AM radio receiver
US5909644A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1996 |
| Grant date | Jun 1, 1999 |
| Priority date | — |
| Expiry date | Dec 11, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D7/161
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An AM radio receiver of a double superheterodyne type. Where a first intermediate frequency is selected to be a low frequency of several kHz other than 0 kHz. A second intermediate frequency is selected to be several tens of kHz. A first local oscillator circuit formed of a PLL generates first local oscillation signals of two kinds whose phases are different from each other by 90.degree.. First and second mixer circuits are respectively supplied with the first local oscillation signals of two kinds and mix them with a received signals to generate the first intermediate frequency. First and second filters obtain signals each having the first intermediate frequency. A second local oscillator circuit generates second local oscillation signals of two kinds whose phases are different from each other by 90.degree.. Third and fourth mixer circuits are respectively supplied with the signals having the first intermediate frequency and mix them with the second local oscillation signals. An adding circuit adds both signals output from the third and fourth mixer circuits. A third filter is supplied with a signal from the adding circuit and obtains a signal having a second intermediate frequenc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.