Fujitsu Corporation

Manabu Ogino

Akira Nanba

Susumu Nikawa

Kenichi Ogura

Toshinari Fukuda

The present invention is intended to improve the receiving performance of a loop antenna to be connected to an IC chip that is incorporated in an IC card or a portable cellular phone. A loop antenna that is connected to an IC chip which has a CPU and a memory mounted thereon and which is incorporated in a casing, and that transmits or receives predetermined electromagnetic waves to or from a reader writer includes a main loop antenna and at least one sub-loop antenna disposed away from the main loop antenna. The sub-loop antenna is connected to the IC chip in parallel with or in series with the main loop antenna. A transmission/reception frequency at which the sub-loop antenna transmits or receives electromagnetic waves may be different from the one at which the main loop antenna transmits or receives electromagnetic waves.

Loop antenna and electronic equipment including loop antenna

The digital phase locked loop circuit according to the invention includes a GAC circuit () for calculating the average frequency of the phase locked sampling clock signals in selected channels and for feeding back the calculated average to the phase locked loop. The GAC circuit () includes comparators () for comparing the frequency of the sampling clock signals in each channel with an allowable frequency range and for outputting a frequency error signal with respect to any channel in which the frequency of the sampling clock signals is outside the allowable frequency range.

Growing community of inventors

Kato-gun, Japan

Manabu Ogino