continuous wave

(redirected from continuous-wave)
Also found in: Dictionary.

continuous wave

[kən¦tin·yə·wəs ′wāv]
(electromagnetism)
A radio or radar wave whose successive sinusoidal oscillations are identical under steady-state conditions. Abbreviated CW. Also known as type A wave.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

continuous wave

(communications)
(CW) A term from early radio history, when the spark gap method of transmission was replaced by vacuum-tube oscillators. A spark gap initiates a ringing, damped sinusoidal wave in a tuned circuit consisting of an inductor and capacitor. The energy in this circuit is constantly changing between the capacitor's electrostatic field and the inductor's magnetic field. The energy is then coupled, loosely (so as not to dampen the wave too quickly), to the radiating antenna.

In contrast, a vacuum-tube oscillator constantly adds energy to the tuned circuit, compensating for the amount coupled to the antenna, and the transmitted energy or "wave," is therefore "continuous".

Many (especially radio amateurs) continue to understand "CW" to mean transmission by means a signal of a single frequency which is either on or off (e.g. Morse code), as opposed to a carrier which varies continuously in amplitude, frequency or phase. Some would even call the former "unmodulated" even though turning on and off is actually an extreme form of amplitude modulation.
This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)
References in periodicals archive ?
In conclusion, we have experimentally demonstrated a compact continuous-wave intracavity SR-OPO based on MgO:PPLN crystal.
Both of the modulators were driven by a sinusoidal signal with a frequency of 30 GHz, which modulated a continuous-wave (CW) laser wavelength centered at 1540 nm.
Amann, "Low threshold room-temperature continuous-wave operation of 2.24-3.04 [micro]m GaInAsSb/AlGaAsSb quantum-well lasers," Applied Physics Letters, vol.
METHODS: One thousand three hundred and ninetyseven patients were screened for RLS symptoms by questionnaire and interview, and for saphenous vein disease by clinical examination, including continuous-wave Doppler.
BMW Group, according to IPG Photonics (www.ipgphotonics.com), has ordered multi-kilowatt, continuous-wave Ytterbium fiber laser systems for use in welding doors.
The Diamond C series of low-power, continuous-wave C[O.sub.2] lasers consist of sealed lasers with output powers of 30, 40, 55 and 70 watts at 10.6 pm.
Researchers working with continuous-wave lasers in the 1960s were some of the first to observe the high-contrast, fine-scale granular patterns that appeared when laser light was reflected from a rough surface.
Inherently cooler than continuous-wave mercury lamps, these PWB pulsed UV-curing systems provide instant on/off; fast cycle times, and a compact modular design for integration into a variety of host equipment.
Additionally, the contract will provide each ship with three illuminators and the associated antennas for the MK99 fire-control systems, which provide X-band, continuous-wave illumination for the Standard Missile and the Evolved Seasparrow Missile systems.
The university developed a continuous-wave ultrasonic technique that is said to be lower cost, more robust, and easier to operate.
The UltraPulse Encore delivers 60 watts of continuous-wave energy and 60 watts of pulsed energy.
The PTX7458 pulse transmitter offers a 1 kW output over the 8 to 18 GHz frequency band at a duty cycle of up to four percent (in burst mode, a value of up to 50 percent is obtainable); the PTX7459 transmitter covers the same frequency range and provides a 200 W continuous-wave output.

Full browser ?