Integrated front end circuit for VHF receiver
US4194158A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1977 |
| Grant date | Mar 18, 1980 |
| Priority date | — |
| Expiry date | Nov 9, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/28
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention is an integrated front end circuit for a VHF receiver including a high frequency grounded base amplifier, a mixer having a differential type amplifier, a constant current type oscillator, and a bias circuit. In the mixer, a resistor is inserted between common emitters of the transistors of a differential amplifier and the collector of a constat current transistor driving the differential amplifier. In order to keep the oscillation frequency constant during a change in source voltage, there is provided a certain relation between the change in source voltage and the driving current of the oscillator by means of a bias circuit. The collectors and bases of the transistors used for the high frequency amplifier, the differential amplifier and the oscillator use the same D.C. potential. The integrated front end circuit of the invention may be used, for example, as the front end of an FM portable radio receiver, and it is very desirable for practical use because it realizes sure operation even at a low voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.