The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 02, 2002
Filed:
Jun. 01, 2000
Masayuki Atokawa, Kanazawa, JP;
Abstract
A frequency-characteristics variable filter, a duplexer, and a communication apparatus that can be operated at reduced bias voltages that are applied to diodes provided for switching frequency characteristics without reducing the stability of frequency characteristics and without increasing the occurrence of skews. Also, the single duplexer can be used for two frequency bands. As a diode for each of resonators in a transmitting filter and the first resonator in a receiving resonator, a diode having an interterminal electrostatic capacitance in the off state smaller than that of a diode used for other resonators is used. Also, the diodes for the resonators excluding the first resonator in the receiving filter has a lower forward resistance in the on state and an Q value in the off state higher than those of other diodes.