Controllable filter and high frequency apparatus using the same
US6084486A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Oct 15, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2210/015
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A filter comprises an inductor, a first variable capacitance diode, a second variable capacitance diode having nearly identical characteristic as the first variable capacitance diode, a control terminal for applying voltage to the first and the second variable capacitance diodes, an input terminal, an output terminal and a signal line between the input terminal and the output terminal. A cutoff frequency is controllable with the voltage applied to the control terminal. The variable frequency filter which can receive a large signal has reduced size due to a structure in which the first and the second variable capacitance diodes having nearly identical characteristics are connected either in series or in parallel with their polarities reversed against each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.