Showing papers on "Metamaterial antenna published in 1979"

Extended analysis of rectangular microstrip resonator antennas

Abstract: An extended theory on rectangular microstrip resonator antennas is presented using the cavity model. Radiation from all four edges of the open cavity is taken into account as well as dielectric and ohmic losses. For a rectangular microstrip antenna excited in its lowest resonance mode, losses, input conductance, and bandwidth are calculated and plotted versus frequency for some different parameters, showing that bandwidths of up to 15 percent (for a voltage standing-wave ratio (VSWR) of less than two) are possible to achieve in the X band.

Frequency scanning microstrip antennas

Abstract: The principles of using radiating microstrip resonators as elements in a frequency scanning antenna array are described. The resonators are cascade-coupled. This gives a scan of the main lobe due to the phase-shift in the resonator in addition to that created by the transmission line phase-shift. Experimental results in X -band, in good agreement with the theory, show that it is possible to scan the main lobe an angle of \pm30\deg by a variation of the frequency \pm300 MHz, and where the 3 dB beamwidth is less than 10\deg . The directivity was 14.7 dB, while the gain was 8.1 dB. The efficiency might be improved by a trade-off between the efficiency and the scanning angle, or by using a better amplitude distribution.