RU-2861380-C1 - METHOD AND SYSTEM FOR TUNING CERAMIC MONOLITHIC MICROWAVE FILTER

RU2861380C1RU 2861380 C1RU2861380 C1RU 2861380C1RU-2861380-C1

Abstract

FIELD: radio engineering; microwave engineering. SUBSTANCE: invention relates to microwave filters. To this end, a system for tuning a ceramic monolithic microwave filter is proposed, which comprises a measurement means configured to measure the current electrical characteristics of the filter; a contact device configured to connect the filter thereto for transmitting the current electrical characteristics of the filter to the measurement means; a laser installation having a radiation power in the range of 10 W to 50 W, a pulse duration in the range of 4 ns to 200 ns, configured to act with a laser beam on the topological pattern of the filter, which leads to a change in the current electrical characteristics of the filter; a comparison means configured to compare the current electrical characteristics of the filter with the required electrical characteristics of the filter and generate control signals for the laser installation, ultimately specifying the characteristics and position of the laser beam relative to the topological pattern of the filter. EFFECT: increasing the speed of the tuning process of microwave filters. 9 cl, 10 dwg

Inventors

Arkhipov Aleksej Grigorevich
Kuvshinov Vadim Vladimirovich
Shabanov Vladimir Valentinovich

Dates

Publication Date: 20260505
Application Date: 20251217

Claims (18)

1. A method for tuning a ceramic monoblock microwave filter, according to which, at the first stage of tuning the filter, the current electrical characteristics of the filter are measured, the current electrical characteristics of the filter are compared with the required electrical characteristics of the filter, and if the current electrical characteristics of the filter do not correspond to the required electrical characteristics of the filter, then a second stage of tuning the filter is carried out, which consists in the fact that the topological pattern of the filter is affected by a beam of a laser installation having a radiation power in the range from 10 W to 50 W, a pulse duration in the range from 4 ns to 200 ns, in order to change the topological pattern of the filter, which leads to a change in the electrical characteristics of the filter, after which a third stage of tuning the filter is carried out, which consists in the fact that the current electrical characteristics of the filter with the changed topological pattern are measured and compared with the required electrical characteristics of the filter, and if the current electrical characteristics of the filter with the changed topological pattern correspond to the required electrical characteristics of the filter, tuning the filter is stopped.
2. The method according to paragraph 1, according to which the range of operating frequencies, the unevenness of the amplitude-frequency characteristic (AFC) in the range of operating frequencies, the insertion attenuation in the range of operating frequencies, the insertion attenuation in the stop bands, the voltage standing wave ratio (VSWR) of the input and output in the range of operating frequencies are measured and compared.
3. The method according to paragraph 1, according to which the first, second and third stages of filter adjustment are repeated until the current electrical characteristics of the filter with the modified topological pattern and the required electrical characteristics of the filter are matched.
4. A system for tuning a ceramic monoblock microwave filter, comprising:
- a measuring device designed with the ability to measure the current electrical characteristics of the filter before and after changing the topological pattern of the filter;
- a contact device designed with the possibility of connecting a filter to it, for transmitting the current electrical characteristics of the filter to the measuring instrument;
- a laser installation having a radiation power in the range from 10 W to 50 W, a pulse duration in the range from 4 ns to 200 ns, designed with the ability to act with a laser beam on the topological pattern of the filter to change it, which leads to a change in the current electrical characteristics of the filter; and
- a comparison means configured to compare the current electrical characteristics of the filter with the required electrical characteristics of the filter and to generate control signals for the laser installation, ultimately setting the characteristics and position of the laser beam relative to the topological pattern of the filter;
at the same time
the contact device contains an input for connecting the filter and an output for transmitting the current filter characteristics to the measuring instrument;
the measuring device contains an input for receiving the current characteristics of the filter from the contact device and an output for transmitting the current electrical characteristics of the filter to the comparison device;
the comparison means comprises a first input for receiving the current characteristics of the filter, communicated with the output of the measuring means for transmitting the current electrical characteristics of the filter to the comparison means, and a first output for transmitting control signals to the laser installation;
the laser installation contains an input for receiving control signals from the comparison means, communicated with the first output of the comparison means.
5. The system according to claim 4, in which the measuring means is configured to measure the range of operating frequencies, the unevenness of the amplitude-frequency characteristic (AFC) in the range of operating frequencies, the insertion loss in the range of operating frequencies, the insertion loss in stopbands, the voltage standing wave ratio (VSWR) of the input and output in the range of operating frequencies.
6. The system according to claim 3, further comprising a storage means configured to store and transmit the required electrical characteristics of the filter to the comparison means, wherein the storage means comprises an output for transmitting the required electrical characteristics of the filter to the comparison means, and the comparison means comprises a second input for receiving the required electrical characteristics of the filter from the storage means, communicated with the output of the storage means.
7. The system of claim 3, further comprising means for moving the filter into and out of the laser beam exposure area.
8. The system according to claim 5, in which the comparison means is configured to generate and transmit control signals that ultimately determine the position of the filter movement means, wherein the comparison means comprises a second output for transmitting control signals to the movement means, and the movement means comprises an input for receiving control signals, communicated with the second output of the comparison means.
9. The system according to claim 6, in which the storage means and the measuring means are combined into a single electronic computing device.

Description

The invention relates to the field of radio engineering and microwave technology, in particular to microwave filters, and more specifically to a method and system for tuning a ceramic monoblock microwave filter. The present invention will find application in tuning monoblock ceramic microwave filters intended for various microwave electronic devices, for example, for preselectors. The creation of modern electronic devices requires a large number of different active and passive elements. One such passive element is a ceramic monoblock microwave filter. The inevitable variation in the geometric dimensions of filter elements, the permittivity of the ceramic material used to manufacture them, and manufacturing inaccuracies in the topological design necessitate checking each manufactured filter for compliance with the technical specifications, i.e., ensuring that the filter's current electrical characteristics match the required characteristics. In other words, if the filter's current electrical characteristics do not match the required characteristics, filter tuning is required to ensure that the current electrical characteristics match the required characteristics. However, it should be understood that such tuning is currently unavoidable, as the current characteristics never initially match the required characteristics. Specialists in this field of technology are aware of various methods for tuning ceramic monoblock microwave filters, but they all boil down to the fact that the filter tuning is carried out by periodically measuring the current electrical characteristics of the filter, such as the operating frequency range, the unevenness of the amplitude-frequency characteristic (AFC) in the operating frequency range, the insertion attenuation in the operating frequency range, the insertion attenuation in the stopbands, the voltage standing wave ratio (VSWR) of the input and output in the operating frequency range, comparing them with the required electrical characteristics of the filter, and in the event that the current electrical characteristics of the filter do not correspond to the required ones, then a change in the topological pattern of the filter is carried out by locally removing the metallization (silver layer) applied to the front end of the filter, while it is necessary to pay attention to the fact that to perform this operation, tuning engineers are involved, who carry out the removal manually using specialized mechanical and optical tools. In other words, filter tuning is performed manually by a tuning engineer, who must possess the appropriate tuning skills. Miniature mechanical drills are used to remove metallization, altering the filter's topological pattern. Optical instruments, such as magnifying glasses and microscopes, are also used to magnify the topological pattern. As a result, filter tuning using conventional methods is generally labor-intensive and inefficient. Typically, a tuning engineer can tune no more than twelve to thirty filters in a single work shift. Therefore, the productivity of the tuning process depends directly on the number of tuning engineers. In addition, it should be emphasized that the performance of filter tuning also depends on the qualifications of the tuning engineer, i.e., the tuning engineer must have specific knowledge and experience that allows him to determine the places where the topological pattern changes, and this is also a problem. Furthermore, it should be noted that if, during tuning, specifically while modifying the topological pattern, the tuning engineer alters the topological pattern in such a way that further filter tuning is impossible, which happens quite often, the filter is ultimately rejected, or the filter undergoes a topological pattern retouching operation to restore the filter's electrical characteristics and re-tune it. This also negatively impacts performance. It should also be noted that filters tuned using the "manual" tuning method are characterized by low repeatability of their electrical characteristics. By repeatability of electrical characteristics, we mean the ability of filters to reproduce the same electrical parameters during repeated manufacturing or tuning. In other words, this means that when producing filters from the same batch, manufacturers should strive to ensure that the filter characteristics, such as frequency response, are as close as possible to each other. In practice, this leads to a wide range of permissible errors in electrical characteristics with the "manual" method of tuning, which often does not always satisfy the end user of filters, who always require filters from the same batch to operate stably and have the closest possible electrical characteristics. These requirements are difficult to meet in practice precisely because of manual tuning, i.e., simply put, because of the negative influence of the so-called human factor. The present invention is based on the task of creating a new method for tuning