SU1478156A1 - Transistor holder for devices for measuring electric parameters - Google Patents

Abstract

The invention can be used in measuring the complex parameters of microwave two-port and two-terminal, in particular, when measuring the complex parameters of strip transistors and diodes with planar outputs. The transistor carrier contains two coaxial-strip transitions 1 and two pieces of strip line 2 installed on a common base, pedestal 4, transistor 5, a cover, directional couplers 7 on connected lines with a weak connection, detectors 8, polycor boards 9 with matched loads 10, the contact node located in the socket 12 of the base, the locking contact node, dielectric pins, thrust springs, mounting groove 16, pins. When measuring the parameters of the transistor 5, it is placed on a pedestal 4, which is mounted on the latches of the contact node and fixed. Then the contact node is installed in the socket 12 of the base, while the pedestal 4 with the transistor 5 enters the installation groove 16, and the dielectric pins press the leads of the transistor 5 to the strips of the segments of the strip lines 2 with the help of a retaining spring and a cover. Then the parameters are measured. Increases measurement accuracy by increasing holder calibration accuracy. 6 Il.

Description

114

The invention relates to radio metering technology and can be used in measuring complex parameters of microwave four-pole and two-pole, precisely when measuring the complex parameters of strip transistors and diodes with planar outputs.

The purpose of the invention is to improve the measurement accuracy by improving the calibration accuracy of the holder.

FIG. 1 shows the transistor holder; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. 2; in fig. 4 and 5 - pedestal; in fig. 6 is a simplified diagram of a complex parameter meter.

The holder contains two coaxial-strip transitions 1, two pieces of strip line 2 mounted on a common base 3, pedestal 4, a transistor (for example ZP602) 5, a cover 6, directional couplers 7 included in the strip line 2, detectors 8, polycor board 9 with matched loads 10, contact node 11 placed in the socket 12 of the base 3, latch 13 of the contact node 11, dielectric pins 14-, thrust springs 15, mounting groove 16 and pins 17.

Strip pins 19 were soldered to pedestal 4 (fig. 4) with a strip of strip line 18, and strip pins 19 serving as a short circuit were soldered to pedestal 4 (fig 5).

The circuit for measuring the complex parameters of transistors contains a microwave generator 20, a power divider 21, microwave switches 22, the free outputs of which are loaded for matched loads 23, matching transformers 24, meters 25 complex reflection coefficients, indicator-voltmeter 26 and holder 27 of transistors.

We derive mathematical expressions describing the quadrupoles of the error of the transistor holders necessary for its calibration.

The four-port error parameters are conventionally divided into input parameters (Fig. 6) and output parts, shown as a directed graph (pos. 28 and 29, respectively), between which the S-matrix of the strip line 30 with the length

562

segment 1E. The oriented graph 28 of the input quadrupole error is a cascade connection of the S-matrix of the coaxial-strip transition, to which a uniform strip of the strip line is connected with the transmission coefficient Ce 1, where S m, S (r, Sai, S22; CS matrix of coac the sial-strip transition C; ftl, the modulus and phase of the transfer coefficient of a uniform stripline line; 1 is the length of a segment of a uniform stripline; fi 2ft / fh is a phase constant. A stripline line is considered to be homogeneous under the condition of weak coupling author. We introduce the notation:

D C A C C A I C N (D,, tt.Ј 02,, ttj D22

where S,; S, 2; S; S, a is the S-matrix of the cascade connection of two quadrupoles. Then, subject to the condition Pts 0 (in the section

1-1) according to the graph we get

О -о +, iн i Г Sn + | -si. S "from where

and

s, 1, s ,,, / A (,, /, tfA, (fs;,:

v

(one)

where I p, /, JtfpJ is the modulus and phase of the complex reflection coefficient measured in section 2-2 under the condition rc 0. (in section 1-D.

In the first approximation, we assume that the S-matrix of a coaxial-strip transition is an S-matrix of a reactive symmetric quadrupole to which a segment of a uniform strip line is connected without loss (). Using the property of the unitarity of the S-matrix of a cascade connection, we obtain

NRDC q A.rcV / A ,, (PA, -2 (f4-4pl + ffT

where / Aj /, and DM, Oue- (moduli and phases of the unitary S-matrix; CPL is the phase of the complex reflection coefficient D2, measured in section 2-2 under the condition pH -1 (in section 1-1

Wed Phase | obtained from condition 1,

S, j2 "1. DH -1 according to the formula

i-R «pM

q q I

11 21

 g

from where

rv-

The presence of losses in a segment of a homogeneous strip line (including losses in the weakly coupled region of the directional coupler) violates the unitarity of the S-matrix of the cascade connection, in which only the parameters A, A are changed (T0e. S / 4, S,, Sja). At the same time, for cascade connection of a reactive quadrupole and a uniform quadrupole with losses, the loss can be conditionally attributed to the known load, connected in section 1-1, and its reflection coefficient can be represented as DpH. D is an unknown complex coefficient taking into account losses. Then for the reflection coefficient p2 in section 2-2 with the condition ph -1 (in section 1-1) we get

D s + (3) Р S «1-S DpH A 1 + A D U;

from where

(

(AGrg) A GAЈ

3

The measurement of the complex reflection coefficient p in section 2-2 when the bodies shown in FIG. 5, pH -1 allows the determination of the coefficient D, which is a multiplier for the parameters A, A1 (expression 3). In addition, the coefficient takes into account first-order errors by the parameters A, A, and 3. By a known value of the parameter D, it is possible to determine the elements of the non-unitary S-matrix of the cascade connection

(five)

| A, | | | p.1. Chd, KHAkllDl At- + tPj, lAjHA illDl. J50

pr-1, satisfying the equation

AI

BUT,)

, L1t nUl

A g T; d- p2

Similarly, from expressions 5 (O, (2), (4), (5), it is possible to determine the parameters of the quadrupole error of the output part of the holder B ,,

15

55

20

thirty

35

50

Yu

five

B4, B.} with the corresponding replacement of 1, by A4, Ar, A. by B (, B, B3.

When calibrating the transistor holder works, as follows. In the transistor holder (Figs. 1-3), instead of the pedestal 4 with the transistor 5, a pedestal is installed with a strip line segment (Fig. 4). Then, using the microwave switch 22 (Fig. 6), a microwave signal is applied to the input of the transistor support holder 27. And with the help of a matching transformer 24 connected to the output side of the holder 27, the matching is performed in section 1-1, which is recorded at zero (or minimal) indication of the indicator-voltmeter 26 taken from the detector 8 of the directional coupler of the reflected wave of the input part of the holder 27 and meets the condition П 0 Then the measurement of the complex reflection coefficient p is carried out, at the input of the holder 27, cheneno-section 2-2. When measuring the complex reflection coefficient p. in cross section

eleven

2 -2 The microwave signal is fed to the output of the holder 27 of the transistors at the input of the microwave signal) and with the help of a matching transformer 24 connected to the input side of the holder 27, it is matched in section 1-1, which is recorded by the indicator-voltmeter 26 taken from the detector 8 of the directional coupler of the reflected; wave output part of the holder 27, and meets the condition p n 0. Then the reflection coefficient is measured p | at the output of the holder 27. Next, a pedestal short circuit (Fig. 5) is installed in the transistor holder 27 (Fig. 5) and a cross-section coefficient of the short sniper pg is measured in section 2-2,, 2 -2, respectively. According to measured complex reflection coefficients, n ,, pj. , pj, p from expressions 1, 2, 4 and 5, calculate the parameters of the quadrupole error A, AJ, A3 and P s B, BS.

When measuring the parameters of the transistors holder works as follows. The transistor is placed on a pedestal 4 (Fig. 1-3), which is mounted on (bikatorov 13 contact node 11, while the dielectric pins 14 fix transistor 5 on

51

pedestal 4. After that, the contact node H is installed in the socket 12 of the base 3, while the pedestal 4 with the transistor 5 enters the installation PA 16 of the base 3 (with the pins 17), and the dielectric pins 14 press the leads of the transistor 5 to the strips of strip segments lines 2 with the help of a stop spring 15 and a cover 6. After that, the parameters of the transistor are measured in the plane of connection of the transistor 27 holder to the meter (Fig. 6). The measurement is carried out with the help of gauges 25 of the complex reflection coefficients in sections 2-2, 2-2 (with the subsequent exclusion of the parameters of the quadrupole holder error, i.e.

determine the parameters of the transistor in cross section 1-1, 1 -1.

When measuring the input and output impedances of transistors, the exclusion of four-pole errors is performed using the expressions

JL .lA.

(ri-A) A, + A,

Bl,

(p; -B4) in + B2

(6)

which are related to the input and output impedances of the transistor by

- llPM "1 + rm J

 you

(7)

Where

1-ph

Pu PH complex reflection coefficients in section 1-1,

, 1-1 PniPn complex coefficients

reflections measured in cross section 2-2, 2 -2 ;. When measuring the S-parameters of the transistor, the R-matrix of cascade switching of the holder with the transistor in section 2-2, 2-2 is measured, followed by the determination of the S-matrix of the transistor by excluding the quadruple values of the holder error. S-napa-meters of the transistor in cross section 1-1, 1 -1 are determined by the expressions

S "-Ai5 g S

r about 2

AT,

§ „A, -u (S ,, A, -th) (& 4гВ, -th)

AL X

l-ll2l a 3

AL, AZ-L KZAA A)

S2 (S4, -0-S4Z B,) (1-A 3) /

 A

. S C S, j, / Sji,

where & A ,, & B ,, B3-B2.

IC expressions (6) and (8) it follows that the exact value of the parameters of the quadrupole error A, A2, A5 and BO B2, B, contributes to improving the accuracy of measurement of the parameters of transistors.

The table shows the main technical characteristics of the known and proposed transistor holders.

The proposed transistor holder has a higher calibration accuracy compared to the known ones, which provides higher accuracy in measuring transistor parameters up to ± 2% modulus and ± 5 ° in phase (not including meter errors); calibrated with one calibration load that does not require certification; has more

IrtSj, A,

() (§ГД-л) J;

, .eleven .

(S "A, - / b) (3" B, -A) J

(eight)

high repeatability of the transistor installation, which is provided by pins 17 (Fig. 3).

Claims (1)

Invention Formula A transistor holder in an electrical parameter measuring device, comprising two coaxial-strip transitions with strip line lines connected to them located on a common base, and a contact node for connecting a transistor, which is installed between the strip line segments, characterized in that measurement accuracy by increasing the calibration accuracy; it is equipped with two directional couplings on connected lines with weak coupling, which are connected by their own outputs with strip line strippers, and two detectors that are connected to the free outputs of directional taps. .Fig.1 fig.Z ld, 5 lz C 211 G Phage.ch Phases. five