| 摘要 |
PURPOSE: A device for providing a standard RF(Radio Frequency) power source in an SAR(Specific Absorption Rate) measurement system is provided to compensate the loss of a cable and offer the standard RF power source with high reliability. CONSTITUTION: A fixed attenuator(1) attenuates an inputted RF power at a certain level. The first switching unit(2) selectively outputs an external signal to the first and second amplifying units(12,13). The first and second sensors(3,4) detect the power outputted from the first switching unit(2), and transmit the detected power to an RF power meter(5). The RF power meter(5) receives RF powers detected in the first to fourth power sensors(3,4,16,17), and indicates the current states of the RF powers. A control unit(6) adjusts the output power of the RF power meter(5), and transmits the adjusted power to a programmable attenuating unit(10). A DC power supply unit(7) supplies a stable DC power to the control unit(6). A dual DRO(Dielectric Resonator Oscillator) frequency output and synthesis unit(9) generates two frequencies according to the control of the control unit(6). The programmable attenuating unit(10) suitably adjusts the strength of the two frequencies inputted from the dual DRO frequency output and synthesis unit(9) according to the control of the control unit(6). The second switching unit(11) selectively outputs the signal inputted from the programmable attenuating unit(10) to the first and second amplifying units(12,13). The first and second amplifying units(12,13) amplify the signal inputted from the second switching unit(11) at certain levels. The first directional coupler(14) detects an output power of the signal amplified by the first amplifying unit(12). The second directional coupler(15) detects an output power of the signal amplified by the second amplifying unit(13). The third and fourth power sensors(16,17) connect to the first and second directional couplers(14,15), detect a lastly outputted power, and transmit the detected power to the RF power meter(5). The third switching unit(18) selectively outputs the output signals of the first and second directional couplers(14,15) according to the control of the control unit(6).
|
