Reflection loss suppression circuit

摘要

An object is to suppress a reflection loss in any desired frequency band outside a required band, without affecting circuit characteristics in the required frequency band. The output impedance of a circuit in a specified frequency band is transformed into a high impedance by a transmission line 15 . A resistance grounding circuit 18 having a frequency selectivity is connected in parallel. The resistance grounding circuit 18 is constructed of a resistor 16 which has a resistance close to a load resistance, a capacitance C which is selected so as to satisfy an equation Im[tan h{gamma(lambda/2-delta)}]=-omega₀CZ₀ at an angular frequency omega₀ included in the frequency band, and a (lambda/2-delta)-long end-open stub.