Dual state phase detector having frequency steering capability
Patent 4959617 Issued on September 25, 1990. Estimated Expiration Date: 
May 30, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 30, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesPhase velocity sign detector for frequency shift key demodulation Sampling average phase meter Phase-locked loop with redundant reference input Patent #: 4868513 InventorAssigneeApplicationNo. 357912 filed on 05/30/1989US Classes:327/12, With logic or bistable circuit327/3Comparison between plural inputs (e.g., phase angle indication, lead-lag discriminator, etc.)ExaminersPrimary: Callahan, Timothy P.Attorney, Agent or FirmInternational ClassesH03K 009/06H03D 013/00 AbstractA digital phase detector for providing an output characterized by the phase difference of a first input signals and a second input signal is provided. The phase detector comprises a first and a second dual state phase detector, each providing an output having a duty cycle corresponding to the phase difference of the input signals. The phase detectors operate linearly for a range of 360 degrees of phase difference, and provide a signal when the phase diference between the two input signals has exceeded the 360 degree range. The first phase detector provides the phase difference of the first and second input signals, while the second phase detector provides the phase difference between the second and the inverse of the first input signal. The output of the phase detector of the invention is provided by the phase detector having the phase difference within the 360 degree range. | |
