Push-pull amplifier output circuit
US4167709A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 17, 1978 |
| Grant date | Sep 11, 1979 |
| Priority date | — |
| Expiry date | Mar 17, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/26
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A high frequency push-pull amplifier which includes an improved output circuit to eliminate spurious emissions, typically low frequency parametric oscillations. The output circuit includes a low pass filter with an inductive input so as to avoid a series resonance to any harmonic of the desired output signal of the amplifier. A resistive termination is provided to any of the in phase signal components between the push-pull amplifier and the low pass filter. Also, to inhibit any tendency towards parametric oscillations, the variation in output capacitance with respect to collector voltage of the transistors is minimized by placing a capacitor in parallel with the collector capacitance, which is several times the collector to emitter capacitance of the transistors at their normal collector voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.