摘要:
A multiple-frequency common antenna has a first substrate sheet and a second substrate sheet respectively structured by an HIP consisting of a metal plate, small metal plates disposed in two dimensions and linear metal bars connecting these elements. The antenna restricts propagation of surface currents of the first and second frequency bands which are not overlapping with each other. An inverse L-shape antenna and a monopole antenna which are fed with a center conductor and an external conductor of the coaxial line respectively operate as the antenna on the first substrate sheet in the first frequency band and second frequency band. The second substrate sheet does not propagate the radiated wave of the monopole antenna, thereby avoiding unwanted re-radiation.
摘要:
A multiple-frequency common antenna has a first substrate sheet and a second substrate sheet respectively structured by an HIP consisting of a metal plate, small metal plates disposed in two dimensions and linear metal bars connecting these elements. The antenna restricts propagation of surface currents of the first and second frequency bands which are not overlapping with each other. An inverse L-shape antenna and a monopole antenna which are fed with a center conductor and an external conductor of the coaxial line respectively operate as the antenna on the first substrate sheet in the first frequency band and second frequency band. The second substrate sheet does not propagate the radiated wave of the monopole antenna, thereby avoiding unwanted re-radiation.
摘要:
A line-waveguide converter includes a backside electrode disposed on a first face of a dielectric substrate, a waveguide attached to a second face of the dielectric substrate opposite the first face and having electrical conduction to the backside electrode, and multiple electrodes disposed inside the waveguide on the second face. The electrodes are identical in shape and size, and the intervals between adjoining ones of the electrodes are identical. At least one of the electrodes can be fed with power from a line.
摘要:
A first metal plate for transmission and a second metal plate for transmission are closely-attached to a first surface and a second surface of a dielectric body, respectively. An outer edge of the first metal plate substantially symmetrically faces an outer edge of the second metal plate via the dielectric body. A metal plate for matching is arranged inside a hole formed on the second metal plate, with a slit formed with an inner wall of the hole, and is fixed to the dielectric body. The metal plate for matching is electrically connected to the first metal plate via a through hole penetrating the dielectric body. An IC chip is surface-mounted to connect the second metal plate with the metal plate for matching.
摘要:
An antenna comprises a first conductive layer, a second conductive layer and an LC resonance circuit. The first conductive layer has plural elements and is disposed adjacently to each other. The second conductive layer is disposed at a predetermined distance from the first conductive layer via a dielectric substrate. The LC resonance circuit comprises connection for electrically connecting the elements and the second conductive layer. The LC resonance circuit takes a resonance state in which impedance becomes high in the operating frequency of the antenna. Of the plural elements, a power feeding section is provided in each of any two adjacent elements. Power is fed to the power feeding sections during transmission so that signals of the operating frequency are opposite in phase, and signals of the operating frequency inputted to the antenna are outputted in opposite phase from the power feeding sections during reception.
摘要:
A communication device using orthogonal multiplexing carrier method for determining delay information of received radio waves. In this device, a known signal demodulator performs OFDM demodulation to output demodulated signal, and a divider performs a complex division of the demodulated signal with a data sector of known signal of a database for each sub-carrier. By the data section of the known signal, the computation result of the amount of shift can be determined for each of sub-carriers. A delay analytical calculation circuit uses the computation result of the amount of shift for sub-carriers to analyze the delayed waves. For delay analysis, ESPRIT method is used to determine delay information by means of computation result of the amount of shift for each sub-carrier.
摘要:
An frequency division multiplexing (OFDM) system transceiver for transmitting frequency dividing data in parallel includes antenna elements for receiving known reception and reception data signals. The fast Fourier transforms (FFTs) transform the known reception signals and the reception data signals to obtain known reception sub-carrier signals and reception data sub-carrier signals. The estimator estimates propagation path estimating values of each of the reception data sub-carrier signals with respect to each of the known reception sub-carrier signals. The weight calculator calculates a maximum ratio composition weight to composite the reception data sub-carrier signals. The setting means sets a transmission weight based on the maximum ratio composition weight. The generator generates a transmission data signal by arranging transmission sub-carrier signals on the frequency axis. The multipliers multiply the transmission data signals by the transmission weight and output the multiplied resultant to the respective antenna elements.
摘要:
In a CSMA wireless LAN, a sector antenna power detectors detects the power received by antenna elements of a sector antenna. A reference power generator generates a reference power, and a comparator compares the detected power with the reference power. A controller unit, based on the comparison result, determines whether there is a hidden terminal station. If a hidden terminal station is determined to exist, the controller outputs control signals so as to direct the terminal station to increase the transmission power. The terminal station in turn will increase the transmission power in response to the control signals to widen the communication area.
摘要:
A line-waveguide converter includes a backside electrode disposed on a first face of a dielectric substrate, a waveguide attached to a second face of the dielectric substrate opposite the first face and having electrical conduction to the backside electrode, and multiple electrodes disposed inside the waveguide on the second face. The electrodes are identical in shape and size, and the intervals between adjoining ones of the electrodes are identical. At least one of the electrodes can be fed with power from a line.
摘要:
A radio communication system includes: a communication control device; a radio tag for communicating with the communication control device; an antenna for transmitting an incident wave; and a first reflective plate for reflecting the incident wave as a first reflected wave. The radio tag is disposed between the antenna and the first reflective plate. The radio tag communicates with the communication control device in a region, in which the incident wave and the first reflected wave are overlapped. The first reflective plate reflects the incident wave in such a manner that the first reflected wave has a polarization different from a polarization of the incident wave.