Abstract: An analog Viterbi decoder realizes a part of the signal processing operations necessary to produce a decoded signal by, for example, calculation of branch metrics in branch metric calculation circuit, and addition, comparison, and selection an ACS circuit, using analog signal processes, to remarkably decrease the number of elements, and to realize a high speed Viterbi decoder with a relatively small size.

Abstract: A dielectric filter in which a plurality of holes are made at predetermined intervals in a dielectric block of small dielectric loss, and a conductor film is formed on the surface of the dielectric block including the interior surfaces of the holes to constitute resonators using the conductor film on the interior surface of each hole as an inner conductor of the resonator and the conductive film on the outer peripheral surface of the dielectric block as an outer conductor, the resonance frequency of the resonators being based on the depth of each hole.