Variable capacitance element controllable by a D.C. voltage
US4721985A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1985 |
| Grant date | Jan 26, 1988 |
| Priority date | — |
| Expiry date | Jul 1, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/64
Abstract
The invention relates to a variable capacitance element operating in the ultra-high frequency range. In order to integrate this element on to an integrated circuit chip, the element is designed so that the control voltage does not interfere with the ultra-high frequency signal and has neither filters nor shock chokes which are not integrable. The element according to the invention utilizes the junction capacitances variation of at least one diode, reverse-biased by a voltage across a resistor, the high frequency signal being at the diode anode. The element construction comprises an active zone in a semiinsulating substrate. Two metallizations partly cover the active zone and form therewith at least one diode. A projection to the active zone forms the resistor, to which is applied the control voltage. The diodes are p-n junctions of schottky diodes. The semiconductor material is Si or from the III-V group. Application to oscillators, filters, phase shifters, etc. in ultra-high frequency equipment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.