Found 151 Articles for Science & Technology

Geiger Muller Counter is named after its developers: Geiger and Muller. It is a metal cylinder filled with low-pressure gas sealed with a plastic or ceramic window at one end. This counter works in Geiger region with two specialities.The gas multiplication factor is so large that an avalanche dies in at one point but spreads all over the entire length of the central wire.Large output pulses are obtained as the output pulse is independent both of the energy and nature of the particles detected.The Principle of Working of GM CounterThe ionizing particle passing through the tube ionizes the gas and ... Read More

Noise is an unwanted signal which interferes with the original message signal and corrupts the parameters of the message signal. This alteration in the communication process makes the message to get altered after reaching. It is most likely to be entered at the channel or the receiver.The noise signal can be understood by having a look at the example figure below.Hence, it is understood that noise is some signal which has no pattern and no constant frequency or amplitude. It is quite random and unpredictable. Measures are usually taken to reduce it, though it can’t be completely eliminated.Most common examples ... Read More

Among the modulation systems in the communication field, the DSBSC and SSB are the mostly used once till the VSB was invented. If the carrier is suppressed and the power saved is distributed to the two sidebands, such a process is called as Double Side Band Suppressed Carrier system, or simply DSBSC.The process of suppressing one of the sidebands, along with the carrier and transmitting a single sideband is called as Single Side Band Suppressed Carrier system, or simply SSBSC or SSB. In the case of Single Sideband modulation, when a sideband is passed through the filters, the bandpass filter ... Read More

Multiplexing is the process of combining multiple signals into one signal, over a shared medium. If analog signals are multiplexed, it is Analog Multiplexing and if digital signals are multiplexed, that process is Digital Multiplexing.The process of multiplexing divides a communication channel into several number of logical channels, allotting each one for a different message signal or a data stream to be transferred. The device that does multiplexing can be simply called as a MUX while the one that reverses the process which is demultiplexing, is called as DEMUX.Types of MultiplexersThere are mainly two types of multiplexers, namely analog and ... Read More

A Magic Tee junction is formed by attaching two simple waveguides one parallel and the other series, to a rectangular waveguide which already has two ports. This is also called an E-H Plane Tee junction or Hybrid or 3dB coupler.The arms of rectangular waveguides make two ports called collinear ports i.e., Port 1 and Port 2, while the Port 3 is called as H-Arm or Sum port or Parallel port. Port 4 is called as E-Arm or Difference port or Series port.The connections are made by the side arms to the bi-directional waveguide to form both the parallel and serial ... Read More

Yagi-Uda antenna is the most commonly used type of antenna for TV reception over the last few decades. It is the most popular and easy-to-use type of antenna with better performance, which is famous for its high gain and directivity. The frequency range in which the Yagi-Uda antennas operate is around 30 MHz to 3 GHz which belong to the VHF and UHF bands.Construction of Yagi-Uda AntennaA Yagi-Uda antenna was seen on top of almost every house during the 90's when we had only Doordarshan Channels. The parasitic elements and the dipole together form this Yagi-Uda antenna. It is seen ... Read More

A Directional coupler is a device that samples a small amount of Microwave power for measurement purposes. The power measurements include incident power, reflected power, VSWR values etc. Directional coupler is used to couple the Microwave power which may be Uni-directional or bi-directional. It is a 4 port waveguide junction consisting of a Primary main waveguide and a Secondary auxiliary waveguide. The below figure shows the image of a directional coupler.PropertiesThe properties of an Ideal directional coupler are as follows.All the terminations are matched to the ports.When the power travels from port 1 to port 2, some portion of it ... Read More

Whenever a current carrying conductor is placed in a magnetic field, it experiences a force. The relation between these three is stated by Fleming’s left-hand rule. To understand this rule, the thumb, middle and index fingers are placed in perpendicular to each other.Thumb RuleImagine a current carrying conductor placed in-between a horseshoe magnet. This magnet produces some magnetic field which will be in the direction indicated by the forefinger or Index finger. The current passing through the conductor will be in the direction of the middle finger. This conductor experiences a force which is indicated in the direction of thumb. ... Read More

To improve the radiation efficiency and directivity of the beam, the waveguide should be provided with an extended aperture so as to make the abrupt discontinuity of the wave into a gradual transformation, so that all the energy in the forward direction gets radiated. This can be termed as Flaring. Flaring is done to provide greater directivity and narrower beam width. The types of horn antennas depend on how they are flared.Sectoral HornThis type of horn antenna, flares out in only in one direction. Flaring in the direction of Electric vector produces the sectorial E-plane horn. As well, flaring in ... Read More

Cryogenic Sleep is the process of freezing a person into a deep sleep for a long time with no supply of food and water. This process was proposed so as to pass time more quickly during the space travel. Cryogenic sleep also stops ageing. This is mostly addressed in science fiction movies.How did this idea develop?During the space travel, the travelers need to take more materials such as food, water, exercise equipment, television etc. as they need to perform exercises to keep themselves healthy and also to keep themselves engaged, as sitting idle for hours would affect them mentally. Now, ... Read More