فهرست مطالب

Majlesi Journal of Telecommunication Devices - Volume:6 Issue: 2, Jun 2017

Majlesi Journal of Telecommunication Devices
Volume:6 Issue: 2, Jun 2017

  • تاریخ انتشار: 1396/04/22
  • تعداد عناوین: 6
|
  • Ehsan Moeini Korbekandi, Mohsen Ashourian, Sayed Ali Hashemi Pages 31-35
    One of looped networks that in recent years has been much noticed is standard known as IEEE 802.17 RPR ring network or the return packet. Architecture RPR ring network protocol that transmits data between nodes connected in a double ring structure to support. RPR has two single transit buffer structure (STB) and double transit buffer (DTB), respectively. Single transit buffer architecture, just a high-priority traffic buffering (HP) and low priority (LP) passing through the ring buffer architecture serves and double, two separate buffer for high-priority and low priority traffic is considered passing.
    Send information for scheduling algorithms used in network nodes RPR, queue priority (Priority-Queue), respectively. In this way, the separation of traffic based on priority and high priority traffic has absolute priority over lower priority traffic so that always the highest priority to transit buffer appropriated therefore of high priority traffic such as video packet, the nodes access to congested suffered numerous delays and instability vibration are ring (Jitter).
    In this thesis addition to scheduling priority queue, plans, schedules DRR and DRR to increase the quality of service to traffic with high priority on congested node in a network with a ring structure with 10 nodes software Opnet simulation and the performance timing of passing information about at least two network nodes in the hub scenario (hUB) in which all the nodes transmit information to a node with video traffic conditions, congestion were examined happened and qualitative results were compared to that, the display shows the relative improvements in reducing delays and instability shaking changes in the timing of DRR and DRR compared to the recommended standard.
    Keywords: return- closed loop network scheduling priority queue-scheduling DRR- timing DRR +
  • Mostafa Ahmadi Pages 37-42
    A new Temperature compensated Ring Oscillator is presented. This CMOS ring oscillator consists of five current starved stage which is fed by a voltage and a current reference. In this paper a new method based on previous works has been proposed, in which required Temperature characteristic is imposed to the oscillator. The oscillation frequency of the proposed oscillator is 14.5 MHz and the simulation results in CMOS 0.18µm technology with a 1.8- V power supply showed that the temperature coefficient is 31.1 ppm/oC in the Temperature range of -15 ºC to 65 ºC. The total power consumption of circuit is 587 µW.
    Keywords: fully integrated frequency reference_Temperature compensation_voltage references_current references_voltage - current controlled ring oscillator
  • Keyvan Amini, Saman Amini, Hadi Veladi Pages 43-48
    In This study, a label-free detection method by using a novel Optofluidic ring resonator sensor (OFRR) structure is presented. Optofluidic is a developed young research subject suitable to create an appropriate cooperation between optics and fluidics. The combination of fluidic and optical methods achievable. by using the optofluidic methods makes it expedient to obtain an inventive type of sensors, which have been tried to have an ameliorate sensitivity, denseness and adaptivity. OFRR is a recent detection method that integrates Optic and fluid technologies with low-limit and low-cost and small- sample volume detection sensitivity. The objective of this article is the detection of the tuberculosis by offering a unique and a novel useful structure that is able to fabricate. The material of the proposed structure is PDMA that is completely flexible polymer. The width of the waveguide, the waveguide length and width of the ring of the proposed structure respectively is 500nm, 250 nm, 1500 nm. Also, the inner radius of the resonator ring in 4700 nm. The simulation Result of proposed structure by Opti-FDTD software shown 649 nm/RIS for the slope of the sensitivity curve.
  • Emine AvŞ, Ar Aydin Pages 49-52
    In this paper, Microstrip-fed Vivaldi antenna is presented for Ultra-Wide Band (UWB) biomedical applications and antenna characteristic parameters such as radiation pattern, return loss (S11), and voltage standing wave ratio (VSWR) are evaluated. However, by using different values of antenna parameters such as stub angle, substrate thickness, and relative dielectric constant, antenna performance in the UWB frequency range is developed to create antenna structure with the best efficiency, gain, and directivity. The design and modeling of the antenna are performed in CST Microwave Studio. Additionally, this can be used in terms of an attractive configuration for biomedical applications.
    Keywords: Vivaldi Antenna, ultra-wide band (UWB), radiation pattern, return loss (S11), voltage standing wave ratio (VSWR), biomedical applications
  • Turgut İ., Kiz., Emine AvŞ, Ar Aydin Pages 53-57
    An analytical method has been developed for the scattering of high-frequency plane electromagnetic waves from a perfectly conducting strip. The solution is much simpler compared to the other methods and gives quite accurate results for ka>>1. Using Green’s Theorem, the scattering field has been expressed by an integral of the current induced on the strip. With the integral expression of Hankel function, a Fourier transform of the induced current and thus, an integral equation in spectral domain has been derived. Using some required transformation on the induced surface current, the obtained spectral equation has been reduced to its simplest form and then an approximate solution could be derived for the reduced spectral equation for ka>>1. Using this approximate solution the field related quantities such as radiation pattern and radar cross section can be obtained easily; but the induced current and current related quantities requires the numerical solution of the algebraic set of equations obtained by expressing the current in the form of an infinite series which satisfies the boundary conditions on the surface of the conducting strip.
    Keywords: Strip, Impedance, Scattering, Perfect Conductor
  • Reza Fatemimofrad, Morteza Shahidinasab Pages 59-65
    Todays, Pulse Doppler Radars are used in most of industries needed radar, but it is necessary to note that despite these radars have some benefits, they also face several problems including range and velocity ambiguity. Obtaini ng range and velocity because is base of use of pulse Doppler radars, therefore these radars should use new methods in their technologies to use them to eliminate range and velocity ambiguity. Using high pulse repetition frequency radars will create velocity ambiguity. Introducing the methods mentioned in this paper, we will seek to eliminate ambiguity in range. despite, there are many methods to eliminate ambiguity, we will engage to assess Particle Filter and Chinese Remainder model in this study and finally, we will explain method of using Vernier on the timing gates in the different distances.
    Keywords: Unambiguity, Particle filter, Chinese Remainder Theorem, Vernier frequency, High pulse repetition frequency