Conductivity and noise problem of plasma antennas
Investigation the plasma antenna on the basis of UHF discharge near the second Langmuir resonance (subresonance) is continuing. Measurements are given on the admission of signals. It is provied reducing the thermal and fluctuation noise of UHF discharge compared with metal.
Plasma antennas based on UHF discharge
Studied are the antenna properties of the UHF discharge plasma at the threshold of the resonance of the electron Langmuir frequency with the pump second harmonic. The results of experimental measurements of some characteristics of a plasma antenna-amplifier at the LF range are shown. A mathematical model of a similar antenna, which allows proceeding to a physical model of the distributed parametric amplifier, is built.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.