Diffraction of electromagnetic waves by concave circumferential surfaces: Application for hybrid reflector antennas

The Analysis of Hybrid Reflector Antennas and Diffraction Antenna Arrays on the Basis of Surfaces with a Circular Profile

“…Such effects are multireflections and effect of "whispering gallery" which can be seen when the source of a field is located near a concave wall of a reflector. By means of surface waves additional excitation of peripheral areas of hemispherical reflector can raises the gain and decreases a side lobes level (SLL) of pattern (Ponomarev, 2008). Use of surface electromagnetic waves (EMW) together with traditional methods of correction of a spherical aberration are expedient for electronic and mechanical control of pattrn in the spherical antennas.…”

“…By means of mutual control of amplitude-phase distribution between feeds by phase shifters 4, 5, 9, attenuators 6, 7, 10 and power dividers 8, 11 (waveguide tees), can be reduce SLL. There are experimental data of measurement pattern at far-field with SLL no more -36 dB ( fig.7) (Ponomarev, 2008). …”

Scattering of Toroidal Waves by Semitransparent Reflectors of Revolution in Application to Omnidirectional Antennas

“…Some particular cases of a toroidal wave scattering by perfectly electrically conducting (PEC) and semitransparent reflectors are investigated in [1,2,[10][11][12][13][14][15][16][17][18][19][20]. In particular, the scattering of a field induced by an annular current on a PEC disk is investigated in [10][11][12][13][14][15].…”

“…In particular, the scattering of a field induced by an annular current on a PEC disk is investigated in [10][11][12][13][14][15]. Some asymptotic solutions for a scalar toroidal wave scattering by the PEC concave surface of a sphere are considered in [16][17][18]. A numerical solution for the scattering of an in-phase azimuthal annular electric current field by a PEC conical reflector is considered in [19].…”