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:
Feb. 28, 1989
Filed:
Nov. 23, 1987
Ruy L Brandao, Ft. Lauderdale, FL (US);
Henri Baran, Coral Springs, FL (US);
Arezki Manseur, Boca Raton, FL (US);
Steven R Sweet, Margate, FL (US);
Allied-Signal Inc., Morris Township, NJ (US);
Abstract
The invention comprises a weather radar system in which a magnetron transmitter is controlled in frequency by injecting therein a low power locking signal from a stable frequency source. Frequency lock between the source and the magnetron is maintained without requiring injection signals of excessive power by an automatic frequency control (AFC). The AFC determines the frequency and phase error between the injection signal and the magnetron output and adjusts the frequency of the source so as always to be within a narrow band of frequencies centered about the natural frequency of the magnetron. Over the long term, therefore, the frequency of the source will vary by an amount equal to the change in the natural frequency of the magnetron occurring during that time. Over the short term, however, the difference in frequency between the injection signal and the magnetron output is zero, while the phase difference is less than 90.degree.. The frequency source controlling the magnetron also serves as a frequency source for generating the several local oscillator frequencies required by the system receiver. Thus, the pulse to pulse transmitted signals, return signals and receiver i.f. signals all possess a high degree of phase coherence, readily permitting detection and determination of the doppler frequencies contained in the return signals.