公开(公告)号：EP2009783A4

公开(公告)日：2013-12-25

申请号：EP08720373

申请日：2008-03-07

Applicant: PANASONIC CORP

Inventor： TAKESHI FUJII ,  YASUO OOBA ,  MINEYUKI IWAIDA ,  HIROAKI OZEKI

IPC: H03B5/12 ,  H03L7/087 ,  H03L7/099 ,  H03L7/10 ,  H03L7/18 ,  H04B1/26

CPC classification number: H03L7/10 ,  H03B5/1215 ,  H03B5/1231 ,  H03B5/1265 ,  H03B2201/0208 ,  H03B2201/025 ,  H03J2200/10 ,  H03L7/087 ,  H03L7/099 ,  H03L7/18 ,  H03L2207/06

Abstract: A broad oscillation frequency range and good phase noise characteristic are achievable simultaneously by an oscillation circuit and a resonance circuit connected to the oscillation circuit. The resonance circuit includes an inductor element connected to the oscillation circuit, a first variable capacitance section connected to the inductor element, and a second variable capacitance section connected in parallel to the first variable capacitance section. The first variable capacitance section includes a first variable capacitive element connected to the inductor element, and a second variable capacitive element connected in parallel to the first variable capacitive element. The first variable capacitive element changes its capacity value based on a control voltage and a first reference voltage. The second variable capacitive element changes its capacity value based on the control voltage and a second reference voltage. The first reference voltage and the second reference voltage are controlled based on the capacity value of the second variable capacitance section.