Hiroki Kojima

Title: Hiroki Kojima: Innovator in Variable Capacitor Technology

Introduction

Hiroki Kojima is a prominent inventor based in Otsu, Japan. He has made significant contributions to the field of electronics, particularly in the development of variable capacitors and frequency synthesizers. With a total of 2 patents to his name, Kojima's work has had a notable impact on modern electronic devices.

Latest Patents

Kojima's latest patents include a variable capacitor element and an integrated circuit featuring a variable capacitor element. The variable capacitor element consists of a buried electrode layer of a different conductivity type from the semiconductor substrate, along with a wiring layer connected to the lead portion of the buried electrode layer. This innovative design allows for a change in capacitance value by adjusting the voltage between the buried electrode layer and the conductor layers, while also reducing parasitic capacitance between the variable capacitor elements.

Another significant patent is the fractional-N frequency synthesizer with multiple clocks having different timings. This device includes a PLL circuit and a frequency-division ratio control circuit. The PLL circuit features a phase comparator, low-pass filter, voltage-controlled oscillator, and a variable frequency divider. The frequency-division ratio control circuit adjusts the variable frequency divider's ratio over time, ensuring that the average value remains below a decimal point. This design minimizes variations in substrate potential and power supply voltage, thereby enhancing the performance of the frequency synthesizer.

Career Highlights

Kojima is currently employed at Matsushita Electric Industrial Co., Ltd., where he continues to innovate in the field of electronics. His work has been instrumental in advancing technologies that are essential for modern communication and electronic systems.

Collaborations

Throughout his career, Kojima has collaborated with notable colleagues, including Hisashi Adachi and Yukio Hiraoka. These partnerships have fostered a creative environment that has led to groundbreaking advancements in their respective fields.

Conclusion

Hiroki Kojima's contributions to variable capacitor technology and frequency synthesizers highlight his role as a key innovator in the electronics industry. His patents reflect a commitment to enhancing electronic device performance and functionality.