HIGH FREQUENCY SUPPRESSING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To miniaturize a high frequency suppressing circuit of fundamental waves and tertiary higher harmonic waves by setting an electric length at the prescribed frequency of a second high frequency transmission line to a specified value within a specified range, and respectively setting the capacitance values of first and second capacitors to respective specified values having prescribed errors. SOLUTION: An electric lengthθ1 at a frequency f0 of a high frequency transmission line 4 is set to tan<-1> (((αβ+((αβ))<2> +4)<(1/2)> )/2)<(1/3)> +((αβ-((αβ)<2> +4)<(1/2)> )/2)<(1/3)> . Here, with an ideal value represented byα=Z2 /Z1 andβ=(3tan<5>θ2 +5tanθ2 )/(5tan<2>θ2 +1) as a center, the length has a value determined by characteristic impedances Z1 and Z2 and an electric lengthθ2 within the range of the prescribed errors and a range of 0<θ1 <π/2. Capacitance values C1 and C2 of capacitors 5 and 6 are set within the prescribed error range with C1 =1/2π.f0 Z1 .tanθ1 ) and C2 =1/(6π.f0 .Z2 .tan(3θ2 )) as central values.