Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation this delay is essential for budget and planning. This study investigates in three Nigeria cities: Abuja, Lagos, Port Harcourt using two different models (Saastominen Hopfield). Three-year atmospheric data surface pressure, relative humidity temperature obtained at 5-min interval were acqu...

We present the application to transmission line systems of a new theory of the optical theorem that describes the energy budget of electromagnetic scattering in lossless wave propagation media. The insight gained by exploring this, simplest of the electromagnetic wave propagation systems from the point of view of the optical theorem, is important for understanding power budget of electromagneti...

This paper presents the Waveguide Filter Design (WFD) program using principle of electromagnetic wave theory and Wave Iterative Method (WIM) based on propagation of incident, reflected and transmitted waves in the waveguide for microwave engineering education. After the surveying by questionnaire about the nature in the microwave engineering course, the instructors found that the microwave engi...

Single-scattering theory is shown to be insufficient for the estimation of effective propagation constant in foliage at high microwave and millimeter-wave frequencies. Clusters of broad leaves and needles are treated as a unit scatterer whose ensemble forward scattering is used in Foldy’s approximation to estimate attenuation rate in foliage. It is shown that single-scattering approximation ove...

Ernest P. Manly, W7LHL PO Box 1307 Graham, WA 98338-1307 epmanly@ispwest.com The selection of propagation modes for amateur microwave stations is often progressive. Most of us start with simple equipment and the contacts are usually by line-of-sight propagation. Longer distances are then accomplished by going to high locations. As equipment gets better, the use of various objects for reflection...

Ernest P. Manly, W7LHL PO Box 1307 Graham, WA 98338-1307 epmanly@ispwest.com The selection of propagation modes for amateur microwave stations is often progressive. Most of us start with simple equipment and the contacts are usually by line-of-sight propagation. Longer distances are then accomplished by going to high locations. As equipment gets better, the use of various objects for reflection...

Using liquid crystals to control the propagation of microwaves is a potentially interesting technology. By incorporating small amounts of liquid crystal in thin slat metal structures through which the microwaves may resonantly pass a whole new range of voltage tuned microwave devices are becoming available. Metallic sub-wavelength slit structures at microwave frequencies have been constructed w...

Creating a train of single photons and monitoring its propagation and interaction is challenging in most physical systems, as photons generally interact very weakly with other systems. However, when confining microwave frequency photons in a transmission line resonator, effective photon-photon interactions can be mediated by qubits embedded in the resonator. Here, we observe the phenomenon of p...

This paper mainly presents a briefly review for recent progress in MEMS-based transmission lines for use in microwave and millimeterwave range. MEMS-based transmission lines including different transmission line structure such as membranesupported microstrip line microstrip line, coplanar microshield transmission line, LIGA micromachined planar transmission line, micromachined waveguides and co...