Abstract: A surface mounting antenna in which non-contact excitation can be achieved via a capacitor, and easy impedance matching can be provided even when the antenna is downsized. A communication apparatus loaded with the above antenna is also disclosed. A radiation electrode is disposed on the obverse surface of a substrate. A ground electrode is formed on substantially the overall area of the reverse surface of the substrate. The radiation electrode is connected at one end to the ground electrode via a first end surface of the substrate, and extends at the other end to the portion adjacent to a second end surface opposedly facing the first end surface so as to form a free end. An excitation electrode is disposed to face the forward end of the free end of the radiation substrate across a gap g and to extend from the obverse surface of the substrate to the reverse surface via the second end surface of the substrate.

Abstract: A substantially-rectangular-prism-shaped base member is made from at least one of a dielectric material and a magnetic material. A radiation electrode is formed on a surface of the base member such that the electrode is routed from one end face of the base member to the opposing end face through a main surface, changes direction on the end face, and then is routed from the end face to the former end face through the main surface in an almost gate-shaped path. A gap is provided at a part of the radiation electrode, which divides the electrode. With this configuration, a surface mounting antenna is made. This surface mounting antenna is placed on a printed circuit board. One end of the radiation electrode is connected to a power-supplying electrode on the printed circuit board and the other end of the radiation electrode is connected to a ground electrode on the printed circuit board by soldering or adhesion. Then, an antenna apparatus is formed.

Abstract: A surface mounting antenna in which easy formation of a radiation electrode can be achieved by forming it on the surface of a substrate, and also the antenna can be downsized by bending the radiation electrode. A communication apparatus using the above antenna is also disclosed. A ground terminal and a feeding terminal are separately disposed on one lateral surface. A loading capacitor electrode is formed on another lateral surface opposedly facing the surface on which the ground terminal and the feeding terminal are disposed. A stripline radiation electrode is further formed on the obverse surface of the substrate and is connected at the respective ends to the ground terminal and the loading capacitor electrode. A feeding electrode for connecting the matching portion of the radiation electrode and the feeding terminal is disposed on the obverse surface of the substrate.

Abstract: A surface-mount antenna using a dielectric base of a relatively low dielectric constant to obtain a wide frequency band and a small size. There is also disclosed a communication device using such a surface-mount antenna. The antenna comprises a dielectric base provided with at least one hole extending through the base between two opposite end surfaces of the base. A radiating electrode is formed in the hole. One end of the radiating electrode is connected with a grounding electrode which is formed at one end surface of the dielectric base. The other end of the radiating electrode is connected with a feeding terminal via a capacitor.

Abstract: A method of regulating the resonance frequency of a surface-mountable antenna includes (a) a step of preparing a surface-mountable antenna including a substrate which is made of a dielectric material, a groove which is formed on an upper surface of the substrate to have end portions at a pair of opposite end surfaces of the substrate, a radiating electrode which is formed on the inner peripheral surface of the groove, a feeding electrode which is formed on one of the pair of opposite end surfaces of the substrate and connected with the radiating electrode, a ground electrode which is formed on one of the pair of end surfaces and insulated from the feeding electrode, and an end electrode which is formed on the other one of the pair of opposite end surfaces of the substrate, and (b) a step of either (1) partially trimming the radiating electrode, the ground electrode or the end electrode, or (2) mounting a dielectric member on the substrate, for changing the resonance frequency of the surface-mountable antenna.

Abstract: A surface-mount-type antenna that is capable of being surface-mounted on a printed circuit board includes a dielectric substrate, a through-hole formed within the dielectric substrate and having its openings in opposed side surfaces of the dielectric substrate, a radiation electrode formed in the inner periphery of the through-hole, a feeding electrode, and side electrodes formed on the side surfaces in which the through-hole has its openings. The antenna can be placed on a printed circuit board having an electrode pattern, and the feeding electrode and the electrode pattern can be soldered together to thereby surface-mount the antenna on the printed circuit board.

Abstract: A surface-mountable antenna is mounted on a substrate at one surface of its dielectric substrate, and is supplied with an RF signal by a feeding part which is provided on the substrate. The dielectric substrate is provided with one feeding through hole and at least one auxiliary through hole in parallel with each other, while a radiating electrode is formed on the inner peripheral surface of the feeding through hole. Further, end electrodes are formed on a surface of the dielectric substrate around the feeding and auxiliary through holes respectively, while an auxiliary electrode is formed on the inner peripheral surface of the auxiliary through hole. Due to this structure, it is possible to provide an antenna which is surface-mountable, has a high gain and controllable directivity.

Abstract: A broad-band mixing circuit comprises a transmission line transformer connected between a port adapted to receive a radio frequency signal and a double balanced mixing section, the transformer serving to convert an unbalanced radio frequency signal into a balanced signal, a transmission line transformer connected between a local oscillation signal port and the mixing section, the transformer serving to convert an unbalanced local oscillation signal into a balanced signal, and a transmission line transformer connected between the mixing section and an intermediate frequency signal port, the transformer serving to convert the balanced signal from the mixing section into an unbalanced signal. The noise figure is improved by connecting an electrolytic capacitor in parallel with the balanced output end or the input end of the transmission line transformer for the local oscillation signal.

Abstract: A broad-band mixing circuit comprises a transmission line transformer connected between a port adapted to receive a radio frequency signal and a double balanced mixing section, the transformer serving to convert an unbalanced radio frequency signal into a balanced signal, a transmission line transformer connected between a local oscillation signal port and the mixing section, the transformer serving to convert an unbalanced local oscillation signal into a balanced signal, and a transmission line transformer connected between the mixing section and an intermediate frequency signal port, the transformer serving to convert the balanced signal from the mixing section into an unblaanced signal. The noise figure is improved by connecting an electrolytic capacitor in parallel with the balanced output end or the input end of the transmission line transformer for the local oscillation signal.