Search results
Results from the WOW.Com Content Network
A radio-frequency power amplifier (RF power amplifier) is a type of electronic amplifier that converts a low-power radio-frequency (RF) signal into a higher-power signal. [1] Typically, RF power amplifiers are used in the final stage of a radio transmitter , their output driving the antenna .
A linear amplifier is an electronic circuit whose output is proportional to its input, but capable of delivering more power into a load. The term usually refers to a type of radio-frequency (RF) power amplifier, some of which have output power measured in kilowatts, and are used in amateur radio.
A valve RF amplifier (UK and Aus.) or tube amplifier is a device for electrically amplifying the power of an electrical radio frequency signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers during the 1960s and 1970s, initially for receivers and low power stages of ...
In electronics, power amplifier classes are letter symbols applied to different power amplifier types. The class gives a broad indication of an amplifier 's characteristics and performance. The first three classes are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a ...
The inductive output tube (IOT) or klystrode is a variety of linear-beam vacuum tube, similar to a klystron, used as a power amplifier for high frequency radio waves. It evolved in the 1980s to meet increasing efficiency requirements for high-power RF amplifiers in radio transmitters. [1]
Block diagram of a basic class-D amplifier. Note: For clarity, signal periods are not shown to scale. A class-D amplifier or switching amplifier is an electronic amplifier in which the amplifying devices (transistors, usually MOSFETs) operate as electronic switches, and not as linear gain devices as in other amplifiers.
The Doherty amplifier is a modified class B radio frequency amplifier invented by William H. Doherty of Bell Telephone Laboratories Inc in 1936. Whereas conventional class B amplifiers can clip on high input-signal levels, the Doherty power amplifier can accommodate signals with high peak-to-average power ratios by using two amplifier circuits within the one overall amplifier to accommodate ...
For high power, high frequency systems it is normal to use valves, see Valve RF amplifier for details of how valved RF power stages work. Valves are electrically very robust, they can tolerate overloads which would destroy bipolar transistor systems in milliseconds. As a result, valved amplifiers may resist mistuning, lightning and power surges ...