recently, time reversal (tr) method, due to its high functionality in heterogeneous media has been widely employed in microwave imaging (mi) applications. one of the applications turning into a great interest is through-wall microwave imaging (twmi). in this paper, tr method is applied to detect and localize a target obscured by a brick wall using a numerically generated data. regarding this, i...

The effective nonlinearity ENL of periodically poled KTiOPO4 crystal is precisely measured with SHG experiment at various focusing conditions. The result shows the optimum focusing condition which maximizes the ENL at focusing parameter ξ at around 2.8 and is consistent with Boyd and Kleinman theory. The analysis based on the theory shows the nonlinear optical coefficient d33 of 17.5 [pm/V].

For SASE-FELs the total undulator length increases with decreasing wavelength. In the X-ray wavelength range, the optimum -function is of the order of 40 m, which makes a separate focusing structure the best choice. In principle, three periodic focusing structures can be considered, namely a singlet (FODO), doublet or a triplet structure. In this report, the three different types of focusing fo...

We demonstrate aberration-free dynamic focusing with a low-cost 19-channel continuous-surface micromachined membrane deformable mirror (MMDM). A lookup table of the optimum control voltages for various focal lengths is obtained with an adaptive optics algorithm. Diffraction-limited imaging resolution is achieved owing to the capability of the MMDM for aberration compensation. The measured speed...

Ultrasonic testing has been used for many decades, proving itself very efficient detecting defects in industrial sectors. The desire to apply ultrasonic geometrically complex structures, and anisotropic, inhomogeneous materials, together with the advent of more powerful electronics software, is constantly pushing applicability waves their limits. General ray tracing models, suitable calculating...

The suppression of constant-input limit cycles when designing second-order-state-space digital filters is addressed in this paper. A set of three sections yet proposed in the literature is revisited, focusing on the specific block called type III structure. It is shown that there is an optimum version of that section, what is the main contribution of the paper. The noise performance of the opti...

The suppression of constant-input limit cycles when designing second-order-statespace digital filters is addressed in this paper. A set of three sections yet proposed in the literature is revisited, focusing on the specific block called type III structure. It is shown that there is an optimum version of that section, what is the main contribution of the paper. The noise performance of the optim...

Hydrodynamic focusing was used to increase the sensitivity of an impedance-based biosensor. A modified T-junction channel allowed the focusing of conducting fluid from the top and sides by a non-conducting fluid from a single sheath stream. A 4-electrode impedance setup was used as it is less susceptible to electrode polarization at low signal frequencies. Impedance measurements performed befor...