Patent 可変利得増幅器、及び増幅回路 山口陽, 加保貴奈, 赤羽和徳, 上原一浩 Application no. 特願2012-107849 Date applied May 9, 2012 Announcement no. 特開2013-236271 Date announced Nov 21, 2013 Patent/Registration no. 特許5485332 Date registered Feb 28, 2014 Date issued