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AssigneeHitachi Denshi Kabushiki Kaisha
InventorFumihito Tomaru
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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.
A fractional-N system frequency synthesizer comprising:
A frequency synthesizer comprising:
A field pickup unit for digital signal transmission, comprising:
A field pickup unit for digital signal transmission, comprising:
A frequency synthesizing method comprising the steps of:
A frequency synthesizing method comprising the steps of:
Dependencies are inferred from the claim text.