MILLIMETER-WAVELENGTH RELATIVISTIC MAGNETRON: PROBLEMS OF MICROWAVE POWER EXTRACTION

The relativistic magnetrons operating at millimeter wavelengths demonstrate problems with microwave power extraction, both in the radial and in axial direction. The preferred axial extraction concept can be implemented ei-ther as ‘diffractional output’ or via introduction of additional resonant elements into the output waveguide. In this paper several solutions for axial-directed extraction are discussed, including circular ring ‘antennas’ at the end of the anode-cathode space, and resonance-length rods at the faces of the anode-block cavities. These have allowed increasing the power extraction efficiency by a factor of 101 to 102.

Analysis of ARROW Waveguide based Microcantilever for Sensing Application

Analysis of microcantilever beam and ARROW microcantilever waveguides are presented in this work. The microcantilever is simulated by using the silicon nitride material. Electric voltage applied creates the deformation in the cantilever beam. The deformation leads to displacement of the beam. The displacement is due to bending of the cantilever tip. The integration of MEMS cantilever and ARROW waveguide results in the ARROW microcantilever waveguide. The ARROW microcantilever waveguide quality factor, electric filed intensity and sensitivity analysis are the three important parameters presented. The quality factor is obtained by varying the air gap distance between cantilever waveguide and output waveguide. Through this simulation using FDTD sensitivity up to 73.78 nm/RIU has been achieved for the microcantilever arrow waveguide.

Comparing Novel MMIC and Hybrid Circuit High Efficiency GaAs Schottky Diode mm-Wave Frequency Doublers

A novel Schottky diode frequency doubler in E-band, using biased series-connected diodes in the output waveguide, is reported. The doubler was implemented using a GaAs Schottky Monolithic Microwave Integrated Circuit (MMIC) process with integrated capacitors and beam leads. A comparison is made with a hybrid doubler using a more conventional single-ended configuration with two discrete diodes in a planar transmission line circuit. Both devices exhibit excellent performance over the 67–78 GHz design bandwidth, with the novel MMIC design producing 25 to 55 mW at 12 to 22% power conversion efficiency. Good agreement of measurements with simulations was also found.

Акустооптическая коммутация волоконно-оптических каналов

An acousto-optic commutator of fiber-optic channels based on a ТеО_2 two-coordinate deflector has been proposed and realized. The commutator yields switching of optical radiation from a single output waveguide into a two-dimensional input matrix of waveguides, or vice versa, switching from any matrix waveguide into a single output one. The main interrelated parameters have been obtained. It has been established that the commutator has a short response time of 2–10 μs, yields up to several hundreds of switching channels, low insertion losses of 2–5 dB, and a considerable inter-channel isolation from –35 to –60 dB. Experiments were performed for the output matrix containing 19 waveguides. The channel multiplexing operating mode of this commutator has been demonstrated, which is simultaneous transmission of a signal from the output waveguide into a given number of waveguides of the input matrix.