The field of the invention relates to horizontally polarized omnidirectional antennas.
Several techniques for producing a horizonally polarized omnidirectional antenna are described in the literature; such as, "Antenna Handbook" by H. Jasik. The techniques usually relate to some form of resonant coupling resulting in a frequency bandwidth in the order of 10 percent.
Another method of providing a horizontally polarized omnidirectional radiation pattern is the so called "Pick Axe" antenna. The essential elements of this configuration are:
1. Waveguide power divider or waveguide hybrid PA1 2. Two sections of waveguide transmission lines PA1 3. Two waveguide 90.degree. bends PA1 4. A coax to waveguide transistion may be necessary PA1 1. Coax to waveguide transition PA1 2. One waveguide section PA1 3. Two radiating elements
This configuration results in a costly, complicated and heavy waveguide structure manifesting in extreme small mechanical tolerances in all five elements to maintain the electrical characteristics necessary to provide an omnidirectional radiation pattern with less than .+-.2 dB of ripple for the full 360.degree.. The most important element in this configuration is the waveguide power divider/hybrid combination. The outputs of this element must maintain accurate tracking from both outputs ports for both phase and amplitude.