| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a filter cover having only a small degree of electromagnetic effect to a dielectric resonator and capable of elongating the life of a press die long without a loss of isolation between transmission and reception. <P>SOLUTION: The dielectric resonator, a high-frequency transmitter connected to the dielectric resonator, a base to which the dielectric resonator and the high-frequency transmitter are to be mounted, and a base are jointed together. A cover covers the dielectric resonator and the high-frequency transmitter. The distance between the surface of the cover in the direction of the presence of the dielectric resonator and the surface of the base in the direction of the presence of the dielectric resonator is the 1/2 effective wavelength of the frequency of the oscillator or shorter. The cover comprises periodic recesses and protrusions of the 1/4 effective wavelength of the frequency of the oscillator in the direction of the presence of the dielectric resonator to form a VCO (Voltage-Controlled Oscillator). In the VCO, the most proximate distance between at least the surface of the dielectric resonator in the direction of the presence of the cover and the surface of the cover in the direction of the presence of the dielectric resonator is the 1/4 effective wavelength of the frequency of the oscillator or longer. <P>COPYRIGHT: (C)2004,JPO |
