The APEDE is the venue traditionally organized and hosted by Saratov Technical State University (SSTU). In comparison with the previous meeting (see Waveguide, Feb 1997), this time the number of registrants was increased from 127 to 147 whereas the number of papers was the same: 110. In fact, the conference was working in the period which coincided with the start of the reportedly full-scale economic and financial crisis in Russia that defeated virtually all areas of professional activity and business. So there is nothing surprising that in contrast to APEDE'96 the conference site was changed - from a holiday hotel on a picturesque cliff on the bank of Volga River to the SSTU lecture-rooms. Neither were al of the participants able to attend the venue, due to external difficulties which resulted in many last moment cancellations.

In general, the conference work was very successful and fruitful. During the previous several months the Organizing Committee undertook strong efforts to provide appropriate arrangement and got sponsorship from two large state scientific and industrial corporations, Toriy in Moscow and Kontakt in Saratov. Technical cosponsorship was also provided by the local branch of the Institute of Electrical and Electronic Engineers, The Electron Devices Society (IEEE/EDS).

The conference program was divided into three sections entitled Microwave Electronics, Microwave Theory & Techniques, and Electron Devices, Applications & Technology. While the discussions covered a wide area of topics in relevant science and technology, a certain part of papers had direct or indirect relation to microwave power engineering.

In the first section, papers devoted to problems of modeling and design of klystrons, magnetrons, and traveling wave tubes were included. A group of simple single-factor models for creation of an algorithm of synthesis of klystron with synchronized distuning was presented. Calculation of characteristics of klystron-type multibeam devices was shown for the case of matrices of autoemitting cathodes. Issues related to mathematical modeling of multifrequency operating regime of klystrods were discussed. Along with mathematical modeling, results of physical modeling of multi-cavity relativistic klystrons were demonstrated for the high signal mode. The ways of design and manufacturing of powerful (less than 100 MW) and superpowerful (more than 100 MW) klystrons with efficiency not less than 70% were also reported.

Special digital multimode model was suggested for the analysis of processes in a KA band magnetron. Several numerical models for calculation of main output characteristics of magnetron amplifiers were proposed for the practical use. Attention of engineers was also focused on a comparative analysis of different methods of the approximate calculation of magnetron characteristics.

Problems of computation and design of effective traveling wave tubes were also discussed. Particular attention was given to the analysis of pulse signal amplification in boardband TWT, and the use of Monte-Carlo method for creation of non-linear one dimensional model of a tube of O-type interaction.

An integrated system especially designed for 3D volumetric heating and built on the powerful resotrodes was introduced. The heating cavity was suggested being a part of the resotrode output construction. The system was created for the use in various industrial applications.

Papers included in the section devoted to microwave theory & techniques were mainly about results of calculations. A technique of elimination of the spurious solutions in computation of dielectric waveguides by FEM was presented. Mathematical simulation of resonators of the space-advanced structure was analyzed using the equivalent circuits with half-distributed parameters.

Various partially filled waveguides were in the focus of the interest. Influence of the dielectric absorption on the field structure of a rectangular waveguide was studied by the method of partial plane waves. The results of FEM computation of the band characteristics of dielectric-loaded ridged, double ridged and other complex waveguides were reported. A ridged waveguide was also considered in a paper on the analysis and synthesis of bandmincing filters. A spiral surrounded by a metal shield was considered as an element of a slow wave system of a broadband TWT, and the dispersion of the phase velocity and interaction impedance were determined via the rigorous solution of the Maxwell's equations.

Several papers presented in Electron Devices, Applications, and Technology section directly addressed characteristics and technologies of microwave thermoprocessing. An example of medical application of microwaves was demonstrated when presenting an experimental study of microwave acceleration of dibasole synthesis. Dibasole was synthesized both in solution and in solid, and significant advantage in comparison with conventional technology was shown: when using microwaves, the time of synthesis is drastically shortened (from several hours to a few minutes).

Technique of modeling of process of defrosting of meat products in a microwave setup of a beam type was suggested. The properties of the product were considered temperature-dependent. An attenuation coefficient was calculated in microwave dryers built in a rectangular waveguide. Waveguide types were analyzed as possible basic elements of traveling wave chambers, and criteria of their choice for the installation for processing of liquids, tenacious, and intersperse materials were proposed.

The general evaluation of the APEDE'98 program exposes a specific observation, which has to be mentioned. In the past, Russian conferences of the APEDE's level were satiated with results of big budget research and large-scale projects (both experimental and theoretical). At this meeting, a number of papers presented by industry were looking like pedestrian efforts targeted merely on certain amendments of available technologies and devices; results demonstrated by academia appeared to possess quite particular values, and some papers seem to be prepared on the basis of routine student work. In other words, the scale of activities in the relevant areas certainly looks more modest. This feature, however, appears to be natural in the current general situation.

It is well known that science and technology (in particular, microwave and electronic engineering) now endure a difficult time in Russia. Previously, extensive cooperation between industrial and academic institutions (including significant financial investment from industry) was traditionally a key issue in the development of the both parties. For several years, all forms of this interaction have been decaying in Russia. When 3-5 years ago a collaboration with Western and Asian partners turned out to be possible, it was supposed that at least some potential prospective Russian technologies might find appropriate development and thus more extensive activity in their and other relevant areas could be initiated. However, the progress here has been minimal - the level of international cooperation still looking very promising remains extremely low. (At APEDE'98, only one paper was authored by participants of a joint Russian-Japanese research project.)

This review is not an appropriate place to discuss the reasons for that, but, in fact, the state of the Russian microwave and electronic science and engineering is extremely hard. Thus the work done the APEDE's Organizing Committee has to be highly appreciated. They succeeded in gathering many scientists and engineers who, attending this meeting, got a rare opportunity to feel that their community is alive and working despite all incredible difficulties.

Similarly to APEDE'94 and '96, the conference proceedings have been published in Russian. However, this year's publication has been more detailed (3 volumes, 630 pages totally) and included several line abstracts of all the papers in English. These abstracts have also been put on the APEDE'98 web site at http://www.sstu.runnet.ru/apede98/apede98.html. For more information, contact Vadim Yakovlev at Worcester Polytechnic Institute; e-mail: vadim@wpi.edu.