Patent 7856216 was granted and assigned to NEC Corporation on December, 2010 by the United States Patent and Trademark Office.
Reception levels are measured in respective branches to compare the results of the measurements with one another to select the result of the measurement of a maximum reception level which is the highest reception level. The gains of variable gain amplifiers (6, 7) of all the branches including variable gain amplifiers (6, 7) included in a branch corresponding to the maximum reception level are adjusted to the same value such that output levels of the variable gain amplifiers (6, 7) are set to a preset target level.