摘要:
A FM-CW radar device is provided for frequency-modulating a high frequency signal with a modulation signal, transmitting the modulated high frequency signal, receiving a signal reflected by a target object and frequency-modulating the reflection signal with a signal generated by a local oscillator signal source provided by branching a portion of the transmitting signal. A modulator is disposed between a radar transmitting section and a transmitting antenna. The modulator modulates the transmitting signal with a second frequency which is far lower than the radar transmitting frequency and twice as much as the sum or the difference of a Doppler frequency generated by a relative propagation velocity and a beat frequency generated by a propagation delay time. A first frequency converter frequency modulates the received signal reflected by the target object with the local oscillator. A second frequency converter frequency modulates the received signal with the second frequency, the second frequency being far lower than the radar transmitting frequency and twice as much as the sum or the difference of a Doppler frequency generated by a relative propagation velocity and a beat frequency generated by a propagation delay time.
摘要:
A single antenna is used so that time-division transmission and reception is carried out in a radar apparatus for obtaining a distance and a relative speed with respect to a target object based on a beat signal obtained by transmitting a frequency modulated signal and mixing a received signal reflected by said target object with the frequency modulated signal that is transmitted.
摘要:
An array antenna radar apparatus has a single front end shared by a plurality of antennas, a first switch for cyclically connecting the antennas to the front end at a prescribed switching frequency, and a second switch for cyclically connecting the output of the front end to frequency converters corresponding to the antennas. The frequency converters frequency-convert intermediate-frequency signals of the respective antennas output by the front end to baseband signals at the switching frequency. Phase shifters and amplitude adjusting units apply a phase shift or amplitude adjustment to the outputs of the frequency converters and combine the resulting signals, thereby making it possible to detect a target in a desired direction.
摘要:
There is provided a radio interrogator system which reduces the interference with a radio transponder and avoids the decrease in throughput of the entire system in a case in which a plurality of radio interrogators are disposed at positions brought relatively close to each other and are simultaneously placed into operation.The plurality of radio interrogators are classified into two groups and each of the radio interrogators has an operation mode setting unit capable of exclusively setting, for each of the classified groups, a transmission mode for transmitting a radio transmission signal to a radio transponder or a reception mode for receiving a radio response signal transmitted from the radio transponder as a response to a radio transmission signal from the radio interrogator.
摘要:
An antenna device performs communications with an identification tag by being connected to a reading device that reads identification information of the identification tag. The antenna device includes a first power feeding unit configured to receive power from the reading device; a resonator that is electromagnetically coupled to the first power feeding unit, the resonator having a predetermined bandwidth including a working frequency of the reading device; and a second power feeding unit that is electromagnetically coupled to the resonator, the second power feeding unit being terminated according to a predetermined resistance value.
摘要:
A radio-frequency identification (RFID) unit includes a radio-frequency identification (RFID) tag configured to receive radio signals having a wavelength λ. A block has the top surface on which the radio-frequency identification tag is set. The block is made of a metallic material. The height of the block is set equal to or larger than one sixteenth the wavelength λ.
摘要:
The container for accommodating at least one article bearing a wireless tag that wirelessly communicates with a reader/writer antenna includes a conductor which electromagnetically couples with an antenna of the wireless tag when an interrogation signal is radiated from the reader/writer antenna toward the wireless tag or when a response signal is radiated from the wireless tag toward the reader/writer antenna.
摘要:
An apparatus for determining a position of a mobile wireless station comprises means for determining the position of the mobile wireless station in accordance with a position of a first reference wireless station, a position of a second reference wireless station, a first relative angular direction between the mobile wireless station and the first reference wireless station, and a second relative angular direction between the mobile wireless station and the second reference wireless station.
摘要:
There is provided a radio interrogator system which reduces the interference with a radio transponder and avoids the decrease in throughput of the entire system in a case in which a plurality of radio interrogators are disposed at positions brought relatively close to each other and are simultaneously placed into operation. The plurality of radio interrogators are classified into two groups and each of the radio interrogators has an operation mode setting unit capable of exclusively setting, for each of the classified groups, a transmission mode for transmitting a radio transmission signal to a radio transponder or a reception mode for receiving a radio response signal transmitted from the radio transponder as a response to a radio transmission signal from the radio interrogator.
摘要:
An RFID transceiver device is capable of high sensitivity reception, by the reduction of noise, irrespective of the distance to the tag. The RFID transceiver device includes a delay circuit between a local oscillation circuit and a demodulation circuit, wherein the amount of delay of the delay circuit is set to a magnitude corresponding to the path difference between the path of leakage, via a duplexer into the demodulation circuit, of transmission signal output from the local oscillation circuit for transmission, and the path of direct input of the local oscillation signal from the local oscillation circuit to the demodulation circuit.