An investigation on plasma antennas

Tiğrek, Recep Fırat
The plasma antennas offer a new solution to new requirements that are imposed on antenna systems with the advancing communication technology and increasing demand on wider frequency bands. In this thesis the plasma antennas are investigated for the radar and communication applications. The interaction of gas and semiconductor plasma with electromagnetic waves is inspected theoretically, and several experiments on the interaction of microwaves with gas plasma are conducted. Results of these experiments show that a relatively simple setup can produce plasma dense enough to interact with microwaves of frequency about 8 GHz. The previous studies of other institutes on plasma antennas are surveyed, emphasizing the results important for the use in radar and communication applications. Finally, semiconductor plasma is introduced, and an antenna system utilizing the semiconductor plasma generated by optical excitation is proposed.


Design of log-periodic dipole array feed and wide band reflector antenna system
Tanyer, Fatma Müge; Tanyer, Fatma Müge; Department of Electrical and Electronics Engineering (2005)
The introduction of broadband systems to communication and radar technologies has demanded the design of broadband antennas. In this thesis, broadband log-periodic dipole antennas and reflector antennas are investigated. A dual polarized log-periodic dipole antenna and a reflector antenna are designed and analyzed within the frequency band of 0.4-18 GHz. Basic theory and calculations about mutual coupling between the linear antenna elements are given. The currents at the bases of dipoles of the log-periodic...
Dual band microstrip patch antenna structures
Okuducu, Yusuf; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2005)
Wideband and dual band stacked microstrip patch antennas are investigated for the new wideband and dual band applications in the area of telecommunications. In this thesis, aperture-coupled stacked patch antennas are used to increase the bandwidth of the microstrip patch antenna. By this technique, antennas with 51% bandwidth at 6.1 GHz and 43% bandwidth at 8 GHz satisfying S11<-15 dB are designed, manufactured and measured. A dual-band aperture coupled stacked microstrip patch antenna operating at 1.8 GHz ...
Investigations on frequency beam scanning microstrip (bsms) antenna structures
Dündar, Burhan; Birand, Mehmet Tuncay; Department of Electrical and Electronics Engineering (2009)
Beam scanning Microstrip (BSMS) antenna is designed to work at center frequency of 10 GHz for using in the scanning applications of 9 GHz to 11 GHz band. The design parameters are defined and by using an Electromagnetic Simulation software program, the parameters are optimized. A Beam Scanning Microstrip Antenna is produced as a prototype and the measurement’s results are compared with theoretical results. In conclusion, the values of deviation between theoretical and experimental results are discussed.
Mutual coupling calibration of antenna arrays for direction-of-arrival estimation
Aksoy, Taylan; Tuncer, Temel Engin; Department of Electrical and Electronics Engineering (2012)
An antenna array is an indispensable portion of a direction-of-arrival (DOA) estimation operation. A number of error sources in the arrays degrade the DOA estimation accuracy. Mutual coupling effect is one of the main error sources and should be corrected for any antenna array. In this thesis, a system theoretic approach is presented for mutual coupling characterization of antenna arrays. In this approach, the idea is to model the mutual coupling effect through a simple linear transformation between the mea...
Implementation of stanag 428 hf modem software on tms320c54x digital signal processor
Örümlü, Erhan; Baykal, Buyurman; Department of Electrical and Electronics Engineering (2004)
In this research, STANAG 4285 HF modem software is implemented on TMS320C54x fixed point digital signal processor. The software is optimized in order to meet real-time operation requirements. A fractionally spaced least mean square (LMS) decision feedback equalizer (DFE) is employed for the receiver. In order to improve the convergence of the LMS algorithm a multipass technique is utilized. Based on Watterson̕s model, an HF channel simulator is employed for evaluating the performance of the modem. The simul...
Citation Formats
R. F. Tiğrek, “An investigation on plasma antennas,” M.S. - Master of Science, Middle East Technical University, 2005.