Abstract: A flexible substrate having a meandering antenna element and a matching circuit formed thereon is wound within an antenna cap and mounted on a terminal body. A rod-like antenna is arranged extensible within the flexible substrate. If the rod-like antenna is withdrawn, a linear antenna element is coupled by a capacitive coupling with the matching circuit formed on the flexible substrate. Also, if the rod-like antenna is returned into the terminal body, the capacitive coupling between the linear antenna element and the matching circuit is released, and the meandering antenna element is coupled by a capacitive coupling with the matching circuit on the flexible substrate.

Abstract: Power is supplied to antenna elements of a helical antenna section, which are arranged at an angular distance of 90° therebetween, with a phase difference of 90°. When a reception wavelength is &lgr;, the height of the helical antenna section is 0.6 &lgr; to 0.75 &lgr;, the number of turns, T, of each antenna element is about 1, and the pitch angle &agr; of each antenna element is 50° to 60°. A straight portion with a length corresponding to ¼ of the height of the antenna section is formed at a location corresponding to ½ to ¾ of the height of the antenna section, the height of the antenna section is about 0.3 &lgr; to 0.35 &lgr;, the number of turns, T, is about 1, and the pitch angle &agr; is about 22°.

Abstract: Power is supplied to antenna elements of a helical antenna section, which are arranged at an angular distance of 90° therebetween, with a phase difference of 90°. When a reception wavelength is &lgr;, the height of the helical antenna section is 0.6 &lgr; to 0.75 &lgr;, the number of turns, T, of each antenna element is about 1, and the pitch angle &agr; of each antenna element is 50° to 60°. A straight portion with a length corresponding to ¼ of the height of the antenna section is formed at a location corresponding to ½ to ¾ of the height of the antenna section, the height of the antenna section is about 0.3 &lgr; to 0.35 &lgr;, the number of turns, T, is about 1, and the pitch angle &agr; is about 22°.

Abstract: A cellular phone includes two antennas, namely, a first antenna made as a rod antenna and a second antenna made as a helical antenna. A circuit board is housed in the casing of the cellular phone. The circuit board has an extended board portion which is projected upward from the upper edge and which corresponds in position to the antennas. An impedance matching circuit, which is made as a folded wiring pattern, and a feeding pad are formed on the extended board portion of the circuit board.

Abstract: A antenna of a mobile station is composed of a first antenna section having a helical section and a first contact and a rod-like second antenna section coupled at its one end to the first contact and having a second contact at the other end. When the second antenna section is housed in the casing, the first contact comes to face the internal surface of a feeding terminal with the result that it is capacitive-coupled with a matching circuit. When the second antenna section is pulled out of the casing, the second contact comes in direct contact with the feeding terminal with the result that it is directly connected to the matching circuit. Thereby, the band of resonant frequencies when the antenna is housed in the casing is widened and the antenna gain when the antenna is pulled out of the casing is improved.

Abstract: A multifrequency antenna, which may be used as a built-in antenna of a small and thin radio communication terminal, such as a mobile telephone, is able to receive radio waves of multifrequency bands without enlarging the shape thereof. The antenna is structured using a main mode resonance frequency and a high-order mode resonance frequency of a single-frequency plane antenna with a short-circuit plate. Specifically, a radiator conductor plate in an optional shape is arranged on a ground plate, and the radiator conductor plate is connected to the ground plate via the short-circuit plate. Power is supplied to the radiator conductor plate from a power-feeding source via a feeder cable. In the radiator conductor plate, a cut portion for shifting the high-order mode resonance frequency to the location at a predetermined distance from the short-circuit plate is formed, and the high-order mode resonance frequency is shifted into a desired band by this cut portion.

Abstract: A multifrequency inverted F-type antenna which can receive muntifirequency band radio waves without the enlargement of its shape. A cut-out part (12b) is formed in an emission conductor (12) one end of which is connected to a short-circuit plate (13) planted in a ground conductor (11) and which has a feeding point (12a) to form on the emission conductor (12) a first emission conductor (12-1) and a second emission conductor (12-2) which resonate at respective frequency bands different from each other. By this construction the radio waves of two different frequency bands, i.e. a first frequency band determined by the shape of the first emission conductor (12-1) and a second frequency band determined by the shape of the second emission conductor (12-2), can be received.

Abstract: A patch and a ground conductor are shortcircuited with two shortcircuit portions that are composed of conductive plates and that pass through a dielectric substrate. The shortcircuit portions are connected to the inner periphery of the patch and have large widths therealong. A first shortcircuit portion is disposed on a first line that connects a microstrip feeder line and the center point of the patch. A second shortcircuit portion is disposed on a second line that passes through the center point. The inner angle of the first line and the second line is in the range from 80 degrees to 110 degrees.

Abstract: A patch having a circular shape for instance is formed on the main surface of a substrate in the shape of, for example, an equilateral triangle. The center of the main surface of the patch is at a position different from the center of the substrate. A grounding conductor is disposed on the backside of the substrate. Power is supplied to the patch through, for example, a microstrip line, triplate line, coplanar waveguide, slot line or the like. An antenna configured as described above has the center of the patch at a position different from the center of the triangle substrate, so that beams can be tilted in a desired direction by a single patch and a single feeder circuit.

Abstract: On respective ground conductor plate surfaces, first and second dielectric substrates are formed. First and second antenna elements made of a conductor film of a rectangular cooper leaf or the like are formed on opposite surfaces of the first and second dielectric substrates to the ground conductor plate. The first and second antenna elements-are fed by, for example, a coplanar waveguide feed line, slot feed or the like. Thus, an omnidirectional antenna is realized having simple construction, reducing a size and production cost.

Abstract: A patch and a ground conductor are shortcircuited with two shortcircuit portions that are composed of conductive plates and that pass through a dielectric substrate. The shortcircuit portions are connected to the inner periphery of the patch and have large widths therealong. A first shortcircuit portion is disposed on a first line that connects a microstrip feeder line and the center point of the patch. A second shortcircuit portion is disposed on a second line that passes through the center point. The inner angle of the first line and the second line is in the range from 80 degrees to 110 degrees.

Abstract: A microstrip antenna is disclosed which comprises a ground conductor plate and a patch opposed to the ground conductor plate with a particular distance, a transmission feed line and a reception feed line being disposed between the ground conductor plate and the patch. Signals are fed from these feed lines to the patch by electromagnetic coupling. The angle made by the extended lines of these feed lines is nearly 90.degree.. When four patches are disposed in a square arrangement, the transmission feed line feeds signals in directions of first lines which pass through the center point of each patch in such a way that the directions are line-symmetrical with respect to a horizontal line and a vertical line which pass through the center point of the square arrangement. On the other hand, the reception feed line feeds signals in the directions of second lines which pass through the center point of each patch and intersect with each first line at right angle.