Although many microwave measurement techniques are heavily based on special purpose software, the application of modern software techniques like object oriented programming and new programming language like C++ is seldom used. The impact of such new software solutions can drastically improve the overall design of a microwave test set. The paper presents the design and implementation of a new multiport network analyzer with particular attention to the control program architecture. The use of Object Oriented Programming techniques results in a clear and easy to maintain solution which boosts both the user interface and the overall test set organizatio

A. Ferrero

G. L. Madonna

U. Pi

Umberto Pisani

English

Crossref

Novel Software Techniques for Automatic Microwave Measurements

Ferrero, Andrea Pierenrico

Madonna, G.L.

Pisani, Umberto

PORTO Publications Open Repository TOrino

Novel Software Techniques for Automatic Microwave 
Measurements 
A.Ferrero, G.L.Madonna and U.Pi& 
Dipartimento di Elettronica, Politecnico di Torino 
Corso Duca degli AbrUzzi 24, 10129 Torino, Italy 
Phone: (xx3911) 5644082 Fax: (xx3911) 5644099 e-mail: ferrero@polito.it 
Abstract: Although many microwave measurement 
techniques are heavily based on special purpose software, 
the application of modem software techniques like object 
oriented programming and new programming language 
like C* is seldom used. The impact of such new sohare  
solutions can drastically improve the overall design of a 
microwave test set. The paper presents the design and 
implementation of a new multiport network ahalyzer with 
particular attention to the control program architecture. 
The use of Object Oriented Programming techniques 
results in a clear and easy to maintain solution which 
boosts both the user interface and the overall test set 
organization. 
I INTRODUCTION 
The comprehensive characterization of microwave 
devices, complex circuits and subsystems for application 
in telecommunications is rapidly becoming an 
indispensable tool in any RF/microwave design. 
The available instrumentation for network analysis is 
almost entirely devoted to the characterization of two- 
port devices under small signal excitation, but the 
increasing complexity of microwave circuits demands for 
novel techniques to characterize multiport circuits, such 
as high speed digital circuits, beam forming network, 
mixers and multifunction MMICs. 
The main problems which constrain the development of 
multiport (i.e. more than 2 ports) NWA are the calibration 
technique, the high complexity of the required instrumen- 
tation and a simple and flexible user interface. 
In this paper we present a simple low cost Frequency and 
Time Domain Multiport Network Analyzer architecture 
and, in particular, the design and the features of its 
Control software. The code widely uses the Object 
Oriented Programming (OOP) paradigm both for the 
instrument driver organization and the user interface. The 
result is a clear and easily to expand software architecture, 
where all the traditional sections of a microwave 
automatic measurement program: Reading, Calibration 
and Presentation have been integrated in a series of 
interacting objects. First a brief description of the 
multiport test set will be given, then we will  focused the 
attention on the particular software solutions which allow 
simple and user friendly procedures both for calibration. 
and measurement. 
II TEST SET DESCRIPTION 
The block diagram of the four port ANA is shown in 
figure 1. The system comprises essentially a microwave 
transition analyzer (MTA) used as a fresuencyhme 
domain receiver and a test set based on two switching 
matrices and 4 dual directional couplers. The source 
switching matrix routes the RF signal source to the 
various device ports. One of the two channels of the h4TA 
is used as fixed phase (trigger) reference while the other 
samples in turn all the forward and reverse waves through 
the receiver switch. This solution provides fresuency and 
time domain measurements and it is easily expandable 
just by adding more channels into the switching matrices 
and more couplers. On the other hand the number of 
possible measurements dramatically increases respect to 
an ordinary two port NWA Over the possible 
measurements that we could get with an ordinary 
transition analyzer (time domain waveform analysis, 
frequency domain response), with such multiport scheme, 
we have to take also into account the possibility of mixed 
port excitation, harmonic fieqwncy measurements over 
Merent ports, simultaneous device measurements of two 
port devices and so on. Some measurements examples that 
couldbe obtained with this system are: 
single tier four port device S parameter 
time domain waveforms of mixer and other 
non linear devices 
on wafer measurement of complex MM3C 
digital bus response at microwave frequencies 
simultaneous measurements of two port 
devices to increase the production testing 
speed 
EMC measurement of complex structure up to 
microwave fresuencies 
An effective calibration procedure is also mandatory to 
reduce the number of standard insertions and, in 
particular, where geometric or mate problems arise. 
156 
HP70820A 
Micremave 
Tramition 
Analyzer 
M a m i  2031 
SigMl @?tll?mOr 
Figure 1: Multiport Timerequency Domain Network Analyzer block scheme 
Two calibration techniques are derived from [l] and 
optimized for on wafer environment: the first is a TRL- 
like technique, while the second uses fully known open 
and short standards. Note that, due to the geometrical 
constraints, if the probe position is fixed, a straight line 
thru can be used. only between faced probes (probes 1-4 of 
Thus to compute the error box terms which links two side 
probes, an undefined thru technique have to be used [2]. 
Finally, to allow an absolute power-phase calibration for 
on-wafer time domain measurements, a technique similar 
to [3] is adopted 
figure2). 
:: 1=4 2 > + K 3  2 THRU 
THRU Unknown THRU 
Figure 2: Standard displacement problempormal thm 
connection for two faced probes (case a), an unknown 
thm is necessary for side by side probes (case b). 
III SOFTWARE DESIGN 
The targets for the design wftware were: 
1) A simple and user friendly interface 
2) Extreme flexibility on the microwave receiver 
type, such that a different one rather than the 
MTA could be used 
3) Easy expandability of the measurement 
capabilities with extra measurement modules 
such as multitone measurements. 
The use of a Windows PC-based approach is mandatory 
to obtain a simple and user hendly interface. Rather than 
using the classical procedural approach to handle the 
several system functions, Object Oriented Programming 
(OOP) paradigm has been widely used for the design of 
the control software and the user interface. Although 
commercial software based on OOP like LabView is now 
available, the complexity of the microwave measurement 
problem suggested a fblb new development in Cte. The 
OOP approach offers a better way to model the complexity 
of our measurements which result in a well defined series 
of interacting objects, as shown in figure 4. 
As example, the calibration problem is handled through a 
calibration object based on two other basic objects (see 
figure 3): a collection of standards and a collection of 
error coefficients. Each member of the standard collection 
computes its frequency response based on its physical 
parameters (inserted in a standard specific insertion 
157 
dialog). Ha new standard model is added there is no need 
to change any part of the old code but simply add an item 
to the collection. According to the traditional procedural 
paradigm, on the contrary, a single function, containing a 
switchcase statement, would compute the frequency 
response for the dif€erent standard models, thus to add a 
new one this basic routine needs to be changed. 
Furthermore, if the new model requires more parameters 
than the old one, the overall internal structures, which 
contains the standard data, and the user interface to input 
the model parameters have to be changed. In the OOP 
approach each standard bas its own data and user input 
dialog while the only link with the other parts is the 
m e a c y  response. 
Calibration 
approach. We defined a common measurement object 
which handles the basic test set functionality thus 
automatically gives to each derived object the access to the 
measurement data (such as complex waveform). This 
solution leaves to the high level object the organization of 
the measurement process and the user interface for the 
particular application. The user is so free to design his 
own measurement, such as complex mixer multitone 
characterization, or particular digital measurements. As 
e m e ,  the time domain object shares the same basic 
data as the S-piuameter one, but tban owns a different 
method to correct the raw data and to show the corrected 
results. The measurement objects are grouped in a 
measurement list which allows to easily add new custom 
modules. 
IV CONCLUSION 
A new sohare organization applied to a multiprt NWA 
is presented. The software model of the measurement 
reality offers a better understanding of the processes 
involved and it is easy to expand and suitable for re-use. 
The use of the OOP has been filly exploited both for the 
user interface and the more critical ahbration and 
measurement processes. 
ACKNOWLEDGEMENT 
The authors wish to thank Prof. F.M.Ghannouchi and the 
entire microwave laboratory of the Ecole Polytechnique of 
Montreal for the interesting suggestions and the help 
during the development of this work. 
* *(...) 
REFERENCES 
Figure 3: Calibration objects hierarchy 
Another example is given by the basic instrument 
hierarchy (see figure 4). We have a single NWA object 
which is a part of a test-set object and includes both the 
data and the measurement functionality. On the other 
side, the traditional procedural paradigm would have a 
series of routines for the NWA data acquisition and 
common or local arrays for data storage. A typical 
consequence of a traditional design is the need of different 
high level routines when different instruments are used 
as a network analyzer (i.e. an MTA or a more traditional 
HP8510). Instead, in an OOP technique there are several 
NWA objects, one for each particular actual instrument, 
and the upper level objects do not need to know which 
type of instrument is used 
Probably the more useful application of OOP techniques 
in this design is the so-called custom measurement 
[ 11 AFerrero, F. Sanpietro and U.Pisani, “Multiprt vector 
network analyzer calibration: a general formulation”, 
IEEE Trans. Microwave Theory Tech., vo1.42, pp.2455- 
2461, Dec. 1994. 
[2] AFerrero and U.Pisani, “Two-port network analyzer 
calibration using an unknown thru”, IEEE Microwave 
GujdedLett., v01.2, pp.505-507, Dec. 1992. 
[3] T. Van den Broeck and J.Verspect, “Calibrated 
vectorial nonlinear-network analyzer”, 1994 IEEE MTTS 
Intl. SVmposium Dig., San Diego, Ca., May 1994. 
158 
theApplication w 
accesses to 
r I I 
f \ 
Measurelist Calibration 6 > 
L 1 
uses V \ 
Configuration initializes uses 
uses J 
V 
Testset i ........... :. (.J 
SwitchMatrix 
Analyzer 
Figure 4: Measurement Software Object Oriented Model 
159 


[2] AFerrero and U.Pisani, “Two-port network analyzer calibration using an unknown thru”,

Calibrated vectorial nonlinear-network analyzer”,

Novel software techniques for automatic microwave measurements

Abstract: Although many microwave measurement techniques are heavily based on special purpose software, the application of modem software techniques like object oriented programming and new programming language like C * is seldom used. The impact of such new sohare solutions can drastically improve the overall design of a microwave test set. The paper presents the design and implementation of a new multiport network ahalyzer with particular attention to the control program architecture. The use of Object Oriented Programming techniques results in a clear and easy to maintain solution which boosts both the user interface and the overall test set organization. 

CiteSeerX

Although many microwave measurement techniques are heavily based on special purpose software, the application of modern software techniques like object oriented programming and new programming language like C++ is seldom used. The impact of such new software solutions can drastically improve the overall design of a microwave test set. The paper presents the design and implementation of a new multiport network analyzer with particular attention to the control program architecture. The use of Object Oriented Programming techniques results in a clear and easy to maintain solution which boosts both the user interface and the overall test set organization

FERRERO, ANDREA PIERENRICO

PISANI, Umberto

PORTO@iris (Publications Open Repository TOrino - Politecnico di Torino)

04 August 2020POLITECNICO DI TORINORepository ISTITUZIONALENovel software techniques for automatic microwave measurements / A. Ferrero; G. L. Madonna; U. Pisani. - STAMPA. -29(1996), pp. 156-159. ((Intervento presentato al convegno ARFTG Conference Digest tenutosi a San Francisco, CA(USA) nel June 1996.OriginalNovel software techniques for automatic microwave measurementsPublisher:PublishedDOI:10.1109/ARFTG.1996.327176Terms of use:openAccessPublisher copyright(Article begins on next page)This article is made available under terms and conditions as specified in the  corresponding bibliographic description inthe repositoryAvailability:This version is available at: 11583/2497913 since:Novel Software Techniques for Automatic Microwave Measurements A.Ferrero, G.L.Madonna and U.Pi& Dipartimento di Elettronica, Politecnico di Torino Corso Duca degli AbrUzzi 24, 10129 Torino, Italy Phone: (xx3911) 5644082 Fax: (xx3911) 5644099 e-mail: ferrero@polito.it Abstract: Although many microwave measurement techniques are heavily based on special purpose software, the application of modem software techniques like object oriented programming and new programming language like C* is seldom used. The impact of such new sohare  solutions can drastically improve the overall design of a microwave test set. The paper presents the design and implementation of a new multiport network ahalyzer with particular attention to the control program architecture. The use of Object Oriented Programming techniques results in a clear and easy to maintain solution which boosts both the user interface and the overall test set organization. I INTRODUCTION The comprehensive characterization of microwave devices, complex circuits and subsystems for application in telecommunications is rapidly becoming an indispensable tool in any RF/microwave design. The available instrumentation for network analysis is almost entirely devoted to the characterization of two- port devices under small signal excitation, but the increasing complexity of microwave circuits demands for novel techniques to characterize multiport circuits, such as high speed digital circuits, beam forming network, mixers and multifunction MMICs. The main problems which constrain the development of multiport (i.e. more than 2 ports) NWA are the calibration technique, the high complexity of the required instrumen- tation and a simple and flexible user interface. In this paper we present a simple low cost Frequency and Time Domain Multiport Network Analyzer architecture and, in particular, the design and the features of its Control software. The code widely uses the Object Oriented Programming (OOP) paradigm both for the instrument driver organization and the user interface. The result is a clear and easily to expand software architecture, where all the traditional sections of a microwave automatic measurement program: Reading, Calibration and Presentation have been integrated in a series of interacting objects. First a brief description of the multiport test set will be given, then we will  focused the attention on the particular software solutions which allow simple and user friendly procedures both for calibration. and measurement. II TEST SET DESCRIPTION The block diagram of the four port ANA is shown in figure 1. The system comprises essentially a microwave transition analyzer (MTA) used as a fresuencyhme domain receiver and a test set based on two switching matrices and 4 dual directional couplers. The source switching matrix routes the RF signal source to the various device ports. One of the two channels of the h4TA is used as fixed phase (trigger) reference while the other samples in turn all the forward and reverse waves through the receiver switch. This solution provides fresuency and time domain measurements and it is easily expandable just by adding more channels into the switching matrices and more couplers. On the other hand the number of possible measurements dramatically increases respect to an ordinary two port NWA Over the possible measurements that we could get with an ordinary transition analyzer (time domain waveform analysis, frequency domain response), with such multiport scheme, we have to take also into account the possibility of mixed port excitation, harmonic fieqwncy measurements over Merent ports, simultaneous device measurements of two port devices and so on. Some measurements examples that couldbe obtained with this system are: single tier four port device S parameter time domain waveforms of mixer and other non linear devices on wafer measurement of complex MM3C digital bus response at microwave frequencies simultaneous measurements of two port devices to increase the production testing speed EMC measurement of complex structure up to microwave fresuencies An effective calibration procedure is also mandatory to reduce the number of standard insertions and, in particular, where geometric or mate problems arise. 156 HP70820A Micremave Tramition Analyzer M a m i  2031 SigMl @?tll?mOr Figure 1: Multiport Timerequency Domain Network Analyzer block scheme Two calibration techniques are derived from [l] and optimized for on wafer environment: the first is a TRL- like technique, while the second uses fully known open and short standards. Note that, due to the geometrical constraints, if the probe position is fixed, a straight line thru can be used. only between faced probes (probes 1-4 of Thus to compute the error box terms which links two side probes, an undefined thru technique have to be used [2]. Finally, to allow an absolute power-phase calibration for on-wafer time domain measurements, a technique similar to [3] is adopted figure2). :: 1=4 2 > + K 3  2 THRU THRU Unknown THRU Figure 2: Standard displacement problempormal thm connection for two faced probes (case a), an unknown thm is necessary for side by side probes (case b). III SOFTWARE DESIGN The targets for the design wftware were: 1) A simple and user friendly interface 2) Extreme flexibility on the microwave receiver type, such that a different one rather than the MTA could be used 3) Easy expandability of the measurement capabilities with extra measurement modules such as multitone measurements. The use of a Windows PC-based approach is mandatory to obtain a simple and user hendly interface. Rather than using the classical procedural approach to handle the several system functions, Object Oriented Programming (OOP) paradigm has been widely used for the design of the control software and the user interface. Although commercial software based on OOP like LabView is now available, the complexity of the microwave measurement problem suggested a fblb new development in Cte. The OOP approach offers a better way to model the complexity of our measurements which result in a well defined series of interacting objects, as shown in figure 4. As example, the calibration problem is handled through a calibration object based on two other basic objects (see figure 3): a collection of standards and a collection of error coefficients. Each member of the standard collection computes its frequency response based on its physical parameters (inserted in a standard specific insertion 157 dialog). Ha new standard model is added there is no need to change any part of the old code but simply add an item to the collection. According to the traditional procedural paradigm, on the contrary, a single function, containing a switchcase statement, would compute the frequency response for the dif€erent standard models, thus to add a new one this basic routine needs to be changed. Furthermore, if the new model requires more parameters than the old one, the overall internal structures, which contains the standard data, and the user interface to input the model parameters have to be changed. In the OOP approach each standard bas its own data and user input dialog while the only link with the other parts is the m e a c y  response. Calibration approach. We defined a common measurement object which handles the basic test set functionality thus automatically gives to each derived object the access to the measurement data (such as complex waveform). This solution leaves to the high level object the organization of the measurement process and the user interface for the particular application. The user is so free to design his own measurement, such as complex mixer multitone characterization, or particular digital measurements. As e m e ,  the time domain object shares the same basic data as the S-piuameter one, but tban owns a different method to correct the raw data and to show the corrected results. The measurement objects are grouped in a measurement list which allows to easily add new custom modules. IV CONCLUSION A new sohare organization applied to a multiprt NWA is presented. The software model of the measurement reality offers a better understanding of the processes involved and it is easy to expand and suitable for re-use. The use of the OOP has been filly exploited both for the user interface and the more critical ahbration and measurement processes. ACKNOWLEDGEMENT The authors wish to thank Prof. F.M.Ghannouchi and the entire microwave laboratory of the Ecole Polytechnique of Montreal for the interesting suggestions and the help during the development of this work. * *(...) REFERENCES Figure 3: Calibration objects hierarchy Another example is given by the basic instrument hierarchy (see figure 4). We have a single NWA object which is a part of a test-set object and includes both the data and the measurement functionality. On the other side, the traditional procedural paradigm would have a series of routines for the NWA data acquisition and common or local arrays for data storage. A typical consequence of a traditional design is the need of different high level routines when different instruments are used as a network analyzer (i.e. an MTA or a more traditional HP8510). Instead, in an OOP technique there are several NWA objects, one for each particular actual instrument, and the upper level objects do not need to know which type of instrument is used Probably the more useful application of OOP techniques in this design is the so-called custom measurement [ 11 AFerrero, F. Sanpietro and U.Pisani, “Multiprt vector network analyzer calibration: a general formulation”, IEEE Trans. Microwave Theory Tech., vo1.42, pp.2455- 2461, Dec. 1994. [2] AFerrero and U.Pisani, “Two-port network analyzer calibration using an unknown thru”, IEEE Microwave GujdedLett., v01.2, pp.505-507, Dec. 1992. [3] T. Van den Broeck and J.Verspect, “Calibrated vectorial nonlinear-network analyzer”, 1994 IEEE MTTS Intl. SVmposium Dig., San Diego, Ca., May 1994. 158 theApplication w accesses to r I I f \ Measurelist Calibration 6 > L 1 uses V \ Configuration initializes uses uses J V Testset i ........... :. (.J SwitchMatrix Analyzer Figure 4: Measurement Software Object Oriented Model 159 

https://www.researchgate.net/profile/Alessandro_Ferrero/publication/251774154_Novel_Software_Techniques_for_Automatic_Microwave_Measurements/links/543d1b890cf20af5cfbfa8b1.pdf

Novel software techniques for automatic microwave measurements

Abstract

Similar works

Full text

Available Versions

Crossref

PORTO Publications Open Repository TOrino

CiteSeerX

PORTO@iris (Publications Open Repository TOrino - Politecnico di Torino)