ALEXANDRIA, Va.—William H. Doherty was an engineer with Bell Telephone Laboratories in 1936 when he invented a circuit that used two tubes running in Class B configuration to act as a linear amplifier ...

During broadcast radio’s first decade, little thought was given to transmitter efficiency. Main concerns of the industry were availability of broadcast spectrum (sound familiar?); keeping transmitter ...

SOUTHWICK, MASS.—Hitachi Kokusai Electric Comark LLC has a long standing history in the broadcast TV market. Comark started more than 40 years ago manufacturing RF components for UHF transmitters and ...

In a world of everything Doherty, there can be several variations on the standard Doherty amplifier architecture, in order to optimize the operation for different signal conditions. All of the ...

The world's first fully integrated Doherty amplifiers for TD-SCDMA and WCDMA base stations has been launched by NXP Semiconductors to expand the company's portfolio of RF power transistors. The ...

Peregrine Semiconductor’s line of UltraCMOS Monolithic Phase & Amplitude Controllers (MPACs) offers a monolithic RF solution to maximize Doherty amplifier performance. Through a digital interface, ...

In general terms, power amplifiers (PAs) used in communications systems must be large enough to amplify envelope peaks. This leads to amplifiers designed to offer the best efficiency at peak power ...

Your article (“KRLD’s Dougherty Transmitter,” July 1) discussed “the Western Electric 407A2 50 kW water-cooled Dougherty transmitter at KRLD in Dallas.” When I took my FCC first class radiotelephone ...