Abstract: A patch antenna includes a ground electrode arranged on one surface of a dielectric layer, a first patch which has a shape of a trapezoid, is arranged inside the dielectric layer and radiates a signal having a first frequency, a second patch which has a shape of a trapezoid, is arranged on the other surface of the dielectric layer and radiates a signal having a second frequency, and two conductors which connect the short sides of the two patches with the ground electrode. The two patches are arranged such that the short sides are both located on the side of the same end of the dielectric layer. The first patch is fed power via a feeding point near the short side, and the second patch is fed power via a feeding point which is located between the end of the dielectric layer and the short side of the first patch.

Abstract: A patch antenna includes a ground electrode arranged on one surface of a dielectric layer, a first patch which has a shape of a trapezoid, is arranged inside the dielectric layer and radiates a signal having a first frequency, a second patch which has a shape of a trapezoid, is arranged on the other surface of the dielectric layer and radiates a signal having a second frequency, and two conductors which connect the short sides of the two patches with the ground electrode. The two patches are arranged such that the short sides are both located on the side of the same end of the dielectric layer. The first patch is fed power via a feeding point near the short side, and the second patch is fed power via a feeding point which is located between the end of the dielectric layer and the short side of the first patch.

Abstract: An antenna includes a first arm whose one end is connected to a feeding unit, a second arm whose one end is connected to the first arm at a position that is away from the one end of the first arm and whose other end is connected to ground, and a variable impedance unit whose impedance is variable, provided between the ground and the other end of the first arm.

Abstract: There is provided an antenna for tuning a resonant frequency. The antenna includes a first and a second arms connected to the antenna feeding portion at a common end thereof. The second arm has each of the plurality of branches including a switch for selecting a length of an electrical loop formed by the second arm and an end of a ground plane, each of the switches is connected to the ground plane. A first resonant frequency performed by the first arm is higher than a second resonant frequency by the second arm when each of the switches is open, and the first resonant frequency is lower than a third resonant frequency by the second arm when one of the switches is selected to connect the second arm and the ground plane so that the length of the electrical loop is maximum.

Abstract: An antenna device includes an antenna element having an external form shaped into a substantially rectangular-shaped planar spiral coil and a switch provided to the antenna element.

Abstract: A single-layer adaptive plane array antenna device includes a variable reactance circuit including a variable capacitance circuit controlled by bias voltage, a resonating folded line bias circuit having an AC grounding node for supplying the bias voltage to the variable capacitance circuit, for transmitting the bias voltage to the variable capacitance circuit including a thin line interconnecting spacer for transmitting the bias voltage to the variable capacitance circuit side and first and second open folded stubs each of which is connected to the thin line interconnecting spacer, each of which is also disposed in parallel with a longitudinal direction of each other in a prescribed small gap with the thin-line interconnecting spacer, each of which has a folded shape and each of which functions as an inductance element and a capacitance element respectively for separating the variable capacitance circuit from the AC grounding node.

Abstract: An antenna includes a first arm whose one end is connected to a feeding unit, a second arm whose one end is connected to the first arm at a position that is away from the one end of the first arm and whose other end is connected to ground, and a variable impedance unit whose impedance is variable, provided between the ground and the other end of the first arm.

Abstract: There is provided an antenna for tuning a resonant frequency. The antenna includes a first and a second arms connected to the antenna feeding portion at a common end thereof. The second arm has each of the plurality of branches including a switch for selecting a length of an electrical loop formed by the second arm and an end of a ground plane, each of the switches is connected to the ground plane. A first resonant frequency performed by the first arm is higher than a second resonant frequency by the second arm when each of the switches is open, and the first resonant frequency is lower than a third resonant frequency by the second arm when one of the switches is selected to connect the second arm and the ground plane so that the length of the electrical loop is maximum.

Abstract: An apparatus performing wireless communication with a group of a plurality of base station antennas disposed on a wireless base station apparatus side in accordance with a multi-input multi-output wireless communication system includes a group of a plurality of repeater antennas disposed around the body of a user. The apparatus further includes a repeater base apparatus being connected to the group of the repeater antennas, communicating, with a handheld mobile terminal apparatus carried by the user, transmission/reception data in the handheld mobile terminal apparatus in accordance with a short-distance wireless communication system, and communicating, between the group of the plurality of the repeater antennas and the group of the base station antennas, the transmission/reception data in accordance with the multi-input multi-output wireless communication method.

Abstract: A single-layer adaptive plane array antenna device includes a variable reactance circuit including a variable capacitance circuit controlled by bias voltage, a resonating folded line bias circuit having an AC grounding node for supplying the bias voltage to the variable capacitance circuit, for transmitting the bias voltage to the variable capacitance circuit including a thin line interconnecting spacer for transmitting the bias voltage to the variable capacitance circuit side and first and second open folded stubs each of which is connected to the thin line interconnecting spacer, each of which is also disposed in parallel with a longitudinal direction of each other in a prescribed small gap with the thin-line interconnecting spacer, each of which has a folded shape and each of which functions as an inductance element and a capacitance element respectively for separating the variable capacitance circuit from the AC grounding node.