Abstract: A dielectric antenna duplexer used in a high frequency radio device such as a portable telephone, and a dielectric filter for forming the duplexer of the SIR (stepped impedance resonator) composed by cascade connection of first transmission lines having one end grounded and second transmission lines having one end open and lower in characteristic impedance than in the first transmission lines, first transmission lines and second transmission lines are individually coupled in electromagnetic field, thereby forming an antenna duplexer and a dielectric filter of small insertion loss, high bandwidth selectivity, excellent band pass characteristic, and low cost.

Abstract: A dielectric antenna duplexer used in a high frequency radio device such as a portable telephone, and a dielectric filter for forming the duplexer of the SIR (stepped impedance resonator) composed by cascade connection of first transmission lines having one end grounded and second transmission lines having one end open and lower in characteristic impedance than in the first transmission lines, first transmission lines and second transmission lines are individually coupled in electromagnetic field, thereby forming an antenna duplexer and a dielectric filter of small insertion loss, high bandwidth selectivity, excellent band pass characteristic, and low cost.

Abstract: An inexpensive high-frequency circuit device and its electronic component which allows two traces or lines to cross on the same surface without affecting other circuits characteristics. At least one of the lines is a high-frequency signal line.

Abstract: A dielectric antenna duplexer used in a high frequency radio device such as a portable telephone, and a dielectric filter for forming the duplexer of the SIR (stepped impedance resonator) composed by cascade connection of first transmission lines having one end grounded and second transmission lines having one end open and lower in characteristic impedance than in the first transmission lines, first transmission lines and second transmission lines are individually coupled in electromagnetic field, thereby forming an antenna duplexer and a dielectric filter of small insertion loss, high bandwidth selectivity, excellent band pass characteristic, and low cost.

Abstract: An antenna switching apparatus for selectively connecting an antenna to either a transmitter for transmitting a transmitting signal having a transmitting frequency, or a receiver for receiving a receiving signal having a receiving frequency, which is different from the transmitting frequency, includes an antenna terminal electrically connected to the antenna; a transmitting terminal electrically connected to the transmitter, and a receiving terminal electrically connected to the receiver. A receiving filter for passing a receiving signal therethrough is electrically connected between the antenna terminal and the receiving terminal. An impedance adjusting element is electrically connected to an input end of the receiving filter, and has an element value such that an impedance when seen from the antenna terminal looking toward the receiving filter becomes substantially infinity at the transmitting frequency.

Abstract: This invention offers a compact and high performance dielectric filter consisting of a quarter wavelength dielectric body provided with a through-hole between the upper and lower surfaces of the dielectric body, electrodes deposited on external and lower surfaces of the dielectric body, and at least two independent electrodes provided on an internal surface of the through-hole, extending to the upper and lower surfaces of the dielectric body. With this dielectric filter construction, the through-hole performs the role of constructing plural quarter wavelength resonators and performs, at the same time, the role of adjusting the coupling between the plural resonators, thus yielding a compact dielectric filter of simple construction.

Abstract: This invention relates to a compact and high performance microwave stripline resonator consisting of a dielectric substrate provided with a strip electrode and a depression coated with an electrode which is connected to an end of the strip electrode provided on one of the surfaces of the dielectric substrate and a grounding electrode provided on the other surface of the dielectric substrate, and the grounding electrode is connected to the other end of said strip electrode. With this dielectric resonator construction, the characteristic impedance of the strip electrode and the characteristic impedance of the electrode coated on the depression are made different. As a result of this, the length of microwave stripline can be shortened without sacrificing the Q of the resonator. This is highly effective to realize compact resonators.

Abstract: A dielectric resonator includes a resonator body having a groove formed in its upper surface adjacent to an outer periphery of a through hole formed through the body. An electrically-conductive film on the inner surface of the groove is electrically connected to an electrically-conductive film formed on the inner peripheral surface of the through hole, via an electrically-conductive film formed on a portion of the upper surface of the body lying between the groove and the through hole. The groove having the electrically-conductive film formed on its inner surface enables the length of the body to be reduced and the overall resonator to have a reduced size.

Abstract: A quartz vibrator mounted on a terminal substrate member having a through-hole. The ratio of through hole area being from 0.5 to 0.8 of the vibrators electrode area. Fine frequency adjustment is obtained by evaporation of material thru the through hole.