Microstrip dual mode multi-bandpass filters based on tree fractal slotted resonator for wireless communication

Dual mode microstrip multi-bandpass filter is proposed with tree fractal slot on a square patch resonator. The tree fractal slotted resonators are generated from conventional square patch using an iterative tree fractal generator method. A single square patch is used for realizing both dual and tri-bandpass filters exploiting the dominant, higher order and its corresponding degenerate resonant modes by the tree fractal iteration on the diagonal unequal slots on the square patch.The resonant peaks, transmission zeros and bandwidth of the pass bands can be tuned by varying the length and width of the fractal slot. By optimizing various parameters dual mode dual and tri-band pass filters are simulated, fabricated and measured. The proposed filter finds application in wireless communication devices and falls in the bands of GSM, WLAN, Bluetooth, Zigbee, WiMax and WiFi

Ultra-wideband bandpass filter with notch band based on quadratic Koch Island structure

An ultra-wideband bandpass filter with a notch band centered at 7.2 GHz is proposed to remove the interference caused by satellite communication signal coexciting within the ultra wide band. The filter comprises of two seperated quadratic koch island structures connected to the main transmission line to generate the notch band at the desired frequency. The designed ultra wide bandpass filter passes frequencies from 3.09 GHz to 10.61 GHz with a notch band from 7.12 to 7.46 GHz centered at 7.2 GHz and with a rejection level of 21.3 dB.The resonant frequency and bandwidth of the notch can be varied by the variation in the physical parameter of the filter. The proposed filter is fabricated, tested and compared with simulated results

Series SRR Loaded UHF RFID Tag

AbstractAn RFID tag based on a series loaded split ring resonator (SRR) to operate in the European UHF RFID band of 865-867MHz is reported. A chip of impedance 27-j212Ω is connected at the terminals of the antenna and the read range measurements of the RFID tag are performed in the UHF RFID band. The proposed UHF tag exhibits appreciably good read range over a wide azimuth and elevation angular ranges

Congestion bottleneck avoid routing in wireless sensor networks

A new efficient method for detecting congested bottleneck nodes and avoiding them in the route formation in a wireless sensor network is described. Sensor nodes with a higher degree of congestion are excluded while determining the best routing path from a given source to destination in a multi-hop transmission. In a scenario where different communication paths have different maximum congestion levels, selecting that path which has least maximum congestion, is a challenging task. A modified Bellman-Ford algorithm is proposed to solve this problem efficiently. The proposed technique is very much useful for the optimal route selection for vehicles in metropolitan cities that avoids high traffic density junctions. Once the desired destination is specified, the traffic control system can use this algorithm to provide the least congested routes to the intra-city vehicles

Minimum Bend Shortest Rectilinear Route Discovery for a Moving Sink in a Grid Based Wireless Sensor Network

In a rectilinear route, a moving sink is restricted to travel either horizontally or vertically along the connecting edges. We present a new algorithm that finds the shortest round trip rectilinear route covering the specified nodes in a grid based Wireless Sensor Network.  The proposed algorithm determines the shortest round trip travelling salesman path in a two-dimensional grid graph. A special additional feature of the new path discovery technique is that it selects that path which has the least number of corners (bends) when more than one equal length shortest round trip paths are available. This feature makes the path more suitable for moving objects like Robots, drones and other types of vehicles which carry the moving sink. In the prosed scheme, the grid points are the vertices of the graph and the lines joining the grid points are the edges of the graph. The optimal edge set that forms the target path is determined using the binary integer programming

Microstrip multi-stopband filter based on tree fractal slotted resonator

This paper presents the design and development of a new microstrip multi-stopband filter based on tree fractal slotted resonator. A single square patch with tree fractal slots of different iterations are employed for realizing dual stopband and tri-stopband filters. The tree fractal slotted resonators are generated from conventional square patch using an iterative tree fractal generator method. First, second and third level iterations of the tree fractal slot resonator are used to design dual and tri-stopband filters respectively. The first level iteration introduced for the tree fractal slot realizes dual bands at 2.64 GHz and 3.61 GHz while the second level iteration provides better stopband rejection and insertion loss at 2.57 GHz and 3.56 GHz. The tri-stopband filter generates three resonance frequencies at 1.53 GHz, 2.53 GHz and 3.54 GHz at third level iteration. By varying the slot length and width of the tree fractal slot, the resonant frequencies can be adjusted and stopbands of the proposed filter can be tuned for the desired unwanted frequency to be rejected. The proposed narrowband filters finds application in removing the interference of GPS and Wi-Max narrowband signals from the allotted bands of other wireless communication system

Microstrip antenna with DGS based on CSRR array for WiMAX applications

This paper reports a novel method for designing a miniaturized microstrip antenna with DGS based on CSRR array which operates in the frequency of 2.6GHz for low band WiMAX application. The proposed antenna is designed using ANSYS HFSS simulation software. The antenna with optimized parameters is fabricated using FR-4 substrate of thickness 1.6 mm. The simulated and measured performances of the antenna in terms of return loss, directivity and radiation patterns are presented in this work. When Complimentary Split Ring Resonators (CSRRs) array are placed on the ground plane, the resonant frequency is shifted  to a lower value and patch size is reduced .The measurements were taken and compared with the simulated results. The performance characteristics obtained from the measurements show that the proposed antenna is suited for WiMAX application at 2.6GHz

CPW fed SRR loaded monopole antenna for triple band operations

A planar CPW fed SRR loaded monopole antenna based on split ring resonator with triple-band operations is reported for passive UHF RFID, Wireless Local Area Networks (WLAN) and World Interoperability for Microwave Access (WiMAX) applications. Measured and simulated results show the effect of tapering of the SRR layer on bandwidth improvement and gain enhancement in comparison to monopole with SRR antenna. The CPW fed SRR loaded monopole antenna has a bidirectional pattern with high gain for wireless communication applications

Truncated Microstrip Patch Antenna with DGS Based on Double Looped CSRR Arrays for Enhancement of Bandwidth

This paper presents a novel method for the design of truncated microstrip patch antenna with DGS based on Double Looped CSRR arrays for enhancement of bandwidth. The proposed antenna is suitable for WLAN/Wi-Fi, RFID applications. A truncated microstrip patch antenna without DGS was initially designed for a resonant frequency of 2.86GHz having a bandwidth of 95.6MHz. By integrating a new Double Looped CSRR array (DLCSRR) structure on the ground plane, resonant frequency of the antenna is shifted to 2.47GHz and also the bandwidth is enhanced to 202.5MHz. By implementing DLCSRR array structure on the ground plane size reduction and bandwidth enhancement of 52.79% is achieved. The performance of truncated microstrip patch antenna with DGS based on Double Looped CSRR array structure was also compared by replacing conventional proximity fed microstrip patch antenna with the same physical size. The conventional proximity coupled microstrip patch antenna is designed for a resonant frequency of 2.26GHz with a lower bandwidth of 23.3MHz.The antennas were designed using CST simulation software. The measurement  result shows a good agreement with simulated results

Secure Data Aggregation in Wireless Sensor Network using Chinese Remainder Theorem

A new method of lossless Secure Data Aggregation for Wireless Sensor Network is presented. Secure Data Aggregation is achieved using the popular Chinese Remainder theorem. Here, an ‘Augmented Chinese Remainder System’ is introduced that incorporates additional features to enforce a higher level of security to the aggregated data. The scheme provides inbuilt signature verification and eliminates the need for separate data validation algorithms. The method achieves data integrity and authentication simultaneously in addition to data aggregation for the data forwarded from the Cluster Head to the Base Station. The aggregate contains the entire individual data in the encrypted form and the receiver de-aggregates it to get the original data in full. The Augmented Chinese Remainder System can be extended to secure Multi-level Data Aggregation for WSN