US 4,890,117 A · Antenna and waveguide mode converter

Abstract

In view of the introduction of cellular radio, there is a requirement for an antenna of simple construction which can be sold in a consumer market. While the invention meets this need it also has application to the problem of providing TM.sub.01 to TE.sub.01 made converters. The invention employs radial conductors printed on a dielectric substrate and aligned with the transverse electric field in a waveguide supporting the TM.sub.01 mode. Circumferential conductors, each coupled to one of the radial conductors, act as monopoles radiating the required field in an antenna where the radial conductors project through apertures in the waveguide. For the mode converter, both radial and circumferential conductors are inside the waveguide, with the radial conductors aligned with the transverse electric field of the TM.sub.01 mode. Arrangements for maximizing the field at the position of the radial and circumferential conductors are described as are means for preventing the propagation of unwanted modes.

Claims15

Dependent claims

An antenna comprising:

a waveguide which propagates waves along an axis thereof in a TM.sub.01 mode;
and
a plurality of pairs of elongated coupling elements in a plane at right angles to the axis of the waveguide, each pair of elements comprising a first conducting element partly within the waveguide and aligned with an electric field of the TM.sub.01 mode, and a second conducting element external to the waveguide which is aligned with a required external electric field of the antenna, one end of the first element of each pair extending through an aperture in the waveguide so as to be adjacent to one end of the second element of that pair, and each second element forming a monopole with no corresponding element of the antenna forming a dipole with that second element.

Dependencies are inferred from the claim text.

Antenna and waveguide mode converter

Life of this patent

Antenna and waveguide mode converter

Life of this patent

Abstract

Claims15