CS267064B1 - Connection of six-outlet reflecto-meter - Google Patents

Abstract

The solution belongs to the microwave area techniques and solves a simple type configuration of the six-port reflectometer on measuring the coefficient of reflection r. Its essence is that switching in the reflective phase an angle of three is obtained by the slider q-points of the six-port reflectometer, with only two detectors and configurations are used the reflectometer is broadband. the effect is achieved by the generator being connected to the directional coupler to which it is also a first reflective phase detector is connected slider and power divider input. The divider a second detector a is connected to the power output clamp to connect the measured load.

Description

The invention relates to the connection of a six-port reflectometer, which serves to measure the reflection coefficient § of the connected load.

The basis of the six-port reflectometer is a linear six-port. The state of the six port is determined by the twelve variables, which can be incoming and outgoing waves with amplitudes a ^ and b ^, where i takes values from 1 to 6.

On the measuring port on which the unknown load is measured, the waves are marked as follows:

' ^a 6 ^{= a} ' b, = b O

The following applies to the reflectometer outputs:

^P i = | ^A i ^a + ^B ib | ² (i = 1, 2, 3, 4) ^p i = 1 ^A i | ² M ² Is- 91I ² 'i = i' ² ' ³ ' ⁴ > where ξ = g is the reflection coefficient of the measured load and

B, - are the so-called q-points of the reflectometer. ' ^A i

Several types of six-reflector reflectometer configurations are currently known. According to Samuel and Li Bosisia, a six-port reflectometer with probes is known, whose port 4 samples the wave b and ports 1 to 3 have projecting waves b ^ = c ^ b (^ + e- ^ i), where c ^ is the probe binding coefficient a = 2 ^ f ^ / A is the electrical distance of the probe from the measuring plane. For probe distances, the q-points lie on the unit-j circle.

A six-port reflectometer with directional taps with a short-circuited arm is also known. For the wave emanating from the i-th port (i = 1, 2, 3) b _± = cb (§ - e ² ^^) where c ^ is the coupling coefficient of the respective branch, = 2 ^^ / ^ is the electrical distance of the branch from directional plane and cT = 2 ^ť ířd ^ / A is the electrical distance. short-circuit from the tap, where d1 is half the distance that the wave must travel in addition to the bine b in order to reach the i-th detector. The position of the q-points can be adjusted. location of shorts. The authors are Potter and

Snowden.

Six-port reflectometers with hybrids, power dividers and directional taps are also known. One of the various variations of configurations proposed by Engen, it has four directional taps with a 3 dB link and one directional tap with a 6 dB link. A similar reflectometer was constructed by Griffin, it has all directional taps with a vMzbu of 3 dB.

The six-port reflectometer with a symmetrically matched five-port, constructed by Riblet and Hanson, contains one directional branch that responds only to the incident wave and a symmetrically matched five-port. The advantage of this configuration is the simple construction and the ideal distribution of q-points.

A six-line reflector with bound lines, designed by Collier and Nabil-El-Deeb, is also known. Its advantage is a simple configuration, but the disadvantage is the non-ideal distribution of q-points.

CS 267 064 Bl

A six-port reflectometer realized as a measuring three-port is also known. Its advantage is one detector, which is used to measure all outputs. The disadvantage is the need for a precise attenuator and amplitude modulator.

A common disadvantage of the currently used configurations of six-port reflectometers is, above all, their complex configuration, or in most cases the use of four detectors, or the narrowband of their use.

These shortcomings are substantially eliminated by the connection of a six-port reflectometer consisting of a generator, two detectors and a terminal for connecting a measured load according to the invention, the essence of which is that the generator is connected to a directional tap on the one hand, the input of the power divider. A second detector and a terminal for connecting the measured load are connected to the power divider.

The advantages of the circuit according to the invention are that the number of detectors required is reduced to two of the usual four, thus increasing the measurement accuracy and the disadvantage of narrowband configuration with a double directional tap is eliminated by using one directional tap and one power divider. The configuration has an optimal distribution of q-points, is very simple and it is possible to achieve an optimal angular displacement between q-points of 120 ° and -120 °.

In the accompanying drawing, FIG. 1 shows a block diagram of a circuit according to the invention, and FIG. 2 shows an optimal distribution of q-points.

The circuit according to the invention as shown in Fig. 1 consists of a generator 5 connected to the directional coupler 3 which is still partly connected to a first detector 1 ^ partly reflective phase shifter 2 ^and one power divider £. A second detector 2 and a terminal 2 for connecting the measured load are connected to the power divider £. The directional branch 2 has a power connection c 1 and the power divider 4 has a power connection 03 * in the arm in which the measuring port lies.

The actual operation of the reflectometer according to the invention is as follows. The signal from the generator 2 passes through a directional branch 3, where it branches into two parts. The first part of the signal is reflected with the reflection coefficient = r ^ e ^ after impact on the reflection phase shifter 2, the amplitude of the reflection coefficient being close to one (r ^ SS1) and the phase indicating the angular distribution of q-points, and after passing through the directional branch 2 the first detector 2 · The second part of the signal passes through a power divider 4 _f where it is divided into two parts, part of the signal impinging on the second detector 2, which responds only to the wave b incident on the load and part of the signal on the measured load connected to terminal 6. for connection of the measured load, is reflected and, passing through the power divider 2 ^{and the} directional coupler 3 dopadá.na first detector # 2 which is summed with the first portion of the signal reflected from the reflective phase slide 2 · ^e j ^e ktrická signal path between the directional coupler 2 ^and the reference plane in which the reflection coefficient is measured, ^ 2 is the electrical path between the directional ^{tap 2 and the} reflection phase shifter 2. The aim is to make the difference between these electrical paths zero, in which case the q-point system will not be rotate the whole when the frequency changes. The reflective phase shifter 2 can be implemented as a sliding short circuit, but an electronically controlled broadband reflective shifter can be advantageous, for example.

_{The relation e} 2j (S ₂ - © i) _e jfi applies to the q-points of the system

CS 267 064 B1 where c, is the power coupling of the power divider Z of the arm in which the measured load lies. In the case of 1 symmetrical power division, ie ^c e = j or C j = 3 dB, q 2 = 2. A suitable reflective phase shifter 2 can achieve an ideal distribution of q-points in which the q-points are shifted by 120 ° relative to each other.

Claims (1)

OBJECT OF THE INVENTION Connection of a six-port reflectometer, consisting of a generator, a terminal for connecting the measured bare and two detectors, characterized in that the generator (5) is connected to a directional tap (3) to which a first detector (1) and a reflex phase shifter are connected (7) and on the one hand the input of the power divider (4), to which the second detector (2) and the terminal (6) for connecting the measured load are connected.