Yuriy N. Pchelnikov

Medical application of surface electromagnetic waves

Abstract Advantages of surface electromagnetic waves application in medicine, including increased efficiency and depth of energy penetration are shown. Two types of the electrodes for physiotherapy, based on slow-wave structures (applicators and radiators) are described. It is shown that varying deceleration and frequency can control electric and magnetic field penetration into body tissue. The new method of electromagnetic energy radiation into tissue is implemented. Other examples of surface waves application are demonstrated, including coagulation scalpel and artificial ear. The main parameters of slow-wave structures that are used for the deceleration of electromagnetic waves are also described.

Old Know-How in Helix TWT Development in the USSR

In the USSR, the first traveling wave tube (TWT) was developed in 1946. This was followed by the invention of the first backward‐wave oscillator (BWO) and other important achievements, which could characterize a strong competition existed between American and Soviet scientists and engineers. In the present paper, some of the achievements of the first soviet TWT team, headed by L. N. Loshakov, are discussed. Among those achievements are invention of the two‐anode gun for a low‐noise TWT, development of the first three‐octave TWT, and development of the helix TWT linear theory. In this paper, also such issues as formation of the rotating electron beams, suppression of reflected waves, multi‐stage TWTs, amplification without synchronizing electron and wave velocities, utilization of beryllium oxide and quartz rods in one RF set, dispersion control by application of metal support rods, and many other engineering solutions are presented.

A Delay Line for Compression of Electromagnetic Pulses

A novel method to obtain an electromagnetic signal delay is described. It is shown that the positive magnetic and electric coupling between impedance conductors produces an increase in the time delay. It is also shown that the increase in delay time is obtained without additional attenuation. This allows a reduction in electromagnetic losses, by a factor of several times, for a delay time. An approximate analysis of electromagnetic delay lines based on coupled impedance conductors with “spiral” and “meander” patterns allowed obtaining very simple expressions for the wave deceleration factor, wave impedance, and attenuation factor. The results of the analysis are confirmed by the results of measurements. It is shown that a delay line based on counter‐wound radial spirals can be successfully used for compression of electromagnetic pulses. Although the offered delay line was designed to operate with a relatively small signal, the analysis of the “coupling effect,” taking place in this delay line, might be us...

Advantages of slowed electromagnetic waves

The features of slowed electromagnetic waves and their advantages are considered. Examples of new methods and devices combining the advantages of relatively high and relatively low frequency bands are shown. Concentration of an electromagnetic field caused by wave deceleration leads to a significant increase in parameters of processes and devices based on slowed wave application. It is shown that coupled slow-wave structures application allows electric and magnetic fields to split in transverse direction which leads to an additional improving in parameters and characteristics (the sensitivity and interaction efficiency increase, new processes developing, etc.). The possibilities of slowed wave application for micro-miniaturization of RF and microwave passive elements, for measurements, electromagnetic heating, and for physiotherapy are considered.