Serhan Yamacli

Simulation of a SCARA robot with PD and learning controllers

Abstract In this study, a SCARA robot manipulator is simulated under PD and learning based controllers. The trajectory following performance of the robot is studied against these controllers. The adaptive/learning hybrid controller scheme and learning controller method are utilized as learning based controllers. The results of simulations show that, learning algorithm based controllers reduce the position tracking error effectively. The hybrid adaptive/learning controller has similar performance as the learning controller although it uses partial state information and compensates both mechanical and electrical dynamics, whereas the learning controller needs both position and velocity measurements neglecting electrical dynamics.

A Review of Recent Patents on Ultra Wide Band (UWB) Antennas

In this article, recent patents on UWB antennas are reviewed; different geometries, design parameters and their experimental results are discussed. Several types of UWB antennas including special horn, patch and array antennas in recent patents are explained together while comparing their measured return loss, gain and radiation patterns. Projections to the future developments of UWB antenna technology are also given.

Neural network modeling of voltage-dependent resistance of metallic carbon nanotube interconnects: An ab initio study

In this work, development voltage-dependent resistance models of metallic carbon nanotubes for computer aided design tools is aimed. Firstly, the resistance of metallic carbon nanotube interconnects are obtained from first principles simulations and the voltage dependence of the resistance is modeled through neural networks. Self-consistent non-equilibrium Greens function formalism combined with density functional theory is used for calculating the voltage-dependent resistance of metallic carbon nanotubes. It is shown that voltage dependent resistances of carbon nanotubes obtained from ab initio simulations can be accurately modeled via neural networks which enable rapid integration of carbon nanotube interconnect models into electronic design automation tools.

An improved Elmore delay model for VLSI interconnects

Elmore delay metric is a widely used model to compute signal delays for both analog and digital circuit interconnects. Although it provides a limited accuracy and its applicability is limited to the step function type input signals, this model is extremely popular with simple analytical functions that can be easily incorporated into design and automation software. In this work, a new boundary limiting the Elmore delay is introduced. A general form of traditional Elmore delay is defined and solved by utilizing this boundary. The new solution of the propagation delay problem called the improved Elmore delay model is derived according to the compound interest problem of Jacob Bernoulli. The improved Elmore delay formulation and the traditional Elmore delay model are compared according to SPICE simulation environment performances which verifies the superior accuracy of the novel delay formulation. The test results proved that better accuracy is achieved with the improved Elmore delay model than the traditional Elmore delay model with the same computation speed.

New active-only grounded inductance simulator employing current-mode approach suitable for wide band operation

In this paper, an active-only grounded lossless inductance simulator operating in current-mode is presented. The circuit uses only a current operational amplifier (COA) and an operational transconductance amplifier (OTA). The novelty of the proposed circuit is that it uses a COA instead of a voltage operational amplifier (VOA) to take the wider frequency operation advantage of the current-mode approach. The simulation results obtained through SPICE with 0.5 μm standard CMOS technology verify that the designed circuit can be operated up to 30 MHz, which is much higher than the operation frequency of previously reported inductance simulators utilising VOAs. The inductance value of the presented circuit can be adjusted electronically between 3.9 μH and 37 μH via the biasing current of the OTA. A parallel resonance circuit application is also given validating the operation of the proposed inductance simulator.

Electronically tunable inductance simulator employing dual-X current conveyors (DXCCIIs)

In this study, an electronically tunable inductance simulator employing only two Dual-X Current Conveyors (DXCCIIs) as active building blocks is presented. The proposed circuit can be used in the frequency range from 1kHz to 1MHz and consumes only up to 20mW/Proposed circuit is simulated with SPICE using 0.5Pm Mietec process parameters. Simulation results demonstrate the versatility of the newly introduced inductance simulator.

Resistorless KHN biquad using an DDA (difference diffference amplifier) and two CCCIIs (controlled current conveyor)

In this paper, a resistorless electronically tunable voltage-mode Kerwin-Huelsman-Newcomb (KHN) biquad is proposed. The newly introduced circuit uses a differential difference amplifier (DDA) and two controlled current conveyors (CCCIIs) as active elements. The pole angular frequency and the quality factor of the filter can be tuned independently. Proposed circuit is simulated using SPICE simulation program. Simulation results show the versatility of the circuit.

Resistorless tuneable KHN-filter in current mode with CCCIIs and grounded capacitors

In this work, an electronically tuneable resistorless Kerwin-Huelsman-Newcomb (KHN) filter circuit is proposed, employing multi-output CCCIIs (MO-CCCIIs) and grounded capacitors. The new circuit provides highpass, bandpass and lowpass responses simultaneously without any matching condition. Pole frequency and quality factor of the new circuit can be tuned electronically and orthogonally via biasing currents of MO-CCCIIs. SPICE simulation results verifying the theory are also included.