Phased Array Antenna Beam Steering Research Articles

Electromechanical coupling modelling of distributed MEMS phase shifter for phased array antennas

ABSTRACTMEMS phase shifter has many advantages as the ‘steering wheel’ of phased array antenna beam steering. The deformation of mechanical structures of MEMS phase shifter influenced by the complex environmental factors, which became the biggest obstacle to further enhance the performance of phased array antennas. The electromechanical coupling model between the bridge height and phase shift of the distributed MEMS phase shifter is developed. The coupling model could be used to predict the phase error and determine the bridge height tolerance for the deformed MEMS phase shifter. The simulation results of four-bit distributed MEMS phase shifter with 15 bridges illustrate the validity of coupling model and demonstrate the application potential for engineering design and test.

Microwave Signal Processing over Multicore Fiber

We review the introduction of the space dimension into fiber-based technologies to implement compact and versatile signal processing solutions for microwave and millimeter wave signals. Built upon multicore fiber links and devices, this approach allows the realization of fiber-distributed signal processing in the context of fiber-wireless communications, providing both radiofrequency access distribution and signal processing in the same fiber medium. We present different space-division multiplexing architectures to implement tunable true time delay lines that can be applied to a variety of microwave photonics functionalities, such as signal filtering, radio beamsteering in phased array antennas or optoelectronic oscillation. In particular, this paper gathers our latest work on the following multicore fiber technologies: dispersion-engineered heterogeneous multicore fiber links for distributed tunable true time delay line operation; multicavity devices built upon the selective inscription of gratings in homogenous multicore fibers for compact true time delay line operation; and multicavity optoelectronic oscillation over both homogeneous and heterogeneous multicore fibers.

Phased Array Antenna Beam Steering Scheme for Future Wireless Access Systems Using Radio-over-Fiber Technique

Phased Array Antenna Beam Steering Scheme for Future Wireless Access Systems Using Radio-over-Fiber Technique

Application of optical dispersion techniques in phased array antenna beam steering

Application of optical dispersion techniques in phased array antenna beam steering

A novel wavelength switchable fiber laser source and its application in photonics beamforming for optically controlled phased array antenna

A novel wavelength-switchable fiber laser source that can individually scan 14 required wavelengths within 40 ms, and its application in photonics true time delay beamforming is presented in this paper. The laser source is constructed using a unidirectional fiber ring cavity, a tunable fiber Fabry–Perot filter and two cascaded sampled fiber Bragg gratings with the wavelength spacing of 1.6 nm. A five-channel true-time-delay system using the proposed fiber laser source cooperating with a single-mode fiber and four chirped-grating-based is constructed and demonstrated for the application of phased array antenna beam steering. Continuous beam steering at the microwave frequency up to 20 GHz has been achieved.

Continuous True-Time-Delay System Employing a Novel Tunable Chirped Fiber Grating Delay Line and a Sampled Grating Based Multiwavelength Fiber Laser

A photonics true-time-delay system for phased array antenna beam steering employing a novel tunable chirped fiber grating delay line and a multi-wavelength erbium-doped fiber ring laser source based on a sampled grating filter is proposed. The tunable chirped fiber grating, which act as a continuous time-delay element, is achieved by bending a uniform fiber Bragg grating bonded at a slant onto the lateral surface of a simply supported beam. This technique allows the dynamic control of the chirp rate and spectral width of the grating without center wavelength shift. By adjusting the chirp rate of the fiber grating via bend strain, this kind of tunable chirped fiber grating could achieve very low and adjustable delay times, therefore provides higher angle resolution for scanning microwave beam, even the wavelengths of laser source are fixed and un-tunable. The true-time-delay system using proposed tunable chirped fiber grating delay element and sampled grating based laser source is constructed and demonstrated experimentally.

Optical switch design for true time delay array antenna

A new architecture for an optical system to achieve true time delay phased array antenna beam steering is proposed. This system is based on the association of switching matrixes and optical fibres of different lengths. A comparative study of the different available switch types has been carried out and concludes that total internal reflection (TIR) switches fit the specific requirements. The switch and entire matrix are designed using 2D and 3D finite difference beam propagation methods (FD-BPM). Then, the electrical behaviour of the device is investigated using a drift diffusion model. Results show the following performance: fibre to fibre loss equal to 10 dB, crosstalk around -2.0 dB and bandwidth close to 160 MHz.