Multichannel synthetic aperture radar systems with a planar antenna for future spaceborne microwave remote sensing

Future spaceborne SAR missions will require complete and frequent coverage of the Earth with a reasonably high geometric resolution. To achieve this imaging capacity, multichannel SAR systems with a planar antenna will be widely adopted in the next generation spaceborne microwave remote sensing missions. However, the high data rate, the increased system complexity, the difficulty of multichannel signal processing, the heavy load, and the wide bandwidth downlink may hamper the demonstration of these imaging modes. With the rapid development of electronic engineering and digital signal processing, these problems will be well resolved. Furthermore, regarding the implementation complexity, multichannel SAR systems with a deployable reflector antenna seem to be a better alternative for HRWS imaging [17, 18]. However, the major drawback of the reflector antenna is the limited beam-steering capacity compared with a planar antenna, which will affect some of the remote sensing applications. Thus, multichannel SAR systems with a planar antenna rather than a reflector are more suitable for the higher geometric resolution, especially for the higher-carrier frequency (such as X-band).