The guard channel is very effective in eliminating side-lobe returns, both targets and discrete clutter, in airborne radar's. The ideal design criterion for the guard channel is that all the side lobes of the main antenna are covered by the guard pattern. In this paper a novel design approach of generating the guard using the elements of the main Active Electronically Scanned Array (AESA) antenna, thereby eliminating the need for a separate antenna, is presented. The ground clutter has an angle dependent Doppler and clutter discrete that leak in through the side lobes, especially the inter-cardinal elevation side lobes looking at the near range, needs to be eliminated. Towards this the design of the weighting coefficients for the guard to cover all the side lobes of the main array is discussed. Furthermore a digital threshold scheme is proposed to improve the effectiveness of guard channel in eliminating side-lobe returns. The detection loss and blanking probability are characterized for the design. The measurement results confirm that the design objectives are met.

WSNs are becoming popular in real world uses. Due to resource-constrained and battery-aware features of the sensor; WSNs energy use in a major research topic was found to be interesting. WSNs contain battery powered nodes that for certain action or tasks are connected with the base station. The lifetime of battery-powered sensor nodes, after the consumption of the battery will be dead in WSNs. To prolong the lifetime of WSNs the energy has to be well organized. The cluster head selection and assignment, and construction of clusters require additional overhead. Cluster nodes distributed algorithms designed incorrectly can lead to isolation from cluster heads. Such isolated nodes waste large amount of energy to communicate with the sink. In this paper, energy conservation techniques related to WSNs are discussed. Also, the existing energy conservation algorithms are reviewed and the comparative analysis is also performed.

In this paper a novel rectangular C-shaped planar monopole antenna is designed and analyzed for Radio Frequency Identification (RFID) application in the licensed-free Industrial Scientific and Medical (ISM) band of 2.45 GHz. The proposed antenna uses a 1 mm thicker wearable Jeans fabric {relative permittivity, εr=1.68 and Loss Tangent of δ=0.025} as a substrate material. For better bandwidth, and radiation efficiency the substrate is backed by a truncated copper ground plane. The antenna operate efficiently (92.85%), giving an adequate bandwidth, return-loss, gain and directivity of 12 %, -35.57 dB, 3.144 dB and 3.465 dBi, respectively. The nominated antenna is compact, low profile, and provides a better impedance matching (50.25 ohms) which results in a Voltage Standing Wave Ratio (VSWR) of 1.03. The far-field analysis is carried out via Finite Integration Technique (FIT) in CST Microwave studio.

The formation of P2P logical networks oblivious to the structure of physical topology results in large amount of redundant network traffic. In addition to this mismatch problem, there exists a skew in properties of the participating peers which degrade the performance of P2P networks. So the current P2P systems call for effective overlay formation taking into consideration the underlying physical network topological properties and also inbuilt heterogeneity in participating peers. The heterogeneity of peers in the network can effectively used to bias neighbor selection and improve network performance by assigning more responsibility to nodes with higher capabilities. This paper presents two techniques to solve the problems of topology mismatch and heterogeneity. The proposed methods make use of bandwidth of peers and distance measures for overlay formation in the Gnutella network. The designed systems are tested with proper analysis and simulations to verify the correctness of the methods.

Real and imaginary parts of complex permittivity of Aviation Turbine Kerosine (Hydro-fined) JetA-1 and Aviation Turbine Kerosine (Copper-Sweetened) JetA-1 are measured over the wide frequency range 8-12 GHz using X-band rectangular cavity resonator. The measurement technique uses the cavity perturbation technique. The fuel sample is filled in thin capillary tube of low loss material. It is then inserted through a sample hole at the centre of the broader side of the waveguide cavity resonator. The sample shifts the resonance frequency. The resonance frequency and shift in resonance frequency are measured using PNA Network Analyzer (AT E8362C). Validity of present measurement technique has been checked by measuring the dielectric properties of well-known dielectric materials (Plexiglas). Due to lack of experimental data in literature on dielectric parameters of Aviation fuels, it would be of great interest for the community to find its dielectric properties over wider frequency range. In addition the estimation of measurement error associated with this technique is also discussed.

A multi-band dual polarized log periodic meander-line antenna is presented in this paper. The Ansoft HFSS 3-D EM simulator is employed for design simulation. The proposed antenna is realized on a FR-4 Epoxy substrate with εr = 4.4 and tan ξ = 0.02. The size of the antenna is 14.5 x 20 x 1.59 mm3. The proposed antenna is fabricated and comparison between simulated and measured result for return loss has been observed and is found in good agreement. In addition to micro-strip transmission line feed, a capacitive probe feed has been introduced and enhancement in impedance bandwidth has been observed as compared to only transmission line feeding method. Small size of the antenna enables itself to be introduced in complex systems and can be used for various applications including GSM1800/1900, WCDMA2100 and LTE1800/2300/3700 TDD for mobile handsets and mobile assisted health applications.

An ad hoc network is very popular because of its easy deployment. It is a self-organising network which has dynamic topology. The routing is a major issue in the ad hoc network due to its node mobility. As nodes are moving continuously the source to destination pair is completely broken and repeated route discovery increases delay and network load and reduces throughput of ad hoc network. The routing protocols play a vital role in data transmission and affect the efficiency of the ad hoc network. Also, mobility factor affects the efficiency of the ad hoc network. The ad hoc network is said to be efficient if it transfers data with higher throughput, minimum delay and low overheads. In this paper, researcher studies efficiency of AODV protocol against node mobility. The node mobility term relates to the pause time i.e. the amount of time node is stable at a particular location. The high pause time means nodes in the network have low mobility and low pause time means nodes have high mobility. The performance of AODV protocol is evaluated on the basis of four performance matrices i.e. throughput, delay, routing load, and packet delivery ratio using the Network simulator NS2.34. This study will help the researcher further to regulate the scenario parameters of ad hoc network which will help to improve performance of the protocol.

In this current scenario web application are widely using for various purpose like online shopping, online money transfer, e-bill payment, online mobile recharges etc. As per increasing the dependency on these web applications also raises the attacks on these applications. SQL injection Attacks (SQLIA) and Cross Site Scripting (XSS) are being a major problem for web applications. SQL injection Attack (SQLIA) is the most common type of vulnerability in which a malicious mind person is inserts its own crafted query as input for retrieving personal information about others sensitive users. In this paper, for detection and prevention of SQL injection attacks various techniques are described and perform a comparison between them.