Class-B and-AB amplifiers are sometimes used for RF linear amplifiers as well.

Of the two kinds of RF power amplifier, switching amplifiers ( Class D amplifiers ) cost less and use less battery power than linear amplifiers of the same output power.

They use linear polarization for each of the transponders ' RF input and output ( as opposed to circular polarization used by DBS satellites ), but this is a minor technical difference that users do not notice.

The model can be a linear or non-linear, time-continuous or time-discrete ( sampled ), memoryless or dynamic ( resulting in burst errors ), time-invariant or time-variant ( also resulting in burst errors ), baseband, passband ( RF signal model ), real-valued or complex-valued signal model.

* Requires a linear amplifier to meet the stringent RF specifications that allow it to exist alongside other radio services.

The typical 2 meter station using CW ( Morse code ) or SSB ( single side band ) modes consists of an exciter ( radio ) driving a linear amplifier which generates about 200-500 watts of RF power.

The laboratory's main research facility is the CEBAF accelerator, which consists of a polarized electron source and injector and a pair of superconducting RF linear accelerators 7 / 8 mile ( 1400 m ) in length, connected to each other by two arc sections which contain steering magnets.

Most commercially manufactured one to two kilowatt linear amplifiers used in amateur radio still use vacuum tubes ( valves ) and can provide 10 to 20 times RF power amplification.

A quadrupole ion trap or quadrupole ion storage trap ( QUISTOR ) exists in both linear and 3D ( Paul Trap, QIT ) varieties and refers to an ion trap that uses constant DC and radio frequency ( RF ) oscillating AC electric fields to trap ions.

This significantly relaxes the design of the RF power amplifier, allowing it to achieve greater conversion efficiencies than linear amplifiers.

* Understanding RF Power Amplifiers

The solar system uses both CPV ( SolFocus ) and PV ( Premier Power ) arrays and provides about 17 Kilowatts, or 33 % ( one third ), of the radio frequency ( RF ) power output from the 50KW transmitter ( although transmitter power requirements are up to twice the transmitted power of an AM station ).

Power initially flows through the main breakers into an RF mains filter that prevents the flow of noise back onto the incoming power line.

* Agilent ( July 5, 2006 ), Fundamental of RF and Microwave Power Measurements ( Part 2 ), Application Note 1449-2, Agilent Technologies, Tektronix

* Fundamentals of RF and Microwave Power Measurements ( AN 1449 )

* RF and Microwave Power Meter / Sensor Tutorial ( USB RF Power Sensors )

RF-jamming can be done through RF generators ( e. g. from HP, Anritsu ) or Power signal generators ( e. g. from Terabeam Wireless, Global Gadget or Tektronix ).

* Harden, Paul Introduction to Class C, D, E and F, The Handiman's Guide to MOSFET " Switched Mode " Amplifiers, Part 1-An article on basic digital RF amplifier design intended for ham radio operators but applicable to audio Class D amplifiers.

The fact that in equivalent baseband models of communication systems, the signal spectrum consists of both negative and positive frequencies, can lead to confusion about bandwidth, since they are sometimes referred to only by the positive half, and one will occasionally see expressions such as, where is the total bandwidth ( i. e. the maximum passband bandwidth of the carrier-modulated RF signal and the minimum passband bandwidth of the physical passband channel ), and is the positive bandwidth ( the baseband bandwidth of the equivalent channel model ).

They also tend to have much lower junction capacitance than p – n diodes, which provides for high switching speeds and their use in high-speed circuitry and RF devices such as switched-mode power supply, mixers, and detectors.

Vacuum tubes are still used in some specialist applications such as high power RF amplifiers, cathode ray tubes, specialist audio equipment and some microwave devices.

* RF power amplifier, such as for transmitter final stages ( see also: Linear amplifier ).

When RA is clinically suspected, immunological studies are required, such as testing for the presence of rheumatoid factor ( RF, a non-specific antibody ).

The IF amplifier ( or IF strip ) can be made highly selective around its center frequency f < small >< sub > IF </ sub ></ small >, whereas achieving such a selectivity at a much higher RF frequency would be much more difficult.

This had the additional advantage of being less susceptible to external sources of RF interference such as other network cables, fluorescent lights, and high power lines.

Examples of such readers are RF Tiny by RFLOGICS, ProxPoint by HID, and P300 by Farpointe Data.

: In order to access the components, a housing is typically made in sections ( such as a box and lid ); an RF gasket is often used at the section joints to reduce the amount of interference that leaks through the joint.

* Grounding or earthing schemes such as star earthing for audio equipment or ground planes for RF.

* Decoupling or filtering at critical points such as cable entries and high-speed switches, using RF chokes and / or RC elements.

When high RF emission levels from other sources became a potential problem ( such as with the advent of microwave ovens ), certain frequency bands were designated for Industrial, Scientific and Medical ( ISM ) use, allowing unlimited emissions.

In radio applications, the AFSK-modulated signal normally is being used to modulate an RF carrier ( using a conventional technique, such as AM or FM ) for transmission.

* When conducted by an ordinary electric cable, RF current has a tendency to reflect from discontinuities in the cable such as connectors and travel back down the cable toward the source, causing a condition called standing waves, so RF current must be carried by specialized types of cable called transmission line.

Several different microwave RF flange types exist, such as CAR, CBR, OPC, PAR, PBJ, PBR, PDR, UAR, UBR, UDR, icp and UPX.

These typically involve such low levels of RF power that power-handling and high-voltage breakdown characteristics are unimportant when compared to attenuation.

High-pass filters have many uses, such as blocking DC from circuitry sensitive to non-zero average voltages or RF devices.

RF modulators are used to convert signals from devices such as media players, VCRs and game consoles to a format that can be recognised by a device that accepts an RF signal, such as a radio or television.

Since later television designs include composite, S-Video, and component video jacks, which skip the modulation and demodulation steps, modulators are no longer included as standard equipment, and RF modulators are now largely a third-party product, purchased primarily to run newer equipment such as DVD players with an old television set.

One reason for this is that a device which outputs an RF signal must in general be certified by regulatory authorities — such as the U. S. Federal Communications Commission ( FCC ) — and thus by having an external RF modulator, only the modulator itself needed to be certified, rather than the entire video game system.

Eventually, the cellular companies initiated a system called RF Fingerprinting, where it could determine subtle differences in the signal of one phone from another and shut down some cloned phones.

RF ( radio frequency ) and microwave signal generators are used for testing components, receivers and test systems in a wide variety of applications including cellular communications, WiFi, WiMAX, GPS, audio and video broadcasting, satellite communications, radar and electronic warfare.

* Cellular frequencies, assigned to networks operating in cellular RF bands

There are also meters using AMR with RF technologies such as cellular phone data systems, ZigBee, Bluetooth, Wavenis and others.

Multiple other companies have also applied SOI technology to successful RF applications in smartphones and cellular radios.

* Digitally Tunable Capacitor, a type of capacitor that is used in high performance RF tuning of mobile networks such as GSM cellular and Mobile TV

RF shielding is also used to protect medical and laboratory equipment to provide protection against interfering signals, including AM, FM, TV, emergency services, dispatch, pagers, ESMR, cellular, and PCS.

It is commonly used in modern ultrafast circuits, mostly radio-frequency ( RF ) systems, and in applications requiring a high power efficiency, such as RF power amplifiers in cellular phones.