a consequence, a signal emitted by the TX terminal of the transceiver device 100 is attenuated and delayed by the transmission line 1 and the attenuator 2 before being received at the RX terminal of the transceiver device 100.

Loopback test method is especially pertinent for very high speed transceiver devices like SerDes or high frequency RF where emitted signal is composed of short burst/stream separated by guard interval where burst can represent a bit or a symbol.

For such high speed transceiver devices overall functionality can be verified in a short time without having to invest into high-end measurement instrument on ATE.

For instance at 56 Mbit/s data rate, 10⁷ bits can be sent by the TX channel and received by the RX channel in about 170ms. The classical loopback can be implemented on-chip or off-chip and enables to loop the TX output terminal to the RX input terminal via an attenuator.

For communication systems which are delay sensitive, the loopback can implement a circuit timing delay matching block.

Another known test performed on transceiver devices is Bit Error Rate.

In fact, for transceiver devices which implement translation of modulation and demodulation schemes into digital bit stream, the Bit Error Rate is the ultimate parameter which enables to quantify the quality of a transmission between an emitter and a receiver.

For a transceiver device with two distinct terminals (one terminal for signal transmitting and one terminal for signal receiving), the classical loopback method enables Bit Error Rate measurement by exciting the receiver with signal emitted by the emitter (illustration by FIG. 2).

If the device does not contain any signal processing component for sequence generation and error rate measurement, the digital signal processing can be done externally with standard ATE.

When measurement of Bit Error Rate with classical loopback method is not possible, the known method is to use an appropriate test instrument (represented with a dashed perimeter) as illustrated in FIG. 3.

The test instrument 10 generates a random digital sequence by digital signal processing (DSP) block 11 , which is modulated by analog waveform generator (AWG) 12 into a pulsed signal, e.g. an RF or optoelectronic signal, which matches transceiver modulation schemes.

Then, the signal generated by the test instrument stimulates the transceiver device 100 which is configured in receiver mode.

The transceiver device demodulates the received signal and translates it into a digital sequence Data-OUT which is compared to the original digital sequence Data-IN generated by said test instrument.

In production test, the Bit Error Rate measurement can be done with standard ATE if emitted and received signal frequency is less than 6 GHz.

However, for a RF or optoelectronic pulsed transceiver device with a unique emitting/receiving terminal, it is not possible to perform classical functional test, and Bit Error Rate measurement with a loopback technique since only one terminal is available instead of two.

In addition, for emerging communication technologies which operate at higher frequency (> 6 GHz), standard ATE are obsolete for measuring Bit Error Rate. Therefore a goal of the invention is to provide a method for self-testing of pulsed transceiver device, in particular RF or optoelectronic transceiver device, having only one terminal, whether single or differential, to emit and receive the signal. BRIEF DESCRIPTION OF THE INVENTION

An object of the invention is a method for self-testing of a pulsed transceiver device having a unique terminal for signal emission and reception.

Said method comprises:

- digital reference data stream generation,

- digital reference data stream conversion by the pulsed transceiver device itself into pulsed signal,

- emitting pulses by the terminal of the transceiver device in transmission mode,

- delaying the emitted signal along a terminated transmission line,

- reflecting at least a part of the delayed emitted signal at the terminating end of the transmission line,

- delaying the reflected signal along the terminated transmission line,

- stimulating with the delayed reflected signal the same terminal of the transceiver device in receiving mode,

- converting by the transceiver device itself the received reflected signal into a received digital data stream,

- comparing received digital data stream with reference generated digital data stream With such a method, it is thus possible to carry out both functional test and Bit Error

Rate measurement despite the fact that the transceiver device has only one emitting/receiving terminal.

Said method may further advantageously comprise:

- attenuating the emitted signal at a bidirectional attenuator, and

- attenuating the delayed reflected signal at said bidirectional attenuator, so as to stimulate said terminal of the transceiver device in receiving mode with said attenuated and delayed reflected signal.

According to a preferred embodiment, the transceiver device has a single transmitting/receiving terminal.

The method may further comprise controlling a switch device connected between the transceiver device or a bidirectional attenuator and each of a plurality of terminated transmission lines for selecting one of said transmission lines having different lengths, each transmission line presenting an impedance discontinuity at its terminating end. According to an embodiment, said generation of reference digital data stream and said comparison are processed by the pulsed transceiver device.

According to another embodiment, said generation of reference digital data stream and said comparison are processed outside of the pulsed transceiver device.

Said comparison may advantageously be processed so as to provide a bit error rate.

Said comparison can also be processed so as to provide a pass / fail decision on the functionality of the pulsed transceiver device.

The pulsed signal can be used in a OOK modulation scheme, a PPM modulation scheme, a ASK modulation scheme, a QAM modulation scheme, a FSK modulation scheme, a PSK modulation scheme, or a OFDM multiplexing scheme.

In particular, said pulsed signal is a radiofrequency or optoelectonic signal.

According to an embodiment, the transceiver device has a differential bidirectional transmitting/receiving terminal.

In this case, the method further comprises converting said differential terminal into a single-ended terminal with a balun device.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will be more apparent in the detailed description to follow, based on the appended drawings wherein:

FIG.1 illustrates a signal generated and received by a pulsed transceiver device;

FIG. 2 illustrates the architecture of a known loopback self-testing device of a transceiver device having two distinct terminals for transmission and reception respectively;

FIG. 3 illustrates classical Bit Error Rate test method with a test instrument;

FIG. 4 illustrates the architecture of a pulsed transceiver device with a unique emitting and receiving terminal;

FIG. 5 illustrates the principle of self-testing of a transceiver with a unique emitting/receiving terminal for instance in the case of ASK modulation scheme (Amplitude Shift Keying);

FIG. 6 illustrates self-test method implementation according to an embodiment of the invention;

FIG. 7 illustrates the self-test method implementation according to an embodiment of the invention, wherein path loss can be fixed with a bidirectional attenuator device;

FIG. 8 illustrates the self-test method implementation according to an embodiment of the invention, wherein path loss can be changed and appropriate propagation delay can be selected; FIG. 9 illustrates the self-test method implementation according to an embodiment of the invention, suited for self-testing of a transceiver device with a bidirectional input/output terminal which is differential. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In preferred embodiments of the invention, a method is implemented for self testing of a pulsed transceiver device with only one bi-directional terminal for emitting and receiving signal.

By "self-testing" is meant in the present text that the input signal which stimulates the transceiver is generated by the transceiver itself. In such context, no external instrument is needed to stimulate the transceiver in the receiving mode.

By "pulsed transceiver device" is meant in the present text a device which can emit or receive pulsed signal during a determined time and that can switch from transmit (TX) mode to receive (RX) mode.

By "pulsed signal" is meant the juxtaposition of a symbol interval coding information and a guard interval, carrying no signal and separating two following symbols.

Said signal include any pulse, whatever its amplitude, phase, duration in time, frequency and bandwidth or its shape.

By transceiver device with a unique emitting and receiving terminal is meant in the present text a device which comprises:

- a digital circuit block intended to generate a digital stream to be converted into a signal, e.g. an RF or optoelectronic signal,

an analog circuit block in which modulation and demodulation functions are designed with the same physical transistor, capacitor and inductance circuit network.

Figure 4 illustrates an embodiment of the architecture of such a transceiver device which comprises a digital part 101 , and an analog modulation and demodulation part 102.

The digital part 101 comprises all required digital signal processing functions.

All the digital part or some functions of the digital part can be located outside of the transceiver device. In TX mode, the analog part converts digital input signal into analog RF or optoelectronic signals according to pulse properties. In RX mode, the analog part converts RF or optoelectronic signal into digital output signal. The analog part is physically designed with the same transistor, capacitor and inductance network for TX and RX modes and it has a unique terminal for signal transmission and for signal reception. All modulations types of the information are under interest and can be tested applying the embodied invention, among which AM, OOK, BPSK, QPSK, QAM or any ODFM modulation.

FIG. 5 illustrates pulsed transceiver self test procedure.

The transceiver is switched between TX and RX mode.

For instance in the case of an ASK modulation the bit "1 " corresponds to an emission of a pulse and the bit "0" corresponds to an emission of a lower amplitude pulse.

The TX mode (whose duration is T_tx) which enables pulse or burst emission (whose maximal amplitude is A_tx and duration is T_w) is followed, after a switching time T_Sw, by the RX mode (whose duration is Tr_x) which enables to receive the emitted pulse or burst beforehand properly attenuated (the maximal amplitude being A_rx) and delayed (T_dei).

The graph shows the physical shape of emitted and received signals, for different reference signal data.

The first pulse (from the left) corresponds to a pulse for symbol "1 " emitted in transmission mode TX. The second pulse corresponds to the delayed and attenuated pulse for symbol "1 " which is received in receiving mode RX. The third pulse corresponds to a pulse for symbol "0" emitted in transmission mode TX. The fourth pulse corresponds to the delayed and attenuated pulse for symbol "0" which is received in receiving mode RX.

The method enables to implement functional self-test of pulsed transceiver devices which emit and receive via a bidirectional terminal.

Communication performances between an emitter and a receiver are determined by intrinsic performances of emitter and receiver and by the propagation channel characteristics.

In a context of transceiver self-test, the simplest model of propagation channel can be considered.

This simplest propagation channel is the free space line-of-sight channel with no obstacle between transmitter and receiver.

Path loss and propagation time are parameters which characterize such propagation channel.

The general principle of the method according to the invention consists in self-testing a pulsed transceiver device by stimulating the RX mode with a signal emitted in the TX mode and delayed and reflected at least partially at the terminating end of a terminated transmission line, said end of the transmission line not being connected to the transceiver (i.e. not forming a physical loop). The equivalent propagation time is fixed by the terminated transmission line length and, if appropriate, the path loss can be controlled by a bidirectional attenuator or a lumped impedance connected at the terminating end of the terminated transmission line.

By bidirectional signal attenuator is meant an attenuator that attenuates the signal in both directions.

The main parameters of the transceiver which must be considered are pulse or burst power and duration and switching time between TX and RX mode.

These parameters enable to fix the required delay time and path loss implemented into the present invention.

The embodied invention is based on the physical phenomenon of signal reflection which can be produced by an impedance discontinuity.

In fact, if a transmission line with characteristic impedance Z_c, terminated with a Z_L load, is stimulated with an incident wave, depending on the difference between Z_c and Z_L, a portion of the incident signal is reflected at the terminating end of the transmission line.

The reflected wave is proportional to reflection coefficient defined by:

7 - 7

^{~ ~} Z_L + Zc

In the particular case where the terminating end of the transmission line is left opened, the incident wave is totally reflected.

In classical radiofrequency signal transmission, maximum power transmission efficiency is desired and the load must be matched to transmission line characteristic impedance so called 50 Ohm impedance matching.

Whereas the reflection phenomenon is undesired for power transmission and thus carefully avoided in operating and testing transceivers, the invention takes advantage of such normally detrimental reflection to perform a functional self-testing of pulsed transceiver device, with minimal area overhead on test interface.

In order to avoid overlap/interference between the emitted and the received symbols in functional operation, the minimum time delay between emitting mode and receiving mode must be at least equal to the sum of pulse (Tw) and switching time (Tsw) as described by the below relationship:

Tdel{mm) = Tw + Tsw

To perform functional self-testing, the length of the transmission line has to be chosen and designed as such that the reflected pulsed signal is delayed by the Tdel quantity so that it is fed back at the terminal between two consecutive symbols. FIG. 6 illustrates an embodiment of a device for carrying out the self-testing method according to the invention, presenting a simple architecture.

The transceiver under test is referred to as 100.

In this embodiment, the transceiver 100 is a pulsed transceiver having a unique bidirectional emitting/receiving terminal INOUT.

The testing device comprises a terminated transmission line 200 connected to the transceiver 100 and presenting an impedance discontinuity at its terminating end 300 opposite to the transceiver 100.

The impedance discontinuity at the terminating end 300 of the transmission line 200 can be obtained by leaving it opened (i.e. not connected to anything) or by connecting it to a lumped impedance component which presents impedance that is different from the characteristic impedance of the transmission line, thereby leading to the reflection of at least a part of the signal emitted by the transceiver, according to reflection coefficient expression.

In any case, the terminating end 300 of the terminated transmission line 200 is not connected to the transceiver 100.

The path loss is determined by the reflection coefficient and the transmission line loss. If TLL_OSS represents the loss of the transmission line in decibel, the path loss (in decibel) is given by:

PL = (-2 * TL_LOSS ) + 20 * Logl0(T)

If the transmission line is left opened at the terminating end 300, the incident signal is totally reflected at said terminating end and path loss is only determined by the loss of the transmission line:

PL =—2 * TL_LOSS

FIG. 7 illustrates an embodiment of a device for carrying out the self-testing method according to the invention, where a bidirectional attenuator device 400 connected between transceiver 100 and terminated transmission line 200 enables to control path loss.

In a first approximation, if the matching between device under test and terminated transmission line and between terminated transmission line and attenuator are perfect, the path loss (PL) is determined by attenuation value (Att), reflection coefficient at the terminating end of the transmission line ( Γ ) and transmission line loss (TL_LOss) and is given by:

PL = -2 * (Att + TL_LOSS ) + 20 * Logl 0(Γ)

The 2 times factor is justified by the fact that the incident signal is first attenuated and that the reflected signal is attenuated again turning back through the bidirectional attenuator.

The bidirectional attenuator can be implemented by any suitable component, for example (but not limited to) a connectorized active attenuator component, a surface mounted attenuator component which is soldered on board or a chip which is connected to transmission line via any kind of adapted connection like waveguides, wires or cables, a passive screen printed attenuator component, etc.

Reflected signal caused by the bidirectional attenuator must be minimized.

To that end, a good matching between terminated transmission line and attenuator is required at the two terminals of the bidirectional attenuator.

The attenuator can be passive or active circuit, variable or fixed but it must be bidirectional in order to enable propagation of incident and reflected signal.

The attenuation can also be implemented with a cascade of attenuators but for reproducibility and reliability of the test environment the number of components should be minimized.

The terminated transmission line is characterized by its characteristic impedance, its length and its shape.

For instance, micro strip or strip line technologies can be adopted for terminated transmission line implementation on printed circuit board, but coaxial cables, optical waveguides and other technology may be applicable depending on the signal frequency and physical channel.

In the specific case of a printed circuit board, the characteristic impedance is determined by signal conductor width and thickness, dielectric constant, distance between conductor and dielectric and layer stuck-up.

The transmission line propagation delay is given by delay constant and transmission line length.

The time constant is the propagation delay per nanoseconds and is fixed by the dielectric constant.

All terminated transmission line shape and aspect ratio which enables to save area footprint can be envisaged since for multi-site testing minimizing the test interface area footprint is desired.

The testing device according to the invention, either by its compactness, its flexibility or repeatable physical implementation enables scaling in multisite testing according to high volume manufacturing test guidelines.

Consequences are directly translated into cost reduction when other techniques would not be capable of the same number of test site per test interface, as for instance duplication on a printed circuit board or any other physical interface connected to the device terminals.

For more accurate path loss expression, the mismatch between terminated transmission line and attenuator must be considered. If r_Att-TL is the reflection coefficient at the two terminals of the attenuator, the overall contribution onto path loss which is due to mismatch between terminated transmission line and attenuator is given by:

Att_{mismatch =} = 4 * 201ο_§10(Γ„)

The 4 times factor is due to the fact that the incident signal is partially reflected at the first and the second attenuator terminals and the reflected signal is partially reflected at the second and at the first attenuator terminals.

With electrically controlled variable attenuator for example the path loss can be tuned, enabling if necessary to evaluate equivalent dynamic range of the communication.

For transceivers which are sensitive to channel propagation time, a variable time delay solution may be implemented.

Such solution is shown in FIG. 8, by providing several terminated transmission lines 200, 201 , 200+n with different lengths and terminated, at their respective terminating end 300, 301 , 300+n, by a respective impedance discontinuity, and a controlled switch device 500 connected to each of said terminated transmission lines, the switch device thus enabling to select the appropriate terminated transmission line.

Like attenuator requirements, the controlled switch device 500 can be a SMD or any kind of switch discrete element and control signals from the external test environment can be digital or analog.

Besides, in order to avoid signal reflection at switch terminals, an acceptable matching between the attenuator and the switch device and between the switch device and terminated transmission line must be achieved.

In order to enable self-testing of transceivers with others structures of input-output terminals, an appropriate circuitry interface can be inserted between the transceiver under test and the attenuator as part of the testing device.

For transceivers with one bi-directional terminal which is differential, the differential terminal can be transformed into a single ended one since most of attenuator or switch components are single-ended.

Thus, as shown in FIG. 9, an embodiment of the invention comprises inserting a balun device 600 between the pulsed transceiver device 100 under test and the attenuator 400.

The balun device 600 aims at transforming the differential bi-directional terminal of the transceiver device 100 into a single-ended bi-directional terminal that can be connected to the attenuator 400.

For instance, the balun device 600 can be implemented as a SMD component. Of course, the device of FIG. 9 could also be implemented with a single terminated transmission line having an impedance discontinuity at its terminating end, and the switch device 500 would thus not be necessary, the terminated transmission line being connected directly to the attenuator 400.

If no attenuator is implemented in the testing device, the balun device 600 may be connected directly either to the terminated transmission line or, if appropriate, to the switch device 500.

The self-testing method as described above presents the following advantages.

First, it provides feasibility of functional self-test and bit error rate self-testing of transceiver via one bidirectional emitting/receiving terminal.

In addition, high density of test site in parallel can be achieved into a single testing device.

For instance, on printed circuit board a larger number of test sites can be integrated in the test zone for automatic handling in a manufacturing chain.

A second illustration is the very simple and dense integration of such a test solution on probing circuit interface with embedded electronics or not.

For the former, density is directly translated into parallelism for simultaneous testing in a single touchdown on the terminals of circuits.

For the latter, as the concept is applicable with discrete components, the implementation can be deported away from the probe location with a wave guide.

Besides, manufacturability of such a self-testing device (yield and reproducibility of the corresponding testing device) is very repeatable due to the simple transmission line pattern physical implementation on the printed circuit board and no or only few added passive or active components.

Symmetrical aspect of the implementation is also providing a high reliability when duplication is needed as for instance in multisite test configuration.

At last, higher reliability can be achieved because of very limited number of components and potential soldering points for SMD or mechanical connector for discrete devices.

This reduces drastically the risk of any loss paths on the signal transmission back and forth.

Claims

1. Method for self-testing of a pulsed transceiver device (100) having a unique emitting and receiving terminal, said method comprising:

- generating digital reference data stream,

- converting by the pulsed transceiver device itself the digital reference data stream into a pulsed signal,

- emitting said pulsed signal by the terminal of the transceiver device in transmission mode,

- delaying the emitted signal along a terminated transmission line (200) presenting an impedance discontinuity wherein the impedance at the terminating end (300) of the transmission line is different from the characteristic impedance of the transmission line,

- reflecting at least a part of the delayed emitted signal at the terminating end of the transmission line (200), the length of said terminated transmission line being selected so as to avoid any temporal overlap of the reflected pulsed signal with the emitted pulsed signal,

- delaying the reflected signal along the terminated transmission line (200),

- stimulating with the delayed reflected pulsed signal the same terminal of the transceiver device in receiving mode,

- converting by the transceiver device the received reflected signal into a received digital data stream,

-comparing said received digital data stream to said reference generated digital data stream.

2. Method according to claim 1 , further comprising:

- attenuating the emitted signal with a bidirectional attenuator (400), and

- attenuating the delayed reflected signal with said bidirectional attenuator (400), so as to stimulate said terminal of the transceiver device (100) in receiving mode with said attenuated and delayed reflected signal.

3. Method according to claim 1 or claim 2, further comprising controlling a switch device (500) connected between the transceiver device (100) or a bidirectional attenuator (400) and each of a plurality of terminated transmission lines for selecting one of said transmission lines (200, 201 , 200+n) having different lengths, each transmission line (200, 201 , 200+n) presenting an impedance discontinuity at its terminating end (300, 301 , 300+n).

4. Method according to one of claims 1 to 3, wherein said generation of reference digital data stream and said comparison are processed by the pulsed transceiver device.

5. Method according to one of claims 1 to 3, wherein said generation of reference digital data stream and said comparison are processed outside of the pulsed transceiver device.

6. Method according to one of claims 1 to 5, wherein said comparison is processed so as to provide a bit error rate.

7. Method according to one of claims 1 to 6, wherein said comparison is processed so as to provide a pass / fail decision on the functionality of the pulsed transceiver device.

8. Method according to one of claims 1 to 7, wherein said pulsed signal is used in a OOK modulation scheme, a PPM modulation scheme, a ASK modulation scheme, a QAM modulation scheme, a FSK modulation scheme, a PSK modulation scheme, or a OFDM multiplexing scheme.

9. Method according to one of claims 1 to 8, wherein said pulsed signal is a radiofrequency or optoelectonic signal.

10. Method according to one of claims 1 to 9, wherein said pulsed transceiver device (100) has a differential bidirectional terminal and the method further comprises converting said differential terminal into a single-ended terminal with a balun device (600).