Johns Hopkins University

Darrell A Zinn

Joseph E Sluz

Michael L Dennis

Raymond M Sova

Chun-Huei Bair

Norman H Adams

Eric J Adles

Edward H Darlington

Blair C Fonville

John F Youssef

Jeffrey A Boye

Ian M Hughes

Amit Shah

Adam V Crifasi

Gregory L Weaver

A time transfer modem includes a radio frequency integrated circuit (RFIC), a radio frequency (RF) front end, and processing circuitry. The RF front end is configured to receive and up-convert an input for time transfer with a remote station to generate an up-converted timing signal centered at a select frequency that is outside of a frequency range of interest but within an operational frequency range of the RFIC. The RF front end may also be configured to attenuate, via a pre-selection filter, up-converted adjacent signals to generate a filtered timing signal at the select frequency. The RFIC may be configured to down-convert and digitize the filtered timing signal to generate a digitized timing signal for signal processing by the processing circuitry to determine a clock difference between a local clock signal and the digitized timing signal that originated from the remote station.

Time transfer modem

An optical circuit breaker includes a main optical transmission path including an optical coupler, a delay line and a protection device, and a parallel protection path configured to receive a tapped portion of a signal provided to the main optical transmission path and generate a reference signal based on the tapped portion. The protection device may be configured to be triggered to prevent an overpower condition from passing through the optical circuit breaker responsive to the reference signal exceeding a user selectable threshold. The delay line may be configured to have a longer delay than a time it takes for the protection device to be triggered via the parallel protection path.

Fiber optic circuit breaker

Growing community of inventors

Clarksville, MD, United States of America

Darrell A Zinn