摘要:
In an apparatus for measuring a specific absorption rate (SAR), a first near magnetic field distribution of a radio wave radiated from an array antenna of a reference antenna including a plurality of minute antennas is measured, and an SAR distribution with respect to the radio wave radiated from the array antenna is measured with a predetermined phantom. Then a distribution of a transformation coefficient α is calculated by dividing the measured SAR distribution by a square of the measured first near magnetic field distribution, a second near magnetic field distribution of a radio wave radiated from a measured radio communication apparatus is measured, and an SAR distribution with respect to the radio wave radiated from the radio communication apparatus is calculated by multiplying a square of the measured second near magnetic field distribution by the calculated distribution of the transformation coefficient α.
摘要:
In an apparatus for measuring a specific absorption rate (SAR) for use in a radio apparatus, a first near magnetic field of a radio wave radiated from a reference radio apparatus is measured in free space, and an SAR of the radio wave radiated from the reference radio apparatus by using a predetermined phantom according to a predetermined measurement method. A transformation factor α is calculated by dividing the measured SAR by a square value of the measured first near magnetic field, and a second near magnetic field of a radio wave radiated from a radio apparatus to be measured is measured in free space. Then an SAR of the radio wave radiated from the radio apparatus to be measured is estimated and calculated by multiplying a square value of the measured second near magnetic field by the calculated transformation factor α.
摘要:
An electromagnetic wave measuring apparatus includes a loop probe section having loop probes whose loop planes are placed so as to be perpendicular to each other, and each loop probe is placed so that its magnetic field detection space is not interfered with by other loop probes. If the loop probe section is placed at measurement position coordinates xi, yj, it detects a magnetic field component at the measurement position coordinates xi, yj, which is parallel to an XY plane, and a magnetic field component in a Z-axis direction at measurement position coordinates xi, yj−1, and repeats measurement by pitch p in a positive Y-axis direction. By calculating the root sum square of the detection results at each measurement position coordinate, a three-dimensional magnetic field level of an object to be measured can be obtained at each measurement position coordinate as electromagnetic field distribution with high-precision.
摘要:
An adaptive antenna apparatus includes antenna elements. One of the antenna elements has an electrical length L1 larger than λ/2, and equal to or smaller than a predetermined upper-limit wavelength, where λ is a wavelength of a radio signal. Another antenna element has an electrical length L2 equal to or larger than a predetermined lower-limit wavelength and equal to or smaller than λ/2. A controller adaptive-controls the adaptive antenna apparatus to form a radiation pattern of the adaptive antenna apparatus including a plurality of nulls substantively in a direction of an interference wave by adjusting at least one of an amplitude and a phase of each radio signal received by the first and second antenna elements.
摘要:
In the adaptive control apparatus, a computation unit computes weighting coefficients, using a first adaptive control method in a proportion α of a first computation amount, where the first adaptive control method has a first convergence rate and a first convergence error. Further, a computation unit computes weighting coefficients from initial values of the weighting coefficients computed by the computation unit, using a second adaptive control method in a proportion (1−α) of a second computation amount, where the second adaptive control method has a second convergence rate slower than the first convergence rate and a second convergence error smaller than the first convergence error. A controller controls determination of a ratio α/(1-α) based on a moving speed of a mobile unit, and controls the computation units to perform computing processes.
摘要:
An adaptive antenna apparatus including a reception adaptive control circuit is provided. The reception adaptive control circuit adaptively controls respective received signals received by a plurality of antenna elements, and outputs the adaptively-controlled received signals as a combined received signal. A demodulator demodulates the combined received signal to a demodulated signal, and demodulates the respective received signals separately received by the respective antenna elements to demodulated signals. A controller compares signal quality of the demodulated signal of the combined received signal with signal qualities of the demodulated signals of the respective received signals separately received by the respective antenna elements, respectively, selects a demodulated signal having the highest signal quality, and controls to receive a received signal including a selected demodulated signal.
摘要:
An adaptive antenna apparatus includes two antenna elements and a parasitic element to which a variable reactance element is connected, and selects an adaptive control processing according to detected signal quality. A controller executes a first adaptive control processing for adaptively controlling respective received signals received by the respective antenna elements and outputting the respective received signals after the adaptive control as a combined received signal, and executes a second adaptive control processing for reactance controlling an element value of the variable reactance element. The controller executes the first adaptive control processing. The controller executes a communication processing when the detected signal quality is equal to or larger than a predetermined threshold. The controller executes the second adaptive control processing when the detected signal quality is not equal to or larger than the threshold.
摘要:
In the adaptive control apparatus, a computation unit computes weighting coefficients, using a first adaptive control method in a proportion α of a first computation amount, where the first adaptive control method has a first convergence rate and a first convergence error. Further, a computation unit computes weighting coefficients from initial values of the weighting coefficients computed by the computation unit, using a second adaptive control method in a proportion (1−α) of a second computation amount, where the second adaptive control method has a second convergence rate slower than the first convergence rate and a second convergence error smaller than the first convergence error. A controller controls determination of a ratio α/(1-α) based on a moving speed of a mobile unit, and controls the computation units to perform computing processes.
摘要:
An adaptive antenna apparatus includes two antenna elements and a parasitic element to which a variable reactance element is connected, and selects an adaptive control process according to detected signal quality. A controller executes a first adaptive control process for adaptively controlling respective signals received by the respective antenna elements and outputting the respective signals after the adaptive control as a combined received signal, and executes a second adaptive control process for reactance controlling an element value of the variable reactance element. The controller executes the first adaptive control process. The controller executes a communication process when the detected signal quality is equal to or larger than a predetermined threshold. The controller executes the second adaptive control process when the detected signal quality is not equal to or larger than the threshold.
摘要:
An adaptive antenna apparatus including a reception adaptive control circuit is provided. The reception adaptive control circuit adaptively controls respective received signals received by a plurality of antenna elements, and outputs the adaptively-controlled received signals as a combined received signal. A demodulator demodulates the combined received signal to a demodulated signal, and demodulates the respective received signals separately received by the respective antenna elements to demodulated signals. A controller compares signal quality of the demodulated signal of the combined received signal with signal qualities of the demodulated signals of the respective received signals separately received by the respective antenna elements, respectively, selects a demodulated signal having the highest signal quality, and controls to receive a received signal including a selected demodulated signal.