A “broad beam” in satellite-based telemetry is a beam of radio waves that is focused on a large area of the Earth’s surface. Broad beams are commonly used to transmit data from an orbital satellite to a large number of ground-based receivers simultaneously. Broad beams are also used in satellite-based radar and GPS in order to view large areas of the Earth’s surface at one time. Broad beams typically require more power than spot beams, but provide a much wider coverage area and generally transmit the same amount of data. Read More

A transformer transfers electrical energy between two circuits. It usually consists of two wire coils wrapped around a core. These coils are called primary and secondary windings. Energy is transferred by mutual induction caused by a changing electromagnetic field. If the coils have different number of turns around the core, the voltage induced in the secondary coil will be different to the first. History of Transformers Transformers are based on the theory of electromagnetic induction, which was discovered by Michael Faraday in 1831. It was not until 1836 that the Read More

RFID (Radio Frequency Identification) is a wireless system used to identify tags. These tags may be attached to objects and even embedded under the skin of animals and human beings. Therefore, we can describe RFID as a form of identification tracking that allows retail outlets, airports, zoos, libraries, office buildings, warehouses, and different types of companies to locate and track property or people. For example, a retail store can use this system to locate any item and see on which shelf it is placed. Although there are other tracking methods, Read More

Satellite images are taken by reconnaissance satellites that orbit the Earth at a relatively low altitude, between 300 to 600 miles (or 480 to 970 km). As the majority of today's satellites are custom made in order to accommodate particular needs of the designer, there is no standard on which photo imagery is based on but the principle remains the same. Given the costs of creating and putting a satellite into orbit they tend to have highly specialized functions, as an example, reconnaissance satellites that are used to provide satellite Read More

Night Vision is an imaging technology designed to improve visibility in minimal or no light by amplifying or creating light. This imaging technology utilizes the upper or lower portion of the light spectrum to create a clearer and more detailed picture of the target. In essence, night vision devices utilize the portion of the light spectrum that is invisible to the human eye in order to create a clearer picture. Unlike the visible portion, which depends wholly on light reflection, garnering image data from the infrared spectrum means that the Read More

Medium Earth Orbit (MEO) refers to a satellite which orbits the earth at an altitude below 22,300 miles (geostationary orbit) and above the altitude of Low Earth Orbit (LEO) satellites. Medium Earth Orbit represents a series of tradeoffs between geostationary orbit (GEO) and Low Earth Orbit (LEO). Medium Earth Orbit enables a satellite provider to cover the earth with fewer satellites than Low Earth Orbit, but requires more satellites to do so that geostationary orbit. Medium Earth Orbit terrestrial terminals can be of lower power and use smaller antennas than Read More

Anyone planning to work on electronics or automobiles that have been manufactured in the past decade, need to be able to use a digital multimeter. Modern multimeters contain three measuring devices in one: an ammeter, voltmeter, and ohmmeter. The top section of the device contains the digital read out and it can be viewed in sunlight. What Are the Parts of a Digital Multimeter? The parts of a digital multimeter are fairly common across brands. Beneath the digital readout is the function switch with which the modes that the meter Read More

LNB stands for low noise blocker and it is essentially an amplifier on the end of your small satellite TV dish or communications dish. The “Linear” portion of Linear LNB stands for the characteristics of the radio waves that are transmitted via the satellite in space to your dish (LNB). Two Types of Polarization Circular Polarization Circular polarization is a characteristic of radio waves that are transmitted from a satellite in space, in which the actual radio waves rotate in a spiral. The spiral of radio waves either rotates clockwise Read More

Radio-Frequency Identifier (RFID) technology has become really popular because of the various advantages it comes with. However,   such as passports, national identity cards, credit cards etc have become a serious security concern. Two electrical engineering students (Ilan Kirschenbaum and Avishai Wool) from Tel Aviv University wrote a paper titled "How to Build a Low-Cost, Extended-Range RFID Skimmer." The paper demonstrates just how very simple it has become to 'skim' the RFIDs in your office key or car key. An RFID skimmer can therefore be loosely defined as a device Read More

The argument over whether to use CCD or CMOS has led some industries to suggest one is greater than the other. The truth about them is that they both have very unique strengths and weaknesses. This results in advantages when dealing with different applications. Both do the same thing. Both are imagers that convert light into an electric charge. It then takes this electric charge and processes it into electronic signals. These signals can then be used by the computer. What is CCD? CCD is a charge coupled device. This Read More