Helically corrugated waveguides have recently been studied for use in various applications such as interaction regions in gyrotron traveling-wave tubes and gyrotron backward-wave oscillators and as a dispersive medium for passive microwave pulse compression. The paper presents a summary of various methods that can be used for analysis of the wave dispersion of such waveguides. The results obtai...

It is shown that in a spin-torque microwave oscillator based on a magnetic nanocontact, the nature of the microwave spin wave mode generated at the threshold critically depends on the angle between the external bias magnetic field and the plane of the free layer. When the external bias field is rotating from normal to in-plane orientation, an abrupt transition from a propagating cylindrical wav...

This paper presents the Waveguide Filter Design (WFD) program using principle of electromagnetic wave theory and Wave Iterative Method (WIM) based on propagation of incident, reflected and transmitted waves in the waveguide for microwave engineering education. After the surveying by questionnaire about the nature in the microwave engineering course, the instructors found that the microwave engi...

The pure rotational 6-type spectrum of the van der Waals complex Ne-CO has been measured using a pulsed jet, intracavity millimeter wave spectrometer. The millimeter wave generation is based on the OROTRON principle. The high sensitivity of the spectrometer allowed measurements of R( J), K = 1 0 transitions between 108 and 150 GHz of the Ne isotopomers Ne-CO and Ne-CO. This new millimeter wave ...

The purpose of optical antennas is to convert the energy of free propagating radiation to localized energy, and vice versa. Although this is similar to what radio wave and microwave antennas do, optical antennas exploit the unique properties of metal nanostructures, which behave as strongly coupled plasmas at optical frequencies. It is hoped that optical antennas can increase the efficiency of ...

Microstrip antennas are one of the most widely used types of antennas in the microwave frequency range, and they are often used in the millimeter-wave frequency range. Actually as the demand for high data rates grows and microwave frequency bands become congested, the millimeter-wave spectrum is becoming increasingly attractive for emerging wireless applications. The abundance of bandwidth and ...

Modern microwave and millimeter wave phased array antennas are attractive because of their ability to steer wave beams in space without physically moving the antenna element. A typical phased array antenna may have several thousand elements fed by a phase shifter for every antenna, which can steer the resulting array beam to different directions. Their low loss, low cost and lightweight phase s...

We study the phenomenon of an electromagnetically induced phase grating in a double-dark state system of 87Rb atoms, the two closely placed lower fold levels of which are coupled by a weak microwave field. Owing to the existence of the weak microwave field, the efficiency of the phase grating is strikingly improved, and an efficiency of approximately 33% can be achieved. Under the action of the...

We study the phenomenon of an electromagnetically induced phase grating in a double-dark state system of 87Rb atoms, the two closely placed lower fold levels of which are coupled by a weak microwave field. Owing to the existence of the weak microwave field, the efficiency of the phase grating is strikingly improved, and an efficiency of approximately 33% can be achieved. Under the action of the...