Analysis and Simulation of Active Filters Using Operational Transconductance Amplifier (OTA)

As the transistors are continuously scaling down, it becomes necessary to reduce voltage supply and power requirements of the circuit to increase its performance and stability. Whereas, current- mode devices require less number of stages with high output impedance results in improved performance and large bandwidth as compared to voltage-mode techniques. OTA are current-mode device that takes voltage as input and produces current as output with high gain and large bandwidth. The frequency bands were parameters were determined such as the cutoff frequency (fc), the band width (BW), the quality factor (Q), and the angular frequency (Wo). In this paper the design and the simulation of the transfer function has been done by using (MATLAB) in order to obtain the frequency response for all types of filter (the low pass filter, high pass filter, band pass filter and band stop filter)

GEOGRAPHIC INFORMATION SYSTEM (GIS) SPATIAL ANALYST TECHNIQUES A REFERENCE FOR DETERMINING THE POSITION OF CELLULAR SYSTEMS

The Base Transverse Station (BTS) is one of the main units in the mobile communication system task. It represents the connection chain between the mobile station and the server, and it plays a major role for the completion of the process of communication between users. The towers locations (BTS) and its distributions have negative or positive effect on the active coverage power which affects the communication system. In this paper, the real locations for twenty two towers had been taken and these towers were distributed in six regions in the southern west side of sulaimany city in Iraq. By drawing the pattern for these BTS with radius equal to 200m and 300m using the Geographic Information System (GIS) program, a remarkable difference had been noticed in the radius of these cells. There active coverage areas which are suitable for good communication. Also there are interference regions and weak regions, which are areas with a weak signal or hidden areas; thus both can cause some types of fading. The weakness of the signal at these areas appears because of the irregular distribution of the towers. Finally, this paper summarizes the re-distribution of the towers and as a result the number of the towers had been - eliminated and the - weak area and the - Interference region - had been reduced in order to ensure maximum access of the active coverage area

GEOGRAPHIC INFORMATION SYSTEM (GIS) SPATIAL ANALYST TECHNIQUES A REFERENCE FOR DETERMINING THE POSITION OF CELLULAR SYSTEMS

The Base Transverse Station (BTS) is one of the main units in the mobile communication system task. It represents the connection chain between the mobile station and the server, and it plays a major role for the completion of the process of communication between users. The towers locations (BTS) and its distributions have negative or positive effect on the active coverage power which affects the communication system. In this paper, the real locations for twenty two towers had been taken and these towers were distributed in six regions in the southern west side of sulaimany city in Iraq. By drawing the pattern for these BTS with radius equal to 200m and 300m using the Geographic Information System (GIS) program, a remarkable difference had been noticed in the radius of these cells. There active coverage areas which are suitable for good communication. Also there are interference regions and weak regions, which are areas with a weak signal or hidden areas; thus both can cause some types of fading. The weakness of the signal at these areas appears because of the irregular distribution of the towers. Finally, this paper summarizes the re-distribution of the towers and as a result the number of the towers had been - eliminated and the - weak area and the - Interference region - had been reduced in order to ensure maximum access of the active coverage area