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. 13, 2001
Filed:
Mar. 04, 1998
Fumihito Tomaru, Higashikurume, JP;
Hitachi Denshi Kabushiki Kaisha, Tokyo, JP;
Abstract
A fractional-N system frequency synthesizer and a field pickup unit which uses the synthesizer and adapts to a plurality of different channel frequencies in a microwave band. The synthesizer is made up of a fractional control unit which in turn is made up of a modulo-m counter which counts signals of a predetermined frequency fed from a reference oscillator, a channel setting unit for setting a required channel frequency in a predetermined frequency band and for outputting data on the set channel frequency, a memory which stores information on a dividing ratio at an address determined by the count of signals counted by the modulo-m counter and the data on the set channel frequency outputted by the channel setting unit, wherein switching pulses each for selecting a dividing ratio in a dual modulus prescaler are dispersively arranged at equal intervals in the counting period of the modulo-m counter. The field pickup unit is made up of a transmitter and a receiver. A transmission high-frequency unit of the transmitter and a reception high-frequency unit of the receiver each have a fractional-N system frequency synthesizer which frequency-converts an intermediate frequency signal of 1.5 GHz to a signal in a transmission/reception microwave frequency band.