PURPOSE: To obtain a small strip line filter high in Q by inductive coupling an active element near the short-circuit end of a λ/4 strip resonator and operating it by negative resistance in the state of resonance.
CONSTITUTION: An end of a λ/4 strip resonator 18 is connected to a main strip line 14 by a gap capacity formed by a gap 16 and an active element 20 is cou pled near the short-circuit end of the λ/4 strip resonator 18 by mutual induction by a strip line 22 for phase regulation. The active element 20 operates in the attenuation area, that is, resonance area and shows negative resistance (-r). That is, the active element 20 has ability to supply energy to a resonator 18 in resonance frequency of the λ/4 strip resonator 18. As energy loss consumed by the λ/4 strip resonator 18 is canceled by energy supplied by this way, no-load Q(Qo) of the resonator becomes high equivalently.
| JP2002076706 | FILTER CIRCUIT |
| JP5715701 | antenna |
TANAKA HIROAKI
MICROWAVE FILTERS IMPEDNCE MATCHING NETWORK AND COUPLING STRUCTURE=1964
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