Design of Microstrip Low-Pass Filter Based on Six-Slit-Ring DGS
A novel six-slit-ring defected ground structure (DGS) is presented in this paper. The location of the slit can shift the resonant frequency without changing the overall size of the DGS and its adjustment range can reach 8.81 GHz. By cascading three identical six-slit-ring DGS unit cells, a microstrip low-pass filter (LPF) can be realized. Its 3dB cutoff frequency is 7.27 GHz. The in-band insertion loss is below 0.35 dB and the stop-band width with 20 dB attenuation is over 8.12 GHz. To improve the out-of-band rejection of the filter, shunt branches were added on both sides of the microstrip line. Its 3 dB cutoff frequency is 8.285 GHz. The insertion loss is less than 0.81dB in the pass-band. The stop-band rejection is better than -40 dB at 11.36-20 GHz and the size of the filter is only 28 mm by 11 mm. The simulation results show that the proposed novel six-slit-ring DGS microstrip LPF has the characteristics of compact size, flexible adjustment, flat pass-band, wide stop-band and high selectivity.
A Compact Defected Ground Microstrip Device with Photonic Bandgap Effects
Filters and other devices using photonic bandgap (PBG) theory are typically implemented in microstrip lines by etching periodic holes on the ground plane of the microstrip. The period of such several holes corresponds to nearly half the guided wavelength of the transmission line. In this paper we study the effects of miniaturization of the PBG device by meandering the microstrip line about one single hole in the ground plane. A comparison of the S-parameters and dispersion behavior of the modified geometry and a conventional PBG device with a straight microstrip line shows that these devices have similar behaviors.
Kinematic Modelling and Simulation of a 2R Robot Using SolidWorks and Verification by MATLAB / Simulink Regular Paper
The  simulation  of  robot  systems  is  becoming very popular, especially with  the  lowering of  the cost of computers,  and  it  can  be  used  for  layout  evaluation, feasibility studies, presentations with animation and off‐ line programming. The  trajectory  planning  of  redundant manipulators  is  a very  active  area  since  many  tasks  require  special characteristics  to  be  satisfied.  The  importance  of redundant manipulators has  increased over  the  last  two decades  because  of  the  possibility  of  avoiding singularities  as  well  as  obstacles  within  the  course  of motion.  The  angle  that  the  last  link  of  a  2  DOF manipulator makes with the x‐axis is required in order to find the solution for the inverse kinematics problem. This angle  could  be  optimized  with  respect  to  a  given specified  key  factor  (time,  velocity,  torques)  while  the end‐effector  performs  a  chosen  trajectory  (i.e., avoiding an obstacle) in the task space. Modeling  and  simulation  of  robots  could  be  achieved using  either  of  the  following  models:  the  geometrical model (positions, postures), the kinematic model and the dynamic model. To  do  so,  the  modelization  of  a  2‐R  robot  type  is implemented. Our main  tasks  are  comparing  two  robot postures with the same trajectory (path) and for the same length  of  time,  and  establishing  a  computing  code  to obtain the kinematic and dynamic parameters. SolidWorks  and MATLAB/Simulink  softwares  are  used to check the theory and the robot motion simulation. This  could  be  easily  generalized  to  a  3‐R  robot  and possibly therefore to any serial robot (Scara, Puma, etc.). The verification of the obtained results by both softwares allows  us  to  qualitatively  evaluate  and  underline  the validityof  the  chosen  model  and  obtain  the  right conclusions. The results of  the simulations are discussed and an agreement between the two softwares is certainly obtained.