Center-tapped coil-based tank circuit for a balanced mixer circuit
US5140705A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1990 |
| Grant date | Aug 18, 1992 |
| Priority date | — |
| Expiry date | Jun 13, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D2200/0043
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An RF tank circuit includes a coil with a center tap, the RF tank circuit being for receving an input RF signal, and for providing a balanced mixer circuit by being arranged in one of: a) receiving a local signal through second and third capacitors at first and second coil ends, respectively, with the center tap grounded; and, b) receiving a local signal at the center tap. An impedance is connected between the first and second coil ends of the RF tank circuit, the impedance providing low impendance for a predetermined intermediate frequency signal, and high impedance for a predetermined high frequency signal and a local signal. A bias resistor is connected between a middle connecting point of the impedance and ground. The coil of the RF tank cicuit can be one of a primary and second winding of an isolation transformer, with a remaining one of the primary and secondary windings being connected to an RF signal source, the isolation transformer being for preventing a leakage of a local signal to the RF signal source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.