A History of Microwave Filter Research, Design, and Development

An account of the development of microwave filters is surveyed, commencing from 1937. Much of the foundation of modem filter theory and practice took place during the period of World War II and the years immediately following, especially by such pioneers as the late P. I. Richards, whose subsequent career is briefly described. Filter topics discussed include low-pass, bandpass, high-pass, and multiplexers constructed in a variety of media such as waveguide, coaxial line, microstrip, and stripline, as well as dielectric resonators. All types of filter characteristics are surveyed, such as Chebyshev, elliptic and pseudo-elliptic function, Achieser-Zolotarev, and a variety of generalized designs, including linear phase.