| 摘要 |
PROBLEM TO BE SOLVED: To provide an input attenuation circuit for an active measurement probe receiving an input signal from a device under test in a wide bandwidth. SOLUTION: Each of high frequency signal paths 52, 54 receiving a differential input signal has a Z<SB>0</SB>attenuator voltage divider network. The Z<SB>0</SB>attenuator voltage divider network has series attenuator elements RDP, RDN coupled to shunt attenuator elements RTP, RTN via series connected transmission lines 58, 60 and blocking capacitors CAP, CAN, and thereby the high frequency signal paths have a high pass filter frequency response. A differential active low pass filter circuit 62 receives the differential input signal from the high frequency signal paths prior to the blocking capacitors and generates a low pass filtered differential signal, wherein a low pass characteristic of the filter circuit is matched to the frequency response of the high frequency signal paths. A differential amplifier 56 has first and second inputs with the first input (+) coupled to the shunt attenuator element RTP and the second input (-) coupled to the shunt attenuator element RTN. COPYRIGHT: (C)2010,JPO&INPIT
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