Title :
Active antenna approach to high efficiency power amplifiers with EMI reduction
Author :
Radisic, Vesna ; Qian, Yongxi ; Itoh, Tatsuo
Author_Institution :
Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA
Abstract :
This paper reports two techniques for optimizing harmonic termination in power amplifiers. In the first technique, the active antenna approach, the antenna element acts as radiator and as part of the output tuning circuit. The second method, based on photonic band-gap (PBG) structure, incorporates a periodic harmonic tuning structure for microstrip lines. In this structure, a periodic 2-D pattern is etched in the microstrip ground plane. A wide stopband suitable for broadband harmonic tuning, has been demonstrated experimentally. These methods yield high efficiency power amplifiers, and reduce unwanted radiation from the antenna at harmonics. Two power amplifier examples are presented
Keywords :
UHF antennas; UHF power amplifiers; active antennas; antenna radiation patterns; circuit tuning; interference suppression; microstrip antennas; minimisation; photonic band gap; radio transmitters; transmitting antennas; 2.55 GHz; EMI reduction; PBG structure; active antenna; antenna element; broadband harmonic tuning; harmonic termination; high efficiency power amplifiers; microstrip ground plane; microstrip lines.; output tuning circuit; periodic 2-D pattern; periodic harmonic tuning structure; photonic band-gap structure; stopband; unwanted radiation; Circuit optimization; Electromagnetic interference; Frequency; High power amplifiers; Impedance; Periodic structures; Power amplifiers; Power harmonic filters; Power system harmonics; System performance;
Conference_Titel :
Military Communications Conference, 1998. MILCOM 98. Proceedings., IEEE
Conference_Location :
Boston, MA
Print_ISBN :
0-7803-4506-1
DOI :
10.1109/MILCOM.1998.726914
