Stabilized microwave-frequency source

US9450673B2 · kind B2 · utility

Assignees

• CALIFORNIA INSTITUTE OF TECHNOLOGY · US
• The United States of America, as Represented by the Secretary of Commerce National Institute of Standards and Technology · US

Inventors

• Kerry Vahala · Pasadena, US
• Scott Diddams · Louisville, US
• Jiang Li · Beijing, CN
• Xu Yi · Pasadena, US
• Hansuek Lee · Daejeon, KR

Key dates

• Filing date: Jan 26, 2015
• Grant date: Sep 20, 2016
• Expiry date: Mar 8, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B2210/006
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

A microwave-frequency source at frequency fM comprises: a dual optical-frequency reference source, an electro-optic sideband generator, an optical bandpass filter, an optical detector, a reference oscillator, an electrical circuit, and a voltage-controlled oscillator (VCO). The sideband generator modulates dual optical reference signals at v2 and v1 to generate sideband signals at v1±n1fM and v2±n2fM. The bandpass filter transmits sideband signals at v1+N1fM and v2−N2fM. The optical detector generates a beat note at (v2−N2fM)−(v1+N1fM). The beat note and a reference oscillator signal are processed by the circuit to generate a loop-filtered error signal to input to the VCO. Output of the VCO at fM drives the sideband generator and forms the microwave-frequency output signal. The resultant frequency division results in reduced phase noise on the microwave-frequency signal.