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US 6,714,772 B2Granted
Wireless communication system
AssigneeRenesas Technology Corp.
InventorsMasumi Kasahara, Koichi Yahagi
Life of this patent
Estimating the term…
Abstract
A wireless communication system, which is provided with a PLL circuit having a plurality of oscillators and is capable of processing two or more transmit and receive signal different in frequency band from one another according to the switching between the oscillators, has a reset means which resets a voltage applied to each of filter capacitors lying within the PLL circuit to a predetermined voltage when the switching between the oscillators is performed.
Claims11
A wireless communication system comprising:
- a reception system circuit which processes a signal received by an antenna;
- an oscillation system circuit including a PLL circuit which generates local oscillation signals each merged with the signal processed by said reception system circuit, said PLL circuit having a phase comparator which detects the difference in phase between a frequency signal defined as the reference and a feedback signal, a charge pump which generates a voltage in response to the phase difference detected by said phase comparator, filter capacitors, and a plurality of oscillators which oscillate based on voltages of the filter capacitors;
- control means which controls said reception system circuit and said oscillation system circuit;
- and
- setting means which sets the voltage applied to said each filter capacitor to a predetermined voltage, based on a signal outputted from said control means, when switching is made between said oscillators.
2 more elements
Dependencies are inferred from the claim text.