|
|
Antenna Arrays with Synthesized Frequency Response of Gain
Všetula, Petr ; Polívka,, MIlan (oponent) ; Bonefačic, Davor (oponent) ; Raida, Zbyněk (vedoucí práce)
In the thesis, we present a method of the synthesis of a dipole antenna array with prescribed spectral and spatial filtering capabilities. Thanks to the spatial filtering capabilities, the main lobe direction and the value of gain vary negligibly over the operating band. Thanks to the spectral filtering capabilities, the value of gain is maximal in the operating band and minimal out of the operating band. In order to synthesize a dipole array with prescribed filtering capabilities, amplitudes, phases and dimensions of antenna elements are optimized. The initial optimization is speeded up by considering an idealized antenna array when evaluating objective functions. Since the optimization comprises requirements on the main lobe direction, the value of gain and impedance matching, a multi-objective optimization is used. The optimized antenna array is analyzed by a full-wave simulator to verify results of the synthesis. Finally, the synthesized dipole array is manufactured and its performance is experimentally verified.
|
|
|
Perforated Dielectrics and Higher-Order Mode Dielectric Resonator Antennas
Mrnka, Michal ; Bonefačić, Davor (oponent) ; Mrozowski, Michal (oponent) ; Raida, Zbyněk (vedoucí práce)
The thesis deals with the excitation of higher-order modes in the rectangular and cylindrical dielectric resonator antennas for gain enhancement purpose. The properties and limitations of the antenna elements are studied numerically. Mutual coupling between the higher-order mode dielectric resonators is examined and the results prove the elements to be suitable for antenna array applications. For perforated dielectrics, an analytical model of effective permittivity that respects its anisotropic properties is proposed. The model is based on the Maxwell Garnett approximation of inhomogeneous media. Surface waves on perforated substrates are then studied and the validity of the analytical model is verified also in this case. The dielectric resonator antennas embedded in perforated substrates are studied and certain degradations in antenna properties are pointed out.
|
|
|
Perforated Dielectrics and Higher-Order Mode Dielectric Resonator Antennas
Mrnka, Michal ; Bonefačić, Davor (oponent) ; Mrozowski, Michal (oponent) ; Raida, Zbyněk (vedoucí práce)
The thesis deals with the excitation of higher-order modes in the rectangular and cylindrical dielectric resonator antennas for gain enhancement purpose. The properties and limitations of the antenna elements are studied numerically. Mutual coupling between the higher-order mode dielectric resonators is examined and the results prove the elements to be suitable for antenna array applications. For perforated dielectrics, an analytical model of effective permittivity that respects its anisotropic properties is proposed. The model is based on the Maxwell Garnett approximation of inhomogeneous media. Surface waves on perforated substrates are then studied and the validity of the analytical model is verified also in this case. The dielectric resonator antennas embedded in perforated substrates are studied and certain degradations in antenna properties are pointed out.
|
|
|
Antenna Arrays with Synthesized Frequency Response of Gain
Všetula, Petr ; Polívka,, MIlan (oponent) ; Bonefačic, Davor (oponent) ; Raida, Zbyněk (vedoucí práce)
In the thesis, we present a method of the synthesis of a dipole antenna array with prescribed spectral and spatial filtering capabilities. Thanks to the spatial filtering capabilities, the main lobe direction and the value of gain vary negligibly over the operating band. Thanks to the spectral filtering capabilities, the value of gain is maximal in the operating band and minimal out of the operating band. In order to synthesize a dipole array with prescribed filtering capabilities, amplitudes, phases and dimensions of antenna elements are optimized. The initial optimization is speeded up by considering an idealized antenna array when evaluating objective functions. Since the optimization comprises requirements on the main lobe direction, the value of gain and impedance matching, a multi-objective optimization is used. The optimized antenna array is analyzed by a full-wave simulator to verify results of the synthesis. Finally, the synthesized dipole array is manufactured and its performance is experimentally verified.
|
host ::
RSS.