the geometry of a collector is one of the important factors that can increase the incident radiation on the collector surface. in the present study, the incident radiation for a stationary collector with cone geometry, i.e. a conical collector, is theoretically and experimentally investigated. this type of collector is always stable and does not need a fixture to install. moreover, it has a sym...

Mathematical expressions based on earlier ideas of the author are given to describe the three-dimensional surfaces of hexagonal ice crystals and conical graupel and hail particles. In the former class, the expressions closely parallel the expression for prolate spheroid but the cross section is transformed into a hexagon by an expression designed previously. A special transformation containing ...

The generation of energetic electron and proton beams was studied from the interaction of high intensity laser pulses with pre-drilled conical targets. These conical targets are laser machined onto flat targets using 7–180μJ pulses whose axis of propagation is identical to that of the main high intensity pulse. This method significantly relaxes requirements for alignment of conical targets in s...

In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for configuration. The designed provides an instantaneous frequency range from 370 to 5,000 MHz omnidirectional characteristics. was simulated in CST Microwave Studio, fabricated evaluated; the results are presented. measu...

This paper explains the ultra wideband (UWB) indoor radio channel measurement procedure performed at the main building at the University of Oulu, Finland. The measurement campaign included rooms with various sizes and layouts. The frequency response of the radio channel was recorded using a network analyzer in frequency sweep mode. The impulse response of the radio channel was calculated by tak...

In this paper we develop extensions of the conical techniques exposed in the book [3], and we develop new algorithms as well. We make an effort to keep this paper enough self-contained, however, the book [3] (hereafter often referred to as ”the book” for the sake of brevity) can be useful for further details. Such book is an outgrow of two papers published on the journal Optimization, namely [1...

a newly designed printed slot antenna is presented that incorporates variable two band-notched functions for ultra-wideband (uwb) applications. the two band notches of this coplanar waveguide (cpw) fed antenna are achieved by an m-shaped slot (mss) embedded in the radiating element and a c-shaped strip(css) close to ground plane, therefore two very narrow rejected properties in the wireless loc...

A compact microstrip-fed antenna with dual notched bands is proposed. First, a simple basic configuration is presented for Ultra Wide Band (UWB) applications and then the dual band notched structure is extended from the UWB one. The basic structure of the UWB antenna consists of a simple square radiating patch and a ground plane with a wide square slot on back of the substrate. A semi-circle sh...

Antenna 3D pattern measurement can be a tedious and time consuming task even for antennas with manageable sizes inside anechoic chambers. Performing onsite measurements by scanning the whole 4π [sr] solid angle around the antenna under test (AUT) is more complicated. In this paper, with the aim of minimum duration of flight, a test scenario using unmanned aerial vehicles (UAV) is proposed. A pr...