Akira Ishimaru

Akira Ishimaru passed away quietly and peacefully on November 10, 2025 in Newcastle, Washington, surrounded by his family. He was 97 years old. He is survived by his beloved wife of 68 years, Yuko; their four children John Ishimaru, Jane Riley (Chuck), Jim Ishimaru (Karen), and Joyce Walborn (Gene); his seven grandchildren Katie von Geldern (Will), Patricia Hurst (Chad), Andrew Ishimaru, Eric Ishimaru (Anne Marie), Aaron Ishimaru, Ben Walborn (Natalie), and Emily Walborn; and his four great-grandchildren Grace Hurst, Olivia Hurst, Theo von Geldern, and Niko von Geldern. He also leaves behind his younger brother Tohru and many other relatives in Japan.

We are all very grateful that he was able to be at home with his wife during this time, and that he was in no pain.

Dr. Ishimaru was born in Fukuoka, Japan, on March 16, 1928. At an early age he developed an interest in mathematics and science, and then began to study engineering. He graduated from the University of Tokyo with a Bachelor’s degree in Electrical Engineering in 1951. He was then awarded a Fulbright scholarship to study in the United States, and entered the doctoral program at the University of Washington (UW) in 1952. He graduated in 1958, becoming the first student to earn a Ph.D. in the UW Electrical Engineering department.

Following graduation, he began his professional academic career as an assistant professor in Electrical Engineering at the UW, became a full professor in 1965, then received a joint appointment with the department of Applied Mathematics in 1977. He retired in 1998, and continued to be active in research as Professor Emeritus until his passing. The UW Electrical and Computer Engineering department was Dr. Ishimaru's "second home" for over 70 years, supporting and encouraging him in his work as a student, teacher, and researcher.

He had an endless passion for his work that led to a lifetime of professional achievements. Dr. Ishimaru was acknowledged as one of the world’s preeminent experts in the field of electromagnetic wave propagation in random and complex media. His theoretical and applied research in this field helped lay the groundwork for technological advances and applications in a variety of areas such as medical imaging, satellite communications and cellular communications, remote sensing, laser surgery, radar systems, and astronomy.

During his career Dr. Ishimaru was recognized with numerous awards and honors for his work, including the Institute of Electrical and Electronics Engineers (IEEE) Heinrich Hertz Medal in 1999 in recognition of his work in electromagnetic waves, and the International Union of Radio Science (URSI) John Howard Dellinger Gold Medal in 1999 for outstanding achievements in the field of radio science. In 1996 he was elected to the National Academy of Engineering (NAE) for “contributions to the theory and application of wave propagation and scattering in random media”. He was a Fellow of IEEE, the Optical Society of America, the Acoustical Society of America, and the Institute of Physics, and in 2020 he was inducted as an URSI Lifetime Fellow. In 2025, he was selected as one of the “Legends of Electromagnetics” by the IEEE Antennas and Propagation Society.

He authored two advanced electromagnetics textbooks, including “Wave Propagation and Scattering in Random Media”, which is acknowledged as a groundbreaking work in the field that comprehensively combined fundamental theory with applications spanning a variety of disciplines. Perhaps his most lasting professional legacy is the many outstanding students he had the opportunity to work with during his long academic career. Those students in turn pursued their own work and made their mark in both academia and industry.

While his family was extraordinarily proud of his professional accomplishments, they were even more appreciative of his devotion to his family. No matter how busy he was at the UW, he always made the time to actively participate in his children’s lives, wholeheartedly support their endeavors and interests, and rejoice in all the milestones of their childhoods. He loved his wife deeply, and wholeheartedly supported her in everything she did. He loved his grandchildren and was so proud of the kind and wonderful persons they are. And he always lit up whenever he was around his four great-grandchildren Grace, Olivia, Theo, and Niko. He loved each of their unique and delightful personalities, and enjoyed speculating about the wonderful things they were all destined to accomplish as they grew up.

His kind and caring nature, commitment to his work, strength of character, and principled personal beliefs will always be an inspiration to his family and others who knew him.

A memorial service will be held on Saturday November 29 at 2:00 pm at Sunset Hills Memorial Park & Funeral Home, 1575 SE 145th Place SE, Bellevue, Washington.

In lieu of flowers, please consider making a donation in Dr. Ishimaru’s memory to the Chair’s Fund for Excellence in Electrical & Computer Engineering at the University of Washington (https://www.washington.edu/giving/make-a-gift/).