In this paper, a wideband reconfigurable reflectarray antenna (RRA) using 1-bit resolution for beam scanning with two-dimensional (2D) capability is presented at Ku-band. A 1-bit RRA element with a rectangular patch embedded with slots is proposed for broadband operation. Each element is equipped with a single PIN diode, allowing for resonance tuning while ensuring low cost and minimal power consumption. According to the simulation results, the proposed element is capable of 1-bit phase resolution with a phase difference of ${180^\circ \pm 20^\circ}$ stability from 11.27 to 13.74 GHz, which corresponds to an approximate bandwidth of 19.75%. To demonstrate its capabilities, we developed, fabricated, and tested a wideband electronically RRA with ${14 \times 14}$ elements. The experimental results demonstrate that the realized maximum gain in the broadside direction is 21.1 dB with a peak aperture efficiency of 20.9%. 2D beam scanning within ${\pm50^\circ}$ angular range are obtained and the scan gain reduction is 1.88 dB for ${-50^\circ}$ scanned beam in E-plane while 2.21 dB for ${50^\circ}$ scanned beam in H-plane. The 1-dB gain bandwidth of the RRA is 15.1%.

In this paper, a 2D angle amplifier based on peristrophic multiplexed volume Bragg gratings is designed and prepared, in which a calculation method is firstly proposed to optimize the number of channels to a minimum. The induction of peristrophic multiplexing reduces the performance difference in one bulk of the grating, whereas there is no need to deliberately optimize the fabrication process. It is revealed that a discrete 2D angle deflection range of ±30° is obtained and the relative diffraction efficiency of all the grating channels reaches more than 55% with a root-mean-square deviation of less than 3.4% in the same grating. The deviation of the Bragg incidence and exit angles from the expected values is less than 0.07°. It is believed that the proposed 2D angle amplifier has the potential to realize high-performance and large-angle beam steering in high-power laser beam scanning systems.

Based on a substrate integrated lens (SIL), a compact line source generator (LSG) for feeding continuous transverse stub (CTS) arrays with linear-polarized (LP) beam scanning and dual-polarized (DP) operations is presented in this paper. The SIL consists of metamaterial cells with different sizes being arranged as concentric annulus and is printed on the center surface of two substrate layers. The SIL can convert the cylindrical wave generated by the feed probe of SIW-horn to the planar wave for feeding the CTS array. This rotationally symmetric SIL can be used conveniently to design LSG for feeding CTS arrays with the continuous beam scanning and DP operations, which has been verified by the fabrications and measurements. By simply rotating the SIW-horn along the edge of SIL, the 10-element LP-CTS array obtains a measured beam scanning range of ±35° with the highest gain of 20.6 dBi. By setting two orthogonal SIW-horns at the edge of the proposed SIL, the nine-element DP-CTS array with orthogonal radiation stubs is excited. The DP array obtains the gain of 20.3 dBi at the center frequency with the isolation of 28 dB and the cross-polarization level <−25 dB.

We investigate a strategy to address the problem of low ship detection probability of space-based Automatic Identification System (AIS). A directional AIS antenna and an innovative beam scanning method are proposed, which scan the antenna across a wide swath to provide complete coverage and maintain the advantage of a narrow footprint to reduce signal collision. Aiming at the mission requirement of global ship detection by the year 2016, the appropriate swath, the scanning range and the scanning rate were studied and designed in detail. Theoretical analysis and simulations showed that this scanning antenna can greatly improve ship detection probability and hold the detection probability at an average reporting interval from six to 15 seconds for most oceans when compared with the traditional fixed wide beam antenna. Furthermore, the detection capacity of this scanning antenna was little affected by the heights of different Low Earth Orbits. The results of this work show that the design of the helical antenna along with the beam scanning method can be considered as a building block of future space-based AIS.