Browsing by Subject "Low pass filters"

Now showing 1 - 4 of 4

Open Access
Application of signal-processing techniques to dipole excitations in the finite-difference time-domain method
(Taylor & Francis, 2002) Oğuz, U.; Gürel, Levent
The applications of discrete-time signal-processing techniques, such as windowing and filtering for the purpose of implementing accurate excitation schemes in the finite-difference time-domain (FDTD) method are demonstrated. The effects of smoothing windows of various lengths and digital lowpass filters of various bandwidths and characteristics are investigated on finite-source excitations of the FDTD computational domain. Both single-frequency sinusoidal signals and multifrequency arbitrary signals are considered.
Open Access
Design of all-pole low-pass ladder filters using current-mode damped integrators
(IEEE, 1996) Oralkan, Ömer; Karşılayan, Aydın İlker; Tan, M. A.
A method for operational simulation of all-pole low-pass LC ladders filters by using current-mode damped integrators is introduced. The circuits obtained by this method need only current mirrors and capacitors and are convenient for realization in CMOS technology as well as can be used in other technologies.
Open Access
High resolution time frequency representation with significantly reduced cross-terms
(IEEE, 2000-06) Özdemir, A. Kemal; Arıkan, Orhan
A novel algorithm is proposed for efficiently smoothing the slices of the Wigner distribution by exploiting the recently developed relation between the Radon transform of the ambiguity function and the fractional Fourier transformation. The main advantage of the new algorithm is its ability to suppress cross-term interference on chirp-like auto-components without any detrimental effect to the auto-components. For a signal with N samples, the computational complexity of the algorithm is O(N log N) flops for each smoothed slice of the Wigner distribution.
Open Access
Trajectory control of a quadrotor using a control allocation approach
(IEEE, 2017) Zaki, H.; Ünel, M.; Yıldız, Yıldıray
A quadrotor is an underactuated unmanned aerial vehicle with four inputs to control the dynamics. Trajectory control of a quadrotor is a challenging task and usually tackled in a hierarchical framework where desired/reference attitude angles are analytically determined from the desired command signals, i.e. virtual controls, that control the positional dynamics of the quadrotor and the desired yaw angle is set to some constant value. Although this method is relatively straightforward, it may produce large and nonsmooth reference angles which must be saturated and low-pass filtered. In this work, we show that the determination of desired attitude angles from virtual controls can be viewed as a control allocation problem and it can be solved numerically using nonlinear optimization where certain magnitude and rate constraints can be imposed on the desired attitude angles and the yaw angle need not be constant. Simulation results for both analytical and numerical methods have been presented and compared. Results for constrained optimization show that the flight performance is quite satisfactory.