Activation signal output circuit having multiple amplifier circuits
US7536153B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2004 |
| Grant date | May 19, 2009 |
| Priority date | — |
| Expiry date | Apr 5, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/54
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
With a capacitor C inserted in an interstage portion of multiple stages of amplifier circuits, a high pass filter is generated by the capacitor C and an input impedance |Z| of an amplifier circuit in the next stage. Accordingly, frequency components lower than a cutoff frequency fc are cut off, and therefore are not transferred to the subsequent stage. However, radio frequency components higher than or equal to a fundamental wave component determined by an envelope of a radio frequency signal intermittently transmitted can be transferred. Consequently, transfer of DC offset potentials can be cut off, and noise, such as flicker noise, having great power in a DC or near-DC zone can be effectively cut off. Thereby, the S/N ratio, detection sensitivity, and detection accuracy can be improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.