This paper shows how to design and building low cost Arduino plotter machine based on the open source hardware and software. The Arduino plotter machine has been dependent on the principle of Computer Numerical Control with limited area depends on the motion X, Y and Z axes. The objectives of this paper are to design the Plotter and to develop open source software for control the machine. Basically, the system of this plotter machine is modeling by solidwork software to work with three axes stepper motors (as X, Y and Z axes), this three stepper motors are controlled by shield for movement (X, Y and Z axes). This machine's movement on the X axis is 215 mm and Y axis is 235 mm. Length of travel means the linear movement of stepper motors that control for X, Y and Z axes from point to another point. The left and right movement controlled by X axis stepper motor, front-back movement controlled by Y axis stepper motor and the pen is up-down that is controlled by Z axis stepper motor.

In this paper, a compact UWB antenna with a reconfigurable and sharp dual-band notches filter to cancel the interference with some critical applications (5G WLAN, and X-band satellite downlink) is proposed for underlay cognitive radio (CR) applications. The dual notched bands are produced by coupling a pair of π-shaped resonators on both sides of the feed line and by etching a U-slot inside the feed line of the antenna. The proposed UWB filtenna in this configuration has a surface area of 22×31 mm² and produces simulated (measured) reconfigurable notched frequencies at 5.466 GHz (5.7 GHz) and 7.578 GHz (7.44 GHz) with an impedance bandwidth of 3.024-10.87 GHz (2.825-10.74 GHz). Three PIN diodes are used to switch the presence of the dual-band notch. Two PIN diodes turn ON-OFF simultaneously ( D_1A & D_1B) are inserted within a pair of π-shaped resonators to control the 5G WLAN band notch, and a single diode ( D₂) is embedded within a quarter wavelength resonator which is located inside the feed line of the antenna for controlling the X-band band notch. The simulation and measured results reveal that the proposed filtenna effectively covers UWB with controlled cancellation for the interference with the intended bands. The realized gain is 4.5 dBi through the passband except in the notched frequencies, where it is decreased to less than -11 dBi in both notch frequencies. In other words, the proposed filtenna has a very high VSWR of greater than 20 at the notched frequencies.

This paper presents a compact, low-cost reconfigurable bandpass filter (BPF) for WiMax, 5G, and WLAN applications. The BPF consists of a half-wavelength resonator folded as C-shaped by a pair of symmetrical PIN diodes and a central quarter-wavelength resonator to form an E-shaped stub-loaded multiple-mode resonator (SL-MMR). The feed line is made of two subsections separated by a gap which acts as a fixed capacitance and allows the filter to have bandpass behavior. The proposed filter is modeled using the even and odd mode analysis to predict the locations of the resonant frequencies. The simulation results show that the filter covers the frequency range (3.38-3.95) GHz with a center frequency of 3.52 GHz at the ON state of a pair of PIN diodes. On the other hand, the BPF covers the frequency range (4.7-5.93) GHz with a center frequency of 5.2 GHz, at the OFF state of the diodes. The results also show a small insertion loss at the filter passband with two sharp transmission zeros at the stopband.

The recent advances in the technology of smart devices caused a tremendous increase in wireless traffic in conventional cellular networks, thus leading to overloading the base station, and hence delaying the response to users’ requests. To overcome this, Device to Device (D2D) communication has been proposed recently to alleviate the traffic congestion at the base station (BS) by establishing a direct link between users. However, deciding whether a communication should be performed directly via D2D mode or via the base station is considered one of the challenges of applying such a method. Therefore, a mode selection based model was presented in this paper. The method depends on the probability of a user’s proximity close to 1.0. Furthermore, the proposed method also takes into account the interference with both; other cellular communication and D2D communication. The simulation results showed that a significant reduction in the delay can be achieved when responding to user requests after using the proposed model selection method. The increase in frequency reuse within the cell is considered as the main reason behind this behavior. Also, for a more simplified and less complex model selection method, it is more appropriate to apply the proposed model selection method to only the cell edges.