The SMA (SubMiniature Type A) connector is a type of the radio frequency connector developed in the 1960s to make it easier to connect coaxial cables. Using a screw-type design instead of the common ‘push-pull’ system, the SMA connector allows for a quick connection; and can be used in both alternating and direct current applications. Just like BNC connectors, SMA connectors find use in video and Ethernet applications. The SMA connector can be of two types, the 905 and the 906. The 905 type has a straight connector, while the Read More

A spark-gap transmitter is a mechanism for producing radio signals. It has been the primary radio transmission device during the early years of radio technology. It was soon superseded by other transmitters due to its discontinuous radio wave production and widely varying frequencies. How a Spark-Grap Transmitter Works A spark gap transmitter is basically composed of two capacitors (electrical apparatus designed to store electrical energy). However, the switch that ultimately forms the connection between the two capacitors is ionized gas (the air gap) that facilitates the passage of an oscillating Read More

In order to understand how sunspots effect radio reception, you need to understand that the light waves and radio waves that the sun emits are both categorized as electromagnetic (EM) radiation. While light waves are visible to the human eye, they are still electromagnetic waves that oscillate. There are many electro magnetic waves, some oscillate very slow and some very fast. The slowest are the long-frequency radio waves. X-rays are some of the fastest EM waves and the light that we see usually falls in the middle of the electromagnetic Read More

Pulse Amplitude Modulation (PAM) is the simplest form of pulse modulation. This technique transmits data by varying the voltage or power amplitudes of individual pulses in a timed sequence of electromagnetic pulses. In other words, the data to be transmitted is encoded in the amplitude of a series of signal pulses. PAM can also be used for generating additional pulse modulations. If you look at this from a purely theoretical standpoint, the possible pulse amplitudes in pulse amplitude modulation can be infinite. This is the case with analog pulse amplitude Read More

A fractal antenna is a diamond-shaped antenna that maximizes the total amount of material within a given amount of space that transmits or receives electromagnetic waves. Fractal antennas do this by making each section of the antenna its own separate dipole. Because of this design, fractal antennas operate at many different frequencies and wavebands, allowing them to be used for a wide variety of applications, most of which can be found in the cellular telephone and microwave communication industries. How Fractal Antennas Work Fractal antennas maximize the number of dipoles 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

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

Quadrature Amplitude Modulation (QAM) is a complicated name for a simple technique. In the simplest of terms, Quadrature amplitude modulation is the combination of amplitude modulation and phase shift keying. More technically, quadrature amplitude modulation is a system of modulation in which data is transferred by modulating the amplitude of two separate carrier waves, mostly sinusoidal, which are out of phase by 90 degrees (sine and cosine). Due to their phase difference, they are called quadrature carriers. Unmodulated signals exhibit only two positions enabling a transfer of either a 0 Read More

MCX is a type of connector developed in the 1980’s and used in the microwave transmission range. It carries frequencies of up to 6 GHz and is the second smallest of the subminiature connector families. At approximately 30% smaller than Subminiature B connectors (measuring in at 0.140 inches on the outer diameter of the plug), MCX is designed to completely minimize any leakage at its joints. The MCX connector is used with a standard coaxial cable and features a snap-on interface in which the connectors are simply pressed together to Read More

SSB stands for Single Side Band. In SSB, the carrier and one of the side bands are eliminated before transmission. This enables the power amplifier to focus all transmitter energy on the single remaining sideband. SSB allows greater range with less power consumption. SSB also enables more efficient utilization of the radio frequency spectrum. The SSB receiver reinserts the proper carrier after reception and before modulation.