The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 05, 1978
Filed:
Nov. 30, 1977
Robert A Frosch, , US;
Victor S Reinhardt, Gaithersburg, MD (US);
Peter O Cervenka, Rockville, MD (US);
Other;
Abstract
A maser functioning as a frequency standard stable to one part in 10.sup.14 includes a variable volume, constant surface area storage bulb having a fixed volume portion located in a resonant cavity from which the frequency standard is derived. A variable volume portion of the bulb, exterior to the resonant cavity, has a maximum volume on the same order of magnitude as the fixed volume bulb portion. The cavity has a length to radius ratio of at least 3:1 so that the operation is attained without the need for a feedback loop. A baffle plate, between the fixed and variable volume bulb portions, includes apertures for enabling hydrogen atoms to pass between the two bulb portions and is an electromagnetic shield that prevents coupling of the electromagnetic field of the cavity into the variable volume bulb portion. The maser is operated so that the zero wall shift frequency thereof can be determined by being operated at first and second very accurately controlled temperatures for identical small and large volumes. From the two temperatures and volumes, the zero wall shift frequency is determined as the intersection of two straight lines.