A compact microstrip line-fed ultrawideband (UWB) tapered-shape slot antenna is presented. The proposed antenna comprises a tapered-shape slot and rectangular tuning stub. The antenna is fabricated onto an inexpensive FR4 substrate with an overall dimension of 22 × 24 mm2. The experiment shows that the proposed antenna achieves good impedance matching constant gain, stable radiation patterns over an operating bandwidth of 3-11.2 GHz (115.5%) that covers the entire UWB. The nearly stable radiation pattern with a maximum gain of 5.4 dBi makes the proposed antenna suitable for being used in UWB communication applications.

Compact Tapered-Shape Slot Antenna for UWB Applications

A coplanar waveguide (CPW)-fed planar monopole antenna with triple-band operation for WiMAX and WLAN applications is presented. The antenna, which occupies a small size of 25(L) × 25(W) × 0.8(H) mm3, is simply composed of a pentagonal radiating patch with two bent slots. By carefully selecting the positions and lengths of these slots, good dual stopband rejection characteristic of the antenna can be obtained so that three operating bands covering 2.14-2.85, 3.29-4.08, and 5.02-6.09 GHz can be achieved. The measured results also demonstrate that the proposed antenna has good omnidirectional radiation patterns with appreciable gain across the operating bands and is thus suitable to be integrated within the portable devices for WiMAX/WLAN applications.

Novel CPW-Fed Planar Monopole Antenna for WiMAX/WLAN Applications

Wireless Sensor Networks (WSNs) can be defined as a self-configured and infrastructureless wireless networks to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location or sink where the data can be observed and analysed. A sink or base station acts like an interface between users and the network. One can retrieve required information from the network by injecting queries and gathering results from the sink. Typically a wireless sensor network contains hundreds of thousands of sensor nodes. The sensor nodes can communicate among themselves using radio signals. A wireless sensor node is equipped with sensing and computing devices, radio transceivers and power components. The individual nodes in a wireless sensor network (WSN) are inherently resource constrained: they have limited processing speed, storage capacity, and communication bandwidth. After the sensor nodes are deployed, they are responsible for self-organizing an appropriate network infrastructure often with multi-hop communication with them. Then the onboard sensors start collecting information of interest. Wireless sensor devices also respond to queries sent from a “control site” to perform specific instructions or provide sensing samples. The working mode of the sensor nodes may be either continuous or event driven. Global Positioning System (GPS) and local positioning algorithms can be used to obtain location and positioning information. Wireless sensor devices can be equipped with actuators to “act” upon certain conditions. These networks are sometimes more specifically referred as Wireless Sensor and Actuator Networks as described in (Akkaya et al., 2005).

/pdf/overview-of-wireless-sensor-network-15ybjfh9dr.pdf

Overview of Wireless Sensor Network

A novel compact ultra-wideband (UWB) wide slot antenna with via holes is presented for UWB applications. The antenna is composed of a trapezoidal slot on the ground plane, a rectangular patch in the center of the slot and three via holes connecting the rectangular patch and the microstrip feed-line. The antenna is successfully designed, implemented, and measured. The measured results show that the proposed antenna with compact size of 27:0mm£29:0mm£1:0mm achieves good performance, such as an impedance matching bandwidth of 111.7% (jS11j • i10dB), constant gain and stable radiation patterns over its whole frequency range.

/pdf/a-novel-compact-ultra-wideband-uwb-wide-slot-antenna-with-3tizk4zyrn.pdf

A Novel Compact Ultra-Wideband (UWB) Wide Slot Antenna with via Holes

A low profile printed antenna with triple band operation is presented for simultaneous use in wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. The antenna consists of a rectangular radiating element fed asymmetrically by a 50 Ω microstrip line and a shaped trapezoidal ground plane. Rectangular horizontal strips are attached to the radiation element to form different current paths which make the antenna resonate in WLAN and WiMAX frequency bands. The antenna operates in dipole configuration outlining overall dimensions of 38×30×0.8 mm3.

Compact triple band antenna for WLAN/ WiMAX applications

An experimental investigation was conducted on printed wide-slot antennas fed by microstrip lines for wideband applications. Results show that the impedance matching of this kind of antenna is greatly affected by the feed-slot combination and feed gap width, with the slot shape being a main contributor of the radiation characteristics. By properly choosing suitable slot shapes, selecting similar feed shapes and tuning their dimensions, two designs with significantly enhanced impedance bandwidths and improved radiation patterns are obtained.

Experimental studies of printed wide-slot antenna for wide-band applications

We use experimental data from the Head Start Impact Study to examine the effect of sequential participation in childcare programs on cognitive outcomes. Using a sequential threshold model, which accounts for selection beyond initial randomization, we estimate causal returns to program sequences, including joint and cross returns across skill investment programs. We then estimate a dynamic structural model as a juxtaposition and evaluate a counterfactual policy reform which limits individuals to one year of Head Start. Our results support Head Start implementation earlier in life, and support engaging low-ability children with center-based care and high-ability children with some home care. Reference Details CWPE 2330 Published 20 March 2023

Chan

Papers

Experimental studies of printed wide-slot antenna for wide-band applications

Understanding Program Complementarities: Estimating the Dynamic Effects of Head Start with Multiple Alternatives