different variations of the l shape waveguide 40 can be used to achieve the same radiation characteristics depth d 1 of ridge portion 46 can be adjusted to reduce the width w 3 wall 42 as the vertical portion of the inverted u201c l u201d functions as a component of the waveguide width thus enabling wave propagation similar to a conventional rectangular waveguide of a width approximately equal to the sum of wall 42 and top surface 44 of the u201c l u201d the electromagnetic fields inside the u201c l u201d shaped waveguide 40 have a configuration which is similar to a simple dominant mode te 1 0 rectangular waveguide in fig2 the electric field is forced to be zero by wall 19 on the right side the currents in that narrow wall are vertical and give rise to a magnetic field h field parallel to the axis of the waveguide at locations to the left of that narrow the h field gradually becomes transverse to waveguide axis crossed slots or radiating elements 18 located at the proper position are then excited by the same magnitude of h longitudinal and h transverse and circular polarization is achieved because the two magnetic field components are in time quadrature the use of inverted l shape waveguide 40 allows radiating elements 18 to be more freely positioned on radiating surface 16 of waveguide 40 such that a high elevation beam with good.