Abstract: A communication apparatus includes a first communication circuit, a second communication circuit, and a controller. The first communication circuit performs wireless communication with a gateway using a first communication system. The second communication circuit performs wireless communication with the gateway using a second communication system having a higher transmission speed than the first communication system. The controller is configured to activate the second communication circuit when the first communication circuit receives an activation request signal from the gateway, and to establish a link between the second communication circuit and the gateway when the first communication circuit receives a connection request signal from the gateway after the second communication circuit is activated.

Abstract: Disclosed is a wireless transmitter/receiver provided with: a local oscillator which oscillates at a predetermined local oscillator frequency; a mixer which mixes a local oscillation signal of the local oscillation frequency outputted from an output terminal of the local oscillator and a radio signal received by an antenna; a modulation circuit which modulates the local oscillator signal and generates a radio signal; and a transmission/reception switching unit which selectively switches over between a reception state in which the output terminal of the local oscillator is connected to the mixer and a transmission state in which the output terminal is connected to the antenna without passing through the mixer.

Abstract: A load control switch (1) is provided with a terminal module (2) to which electric wires are connected and which is installed on an installation frame established on a wall surface of a building; and a switch module (3) which is detachably mounted to the terminal module (2) and which turns a load on or off. The load control switch (1) is also provided with an operation handle (4) detachably attached to the switch module (3). The switch module (3) may be an electronic switch or a mechanical switch; an electronic switch may additionally be provided with delay function, timer function, a motion sensor, and so on. This makes it possible for a user to freely replace one load control switch with another having different function without electrical work being required.

Abstract: Disclosed is a wireless transmitter/receiver provided with: a local oscillator which oscillates at a predetermined local oscillator frequency; a mixer which mixes a local oscillation signal of the local oscillation frequency outputted from an output terminal of the local oscillator and a radio signal received by an antenna; a modulation circuit which modulates the local oscillator signal and generates a radio signal; and a transmission/reception switching unit which selectively switches over between a reception state in which the output terminal of the local oscillator is connected to the mixer and a transmission state in which the output terminal is connected to the antenna without passing through the mixer.

Abstract: A tri-band antenna including an center conducting an inner pipe surrounding the center conductor, an outer pipe surrounding the inner pipe and Teflon provided between the inner and outer pipes.