Geometries for measuring radome characteristics can usually be split into two categories. The first category always has the antenna inside the radome pointing along the range axis. The second category has the antenna maintaining a fixed relationship with respect to the radome during each scan of data. A facility can generally be designed to minimize measurement errors in one of the two geometri...

A time-domain technique applicable to numerical and experimental application is used to determine the radiation Q of a turnstile antenna as a function of relatï e phasing between the two dipoles. Results confirm the theory that Q is a minimum with the dipoles in phase quadrature. Q 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 25: 95]100, 2000.

Realistic spatial channel models are essential for development of future wideband mobile communication systems, particularly when adaptive antennas at the base stations are considered. Channel models are prerequisite for the performance evaluation of different adaptive antenna solutions and estimation of the obtained capacity gain. Realistic models require channel measurements to prove their as...

in this paper, a resonant slotted waveguide array antenna with circular boundary has been designed and simulated for mono-pulse airborne radar applications. the antenna parameters are:11% bandwidth in x-band (8.6-9.6ghz),vswr < 2, 38dbi directivity, sidelobes level of - 20db and 3-db beam-widths of 2.1degree. to design this antenna, it is divided into short sections (sub-arrays) each with a uni...

this paper presents the results of a study on the radiation characteristics of a plasma triangular antenna in the vhf band (30-300mhz) applying the method of moment. deriving the current distribution of the antenna, it shows the relationship between radiation characteristics of the plasma antenna and the plasma parameters. both theoretical and numerical results indicate that if the plasma frequ...

SeaWinds is a spaceborne wind scatterometer to be flown on the second Japanese Advanced Earth Observing Satellite (ADEOS-II) in 1999. An important international element of NASA’s earth observing system (EOS), SeaWinds is an advanced follow-on to the NASA scatterometer (NSCAT) on the first ADEOS platform. Unlike previous operational spaceborne scatterometer systems, SeaWinds employs a scanning “...

This paper describes a measurement system enabling the complete real-time characterization of the wideband radio channel. The system is based on a wideband radio channel sounder and a spherical antenna array, and it aims to describe the three-dimensional (3-D) spatial radio channel seen by the mobile terminal, including polarization. This information is highly valuable in designing antennas for...

This paper describes the waveform reconstruction method of the electric field emitted by UWB (ultra wideband) device by using the complex antenna factor and observed waveform with an oscilloscope. The waveform radiated by a doubleridged guide horn antenna and an impulse generator was measured by an oscilloscope and was reconstructed by the method. The peak power measurement using a resolution b...

A wireless network using high altitude platforms located in the stratosphere is attracting interests as a new network infrastructure. This paper provides the design concept and basic performance of the prototype of onboard digital beamforming (DBF) antenna in Ka band, which achieves quick-response and robust space division multiple access (SDMA) schemes. The configuration of the prototype DBF a...