New rubidium frequency standard designs for telecommunications applications

Rubidium atomic frequency standards are being used increasingly in telecommunication applications, particularly wireless telephony networks. The possibility of frequency stability sufficient to eliminate the need for scheduled re-calibrations, along with small size, low power requirements, wide temperature range operation, and low cost make these devices attractive candidates for telecommunication applications. In this paper, two new Rb frequency standard designs are described which have been optimized for such applications. The first design is a low profile device, in a package less than 1 inch in height. This device is designed to operate over the temperature range -10 to +60 C, with less than 1E-10 frequency error. The second design is a wide temperature range device, which operates from -40 to +85 C, with less than 1E-10 frequency error. This unit employs a thermoelectric cooler to maintain the Rb absorption elements at acceptable temperatures at the high end of the ambient temperature range. These devices are presently in production. In this paper, performance results of production devices are presented, and discussed.