Plasma antennas driven by 5–20 kHz AC power supply

Abstract

The experiments described in this work were performed with the aim of introducing a new plasma antenna that was excited by a 5-20 kHz alternating current (AC) power supply, where the antenna was transformed into a U-shape. The results show that the impedance, voltage standing-wave ratio (VSWR), radiation pattern and gain characteristics of the antenna can be controlled rapidly by varying not only the discharge power, but also by varying the discharge frequency in the range from 5 to 20 kHz. When the discharge frequency is adjusted from 10 to 12 kHz, the gain is higher within a relatively broad frequency band and the switch-on time is less than 1 ms when the discharge power is less than 5 W, meaning that the plasma antenna can be turned on and off rapidly. C 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. [http://dx

Experimental characteristics of 2.45 GHz microwave reconfigurable plasma antennas

“…The electron density in the microwave system is much higher than that of the plasma driven by a kHz or few MHz power supply. In [34], we measured the densities of plasmas driven by kHz and MHz power supplies, and the largest density reached 10 17 m −3 . A photomultiplier tube and an oscilloscope were used to estimate the plasma switch-on time using the light-electricity time difference from a previous work [34].…”

“…In [34], we measured the densities of plasmas driven by kHz and MHz power supplies, and the largest density reached 10 17 m −3 . A photomultiplier tube and an oscilloscope were used to estimate the plasma switch-on time using the light-electricity time difference from a previous work [34]. Two channels are connected to the oscilloscope, one of which is used to detect the discharge signals from the microwave power supply and the other used to collect the optical signals from the glow plasma.…”

“…Two channels are connected to the oscilloscope, one of which is used to detect the discharge signals from the microwave power supply and the other used to collect the optical signals from the glow plasma. The method for investigating the switch-on time is described in [34]. Figure 8 shows the measurement results of the switch-on time of the microwave plasma flexible antenna.…”

“…We then could vary not only the plasma parameters, but also the antenna shape very simply allowing setting the characteristics of the plasma antenna as required. However, the gains were not very large because the electron density was not very high, approximately 10 14 to 10 17 m −3 [34,35].…”

Reconfigurable Cylindrical Plasma Antenna

“…Some antennas using plasma have been studied in the literature. In [3][4][5][6][7][8][9][10][11][12][13][14], the authors proposed plasma antenna for which an ionized tube was the radiating element. In [15], the authors proposed a dipole plasma antenna with a lumped element equivalent circuit to represent the input impedance.…”