High-Gain Reflectarray with Compact Aperture Size and a Low Profile Using an Active-Integrated Feeding Antenna

In this paper, we present a gain-enhancement technique for reflectarray applications with compact aperture size and a low profile. To increase antenna gain, reflectarrays are constructed as an electrically large aperture, and the feed is required to be of high directivity, which is accompanied by a longer focal length. This increases the dimensions in two aspects, including the physical aperture size and the profile of the overall structure. To obtain high gain with compact dimensions, we develop a reflectarray that uses an active-integrated feeding antenna. This feeding antenna is connected to a microwave power amplifier, which enhances the gain without reducing the half-power beam widths (HPBWs) of the patterns. Accordingly, the feed can be arranged with a shorter focal length, whereas the spillover efficiency is still high. Moreover, the power amplifier contributes additional gain of 20.6 dB, and thus the proposed structure can achieve realized gain as high as 44.5 dB with dimensions of 9.2 ×6.7 square wavelengths. Such a high-gain and compact antenna is particularly suitable for satellite applications.