Apparatus for selectively receiving carrier wave signals
US6215829A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 29, 1998 |
| Grant date | Apr 10, 2001 |
| Priority date | — |
| Expiry date | May 29, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/28
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus for receiving carrier wave signals includes a frequency converting portion operative to produce an intermediate frequency signal having a carrier frequency of an intermediate frequency, a frequency demodulator for frequency-demodulating the intermediate frequency signal with a demodulation characteristic having a center frequency substantially equal to the intermediate frequency. The apparatus uses, a DC level detector to produce a first level detection output signal having a predetermined level when a DC level of a demodulation output signal obtained from the frequency demodulator is not less than a predetermined level, and an intermediate frequency level detector operative to produce a second level detection output signal having a predetermined level when a frequency component of the intermediate frequency signal, which falls within a predetermined frequency range that includes the center frequency of the demodulation characteristic in the frequency demodulating portion, has a level not less than a predetermined level. A signal discriminating portion is used for discriminating between a desirable condition in which the input signal is a carrier wave signal desired, t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.