HOME TheInfoList.com
Providing Lists of Related Topics to Help You Find Great Stuff
[::MainTopicLength::#1500] [::ListTopicLength::#1000] [::ListLength::#15] [::ListAdRepeat::#3]

picture info

Loading Coil
A loading coil or load coil is an inductor that is inserted into an electronic circuit to increase its inductance. A loading coil is not a transformer as it does not provide coupling to another circuit. The term originated in the 19th century for inductors used to prevent signal distortion in long-distance telegraph transmission cables. The term is also used for inductors in radio antennas, or between the antenna and its feedline, to make an electrically short antenna resonant at its operating frequency. The concept of loading coils was discovered by Oliver Heaviside
Oliver Heaviside
in studying the problem of slow signalling speed of the first transatlantic telegraph cable in the 1860s. He concluded additional inductance was required to prevent amplitude and time delay distortion of the transmitted signal
[...More...]

"Loading Coil" on:
Wikipedia
Google
Yahoo

picture info

Cell Phone
A mobile phone, known as a cell phone in North America, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture, and, therefore, mobile telephones are called cellular telephones or cell phones, in North America. In addition to telephony, 2000s-era mobile phones support a variety of other services, such as text messaging, MMS, email, Internet
Internet
access, short-range wireless communications (infrared, Bluetooth), business applications, video games, and digital photography
[...More...]

"Cell Phone" on:
Wikipedia
Google
Yahoo

picture info

Monopole Antenna
A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor, often mounted perpendicularly over some type of conductive surface, called a ground plane. The driving signal from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the lower end of the monopole and the ground plane. One side of the antenna feedline is attached to the lower end of the monopole, and the other side is attached to the ground plane, which is often the Earth. This contrasts with a dipole antenna which consists of two identical rod conductors, with the signal from the transmitter applied between the two halves of the antenna. The monopole is a resonant antenna; the rod functions as an open resonator for radio waves, oscillating with standing waves of voltage and current along its length. Therefore, the length of the antenna is determined by the wavelength of the radio waves it is used with
[...More...]

"Monopole Antenna" on:
Wikipedia
Google
Yahoo

picture info

Inductor
An inductor, also called a coil, choke or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it.[1] An inductor typically consists of an insulated wire wound into a coil around a core. When the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor, described by Faraday's law of induction. According to Lenz's law, the direction of induced electromotive force (e.m.f.) opposes the change in current that created it. As a result, inductors oppose any changes in current through them. An inductor is characterized by its inductance, which is the ratio of the voltage to the rate of change of current. In the International System of Units (SI), the unit of inductance is the henry (H) named for 19th century American scientist Joseph Henry. In the measurement of magnetic circuits, it is equivalent to weber/ampere
[...More...]

"Inductor" on:
Wikipedia
Google
Yahoo

picture info

Characteristic Impedance
The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in the absence of reflections in the other direction. Characteristic impedance
Characteristic impedance
is determined by the geometry and materials of the transmission line and, for a uniform line, is not dependent on its length. The SI unit of characteristic impedance is the ohm. The characteristic impedance of a lossless transmission line is purely real, with no reactive component. Energy supplied by a source at one end of such a line is transmitted through the line without being dissipated in the line itself
[...More...]

"Characteristic Impedance" on:
Wikipedia
Google
Yahoo

Audio Frequency
An audio frequency (abbreviation: AF) or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human. The SI unit of audio frequency is the hertz (Hz). It is the property of sound that most determines pitch.[1] The generally accepted standard range of audible frequencies for humans is 20 to 20,000 Hz,[2][3][4] although the range of frequencies individuals hear is greatly influenced by environmental factors. Frequencies below 20 Hz are generally felt rather than heard, assuming the amplitude of the vibration is great enough. Frequencies above 20,000 Hz can sometimes be sensed by young people
[...More...]

"Audio Frequency" on:
Wikipedia
Google
Yahoo

picture info

Passband
A passband is the range of frequencies or wavelengths that can pass through a filter. For example, a radio receiver contains a bandpass filter to select the frequency of the desired radio signal out of all the radio waves picked up by its antenna. The passband of a receiver is the range of frequencies it can receive. A bandpass-filtered signal (that is, a signal with energy only in a passband), is known as a bandpass signal, in contrast to a baseband signal.[1]Contents1 Filters 2 Digital transmission 3 Details 4 ReferencesFilters[edit]Unrestricted signal (upper diagram). Bandpass filter
Bandpass filter
applied to signal (middle diagram). Resulting passband signal (bottom diagram)
[...More...]

"Passband" on:
Wikipedia
Google
Yahoo

Carrier System
A carrier system is a telecommunications system that transmits information, such as the voice signals of a telephone call and the video signals of television, by modulation of one or multiple carrier signals above the principal voice frequency or data rate.[1] Carrier systems typically transmit multiple channels of communication simultaneously over the shared medium using various forms of multiplexing. Prominent multiplexing methods of the carrier signal are time-division multiplexing (TDM) and frequency-division multiplexing (FDM). A cable television system is an example of frequency-division multiplexing. Many television programs are carried simultaneously on the same coaxial cable by sending each at a different frequency. Multiple layers of multiplexing may ultimately be performed upon a given input signal. For example, in the public switched telephone network, many telephone calls are sent over shared trunk lines by time-division multiplexing
[...More...]

"Carrier System" on:
Wikipedia
Google
Yahoo

picture info

M-derived Filter
m-derived filters or m-type filters are a type of electronic filter designed using the image method. They were invented by Otto Zobel
Otto Zobel
in the early 1920s.[1] This filter type was originally intended for use with telephone multiplexing and was an improvement on the existing constant k type filter.[2] The main problem being addressed was the need to achieve a better match of the filter into the terminating impedances. In general, all filters designed by the image method fail to give an exact match, but the m-type filter is a big improvement with suitable choice of the parameter m. The m-type filter section has a further advantage in that there is a rapid transition from the cut-off frequency of the pass band to a pole of attenuation just inside the stop band. Despite these advantages, there is a drawback with m-type filters; at frequencies past the pole of attenuation, the response starts to rise again, and m-types have poor stop band rejection
[...More...]

"M-derived Filter" on:
Wikipedia
Google
Yahoo

picture info

Longwave
In radio, longwave, long wave or long-wave,[1] and commonly abbreviated LW,[2] refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the early 20th century, when the radio spectrum was considered to consist of longwave (LW), medium-wave (MW), and short-wave (SW) radio bands. Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short'. In contemporary usage, the term longwave is not defined precisely, and its intended meaning varies. It may be used for radio wavelengths longer than 1,000 m[2] i.e. frequencies[3] up to 300 kilohertz (kHz),[4][5] including the International Telecommunications Union's (ITU's) low frequency (LF, 30–300 kHz) and very low frequency (VLF, 3–30 kHz) bands
[...More...]

"Longwave" on:
Wikipedia
Google
Yahoo

picture info

Radiotelegraphy
Wireless
Wireless
telegraphy is the transmission of electric telegraphy signals without wires (wirelessly). The term is used synonymously for radio communication systems, also called radiotelegraphy, which transmit telegraph signals by radio waves
[...More...]

"Radiotelegraphy" on:
Wikipedia
Google
Yahoo

picture info

Resonator
A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical (including acoustic). Resonators are used to either generate waves of specific frequencies or to select specific frequencies from a signal. Musical instruments use acoustic resonators that produce sound waves of specific tones. Another example is quartz crystals used in electronic devices such as radio transmitters and quartz watches to produce oscillations of very precise frequency. A cavity resonator is one in which waves exist in a hollow space inside the device. In electronics and radio, microwave cavities consisting of hollow metal boxes are used in microwave transmitters, receivers and test equipment to control frequency, in place of the tuned circuits which are used at lower frequencies
[...More...]

"Resonator" on:
Wikipedia
Google
Yahoo

picture info

Lumped Element Model
The lumped element model (also called lumped parameter model, or lumped component model) simplifies the description of the behaviour of spatially distributed physical systems into a topology consisting of discrete entities that approximate the behaviour of the distributed system under certain assumptions
[...More...]

"Lumped Element Model" on:
Wikipedia
Google
Yahoo

picture info

Transmission Line
In communications and electronic engineering, a transmission line is a specialized cable or other structure designed to conduct alternating current of radio frequency, that is, currents with a frequency high enough that their wave nature must be taken into account. Transmission lines are used for purposes such as connecting radio transmitters and receivers with their antennas (they are then called feed lines or feeders), distributing cable television signals, trunklines routing calls between telephone switching centres, computer network connections and high speed computer data buses. This article covers two-conductor transmission line such as parallel line (ladder line), coaxial cable, stripline, and microstrip
[...More...]

"Transmission Line" on:
Wikipedia
Google
Yahoo

picture info

Standing Wave
In physics, a standing wave – also known as a stationary wave – is a wave in which its peaks (or any other point on the wave) do not move spatially. The amplitude of the wave at a point in space may vary with time, but its phase remains constant. The locations at which the amplitude is minimum are called nodes, and the locations where the amplitude is maximum are called antinodes. Standing waves were first noticed by Michael Faraday
Michael Faraday
in 1831
[...More...]

"Standing Wave" on:
Wikipedia
Google
Yahoo

picture info

Wavelength
In physics, the wavelength is the spatial period of a wave—the distance over which the wave's shape repeats,[1][2] and thus the inverse of the spatial frequency. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns.[3][4] Wavelength
Wavelength
is commonly designated by the Greek letter
Greek letter
lambda (λ)
[...More...]

"Wavelength" on:
Wikipedia
Google
Yahoo
.