The design of H- and V-pol waveguide slot array feeds for a scanned offset dual-polarized reflectarray

A unique experimental mission being designed by NASA/JPL is the wide swath ocean altimeter (WSOA). A unique offset-fed reflectarray antenna design was developed to meet the requirements of the mission´s two antennas. Each antenna has two feeds located off-focus to produce two beams scanned ±3.3° from nadir. Waveguide slot arrays were selected as the feeds for the reflectarray for their efficiency, low mass, high power-handling capability, and the relative ease with which to implement amplitude and phase tapers. Amplitude tapers are required to achieve the required secondary beamwidths and phase tapers are required to focus the feed energy on the reflectarray, since the reflectarray is located in the near-field of the feeds. While the design of waveguide slot arrays is not new, this particular design effort shows that very good results can be achieved on a first attempt using established slot array design techniques and commercial software for the waveguide power divider network. The design process is discussed in detail.