R. K. Jha

Near-field analysis of H-plane hollow sectoral dielectric horn antennas

This paper deals with the H-plane hollow sectoral dielectric horn antenna. The metallic wall of the metal horn antenna is replaced by dielectric sheets to obtain this type of antenna. Attempts are made to determine theoretically the approximate fields on the aperture of the antenna under several simplifying assumptions. A comparison is made between theoretically calculated and experimentally observed values for one of the components (the amplitude) at the front aperture of the antenna.

Near field distribution of solid dielectric diagonal horn antennas

Aperture/near field distributions of solid dielectric diagonal horn antennas have been studied, both theoretically and experimentally. Solution of the Helmholtz equation is obtained for TE to x and TE to y modes using separation of variables technique for the horn. Transcendental equations for the transverse components of the propagation constants are obtained by applying proper boundary conditions, i.e. the continuity of the electric and magnetic fields at the dielectric-air boundaries. These transcendental equations are solved for the transverse propagation constants for the fundamental mode for three horns each 1 of axial length = 12.8 cm and flare angle = 8.5° and with dielectric constants e 1 of the materials of the horns equal to 2.54, 2.56 and 2.80 at the frequency 9.418 GHz in the-band X-band. The theoretical aperture field distributions obtained for Hx 11 and Hy 11 modes propagating in these antennas are compared with corresponding

Far field patterns of solid dielectric diagonal horn antennas

Far field patterns of solid dielectric diagonal horn antennas of various dielectric constants (e 1 = 2.54, 2.56 and 2.80) are studied theoretically and experimentally at 9.418 GHz. Theoretical near field distributions at the aperture and at the four side surfaces of a horn under study for TE x to and TE y to modes are obtained by solving Helmholtzs equation using the separation of variables technique. The expressions for the near field components of the horn under study are used to obtain the expression for radiation pattern from Kirchoffs diffraction formula. The theoretical far field patterns obtained for these antennas are compared with the corresponding experimental ones.

Near-field analysis of E-plane sectoral solid dielectric horn antennas

An approximate analysis of the aperture field of an E-plane sectoral solid dielectric horn antenna is described using the TE to x mode. The analysis is based on the solution of Maxwells equations after making some simplifying assumptions. The electric and magnetic fields inside the horn core are matched to those outside at appropriate boundaries to yield transcendental equations which are then solved on a computer for the ropagation constants and field configurations. The theoretical results so obtained are in agreement with experimental results. Characteristic equations for the TM to x mode are also calculated and the results are compared with those of Marcatili, Goell, Eyges and Morita

A new recombinant in-phase microstrip power divider

The theory and design aspects of n-way in-phase power divider employing Goldfarb recombinant topology are described. The merits of this divider over conventional ones are also presented here. A microstrip version of five output port power divider is designed and developed with 1.7 mm Bakelite substrate to operate in S-band. The measured values of input VSWR, insertion loss, isolation, return loss and phase difference between output ports at different frequencies in S-band for the fabricated power divider are presented and discussed.

Comparative studies of near field distributions of solid and hollow dielectric diagonal horn antennas

Near field distributions of solid and hollow dielectric diagonal horn antennas have been studied theoretically and experimentally. Solutions of the Helmholzs equation are obtained for TE to x and TE to y modes using separation of variables technique for the horn. Transcendental equations for the transverse components of propagation constants are obtained by applying proper boundary conditions. These transcendental equations are solved for the transverse propagation constants for the fundamental mode for different horns each of axial length=12.8 cm and flare angle=8.5/spl deg/ and throat dimension=4.7 cm at the frequency of 9.418 GHz in X-band. The theoretical aperture field distributions obtained for H/sub 11//sup x/ and H/sub 11//sup y/ modes propagating in these antennas are compared with corresponding experimental ones. Comparative studies are also done for aperture field distribution of solid and hollow dielectric diagonal horn antennas.

Near field analysis of solid dielectric diagonal horn antenna

In this paper near field distributions of solid dielectric diagonal horn antennas have been studied both theoretically and experimentally. Solution of Helmholtzs equation is obtained for TE to x and TE to y modes using separation of variables technique. Transcendental equations for transverse components of propagation constants are obtained by applying proper boundary conditions i.e. the continuity of the electric and magnetic fields at the interfaces between the dielectric region and outer free space region. These transcendental equations are solved for the transverse propagation constants for the fundamental mode for four horns, each of axial length 12.8 cm, flare angle 8.5/spl deg/ at 9.418 GHz in the X-band. The theoretical near field distributions obtained for these antennas are compared with corresponding experimental results.

Radiation pattern of E-plane sectoral solid dielectric horn antennas

Radiation patterns of an E-plane sectoral solid dielectric horn excited by a rectangular metallic waveguide are predicted and compared with patterns measured at 9-37 GHz.