Editorial: A recognition of Japanese contributions to circuit theory

In the first paper of this issue, the attention of our membership is directed to some remarkable results published by H. Takahasi in 1951. It appears that unbeknownst to most of us, Takahasi gave at that time a complete and unified solution of a family of filter problems for which piecemeal results have been sprinkled through the literature for the last third of a century. The objective of this species of problem was to obtain closed-form solutions for design of wave filters with resistive terminations. Two general approaches emerged which may be descriptively designated as the "maximally flat" and "equal ripple" cases. These terms apply to the way constant loss was approximated in the pass band. The reader may further observe that the second and third articles in this issue also deal with contributions from Japan. This does not signify that a special issue has been attempted, but rather that this order for the regularly accepted papers has been chosen as a reminder of the steady flow of high level contributions from Japanese authors which has continued since the beginning of our journal.