Logarithmic amplifier calibration means
US4335384A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 10, 1980 |
| Grant date | Jun 15, 1982 |
| Priority date | — |
| Expiry date | Jan 10, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S3/023
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A logarithmic amplifier calibrator having a signal generator providing an exponentially decaying calibration signal and a pulse generator providing a sample pulse each time the calibration signal has decayed by a predetermined decibel (db) increment. More specifically, the calibrator includes a crystal which is excited to an energy level through a feedback loop having an amplification means whose gain is controlled by a voltage controlled attenuator. The decay characteristics of the crystal when installed in the calibrator are determined so that the time required for the crystal to decay over an entire calibration range is known. This time is then divided into a plurality of time increments, each time increment corresponding to a predetermined db drop in the calibration signal. Sample pulses derived from a high frequency, high stability oscillator in the calibrator are developed to correspond to each of the predetermined time increments. The calibration signal is amplified by a logarithmic amplifier to be calibrated, and its output values at the time of each sample pulse provides a plurality of calibration points which can be utilized by a computer to compensate for non-theoretical…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.