Title:
VARIABLE CAPACITY CIRCUIT, OSCILLATION CIRCUIT, AND RADIO COMMUNICATION DEVICE
Document Type and Number:
Japanese Patent JP2005285938
Kind Code:
A
Abstract:
To take enough frequency variable ranges without using a large-sized MOS, and to enable it to lessen degradation of the frequency variable ranges even if the number of bands increases.
In the oscillation core of VCO, varactors (Cvara1, Cvara2) are connected with an inductor (inductance: L) in parallel between two branches. The varactor (Cvara2) consists of two varactors comprising a MOS between them which functions as a resistance when turned on, and functions as a capacitor when turned off. Moreover, the MOS is used for ON/OFF switching control when switching oscillation frequency.
Inventors:
HINO YASUSHI
Application Number:
JP2004095053A
Publication Date:
October 13, 2005
Filing Date:
March 29, 2004
Export Citation:
Assignee:
SONY ERICSSON MOBILE COMM JP
International Classes:
H01L27/04; H01L21/822; H01L29/94; H03B5/08; H03B5/12; (IPC1-7): H01L21/822; H01L27/04; H01L29/94; H03B5/08; H03B5/12
Attorney, Agent or Firm:
Atsuro Sasaki