Michihisa Ohkawa

Title: Michihisa Ohkawa: Innovator in Satellite Communication Technology

Introduction

Michihisa Ohkawa is a prominent inventor based in Tokyo, Japan. He has made significant contributions to the field of satellite communication, holding a total of 5 patents. His work has focused on enhancing communication systems, particularly through the use of advanced technologies.

Latest Patents

One of Ohkawa's latest patents is a satellite communication system that facilitates communication among multiple small earth stations, known as very small aperture terminals (VSAT). This system utilizes a relay earth station with higher power than the small earth stations to improve signal transmission. The communication process involves a two-hop propagation method, where signals travel from the originating small earth station to the destination small earth station via a satellite and a relay earth station. The system employs digital communication, with the relay earth station regenerating digital signals and applying error correction techniques to minimize error rates. Additionally, a frequency compensation technique is utilized to ensure high-quality communication with a favorable carrier-to-noise ratio (C/N). A reference clock signal for the operation of the small earth station is derived from a reception signal from the satellite.

Another notable patent involves a phase synchronization circuit within a phase lock loop. This circuit features a phase comparator with hysteresis characteristics, which provides distinct output levels for each input phase difference based on the direction of phase error. This innovation enhances the stability and performance of the phase lock loop, particularly in maintaining synchronization.

Career Highlights

Throughout his career, Michihisa Ohkawa has worked with notable companies, including Kokusai Denshin Denwa Co., Ltd. and Kokusai Denshin Denwa Kabushiki Kaisha. His experience in these organizations has contributed to his expertise in satellite communication technologies.

Collaborations

Ohkawa has collaborated with esteemed colleagues, including Tatsuo Watanabe and Toshio Mizuno. Their joint efforts have further advanced the field of satellite communication.

Conclusion

Michihisa Ohkawa's innovative contributions to satellite communication technology have established him as a key figure in the industry. His patents reflect a commitment to improving communication systems, ensuring high-quality and reliable connections. His work continues to influence advancements in satellite communication.