US 11,965,920 B1
Method for achieving terminal-pair definition of four-terminal-pair impedance and application thereof
Yan Yang, Beijing (CN); Lu Huang, Beijing (CN); Dongxue Dai, Beijing (CN); Wei Wang, Beijing (CN); and Xia Liu, Beijing (CN)
Assigned to NATIONAL INSTITUTE OF METROLOGY, CHINA, Beijing (CN)
Filed by National Institute of Metrology, China, Beijing (CN)
Filed on Nov. 6, 2023, as Appl. No. 18/502,153.
Claims priority of application No. 202211383646.3 (CN), filed on Nov. 7, 2022.
Int. Cl. G01R 27/08 (2006.01); G01R 15/04 (2006.01)
CPC G01R 27/08 (2013.01) [G01R 15/04 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A method for achieving terminal-pair definition of four-terminal-pair (4TP) impedance, comprising:
connecting a current output terminal of a two-stage follower to a high current terminal of impedance through a coaxial line, and connecting a voltage output terminal of the two-stage follower to a high voltage terminal of the impedance through the coaxial line, to thereby make a current of the high voltage terminal of the impedance be zero, and a core wire current and an outer wire current of the high current terminal equal and reverse;
wherein the two-stage follower comprises: a first follower F1, a second follower F2 and a third follower F3; and the first follower F1 is a first-stage follower, the second follower F2 and the third follower F3 are combined to be a second-stage follower;
wherein a power supply ±Vcc of the first-stage follower and a power supply ±Vcc2 of the second-stage follower are independent of each other, and an output terminal of the first follower F1 is connected to a center point of the power supply ±Vcc2 of the second-stage follower;
wherein the method further comprises:
connecting an output terminal of the second follower F2 to a non-inverting input terminal of the third follower F3;
connecting a core wire of the current output terminal Iout of the two-stage follower to a core wire of the voltage output terminal Vout of the two-stage follower through a first resistance R1, and connecting an outer wire of the current output terminal Iout to an outer wire of the voltage output terminal Vout through a second resistance R2;
connecting an input terminal VInput of the two-stage follower to a non-inverting input terminal of the first follower F1 and a non-inverting input terminal of the second follower F2, individually, and connecting the input terminal VInput of the two-stage follower to an outer wire of the input terminal VInput through an input resistance Rin, that is, connecting the input terminal VInput of the two-stage follower to reference ground through the input resistance Rin;
connecting an output terminal of the third follower F3 to the current output terminal Iout of the two-stage follower, and connecting an inverting input terminal of the second follower F2 to the voltage output terminal Vout of the two-stage follower;
connecting the outer wire of the current output terminal Iout of the two-stage follower to a center point of the power supply ±Vcc of the first-stage follower; and
connecting the outer wire of the voltage output terminal Vout of the two-stage follower to the outer wire of the input terminal VInput.