公开(公告)号：JPH02300672A

公开(公告)日：1990-12-12

申请号：JP8763490

申请日：1990-04-03

Applicant: CASCADE MICROTECH INC

Inventor： ANDORIYUU SHII DEBITSUDOSON

IPC: G01R29/26

Abstract: PURPOSE: To decide the noise parameter of a receiver by measuring the noise power of the receiver to a plurality of known power source admittance at first power source noise temperature. CONSTITUTION: The method for deciding noise parameter comprises the steps of measuring the noise power of a receiver at known four different power source terminals having first noise temperature, and deciding one set of the first noise power measurement thereby. The method further comprises the steps of measuring the noise power of the receiver at another known power source terminal having second noise temperature, deciding the another noise power measurement thereby, then deciding relative gains for the power source terminals, and deciding the ratios to the sets of the first noise power measurement for the relative gains. The method further comprises the steps of substituting the ratios into the noise characteristic equation, then calculating the four parameters in the form of scale with the two constants of the parameters, and then utilizing the another noise power measurement for deciding the constant.

公开(公告)号：JPH02181665A

公开(公告)日：1990-07-16

申请号：JP29012789

申请日：1989-11-09

Applicant: CASCADE MICROTECH INC

Inventor： BAANAADO DABURIYUU RIIKU ,  ANDORIYUU SHII DEBITSUDOSON

IPC: G01R21/06 ,  G01R23/00 ,  G01R29/26

Abstract: PURPOSE: To compensate the error by sequentially sending signals having different frequencies, and measuring the inaccuracy of measured frequency of from the noise current of a DUT by the frequency measured at a scattered parameter. CONSTITUTION: The input terminal of a unit DUT 12 during testing is connected to a source admittance 14, and the output terminal is connected to a noise wattmeter 16. In this case, signals having the same power and different frequencies are successively sent from the input terminal to the wattmeter 16. The signals are amplified in the selected narrow frequency range by a frequency converting stage 18. The wattmeter 16 individually measures the power for the signals having the various different frequencies, and measures the central frequency of the signals. Thus, the power measured and larger individually than the threshold measured in the frequency range is obtained. In this case, the difference of the desired measuring frequency, central frequency can be measured. The signal from the DUT 12 is moved by the difference, and the measurement error can be compensated.