Innovative multi-channel synthetic aperture radar (SAR) concepts enable high-resolution wide-swath imaging, but the antenna length typically restricts the achievable swath width. This limitation can be overcome by a novel technique which is based on a single azimuth channel but operates the system with a continuously varied pulse repetition frequency (PRF) by this allowing in principle for arbi...

This paper describes the development of a circularly polarized microstrip antenna, as a part of the Circularly Polarized Synthetic Aperture Radar (CP-SAR) sensor which is currently under developed at the Microwave Remote Sensing Laboratory (MRSL) in Chiba University. CP-SAR is a new type of sensor developed for the purpose of remote sensing. With this sensor, lower-noise data/image will be obta...

Electromagnetic coupling between two aperture antennas in the shape of the open ends of parallel-plate waveguides located on the same metal surface has been analyzed. The design optimization of the surface impedance model is used to solve this problem. The required level of antenna decoupling is obtained taking into account the initial metal surface, which is a natural decoupling structure. The...

This paper presents the foundations of conventional strip-mode synthetic aperture radar (SAR) from a mathematical point of view. In particular, the paper shows how a simple antenna model can be used together with a linearized scattering approximation to predict the received signal. The conventional matched-filter processing is explained and analyzed to exhibit the resolution of the SAR system.

Plasmonic structures shape semiconductor laser beams. Left: A plasmonic collima-tor spreads out radiation from the sub-wavelength aperture into surface waves that are diffracted by the metallic grating to produce a low divergence beam. Right: A resonant optical antenna concentrates most of the laser light into a tens-of-nanometers size spot defined by the gap.

The design of a NF‐ focused DRA phased array antenna is implemented for fixed RFID reader applications at 5.8 GHz. The radiated field is focused in the near‐zone of the array aperture. Numerical investigations on the radiation characteristics of the NF‐ focused array as well as uniform phase array are presented to demonstrate its feasibility for RFID real appl...

Direct sunlight is often deemed incoherent, hence unsuitable for antenna power conversion. However, all radiation exhibits spatial coherence when detected on a sufficiently small scale. We report the first direct measurement of the spatial coherence of solar beam radiation, achieved with a customized tabletop cyclic-shearing interferometer. Good agreement is found between experiment and theory,...

The synthesis of steerable reflect-array antennas, as a synthesis of any antenna, should be realized by solving two problems: external antenna problem and internal antenna problem. The first one includes the investigation of the antenna radiation pattern. The second one concerns a design of the structure providing the required amplitude-and-phase distribution along the antenna aperture. The fir...

In this paper, a new direction of arrival (DOA) estimation method based on minimum redundancy linear array (MRLA) from the sparse signal reconstruction perspective is proposed. According to the structure feature of MRLA which is obtaining larger antenna aperture through a smaller number of array sensors, MRLA is combined with 1 SVD −  method to estimate signal DOAs. Simulations demonstrate tha...