Abstract: An Orthogonal Frequency Division Multiplexing (OFDM) receiving apparatus having a sub-carrier selectively combining mode and an antenna selecting mode. The sub-carrier selectively combining mode is configured to selectively combine signals for each sub-carrier. The antenna selecting mode is configured to select a receiving antenna. The OFDM receiving apparatus operates in a proper operation mode based on a communication environment. As a result, in a poor communication environment, signals are selectively combined for each sub-carrier. However, in a relatively satisfactory communication environment, unnecessarily operation of an RF and IF circuit, an A/D converter, and a DDT connected to each receiving antenna may be avoided.

Abstract: The universal platform for the SDR of the present invention employs the direct conversion approach with the n-port MMIC followed by reconfigurable reprogrammable devices such as DSP's or FPGA's. The universal platform is based on the linear operation of the devices. Thus, the DC offset problem may be solved. It is also possible to support very wide bandwidths compared with conventional I/Q receivers. Therefore, the present universal platform is suitable for multimode and multiband communications.

Abstract: [Object] The present invention provides a UWB transmitter and receiver, the transmission rate of which is increased, and the SN ratio of which is improved.

Abstract: To realize an antenna apparatus capable of measuring a calibration factor accurately and further, capable of estimating an arrival direction of a received signal by composing a calibration circuit by using a directional coupler. The antenna system includes L-number of branch units, a calibration circuit and an operating unit. Each directional coupler composing the calibration circuit is structured symmetrically. Measuring the received signals Yti, i−1 and Yti, i+1 of i−1th and i+1th receivers, respectively, when an ith transmitter transmits a signal, on the basis of the first branch unit, the operating unit calculates a calibration factor at the ith branch unit as Hi=T1Ri/(TiR1)=Yt12Yt23−Yti−1,i/Yt21Yt32−Yti,i−1.

Abstract: A plurality of circuit cells, a plurality of matrix switch sections and a plurality of switch sections for connecting between the plurality of circuit cells, all of which form a part of a circuit cell array, and a plurality of input/output cell sections arranged around the circuit cell array all change their circuit configurations in accordance with a configuration data to be supplied. In some of these circuit blocks, at least a part of the circuit thereof is fixed at a predetermined circuit configuration, and a conversion of the configuration data based on proprietary information regarding the fixed circuit is performed at a supplier of the configuration data. Thus, a differential configuration data for portions of the circuit other than the fixed circuit portion is generated and supplied to the integrated circuit.

Abstract: A high performance demodulator, capable of realizing further broadband characteristics, low distortion, a low power consumption, and small fluctuation in characteristics against fluctuations in temperature and fluctuations over time compared with a conventional multi-port demodulators, wherein a two-terminal first phase shifter 1004, three-terminal second branch circuit 1002, two-terminal second phase shifter 1005, and three-terminal third branch circuit 1003 are connected in series between a first signal input terminal TINSr for a reception signal and a second signal input terminal TINSlo for a local signal, a third terminal c of a first branch circuit 1001 is connected to a first power detection circuit 1006, a third terminal c of the second branch circuit 1002 is connected to a second power detection circuit 1007, and a third terminal c of the third branch circuit 1003 is connected to a third power detection circuit 1008, and comprising an N-port signal-IQ signal conversion circuit 1009 for receiving outpu

Abstract: To realize an antenna apparatus capable of measuring a calibration factor accurately and further, capable of estimating an arrival direction of a received signal by composing a calibration circuit by using a directional coupler. The antenna system includes L-number of branch units, a calibration circuit and an operating unit. Each directional coupler composing the calibration circuit is structured symmetrically. Measuring the received signals Yti, i−1 and Yti, i+1 of i−1th and i+1th receivers, respectively, when an ith transmitter transmits a signal, on the basis of the first branch unit, the operating unit calculates a calibration factor at the ith branch unit as Hi=T1Ri/(TiR1)=Yt12Yt23−Yti−1,i/Yt21Yt32−Yti,i−1.

Abstract: A receiver is provided which can avoid demodulation performance from deteriorating due to changes in circuit constants caused by changes over time and temperature-dependent changes, prevent an increase in the receiver size, and realize a cost reduction. A switch control section is provided to perform control such that an input terminal of one of a plurality of phase varying circuits is selectively connected through a first switch circuit to any of an output terminal of an RF amplifier and a local signal output terminal of a local signal generating circuit, whereby the one phase varying circuit serves as a calibration circuit in the calibration processing that is executed in the non-reception mode. Also, the output terminal of the one phase varying circuit is selectively connected through a second switch circuit or a third switch circuit to any of one input terminal of a signal combiner and a first input terminal of a multi-port junction circuit in a multi-port direct conversion demodulating section.

Abstract: A plurality of circuit cells, a plurality of matrix switch sections and a plurality of switch sections for connecting between the plurality of circuit cells, all of which form a part of a circuit cell array, and a plurality of input/output cell sections arranged around the circuit cell array all change their circuit configurations in accordance with a configuration data to be supplied. In some of these circuit blocks, at least a part of the circuit thereof is fixed at a predetermined circuit configuration, and a conversion of the configuration data based on proprietary information regarding the fixed circuit is performed at a supplier of the configuration data. Thus, a differential configuration data for portions of the circuit other than the fixed circuit portion is generated and supplied to the integrated circuit.

Abstract: A receiver includes a phased array antenna and a demodulator. The phased array antenna includes first and second antenna elements and a phase shifter for shifting the phase of a signal received by the first antenna element by a predetermined amount. The demodulator includes a first junction circuit which receives a local signal and a signal output from the phase shifter and which generates a plurality of signals having a phase difference; a second junction circuit which receives a local signal and a signal output from the second antenna element and which generates a plurality of signals having a phase difference; signal combiners for combining corresponding signals output from the two junction circuits; power detectors for detecting the signal levels of the output signals of the signal combiners; and a converter for converting the outputs signals of the power detectors so as to obtain IQ signals.

Abstract: A receiver is provided which can avoid demodulation performance from deteriorating due to changes in circuit constants caused by changes over time and temperature-dependent changes, prevent an increase in the receiver size, and realize a cost reduction. A switch control section is provided to perform control such that an input terminal of one of a plurality of phase varying circuits is selectively connected through a first switch circuit to any of an output terminal of an RF amplifier and a local signal output terminal of a local signal generating circuit, whereby the one phase varying circuit serves as a calibration circuit in the calibration processing that is executed in the non-reception mode. Also, the output terminal of the one phase varying circuit is selectively connected through a second switch circuit or a third switch circuit to any of one input terminal of a signal combiner and a first input terminal of a multi-port junction circuit in a multi-port direct conversion demodulating section.