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Experimental optimization of the 2nd loop configuration for feedforward amplifiers in terms of their efficiency and linearity

✍ Scribed by Sung-Chan Jung; Dong-Hwan Lee; Youngoo Yang; Cheon-Seok Park


Publisher
John Wiley and Sons
Year
2006
Tongue
English
Weight
159 KB
Volume
48
Category
Article
ISSN
0895-2477

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✦ Synopsis


In this paper, we report the results of the experimental optimization of the 2 nd -loop configuration for feedforward amplifiers in terms of their efficiency and linearity. We consider two parameters in the 2 nd -loop of a feedforward amplifier: (i) the size ratio between the main and error amplifiers and (ii) the coupling factor of the error signal coupler. Experiments are performed using a multicarrier down-link WC-DMA signal under various configurations. The measured data, which are normalized with respect to the overall power capacity of the main and error amplifiers, show that, among the different 2 nd -loop configurations, the best compromised efficiency (13.4%) at a given adjacent channel leakage ratio (ACLR) level (Ϫ50 dBc) is observed for a size ratio of around 3.0 and a coupling factor of around 7.2 dB.