Title :
Linearized saturation amplifier with bidirectional control (LSA-BC) for digital mobile radio
Author :
Chiba, Kohji ; Nojima, Toshio ; Tomisato, Shigeru
Author_Institution :
NTT Radio Commun. Syst. Lab., Yokosuka, Japan
Abstract :
The design and performance of the LSA-BC, a novel power amplifier, are presented. A linear amplifier with the high efficiency of a switching-mode saturation amplifier can be realized. A high-efficiency GaAs FET is roughly linearized by dynamically varying its drain DC voltage with a high-efficiency variable-output DC-DC converter. A negative envelope feedback is utilized to compensate for the residual. The circuit construction is simple enough for use in the portable subscriber units of a digital mobile radio system. A 1.5-GHz-band 1-W LSA-BC was constructed to determine its performance with 32-kb/s roll-off QPSK (quadrature phase-shift keying). As a result, a 40% total efficiency is achieved as well as a stable third-order intermodulation distortion of -50 dB to the signal level
Keywords :
digital radio systems; field effect integrated circuits; microwave amplifiers; mobile radio systems; phase shift keying; power amplifiers; solid-state microwave circuits; 1 W; 1.5 GHz; GaAs; LSA-BC; QPSK; UHF; bidirectional control; design; digital mobile radio; high-efficiency GaAs FET; high-efficiency variable-output DC-DC converter; intermodulation distortion; linearised saturation amplifier; microwave amplifier; negative envelope feedback; performance; portable subscriber units; power amplifier; Bidirectional control; Circuits; DC-DC power converters; FETs; Gallium arsenide; Land mobile radio; Negative feedback; Power amplifiers; Quadrature phase shift keying; Voltage;
Conference_Titel :
Global Telecommunications Conference, 1990, and Exhibition. 'Communications: Connecting the Future', GLOBECOM '90., IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
0-87942-632-2
DOI :
10.1109/GLOCOM.1990.116821
