MSK (Minimum Shift Keying) is a type of continuous frequency shift modulation that is used to transfer radio signals from satellites and radio broadcasting to mobile devices and vice versa. Unlike other forms of frequency modulation, MSK produces a half sine wave that limits problems associated with non-linear distortion. What is GMSK? GMSK (Gaussian Minimum Shift Keying) is a type of MSK that uses the same basic concepts, but applies a Gaussian filter to a signal before its frequency is modulated. A Gaussian filter uses a square wave to shape Read More

Amplitude modulation is a type of modulation where the carrier signal’s amplitude is varied in accordance with the information bearing signal. The amplitude modulated signal’s envelope or boundary embeds the information bearing signal. The total power of the transmitted signal varies with the modulating signal, whereas the carrier power remains constant. A nonlinear device combines the carrier and the modulating signal to generate an amplitude modulated signal. The nonlinear device’s output consists of discrete upper and lower sidebands. A nonlinear device’s output does not vary in direct proportion with the Read More

A circulator is a box-shaped ferrite device that has three or four ports and allows energy from one port to transfer to the next port in line. Circulators are usually used with radio signals but can also be used with microwaves, light, and other electromagnetic waves. This means that a radio signal that is being emitted from a transmitter in port one travels to an antenna in port two and then to a receiver in port three. Any residual energy in the receiver is eventually transferred back to port one. Read More

Pulse position modulation is a signal modulation technique that allows computers to share data by measuring the time each data packet takes to reach the computer. It is often used in optical communication, such as fiber optics, in which there is little multi-pathway interference. Pulse position modulation exclusively transfers digital signals and cannot be used with analog systems. It transfers simple data and is not effective at transferring files. How Pulse Position Modulation Works Pulse position modulation works by sending electrical, electromagnetic, or optical pulses to a computer or other Read More

More properly known as the Bayonet Neill-Concelman connector, the BNC connector is one of several radio frequency connectors on the market today. The name of the connector is derived from a combination of two things: 1) the connecting technology employed; and 2) the names of the two inventors of the device. Paul Neill of Bell Labs and Carl Concelman sought to develop a connector that would employ a bayonet mount mechanism for locking. Building on the research of Octavio M. Salati, the two men perfected an earlier design and created Read More

Pulse Width Modulation, abbreviated as PWM, is a method of transmitting information on a series of pulses. The data that is being transmitted is encoded on the width of these pulses to control the amount of power being sent to a load. In other words, pulse width modulation is a modulation technique for generating variable width pulses to represent the amplitude of an input analog signal or wave. The popular applications of pulse width modulation are in power delivery, voltage regulation and amplification and audio effects. Pulse width modulation is Read More

A Walkie-Talkie is a portable two-way radio transceiver. A transceiver is a device that has a transmitter and a receiver which are combined together to share common circuitry. A Walkie-Talkie is a handheld communication device and it includes a half-duplex channel i.e. it supports communication in both directions but only one person can transmit at a given instant. However, any number of people can receive the transmitted message. A Walkie-Talkie also feature a push-to-talk switch which is used to switch to the transmit mode from the reception mode. A Walkie-Talkie Read More

More than three million people enjoy ham radio hobbies, which is basically amateur radio. These enthusiasts create a network of people that enjoy communicating with one another over different frequencies. However, ham radio operators do use a variety of methods to communicate with one another. The amateur radio operators are known as Hams, and they communicate with one another for fun, self-improvement, or even public service. These operators communicate by transmitting messages by voice, Morse code, or even messages through computers. There are some new ways that allow hams to Read More

The arc transmitter is an instrument for converting direct current into Radio Frequency or (RF) energy. Prior to the development of the arc transmitter, wireless communications were built around the spark-gap transmitter which was inefficient (it wasted bandwidth and used up more energy than required), disruptive (the wide range of frequencies that spark-gap transmitters generated caused massive interference to other radio frequencies), and unstable. The arc transmitter (and later, the high-frequency alternator) was able to focus radio energy along a single frequency (or at least a very narrow frequency range Read More

The crystal radio is a rudimentary radio receiver that can be made from a few easy-to-obtain and inexpensive parts. It is unique for this type of radio does not require a battery pack, has no moving parts, and can be built using ordinary household materials, yet it actually works. The only power it receives comes from the radio signals. Radio Broadcasting Basics It should not be surprising that crystal radios work. The basic principles of radio broadcasting make radio crystal operations more than possible. First, the function of a radio Read More