Henry John Orchard
Encyclopedia
Henry John Orchard was a professor emeritus of electrical engineering at the UCLA Henry Samueli School of Engineering and Applied Science
and an authority on filter design and network theory. He died June 23 of 2004 at his home in Santa Monica
of respiratory failure
. He was 82.
In a monumental breakthrough publication (Electronics Letters, 1966), he explained the "secret" behind the low passband sensitivity of doubly loaded reactance two-ports and showed how to design active two-ports that retain this key attribute. Among Professor Orchard's key contributions was the development of a systematic process for the computer-aided design
of filters. During the early years of computer-aided filter design, when the synthesis of a single circuit required several days of multiple-precision computation, his method had an important beneficial effect. He was instrumental in introducing into switched capacitor
filter design the bilinear s-z mapping, previously used solely in digital filter design, and in developing a methodology that allowed the use of arbitrary active-RC models for switched-capacitor filter syntheses.
Henry Samueli School of Engineering and Applied Science
The Henry Samueli School of Engineering and Applied Science at the University of California, Los Angeles was opened with an enrollment of 379 students in the fall of 1945. It opened as the College of Engineering until it was changed to school on February 21, 1969. The School now has seven...
and an authority on filter design and network theory. He died June 23 of 2004 at his home in Santa Monica
Santa Mônica
Santa Mônica is a town and municipality in the state of Paraná in the Southern Region of Brazil.-References:...
of respiratory failure
Respiratory failure
The term respiratory failure, in medicine, is used to describe inadequate gas exchange by the respiratory system, with the result that arterial oxygen and/or carbon dioxide levels cannot be maintained within their normal ranges. A drop in blood oxygenation is known as hypoxemia; a rise in arterial...
. He was 82.
In a monumental breakthrough publication (Electronics Letters, 1966), he explained the "secret" behind the low passband sensitivity of doubly loaded reactance two-ports and showed how to design active two-ports that retain this key attribute. Among Professor Orchard's key contributions was the development of a systematic process for the computer-aided design
Computer-aided design
Computer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
of filters. During the early years of computer-aided filter design, when the synthesis of a single circuit required several days of multiple-precision computation, his method had an important beneficial effect. He was instrumental in introducing into switched capacitor
Switched capacitor
A switched capacitor is an electronic circuit element used for discrete time signal processing. It works by moving charges into and out of capacitors when switches are opened and closed. Usually, non-overlapping signals are used to control the switches, so that not all switches are closed...
filter design the bilinear s-z mapping, previously used solely in digital filter design, and in developing a methodology that allowed the use of arbitrary active-RC models for switched-capacitor filter syntheses.