PURPOSE: To improve the out-band impedance and to suppress spurious resonance by constituting the resonator with a transmission line, a dielectric substance placed in a cavity of a case and a loop antenna coupled with this dielectric substance through magnetic field.
CONSTITUTION: The dielectric resonator comprising the transmission line 3, the dielectric substance 1 placed in the cavity 2b of the case 2 and the antenna 5 coupled through magnetic field to this dielectric substance 1 is connected by the loop antenna at a phase viewed as series resonance from the transmission line 3. Since a high impedance is shown from the transmission line 3 to the loop antenna 5 in a band of f0±Δf parted by Δf from the center frequency f0 in this constitution, the impedance does not almost give effect on the characteristic impedance of the transmission line 3. Thus, the out-band impedance is improved and also spurious resonance is suppressed and the number of adjusting screws of the transmission line 3 is reduced.
OOYAMA HIROSHI
NISHIDA HARUKI
SOGOU HIROYUKI
