Method for controlling longitudinal dimensions of waveguide systems and assessing soldering quality

Abstract

FIELD: microwave technology.SUBSTANCE: invention can be used to control the manufacturing procedure of waveguide systems for vacuum tube devices. A method for monitoring the longitudinal dimensions of waveguide systems, which are several resonators connected to each other by soldering, and for assessing the quality of soldering, consists of pulling a disturbing body along the required direction of a short-circuited waveguide system and recording the change in the natural frequency proportional to the squares of the field components near the disturbing body, characterized in that the short-circuited waveguide system is connected to a measuring setup and its operating passbands are determined; resonant frequencies are recorded in the operating passband; the distribution of the square of the amplitude of the longitudinal component of the electric field is measured at the resonant frequencies; the position of the centres of the gaps of the resonators is determined and compared with the specified longitudinal dimensions of the structure; the quality of soldering is assessed by comparing the deviation of the amplitude of the resonant peaks from the reference waveguide system.EFFECT: non-destructive testing of deviations in the longitudinal dimensions of waveguide system resonators and assessing the quality of soldering of resonators at the stage of assembly of a vacuum tube device and, as a consequence, increasing the yield of suitable products.1 cl, 1 dwg

Description

[0001] The invention relates to microwave technology and can be used to control the manufacturing technology of waveguide systems of vacuum tube devices.

[0002] Currently, in the production of microwave vacuum devices, much attention is paid to the optimization of technological processes, which allows increasing the yield of good products.

[0003] The method of resonant disturbances is known [Ginzton E.L. Measurements on centimeter waves. - M.: I.L., 1960 - 620 p.]. According to this method, the electrodynamic characteristics of waveguide systems are experimentally studied, allowing one to obtain reliable information about their properties and the laws of wave propagation, necessary for assessing the error in calculating the characteristics of waveguide systems and their subsequent correction, and is adopted as a prototype.

[0004] However, this method is not applicable to assess the dimensional deviation and soldering quality of waveguide system resonators.

[0005] The proposed technical solution is aimed at expanding the scope of application of the resonant disturbance method.

[0006] The technical result is an increase in the yield of suitable products.

[0007] The technical result is achieved by performing the following sequence of actions to control the longitudinal dimensions of waveguide systems, which are several resonators connected to each other by soldering, and to evaluate the quality of soldering, which consists of pulling the disturbing body along the required direction of the short-circuited waveguide system and recording the change in the natural frequency proportional to the squares of the field components near the disturbing body, while:

[0008] 1. connect the short-circuited waveguide system to the measuring setup and determine its operating bandwidth;

[0009] 2. Fix the resonant frequencies in the working bandwidth;

[0010] 3. Measure the distribution of the square of the amplitude of the longitudinal component of the electric field at resonant frequencies;

[0011] 4. determine the position of the centers of the resonator gaps and compare them with the specified longitudinal dimensions of the structure;

[0012] 5. The soldering quality is assessed by comparing the deviation of the amplitude of the resonant peaks from the reference waveguide system.

[0013] The essence of the technical solution is as follows. Determining deviations in the dimensions and soldering quality of a short-circuited waveguide system under study (i.e., during the assembly stage of a vacuum tube) is accomplished by comparing the measured field distribution pattern along the electron beam channel axis with a similar pattern measured for a reference or calculated short-circuited waveguide system.

[0014] To measure the relative natural frequency drifts δf / fc along the center of the electron beam channel of a short-circuited waveguide system, a disturbing body is used. This disturbing body is a thin metal cylinder (no longer than 0.08 of the resonator length), interacting primarily with an electric field parallel to its axis. In this case, the disturbances can be considered small. The shape factor of the disturbing body is usually calculated in a static approximation, assuming that the disturbing body is introduced into a uniform field (however, the field inside the body may be non-uniform). For some idealized bodies, it is given in the literature. Real disturbing bodies usually differ in shape from those that can be rigorously calculated, so for them, the shape factor of the disturbing body is determined experimentally or using finite element calculations in 3D field modeling programs.This method involves comparing the distributions of field-proportional relative natural frequency drifts δf / fc on the electron beam channel axis measured using the same exciter in different instances of a short-circuited waveguide system. Therefore, determining the shape factor of the exciter is not required.

[0015] The field distribution is measured at the natural frequencies of short-circuited waveguide systems in the main (operating) passband. Deviations in longitudinal dimensions and soldering defects explain the deviations in natural frequencies and resonant peak amplitudes.

[0016] The invention is illustrated by drawings. Fig. 1 shows a graph of the distribution of relative deviations of natural frequencies δf / fc along the axis of the electron beam channel at frequencies corresponding to the beginning of the low-frequency passband.

[0017] Implementation example. The reference short-circuited waveguide system of the microwave device is made of copper and contains 21 resonators with a period of 7.5 mm, connected together with PSrMPd65-0-15V solder. The diameter of the waveguide channel is 2.4 mm, and the length of the waveguide system is 157.5 mm.

[0018] The exciting body is made in the form of a metal (for example, copper) cylinder with a thickness of 0.2 mm and a length of 0.3 mm and is fixed on a nylon line with a diameter of 80 μm.

[0019] The system under study, made similar to the reference one, is subject to verification for compliance with the specified longitudinal dimensions of the structure and assessment of the quality of soldering of the resonators.

[0020] Connect the system under test to the N5320C vector network analyzer and determine its operating bandwidth.

[0021] Fixes resonant frequencies in the operating bandwidth.

[0022] The distribution of the square of the amplitude of the longitudinal component of the electric field is measured at resonant frequencies (Fig. 1).

[0023] In Fig. 1, the solid line shows the parameters of the reference system with the specified longitudinal dimensions of the structure and with the soldering quality corresponding to the reliable operation of the device; the dotted line shows the parameters of the system under study with soldering defects (marker 1) and deviations in the longitudinal dimensions in the output part of the system (marker 2).

[0024] Thus, the proposed method for monitoring the longitudinal dimensions of the waveguide system and assessing the soldering quality using the resonant disturbance method and subsequent mathematical processing of its results makes it possible to organize the control of parameters and rejection of waveguide systems at the stage of TWT assembly, which increases the yield of suitable products.

Claims

A method for monitoring the longitudinal dimensions of waveguide systems, which are several resonators connected to each other by soldering, and for assessing the quality of soldering, which consists of pulling a disturbing body along the required direction of a short-circuited waveguide system and recording the change in the natural frequency proportional to the squares of the field components near the disturbing body, characterized in that the short-circuited waveguide system is connected to a measuring setup and its operating passbands are determined; resonant frequencies are recorded in the operating passband; the distribution of the square of the amplitude of the longitudinal component of the electric field is measured at the resonant frequencies; the position of the centers of the gaps of the resonators is determined and compared with the specified longitudinal dimensions of the structure; the quality of soldering is assessed by comparing the deviation of the amplitude of the resonant peaks from the reference waveguide system.

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