Logarithmic amplifier with universal demodulation capabilities
US9397382B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2014 |
| Grant date | Jul 19, 2016 |
| Priority date | — |
| Expiry date | Mar 14, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/294
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A logarithmic amplifier (LDA) is described that includes an amplifier configured to oscillate a modulated input signal, a feedback establishing a 180 degree phase shift between the amplifier input and the output and maintaining oscillation of the input signal, a parallel resonant circuit connected to the amplifier output causing the amplifier to resonate at or around a center frequency, and a controller connected to the amplifier input cyclically terminating oscillation of the input signal each time a pre-determined threshold of current is detected, the controller including a low pass filter configured to generate a second output signal having a repetition frequency. The LDA may be used for AM with or without a PLL and/or a superhetrodyne. The LDA may be implemented as a mixer and used for phase demodulation. The LDA may be used for phase demodulation. The LDA may be used in place of a low noise amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.