• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Dielectric tuner (6) that can be used to tune and reconfigure any device (8) that uses cylindrical tuning elements inserted into a cavity to adjust its electrical performance, for example, microwave filters based on coupled waveguide cavities or any RF or microwave device that uses manually adjustable tuning elements. The dielectric tuner (6) comprises a base body (3) with a hole along its center, a solid sapphire rod (1), placed inside the base body (3), linearly slidable within the base body (3) and intended to penetrate a cavity of a device (8), and a coupling head (2) attached to the sapphire rod (1) at an end opposite the cavity of the device (8) and intended to connect with a linear actuator (7). (Machine-translation by Google Translate, not legally binding)
    公开号:ES2785801A1
    申请号:ES202030640
    申请日:2020-06-25
    公开日:2020-10-07
    发明作者:Marco Guglielmi；Esbert Vicente Enrique Boria；Tillmann Tronser
    申请人:Alfred Tronser GmbH；Universidad Politecnica de Valencia；
    IPC主号:
    专利说明:

    [0003] OBJECT OF THE INVENTION
    [0005] The object of the invention is a dielectric tuner that can be used to tune microwave filters based on coupled waveguide cavities, or any other device that uses cylindrical tuning elements to adjust its electrical performance.
    [0007] BACKGROUND OF THE INVENTION
    [0009] The current development trend of modern communication systems for both terrestrial and space applications is towards greater flexibility and adaptability of all systems. Among the various components currently under development for flexible applications are tunable microwave filters.
    [0011] A tunable cavity-based microwave filter is generally comprised of tunable cavities connected together by coupling devices that must be properly sized to obtain the desired filter performance.
    [0013] The classic method for tuning cavity-based microwave filters is to use various types of metal insert fittings (or tuners) which, by altering the shape of the fields within a cavity resonator, can effectively change the cavity resonance frequency. .
    [0015] A similar approach is also used to fine-tune (or tune) the performance of the coupling devices used to build the filter.
    [0017] One specifically common type of metal tuner is a simple metal screw that is adjusted for proper penetration and is attached to the metal body of the filter with a nut.
    [0019] It is important to remember that the performance of a waveguide-based microwave filter is directly related to the physical dimension of the device. If the device is not constructed according to the exact dimensions obtained during the process of design, the desired filter performance is not obtained. In this context, therefore, metal screws are very frequently used in industry to tune a filter in such a way that the desired filter performance can be obtained even if the device has been manufactured with errors with respect to design dimensions. original. In a normal context, and for filters intended to operate at a fixed frequency, the tuning screws are manually adjusted by a person skilled in the art after the filter has been manufactured.
    [0021] The same basic approach is used in industry to make post-manufacturing adjustments for a wide variety of RF (radio frequency) and microwave components.
    [0023] Metal tuning elements (or screws) could, in principle, be used to build microwave filters that can be dynamically (or remotely) tuned. This can be accomplished simply by attaching a tuning screw to a mechanism (a motor or actuator) that can turn the screw to the desired position.
    [0025] An example can be found in US4001737A, which describes a cavity tuning assembly for use in a tuned cavity, having provisions for coarse tuning adjustment and fine tuning adjustment to change the resonance frequency of the cavity. Coarse tuning adjustment is obtained by sliding a non-threaded cavity tuning rod from the cavity tuning assembly up and down through a threaded bushing to obtain uneven tuning, after which the non-threaded rod is locked in in place by means of a knurled nut that compresses a split end portion of a bolted shaft lock into the threaded bushing in frictional engagement with the shaft lock and threaded bushing, causing the threaded bushing and mating structure to bolt in or out of a pipe reducer for fine tuning.
    [0027] Another example can be found in document EP0035922, which describes a tuning device comprising two coaxial fingers, a fixed finger and a movable finger on the filter body. One of the fingers is hollow and the other comprises a tuning plunger whose end is cylindrical and which can be displaced, for example by screwing it into the body of the finger. The lowest capacitance, obtained when the plunger penetration is minimal, is obtained when the end is aligned with the end of the corresponding finger. The additional variable capacitance is obtained by pushing the tuning plunger further into the hollow finger.
    [0028] Additionally, WO2020 / 011920A1 discloses a resonant cavity filter that includes a housing having a resonator therein and a tuning element that includes an elongated plug member having a conductive outer surface. The tuning element is mounted for insertion of the elongated pin member into the interior of the resonator. The conductive outer surface includes a contact part whereby the elongated plug member is set in a desired position to adjust a frequency response of the resonant cavity filter, where the contact part is free of threads.
    [0030] DESCRIPTION OF THE INVENTION
    [0032] The solution described in the background of the invention relating to the use of metal tuning screws to build microwave filters that can be tuned dynamically or remotely is not feasible in practice for the following reasons:
    [0033] - for correct filter performance, the metal tuning screw must be in perfect electrical contact with the filter body. This is why tuning screws are normally fastened with a nut to the filter body, - the variation in penetration of a metal screw that is required to change the performance of a microwave filter would require a very high mechanical actuator. precision. Although this is possible in theory, the resulting device would be too large and expensive for any practical application, and
    [0034] - even if it were possible to remotely control both the position of the screw and the locking nut, the device would have a very short life due to tribology considerations.
    [0036] The object of the invention consists of a dielectric tuner, which provides a simple and effective solution to the problems described.
    [0038] Specifically, the dielectric tuner comprises:
    [0039] - a solid sapphire rod, of any appropriate shape, preferably circular, and which can be solid or hollow. If the sapphire rod is circular, its diameter is d and its length is l, and it acts as a tuner by penetrating the cavity of a resonator or the coupling opening of a filter,
    [0040] - a coupling head, preferably metallic, to which the sapphire rod is fixed and which is intended to be connected with a linear actuator,
    [0041] - a base body, preferably metal, with a hole in its center of the diameter suitable in which the sapphire rod can slide without significant friction, and which can be attached with appropriate mechanical devices (e.g., but not limited to threads) to both the filter body and the actuator body, and
    [0042] - in addition, it may comprise a coating of the central hole of the base body that guarantees a long service life and low friction movement of the sapphire rod.
    [0044] The main advantages introduced by the dielectric tuner object of the present invention are the following:
    [0045] - the dielectric tuner can be used to tune both the resonance frequency and the couplings of cavity-based waveguide filters,
    [0046] - does not require electrical contact with the filter body as no electrical current flows into the dielectric tuner, and
    [0047] - due to the value of the dielectric constant of sapphire, the diameter of the tuner and the linear movement of the tuner can be adjusted appropriately, such that the positioning precision required for a given application is within what is mechanically and economically feasible for the intended application.
    [0049] The dielectric tuner can also be used in any RF (radio frequency) or microwave device that uses manually adjustable tuning elements.
    [0051] DESCRIPTION OF THE DRAWINGS
    [0053] To complement the description that is made and in order to contribute to a better understanding of the characteristics of the invention, according to a preferred example of the practical embodiment thereof, a set of drawings is attached as an integral part of said description in which, for illustrative and non-limiting purposes, the following has been represented:
    [0055] Figure 1.- Shows a general view of the dielectric tuner.
    [0057] Figure 2.- Shows a table with the position of the dielectric tuner for different frequencies.
    [0059] Figure 3.- Shows a graph with five measurements of a filter centered at 12.995 GHz.
    [0060] Figure 4.- Shows a graph with five measurements of the same filter as in figure 3 but tuned to a central frequency equal to 12.389 GHz.
    [0062] Figure 5.- Shows a graph with five measurements of the same filter as in figures 3 and 4 but tuned to a central frequency of 11.918 GHz.
    [0064] Figure 6.- Shows a graph with five measurements of the same filter as in figures 3, 4 and 5 but tuned to a central frequency of 11.410 GHz.
    [0066] Figure 7.- Shows a graph with five measurements of the same filter as in figures 3, 4, 5 and 6 but tuned to a central frequency of 11.057 GHz.
    [0068] Figure 8.- Shows a group of sapphire rods, each one coupled to the filter and to a linear actuator.
    [0070] PREFERRED EMBODIMENT OF THE INVENTION
    [0072] With the aid of Figures 1 to 8, the preferred embodiment of the present invention is described below.
    [0074] Figure 1 shows a general view of a dielectric tuner (6), object of the invention, which comprises a solid circular sapphire rod (1), intended to penetrate the cavity of a resonator or the coupling opening of a filter (8). Attached to the sapphire rod (1), the tuner comprises a coupling head (2) which is connected, at an opposite end to the sapphire rod (1), which can be connected to a linear actuator (7).
    [0076] The dielectric tuner also comprises a base body (3), preferably metallic and with a hole in its center and a polytetrafluoroethylene (PTFE) coating, of the appropriate diameter in which the sapphire rod (1) can slide without significant friction. , when the linear actuator (7) moves the coupling head (2) and consequently the sapphire rod (1). PTFE guarantees minimal friction, resulting in a smooth tuning experience with no slip and stick effect. Furthermore, it should be noted that without the PTFE housing, metal wear can occur during the tuning process, which would damage both the base body (3) and the sapphire rod (1), and the filter (8) itself.
    [0077] The base body (3) can comprise a threaded section (4) that can be coupled to appropriate mechanical devices, for example, a thread (5), both to the filter (8) and to the linear actuator (7).
    [0079] Additionally, the dielectric tuner (6) may comprise a coating of the central hole of the base body (3) that guarantees a long service life and low friction movement of the sapphire rod (1). The liner is not shown in figure 1.
    [0081] Next, the results obtained with a prototype that demonstrates the functional behavior of the dielectric tuner (6) are described, in order to better understand and demonstrate its advantages.
    [0083] A proof of concept experiment was performed where, as shown in figure 8, a filter (8) was constructed with four sapphire rods (1) placed in the cavities and five more sapphire rods (1) in the openings, to tune or reconfigure the response of the filter (8) between 11 and 13 GHz. For this test, the channel bandwidth was set at 200 MHz. A positioning device was also used, specifically a linear actuator (7). The linear actuator (7) is provided with a specific control board and software to control its position.
    [0085] Previous studies have shown that sapphire tuners can provide the same tuning range as that obtained with metal tuners, but penetrating deeper into the filter (8). This is especially useful since the position of the tuners is critical for correct filter response.
    [0087] The filter (8) is fixed to a base in order to reduce unwanted movement as much as possible and to guarantee the repeatability of the measurements. The linear actuators (7) are placed on both sides of the filter (8) and are also fixed to the base. Each sapphire rod (1) is attached to a linear actuator (7) and is aligned with its respective hole in the filter (8).
    [0089] The next stage is to tune the filter (8) to different center frequencies. Figure 2 shows the relative position of the linear actuators (7) and consequently of the sapphire rods (1) for different central frequencies of the filter (8). As can be seen, when the filter (8) is tuned to a lower frequency, the sapphire rod (1) penetrates deeper into the filter (8).
    [0090] With all this information, filter measurements (8) can begin. For the test, the filter (8) is tuned to the center frequencies by entering in the software of the linear actuators (7) the values from the table in figure 1. In total, the filter (8) will be reconfigured and measured five times for each channel (or center frequency).
    [0092] As can be seen in Figures 3-7, the results show very good repeatability. For the higher frequencies, the results are better than for the lower frequencies. This behavior was expected since, for the lower channels, the sapphire rod (1) needs to penetrate more deeply into the filter (8) and, with the linear actuator (7) being outside, more instabilities are generated in the position. However, the performances of the filter (8) have recovered perfectly.
    [0094] In conclusion, the use of sapphire dielectric tuners (6) in combination with linear actuators (7) makes it possible to reconfigure the filter (8) automatically with the previously calculated table of the positions for the different channels. The different measurements show repeatability for each configured channel throughout the entire available bandwidth, being more critical at the lower frequencies.
    [0096] It is important to mention that, in addition to tuning the center frequency of the filter, the dielectric tuner (6) can also be used to tune the bandwidth of the filter (8).
    [0098] Finally, although the experiment has been carried out with a rectangular waveguide filter (8), the dielectric tuner (6) can in fact be used to tune a wide variety of cavity-based waveguide filters, or any other device for RF (radio frequency) or microwave using adjustable tuning elements.
    权利要求:
    Claims (7)
    [1]
    1. - A dielectric tuner (6), to tune or reconfigure a device (8) that uses cylindrical tuning elements inserted in a cavity to adjust its electrical performance, comprising:
    - a base body (3, 4) with a hole along its center,
    - a sapphire rod (1), positioned and linearly slidable inside the hole of the base body (3), and destined to penetrate a cavity of the device (8), and
    - a coupling head (2) attached to the sapphire rod (1) at an end opposite the cavity of the device (8) and intended to be attached to a linear actuator (7).
    [2]
    2. - The dielectric tuner (6) of claim 1, further comprising a coating of the hole of the base body (3).
    [3]
    3. - The dielectric tuner (6) of claim 1, wherein the sapphire rod (1) is cylindrical.
    [4]
    4. - The dielectric tuner (6) of claim 1, wherein the sapphire rod (1) is solid.
    [5]
    5. - The dielectric tuner (6) of claim 1, wherein the sapphire rod (1) is hollow.
    [6]
    6. - The dielectric tuner (6) of claim 1, further comprising clamping means (5) intended to hold the base body (3, 4) to the device (8) and / or to the linear actuator (7) .
    [7]
    7. - The dielectric tuner (6) of claim 6, wherein the base body (3) comprises a threaded section (4) attachable to the fastening means (5).
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    同族专利:
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    WO2021260247A1|2021-12-30|
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    WO2020011920A1|2018-07-12|2020-01-16|Commscope Italy Srl|Tuning elements with reduced metal debris formation for resonant cavity filters|
    法律状态:
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    优先权:
    申请号 | 申请日 | 专利标题
    ES202030640A|ES2785801B2|2020-06-25|2020-06-25|Dielectric tuner|ES202030640A| ES2785801B2|2020-06-25|2020-06-25|Dielectric tuner|
    PCT/ES2021/070460| WO2021260247A1|2020-06-25|2021-06-21|Dielectric tuner|
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