 | This article relies largely or entirely on a single source. (October 2012) |
A crossed-field amplifier (CFA) is a specialized vacuum tube, first introduced in the mid-1950s and frequently used as a microwave amplifier in very-high-power transmitters.
Raytheon engineer William C. Brown's work to adapt magnetron principles to create a new broadband amplifier is generally recognized as the first CFA, which he called an Amplitron. Other names that are sometimes used by CFA manufacturers include Platinotron or Stabilotron.
A CFA has lower gain and bandwidth than other microwave amplifier tubes (such as klystrons or traveling-wave tubes); but it is more efficient and capable of much higher output power.
Peak output powers of many megawatts and average power levels of tens of kilowatts can be achieved, with efficiency ratings over 70 percent. Their current use is in satellite ground stations and deep space communications networks.