An impedance matching arrangement

Abstract

The present disclosure relates to an impedance matching arrangement (100, 200) comprising a first port (101, 201), a second port (102, 202), a transmission line (103, 109; 203, 228) configured to guide electromagnetic waves between the first and second ports (101, 102; 201, 202), and a movably attached dielectric part (104, 105; 204, 205). The transmission line is formed by a first conductor (103, 203) and a second conductor (109, 228) and comprises a primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) and a secondary section, (106, 107; 146, 147; 206, 207). The dielectric part (104, 105; 204, 205) comprises a dielectric material arranged adjacent to the first conductor (103, 203) and / or the second conductor (109, 228) of a part of the transmission line (103, 109; 203, 228) and arranged movable along the transmission line (103, 109; 203, 228). In absence of the dielectric part (104, 105; 204, 205), the primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) has a primary local characteristic impedance (Z0) and the secondary section (106, 107; 146, 147; 206, 207) has a secondary local characteristic impedance (Z1, Z2) different from the primary local characteristic impedance (Z0).

Description

[0001] TITLE

[0002] An impedance matching arrangement

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to an impedance matching arrangement comprising: a first port, a second port, a transmission line configured to guide electromagnetic waves between the first and second ports and a movably attached dielectric part. The present disclosure also relates to array antennas comprising the impedance matching arrangement and a network node comprising the array antennas.

[0005] BACKGROUND

[0006] A typical antenna for mobile communication usually consists of multiple array antennas which in turn typically is composed of several components which are interconnected by a distribution network comprising cables or other forms of transmission lines such as for example microstrip, stripline and metal structure conductors. Signals that travel between antenna ports and antenna radiating elements are subject to different forms of losses in the form of transmission losses and return loss, where the latter is a measure of the reflected power due to impedance mismatches.

[0007] Both add to total losses and need to be minimized to increase output to input power ratio which translates to higher efficiencies. Practically, when developing antennas (and their sub- components) the design goal is to use materials with low attenuation levels, short signal paths and well-matched sub-components to achieve certain loss and / or efficiency requirements.

[0008] Return loss (RL) can be represented in the form of Voltage Standing Wave Ratio (VSWR) that is defined as the ratio between the maximum voltages of the transmitted and reflected signal power, and the RL and VSWR are related according to the below:

[0009] SL = -201og ( p ) (1)

[0010] p = 10 (2)

[0011] P = l-Snl (3)

[0012] ITSW / ? = (4)

[0013]

[0014] P = - (5)

[0015] Where p is a reflection coefficient and

[0016]

[0017] is a matrix element of a two-port scattering parameter matrix. With several components cascaded within an array antenna, the possibility of impedance mismatches increases. As the components are developed in parallel according to their own set of requirements and their final performance is uncertain, their interplay on antenna level including the resulting RL cannot fully be predicted beforehand. If the assembled array antenna does not comply with specifications regarding RL, either a re- design of components or a better matching of the components using tuning mechanisms is required.

[0018] Some components like phase shifters may incorporate possibilities for tuning, while the tuning range provided often is insufficient. Another possibility for adjustments would be the varying of transmission line lengths between the components as matching may be improved with different phase relations between components. Usually, this only has a desired effect in limited frequency ranges.

[0019] All the available solutions for an assembled array antenna that does not comply with specifications regarding RL are inefficient as they would increase time to market as well as development costs which may disrupt business cases aimed at commercially successful antenna products.

[0020] Passive load tuners are well-known and are typically stand-alone measurement devices used to generate a range of different loads when connected to a certain device under test (DUT), subsequently changing the matching. Presenting different loads to the DUT enables a performance evaluation of said DUT under various framework conditions. These tuners are usually quite massive, expensive devices whose tuning range regarding e.g. impedance changes, bandwidth and other properties, like power handling and sensitivity, does not reach the performance that would be required for the problem described. This is further preventing their integration into an antenna already designed and optimized for size and cost.

[0021] It is desired to provide an impedance matching arrangement that enables an assembled array antenna that initially does not comply with specifications regarding RL to comply with these specifications, while being inexpensive and easy to integrate. The impedance matching arrangement should be uncomplicated and easily maneuverable such that each assembled array antenna can be tuned to meet an acceptable RL in an efficient manner, preferably across a relatively large frequency band of operation, such as for example 1.4 - 2.7 GHz.

[0022] SUMMARY

[0023] It is an object of the present disclosure to provide an impedance matching arrangement that enables an assembled array antenna that does initially does not comply with specifications regarding RL to comply with these specifications, while being inexpensive and easy to integrate. The impedance matching arrangement should be uncomplicated and easily maneuverable such that each assembled array antenna can be tuned to meet an acceptable RL in an efficient manner, preferably across a relatively large frequency band of operation, such as for example 1.4 - 2.7 GHz.

[0024] This object is achieved by means of an impedance matching arrangement comprising a first port, a second port, a transmission line configured to guide electromagnetic waves between the first and second ports and a movably attached dielectric part. The transmission line is formed by a first conductor and a second conductor and comprises a primary section and a secondary section. The dielectric part comprises a dielectric material arranged adjacent to the first conductor and / or the second conductor of a part of the transmission line and arranged movable along the transmission line. In absence of the dielectric part, the primary section has a primary local characteristic impedance and the secondary section has a secondary local characteristic impedance different from the primary local characteristic impedance.

[0025] This means that the transmission line has two different local characteristic impedances in absence of the dielectric part, and a variable local characteristic impedance along a part of the transmission line that is affected and changed when the dielectric part is placed adjacent to said part and when the dielectric part is moved along the transmission line. In this way, when a port is terminated with a load, for example with an impedance equal to the primary local characteristic impedance, the input impedance at the other port can be varied and thus tuned by moving a dielectric part.

[0026] According to some aspects, the dielectric part is arranged to selectively affect wave propagation conditions for a part of the transmission line depending on the position of the dielectric part along the transmission line. This means that the local characteristic impedance is effectively changed in response to movement of a dielectric part.

[0027] According to some aspects, the impedance matching arrangement is configured such that a local characteristic impedance of the secondary section is more similar to the primary local characteristic impedance when the dielectric part is positioned mainly along the secondary section as compared to when the dielectric part is positioned mainly along the primary section.

[0028] This means that when the dielectric parts are positioned mainly along the corresponding secondary sections, the local characteristic impedance along all parts of the transmission line can be set to mainly correspond to the primary local characteristic impedance, which can constitute a default or neutral position. This normally means that when a port is terminated with a load that has an impedance equal to the primary local characteristic impedance, the input impedance at the other port will be equal to, or at least similar to, the primary local characteristic impedance. This way, the dielectric parts can be positioned such that the impedance matching arrangement confers a small or even insignificant effect on the impedance where it is mounted, and the influence of the mounted impedance matching arrangement can thus be more or less neutralized if desired. This also means that a default or neutral position is provided which can constitute a suitable starting point for an impedance matching procedure.

[0029] According to some aspects, in the primary section, a corresponding section of the first conductor and a corresponding section of the second conductor have respective first shapes. Furthermore, in the secondary section, the shape of a corresponding section of the first conductor and / or the second conductor is different than in the primary section of the transmission line.

[0030] This means that in absence of any dielectric part, the primary local characteristic impedance and the secondary local characteristic impedances can be defined by means of the shapes of the corresponding sections According to some aspects, the first shape of the first conductor corresponds to a first conductor width, and in the secondary section the shape of the first conductor corresponds to a reduction of conductor width of the transmission line in relation to the first conductor width. This means that in absence of any dielectric part, the primary local characteristic impedance and the secondary local characteristic impedances can be defined by means of the width of the first conductor.

[0031] According to some aspects, the impedance matching arrangement further comprises a plurality of primary sections, where each primary section of the plurality of primary sections, in absence of any dielectric part, has the primary local characteristic impedance. According to some further aspects, the impedance matching arrangement further comprises a plurality of secondary sections, and a respective movably attached dielectric part for each secondary section of the plurality of secondary sections. Each dielectric part comprises a respective dielectric material arranged adjacent to the first conductor and / or the second conductor of a respective part of the transmission line and arranged movable along the transmission line. In absence of any dielectric part, each secondary section of the plurality of secondary sections has a respective local characteristic impedance different from the primary local characteristic impedance.

[0032] This enables a plurality of dielectric parts or dielectric materials to be used, which increases the variation possibilities significantly. Having for example two dielectric parts means that these can be shifted in the same direction, away or towards each other. One dielectric part can remain in the default position while the other dielectric part is moved and vice versa. Not only are there two different positions where a local impedance change is generated, but also the distance between these positions is variable. This is influencing phase relations within the impedance matching arrangement, and between the impedance matching arrangement and the devices / components / periphery connected to the ports, contributing further to the possible level of electrical influence.

[0033] According to some aspects, every other section is a primary section and every other section is a secondary section, where there is a primary section adjacent each of the first and the second ports. This enables sufficient space for moving a dielectric part away from a secondary section.

[0034] According to some aspects, each dielectric material is arranged between the first conductor and the second conductor. According to some further aspects, each dielectric material is in contact with the first conductor and / or the second conductor. This provides a controllable and predictable influence for each dielectric material.

[0035] According to some aspects, each port comprises a radio frequency (RF) connector. This means that the ports can be connected to, and removed from, other components in an easily performed and well-controlled manner.

[0036] According to some aspects, the first conductor is constituted by a metal sheet part. This means that the first conductor can be stamped or cut from a metal sheet. According to some aspects, each RF connector comprises a contact pin that is adapted to be received in a corresponding slot in the first conductor. This is in particular suitable in the case where the first conductor is constituted by a metal sheet part.

[0037] According to some aspects, the first conductor is formed as a metal conductor that runs on a dielectric carrier material This means that the first conductor can be formed by means of an etching process in a previously well-known manner.

[0038] According to some aspects, there is a metal conductor on opposite sides of the dielectric carrier material, where the metal conductors are electrically connected by means of vias. This allows both metal conductors to act as one common conductor.

[0039] According to some aspects, the impedance matching arrangement further comprises a housing, where the first conductor extends in the housing that constitutes the second conductor. Each dielectric part is movably attached to the housing. The housing may provide rigidity to the impedance matching arrangement and may also constitute ground.

[0040] According to some aspects, the housing comprises a first wall part and a second wall part that extend opposite each other, the first conductor extending between the wall parts. Each wall part has a corresponding first edge and a corresponding second edge, opposite the first edge. Each dielectric part comprises a handle part and snap-fit engagement means, where each handle part is adapted to slide on the first edges and where the snap-fit engagement means are adapted to be in locking engagement with, and slide on, the second edges.

[0041] This means that the impedance matching arrangement can be easily assembled, and different types of dielectric part, having different dielectric properties, can be employed. This also means that the impedance matching arrangement can form a rigid and durable structure that can be easily replaced and re-used.

[0042] According to some aspects, the dielectric carrier material comprises a first main side and a second main side, where the first main side comprises the first conductor and the second main side comprises the second conductor that is constituted by a metal ground plane. The dielectric carrier material further comprises a slot that runs mainly along the transmission line. Each dielectric part comprises a handle part and snap-fit engagement means, where each handle part is adapted to slide along the slot on the first main side and where each snap-fit engagement means is adapted to be in locking engagement with, and slide on, the second main side via the aperture.

[0043] In this way, an impedance matching arrangement based on a printed circuit board (PCB) provided, which for example can be easily formed in, or mounted to, an existing PCB such as for example a PCB with a distribution network, for example as a drop-in component. The dielectric parts can be easily mounted to the dielectric carrier material by means of the snap-fit engagement means. According to some aspects, the impedance matching arrangement further comprises motor means adapted to move each dielectric part. The motor means enable a more or less automatic tuning procedure to be performed.

[0044] This object is also achieved by means of linear array antennas, two-dimensional array antennas and network nodes that are associated with the above advantages.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present disclosure will now be described more in detail with reference to the appended drawings, where:

[0047] Figure 1 shows a schematic view of a linear array antenna according to a first example;

[0048] Figure 2 shows a schematic view of a linear array antenna according to a second example;

[0049] Figure 3 shows a schematic view of a two-dimensional array antenna;

[0050] Figure 4 shows a top perspective view of the impedance matching arrangement according to a first example;

[0051] Figure 5 shows a bottom perspective view of the impedance matching arrangement according to the first example;

[0052] Figure 6 shows a side perspective view of the impedance matching arrangement according to the first example;

[0053] Figure 7 shows an exploded side perspective view of the impedance matching arrangement according to the first example;

[0054] Figure 8 shows a side view of an alternative transmission line;

[0055] Figure 9 shows a detail of connector attachment to the transmission line of the first example;

[0056] Figure 10 shows a top perspective view of an impedance matching arrangement according to a second example without attached dielectric parts;

[0057] Figure 11 shows a top perspective view of the impedance matching arrangement according to the second example with attached dielectric parts;

[0058] Figure 12 shows a side view of the impedance matching arrangement according to the second example;

[0059] Figure 13 shows a simulated impedance for an impedance matching arrangement illustrated in Smith chart; Figure 14 shows a detail of Figure 13;

[0060] Figure 15 shows simulations of how the antenna impedance can be tuned by means of the impedance matching arrangement, illustrated as VSWR; and

[0061] Figure 16 shows a schematic view of a network node.

[0062] DETAILED DESCRIPTION

[0063] Aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings. The different devices, systems, computer programs and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

[0064] The terminology used herein is for describing aspects of the disclosure only and is not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0065] Figure 1 shows a first example of a linear array antenna 300 and Figure 2 shows a second example of a linear array antenna 400. The linear array antenna 300, 400 comprises a plurality of linearly arranged antenna elements 301, 401, at least one antenna port 302, 402, 403 and a distribution network 304, 404 that is adapted to transfer signals between the antenna elements 301, 401 and said antenna port 302, 402, 403. The distribution network 304, 404 comprises at least one impedance matching arrangement 100 that will be described more in detail in the following.

[0066] In this context, a linear array antenna having linearly arranged antenna elements means that the antenna elements are arranged along a line. Such a line is normally more or less straight, but a curved or arcuate line is also conceivable.

[0067] Figure 3 shows a two-dimensional array antenna 500 comprising at least one row 510, 511 of linear array antennas 300, 400 according to the above, each row 510, 511 comprising two or more linear array antennas 300, 400. In this example there are two rows 510, 511 of linear array antennas 300, 400, each row 510, 511 comprising eight linear array antennas 300, 400.

[0068] Now turning to Figure 4-Figure 9, a first example of an impedance matching arrangement 100 will be described. The impedance matching arrangement 100 generally comprises a first port 101, asecond port 102, a transmission line 103, 109 configured to guide electromagnetic waves, or signals, between the first and second ports 101, 102, and a movably attached dielectric part 104, 105. Figure 4 shows a top perspective view of the impedance matching arrangement 100, Figure 5 shows a bottom perspective view of the impedance matching arrangement 100 and Figure 6 shows a side perspective view of the impedance matching arrangement 100. Furthermore, as indicated in the exploded view of the impedance matching arrangement 100 in Figure 7, the transmission line 103, 109 generally comprises a primary section 108a, 108b, 108c; 148a, 148b, 148c and a secondary section, 106, 107; 146, 147. The dielectric part 104, 105 comprises a dielectric material arranged adjacent to the first conductor 103 and / or the second conductor 109 of a part of the transmission line 103, 109 and arranged movable along the transmission line 103, 109.

[0069] In absence of the dielectric part 104, 105, the primary section 108a, 108b, 108c; 148a, 148b, 148c has a primary local characteristic impedance Zo and the secondary section 106, 107; 146, 147 has a secondary local characteristic impedance Zi, Z2 different from the primary local characteristic impedance Zo.

[0070] The characteristic impedance of a uniform transmission line may normally be described as the ratio of the amplitudes of voltage and current of a wave travelling in one direction along the uniform transmission line in absence of reflections in the other direction. Herein, the 'local characteristic impedance' may be described as a local property of the transmission line 103, 109. In some examples, each primary section and each secondary section are locally uniform.

[0071] This means that the transmission line 103, 109 has two different local characteristic impedances in absence of the dielectric part 104, 105, and a variable local characteristic impedance along a part of the transmission line that is affected and changed when the dielectric part 104, 105 is placed adjacent to said part and when the dielectric part is moved along the transmission line. In this way, when a port 101 is terminated with a load, for example with an impedance equal to the primary local characteristic impedance Zo, the input impedance at the other port 102 can be varied and thus tuned by moving a dielectric part 104, 105. In this example there is a first movably attached dielectric part 104, and a second movably attached dielectric part 105, and one of them, or both, can be moved in order to enable such a tuning. According to some aspects, each dielectric part 104, 105 is arranged to selectively affect wave propagation conditions for a part of the transmission line 103, 109 depending on the position of each dielectric part 104, 105 along the transmission line 103, 109. This means that the local characteristic impedance is effectively changed in response to movement of a dielectric part 104, 105.

[0072] Each dielectric material 104, 105 may according to some aspects be arranged between the first conductor 103 and the second conductor 109 as shown in for example Figure 5. Each dielectric material 104, 105 may according to some aspects be in contact, preferably mechanical contact, with the first conductor 103 and / or the second conductor 109. This provides a controllable and predictable influence for each dielectric material 104, 105.

[0073] The dielectric material of each dielectric part 104, 105 can be made from a range of dielectric materials. They may vary in electrical parameters such as in particular dielectric constant, relative permittivity and dielectric dissipation factor, as well as mechanical properties such as in particular material density, tensile strength, various thermal properties, depending on their desired use. Materials from commonly used material classes such as for example Cyclic Olefin Copolymer (COG), Cyclic Olefin Polymer (COP), Polytetrafluoroethylene (PTFE), Perfluoroalkoxy (PFA), Polymethylpentene (PMP), Polystyrene (PS), Polypropylene (PP) or Polyethylene (PE) can be utilized, with others possible. The dielectric constants may vary from 2 to 10, with other values possible but typical ranges from 2 to 4.

[0074] As illustrated in this example, there is a first primary section 108a, 148a, a second primary section 108b, 148b and a third primary section 108c, 148c. Generally, and according to some aspects, the impedance matching arrangement 100 comprises a plurality of primary sections 108a, 108b, 108c; 148a, 148b, 148c, where each primary section of the plurality of primary sections, in absence of any dielectric part 104, 105 has the primary local characteristic impedance Zo.

[0075] Furthermore, as illustrated in this example, there is a first secondary section 106, 146 and a second secondary section 107, 147. Generally, and according to some aspects, the impedance matching arrangement 100 comprises a plurality of secondary sections 106, 107; 146, 147, and a respective movably attached dielectric part 104, 105 for each secondary section 106, 107; 146, 147, of the plurality of secondary sections, wherein each dielectric part 104, 105; comprises a respective dielectric material arranged adjacent to the first conductor 103 and / or the second conductor 109 of a respective part of the transmission line 103, 109 and arranged movable along the transmission line 103, 109. Each secondary section of the plurality of secondary sections, in absence of any dielectric part 104, 105, has a respective secondary local characteristic impedance Zi, Z2 different from the primary local characteristic impedance Zo. This means that there may be one dielectric part 104, 105 for each secondary section 106, 107; 146, 147.

[0076] Some or all secondary local characteristic impedances Z1, Z2 may have mutually different or mutually equal magnitudes in absence of the dielectric part 104, 105.

[0077] This enables a plurality of dielectric parts 104, 105 or dielectric materials to be used, which increases the variation possibilities significantly.

[0078] According to some aspects, the impedance matching arrangement 100 is configured such that a local characteristic impedance Z'1, Z'2 of the secondary section 106, 107; 146, 147 is more similar to the primary local characteristic impedance Zo when a dielectric part 104, 105 is positioned mainly along the corresponding secondary section 106, 107; 146, 147 as compared to when the dielectric part 104, 105 is positioned mainly along a primary section 108a, 108b, 108c; 148a, 148b, 148c. Each local characteristic impedance Z'1, Z'2 of the secondary section 106, 107; 146, 147 in presence of a dielectric part 104, 105 differs from the corresponding secondary local characteristic impedance Z1, Z2 in absence of any dielectric part 104, 105.

[0079] This means that when the dielectric parts 104, 105 are positioned mainly along the corresponding secondary sections 106, 107; 146, 147, the local characteristic impedance along all parts of the transmission line 103, 109 can be set to mainly correspond to the primary local characteristic impedance Zo, which can constitute a default position. This normally means that when a port 101 is terminated with a load that has an impedance equal to the primary local characteristic impedance Zo, the input impedance at the other port 102 will be equal to, or at least similar to, the primary local characteristic impedance Zo. When the dielectric parts 104, 105 are moved away from the corresponding secondary sections 106, 107; 146, 147, the local characteristic impedance at the corresponding secondary sections 106, 107; 146, 147 is changed towards the secondary local characteristic impedance Zi, Z2, and tuning can be performed as described above.

[0080] In other words, with the movement of a dielectric parts 104, 105 away from the default position, or neutral position, the impedance at the ports 101, 102 is changed, influencing electrical behavior of the impedance matching arrangement 100. With this mechanism the RL / VSWR-levels of devices connected to the ports 101, 102 can be influenced and tuned.

[0081] This way, the dielectric parts 1043, 105 can be positioned such that the impedance matching arrangement 100 confers a small or even insignificant effect on the impedance where it is mounted, and the influence of the mounted impedance matching arrangement 100 can thus be more or less neutralized if desired. This also means that a default or neutral position is provided which can constitute a suitable starting point for an impedance matching procedure.

[0082] Introducing more than one dielectric part 104, 105, in this example two dielectric parts 104, 105, increases the variation possibilities significantly. The two dielectric parts 104, 105 in the present example can for example be shifted in the same direction away or towards each other. One dielectric part can remain in the default position while the other dielectric part is moved and vice versa. Not only are there two different positions where a local impedance change is generated, but also the distance between these positions is variable. This is influencing phase relations within the impedance matching arrangement 100, and between the impedance matching arrangement 100 and the devices / components / periphery connected to the ports 101, 102, contributing further to the possible level of electrical influence.

[0083] According to some aspects, in each primary section 108a, 108b, 108c; 148a, 148b, 148c, a corresponding section 108a, 108b, 108c of the first conductor 103 and a corresponding section 148a, 148b, 148c of the second conductor 109 have respective first shapes. Furthermore, in each secondary section 106, 107; 146, 147, the shape of a corresponding section 106, 107; 146, 147 of the first conductor 103 and / or the second conductor 109 is different than in the primary section 108a, 108b, 108c; 148a, 148b, 148c of the transmission line 103, 109. From this it follows that in each secondary section 106, 107; 146, 147 a corresponding section 106, 107 of the first conductor 103 and a corresponding section 146, 147 of the second conductor have respective secondary shapes that differ from the respective first shapes. The first shapes may be mutually equal or mutually more or less different from each other. In the same way, the secondary shapes may be mutually equal or mutually more or less different from each other.

[0084] This means that in absence of any dielectric part 104, 105, the primary local characteristic impedance Zo and the secondary local characteristic impedances Z1, Z2 can be defined by means of the shapes of the corresponding sections 108a, 108b, 108c, 148a, 148b, 148c; 106, 107, 146, 147. The first conductor 103 and the second conductor 109 are preferably mainly separated by air although one or more dielectric materials also can be used. The dielectric properties of the material or substance that separate the first conductor 103 and the second conductor 109 can also be seen as a factor determining the respective local characteristic impedance Zo, Zi, Z2 in absence of any dielectric part 104, 105.

[0085] According to some aspects, the transmission line is formed by a first conductor 103 and a second conductor 109. and, as illustrated in Figure 7, the first conductor 103 can be constituted by a metal sheet part. This means that the first conductor 103 can be stamped or cut from a metal sheet.

[0086] The first conductor 103 and the second conductor 109 basically need to be a combined structure able to carry radio frequency (RF) signals. Instead of a flat sheet metal it may also be a differently shaped metal layout, created with a different manufacturing process. For example, a turned part, circular or not. It may as well be a punched, lasered, extruded, wire-cutted, milled, die-casted or 3D-printed element, or multiple, separate ones combined. Combinations of these are of course also possible.

[0087] Preferably, common materials like aluminum, brass, copper, steel or certain alloys are used, where the surface of the first conductor 103 may be coated with a material enabling soldering processes, e.g. tin, or which additionally reduces transmission losses, e.g. silver.

[0088] Alternatively, as illustrated in Figure 8, the first conductor 103' is formed as a metal conductor 103' that runs on a dielectric carrier material 130. This means that the first conductor 103' can be formed by means of an etching process in a previously well-known manner. According to some aspects, there is a metal conductor 103' on opposite sides of the dielectric carrier material 130 (only one metal conductor 103' shown in Figure 8), where the metal conductors 103' are electrically connected by means of vias 116. In this way, the metal conductors 103' on opposite sides of the dielectric carrier material 130 are connected in a way that allows both metal conductors 103' to act as one common conductor.

[0089] According to some aspects, the first shape of the first conductor 103 corresponds to a first conductor width wi, and in the secondary section 106, 107; 146, 147; 206, 207 the shape of first conductor 103, here the secondary shape, corresponds to a reduction of conductor width W2, W3 of the transmission line 103 in relation to the first conductor width wi. This means that in absence of any dielectric part 104, 105, the primary local characteristic impedance Zo and the secondary local characteristic impedances Z1, Z2 can be defined by means of the width w1 of the first conductor 103.

[0090] According to some aspects, as shown in Figure 7 and Figure 8, every other section is a primary section 108a, 108b, 108c; 148a, 148b, 148c, and every other section is a secondary section 106, 107; 146, 147, where there is a primary section adjacent each of the first and the second ports 101, 102. This enables sufficient space for moving a dielectric part 104, 105 away from a secondary section 106, 107; 146, 147. There may be any suitable number of primary sections 108a, 108b, 108c; 148a, 148b, 148c and secondary sections 106, 107; 146, 147. In the following, the first example will be described in more detail. According to some aspects, the first conductor 103 comprises a first primary section 108a, a second primary section 108b and a third primary section 108c, where each primary section 108a of the first conductor 103 has the first conductor width wi that in absence of any dielectric part 104, 105 presents a local transmission line characteristic impedance that is the primary local characteristic impedance Zo, which for example may be 50Q.

[0091] The first conductor 103 further comprises a first secondary section 106 and a second secondary section 107 where the first secondary section 106 of the first conductor 103 has a second conductor width W2 and where the second secondary section 107 of the first conductor 103 has a third conductor width W3. In absence of any dielectric part 104, 105, the first secondary section 106 and the second secondary section 107 of the first conductor 103 presents a local transmission line characteristic impedance that corresponds to the secondary local characteristic impedance Z1, Z2. The second conductor width W2 and the third conductor width W3 both fall below the first conductor width wi thus resulting in that the corresponding secondary local characteristic impedance Z1, Z2 exceeds the primary local characteristic impedance Zo in absence of any dielectric part 104, 105. The second conductor width W2 and the third conductor width W3 may be equal, or mutually different. If the second conductor width W2 and the third conductor width W3 differ from each other, the corresponding secondary local characteristic impedance Z1, Z2 also differ from each other in absence of any dielectric part 104, 105.

[0092] In absence of any dielectric part 104, 105, the primary local characteristic impedance Zo falls below the secondary local characteristic impedance Z1, Z2 since bringing a dielectric part 104, 105 mainly along the secondary section 106, 107; 146, 147 intends to decrease the local characteristic impedance at the secondary section 106, 107; 146, 147.

[0093] As mentioned previously, the local characteristic impedance Z'1, Z'2 of a secondary section 106, 107; 146, 147 is changed to be more similar to the primary local characteristic impedance Zo when a corresponding dielectric part 104, 105 is positioned mainly along the secondary section 106, 107; 146, 147 as compared to when the dielectric part 104, 105 is positioned mainly along a primary section 108a, 108b, 108c; 148a, 148b, 148c. If the second conductor width W2 and the third conductor width W3 differ from each other, the dielectric parts 104, 105 may need to have different dielectric properties to achieve this.

[0094] The dimensions and the material properties of the dielectric parts 104, 105 may be chosen to compensate the impedance step caused by the second conductor width W2 of the secondary sections 106, 107 of the first conductor 103 such that a secondary section 106, 107; 146, 147 of the transmission line 103, 109 presents a local characteristic impedance that is equal to, or at least close to, the primary local characteristic impedance Zo when a dielectric part 104, 105 is positioned mainly along the secondary section 106, 107; 146, 147, i.e., in the neutral position.

[0095] According to some aspects, in absence of any dielectric part 104, 105, the primary local characteristic impedance Zo has a magnitude that is between 5-25 %, preferably 5-15%, smaller than each secondary local characteristic impedance Z1, Z2. If, for example, the primary local characteristic impedance Zo is —50,0 and the secondary local characteristic impedance Zi, Z2 is 53.5 in absence of any dielectric part 104, 105, the dielectric parts 104, 105 only need to compensate a relatively small impedance step of about -3.5Q. This impedance step will bring the local characteristic impedance at the secondary section 106, 107; 146, 147 towards the same value as the primary local characteristic impedance Zo in absence of any dielectric part 104, 105, when a dielectric part 104, 105 is positioned mainly along the secondary section 106, 107; 146, 147, i.e., in the neutral position. This means that only a relatively small amount of dielectric material with a low relative permittivity is required, for example PTFE dielectric constant sr= 2.1. In order to avoid too small dimensions that are difficult to manufacture and control, the dielectric parts 104, 105 may be equipped with lateral apertures or structures of similar configuration that reduce the accumulation of dielectric material, while still enabling a robust structure.

[0096] Moving a dielectric part 104, 105 away from the neutral position influences the impedance ratios. When the dielectric part 104, 105 is covering or being positioned adjacent sections 108a, 108b, 108c; 106, 107 of the first conductor 103, the local characteristic impedance is decreased, while sections 108a, 108b, 108c; 106, 107 of the first conductor 103 from which the dielectric part 104, 105 has been removed, acquire an increased local characteristic impedance. Moving the dielectric part 104, 105 forward or backward evokes a different behavior as the positions of the local characteristic impedance changes, providing avery good tuning range for the impedance at the ports 101, 102 since many movement options are available.

[0097] According to some aspects, the impedance matching arrangement 100 further comprises a housing 109, where the first conductor 103 extends in the housing 109 that constitutes the second conductor 109, and where each dielectric part 104, 105 is movably attached to the housing 109. This means that the first conductor 103 and the housing together form transmission line 103, 109. The housing may provide rigidity to the impedance matching arrangement 100 and as exemplified here, the housing 109 may constitute ground.

[0098] As mentioned previously, according to some aspects, the shape of a corresponding section 106, 107; 146, 147 of the first conductor 103 and / or the second conductor 109 is different than in the primary section 108a, 108b, 108c; 148a, 148b, 148c of the transmission line 103, 109. This means that in absence of any dielectric part 104, 105 the difference between the primary local characteristic impedance Zo and the secondary local characteristic impedances Z1, Z2 do not need to be defined by means of the shape of the first conductor 103 as exemplified above, but also by means of the shape of the second conductor 109, for example by means of the shape of the housing 109, possibly in combination with the shape of the first conductor 103. Then the dielectric part 104, 105 is movable mainly along and adjacent to the housing 109.

[0099] According to some aspects, the housing 109 comprises a first wall part 114 and a second wall part 115 that extend opposite each other, the first conductor 103 extending between the wall parts 114, 115. Each wall part 114, 115 has a corresponding first edge 116, 117 and a corresponding second edge 118, 119, opposite the first edge 116, 117. Each dielectric part 104, 105 comprises a handle part 121, 122 and snap-fit engagement means 123, 124, where each handle part 121, 122 is adapted to slide on the first edges 116, 117 and where the snap-fit engagement means 123, 124 are adapted to be in locking engagement with, and slide on, the second edges 118, 119. This means that the impedance matching arrangement 100 can be easily assembled, and different types of dielectric part 104, 105, having different dielectric properties, can be employed. This also means that the impedance matching arrangement 100 can form a rigid and durable structure that can be easily replaced and be re-used.

[0100] As described previously for the first conductor 103, the housing 109 may be designed in various ways. It may fully enclose the first conductor 103 or only in part. It may further contain openings / apertures enabling assembly or joining processes like soldering. It could be a single piece or made of multiple parts. The housing 109 may be a stand-alone device or integrated into its surrounding periphery adopting its properties.

[0101] Furthermore, the housing 109 can also be designed in many different ways, with various production processes. For example, it can be formed as a turned part, hollow, circular or not. It may as well be a punched, lasered, extruded, wire-cut, milled, die-casted or 3D-printed element or multiple, separate ones combined. Of course, combinations are also possible.

[0102] Preferably common materials like aluminum, brass, copper, steel or certain alloys are used with others possible in certain circumstances. The surface of the structure may be coated with a material enabling soldering processes, e.g. tin, or which additionally reduces transmission losses, e.g. silver. It may also be a metallized plastic part.

[0103] In the example shown, since the housing 109 retains its dimensions along its length, impedance changes can be easily obtained by changing the dimensions of the first conductor 103. While the thickness of the first conductor 103 is kept constant, this is achieved by changing the width only, as mentioned above.

[0104] As shown in the example above, the transmission line 103, 109 extends along a longitudinal extension E, the first conductor 103 extending between the wall parts 114, 115. The transmission line 103, 109 may, however, at least partly follow an arcuate path instead.

[0105] A sheet metal may thus form the first conductor 103 which is surrounded by the housing 109 that suitably is a metal housing, or at least a metalized housing. With reference also to Figure 1, the ports 101, 102 can for example comprise open first conductor ends that, in the case of a distribution network based on printed circuit board (PCB) technology, are soldered to matching distribution network conductors 350, 351 while the housing 109 is soldered to a ground plane or other ground connection. In the case of an RF cable distribution network, the impedance matching arrangement 100 can be designed with cable interfaces accommodating these, for example the ports 101, 102 may comprise open first conductor ends that alternatively can be soldered to RF cable inner conductors and the housing 109 can be soldered to RF cable outer conductors. The ports 101, 102 can alternatively comprise RF connectors 110, 111 as mentioned above, allowing the impedance matching arrangement 100 to be screwed or plugged to a mating RF connector. Such RF connectors 110, 111 are suitable soldered to the first conductor 103. The ports may also comprise embedded ports 101, 102 and connection means in case the impedance matching arrangement 100 is intended to form an integrated drop-in component.

[0106] The ports 101, 102 may comprise different interfaces depending on the technology of the interconnections or periphery they are supposed to be connected to.

[0107] In the following, a second example of an impedance matching arrangement 200 will be described with reference to Figure 10 - Figure 12. Here, according to some aspects, the first conductor 203 is formed as a metal conductor 203 that runs on a dielectric carrier material 230 in a manner similar to the example described above with reference to Figure 8.

[0108] The dielectric carrier material 230 comprises a first main side 225 and a second main side 226, where the first main side 225 comprises the first conductor 203 and the second main side 226 comprises the second conductor that is constituted by a metal ground plane 228. The transmission line is thus constituted by the first conductor 203 and the metal ground plane 228, and comprises a primary section 208a, 208b, 208c and a secondary section 206, 207 having characteristics and functionality which are the same or similar to those described above for the first example.

[0109] The dielectric carrier material 230 further comprises a slot 227 that runs mainly along the transmission line 203. Furthermore, each dielectric part 204, 205 comprises a handle part 221, 222 and snap-fit engagement means 223, 224, where each handle part 221, 222 is adapted to slide along the slot 227 on the first main side 225. Each snap-fit engagement means 223, 224 are adapted to be in locking engagement with, and slide on, the second main side 226 via the aperture 227.

[0110] In this way, a PCB-based impedance matching arrangement 200 is provided, which for example can be easily formed in, or mounted to, an existing PCB such as for example a PCB with a distribution network, for example as a drop-in component. The dielectric parts 204, 205 can be easily mounted to the dielectric carrier material 230 by means of the snap-fit engagement means 223, 224. With reference also to Figure 1, the ports 201, 202 can for example comprise open conductor ends that are soldered to matching distribution network conductors 350, 351, or can alternatively comprise RF connectors 210, 211.

[0111] The PCB-based impedance matching arrangement 200 is according to some aspects, formed as a dielectric material sheet 230 with copper claddings 203, 228 on the main sides 225, 226, where copper has been partially removed to form the metal structures on each main side, for example by means of etching. Generally, in this context a PCB can comprise several layers of dielectric material sheets with metal layers formed on the outer main sides as well as sandwiched between them. Using copper is of course only an example, other metals are of course possible such as silver and gold. Silver and gold can also be used as plating materials for a base metal such as copper. The dielectric material can be of many types, for example glass-fiber re-enforced epoxy or Polytetrafluoroethylene (PTFE) as well as different types of ceramic materials. A PCB can comprise layers of different mixed dielectric materials. The dielectric material can according to some aspects be formed in the same material as the dielectric parts 204, 205.

[0112] The impedance matching arrangement according to the second example mainly corresponds to the impedance matching arrangement according to the first example as described previously. The configuration of the transmission line 203, 228 and its primary and secondary sections are the same. For example, in absence of any dielectric part 204, 205, each primary section 208a, 208b, 208c has a primary local characteristic impedance Zo and each secondary section 206, 207 has a secondary local characteristic impedance Zi, Z2 different from the primary local characteristic impedance Zo. The tuning and workings of the impedance matching arrangement according to second example mainly corresponds to the impedance matching arrangement according to the first example, it is merely the basic structures that are formed in different manners.

[0113] It should be noted that, as mentioned for the first example, in absence of any dielectric part 204, 205, the difference between the primary local characteristic impedance Zo and the secondary local characteristic impedances Z1, Z2 do not need to be defined by means of the shape of the first conductor 203 as exemplified above, but also by means of the shape of the ground plane 228, possibly in combination with the shape of the first conductor 203. This means that the ground plane 228 may comprise slots and similar that can be used for defining the local characteristic impedances Zo, Z1, Z2 in absence of any dielectric part 204, 205.

[0114] In the following, some aspects of the general concept of the impedance matching arrangement 100, 200 will be discussed.

[0115] Each port 101, 102; 201, 202 may according to some aspects, be considered as a part of the transmission line, in some embodiments only being a virtual boundary, separating or connecting the impedance matching arrangement 100 from / to the periphery, such as for example a PCB. According to some aspects, each port 101, 102; 201, 202 comprises a radio frequency (RF) connector 110, 111; 210, 211. This means that the ports 101, 102; 201, 202 can be connected to, and removed from, other components in an easily performed and well-controlled manner.

[0116] As shown in Figure 9, according to some aspects and exemplified for the first example, each RF connector 110 comprises a contact pin 112 that is adapted to be received in a corresponding slot 113 in the first conductor 103. This is in particular suitable in the case where the first conductor 103 is constituted by a metal sheet part. In general, a port of a first circuit comprises a pair of terminals for connecting the first circuit to a second (e.g., external) circuit.

[0117] The impedance matching arrangement 100, 200 comprises a transmission line 103, 109; 203, 228 that has segments in the form of at least one secondary section 106, 107; 146, 147; 206, 207 with shape / dimension deviating from the ones of the remaining structure, consequently resulting in an impedance change from the primary local characteristic impedance Zo of the at least one primary section 108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c. When a movably attached dielectric part 104, 105; 204, 205 is placed at a secondary section 106, 107; 146, 147; 206, 207, in the neutral position, the deviating shape / dimension is compensated for such that secondary section 106, 107; 146, 147; 206, 207 obtains a local characteristic impedance equal to the primary local characteristic impedance Zo, or at least comes close to the primary local characteristic impedance Zo. The dimensions of each dielectric part 104, 105; 204, 205 have to be defined accordingly.

[0118] According to some aspects, the impedance matching arrangement 100, 200 is configured such that when said dielectric part 104, 105; 204, 205 is positioned mainly along said secondary section 106, 107; 146, 147; 206, 207, in presence of the dielectric part 104, 105; 204, 205, the local characteristic impedance Z'i, Z'2 of the secondary section 106, 107; 146, 147; 206, 207 is less than 10%, preferably 5%, more preferably 2%, larger or smaller than the primary local characteristic impedance Zo. This means that when bringing a dielectric part 104, 105; 204, 205 mainly along the secondary section 106, 107; 146, 147; 206, 207 the local characteristic impedance Z'1, Z'2 of the secondary section 106, 107; 146, 147; 206, 207 is decreased and becomes more like the primary local characteristic impedance Zo in absence of any dielectric part 104, 105; 204, 205. Above, some examples are provided of how close the local characteristic impedance Z'1, Z'2 of the secondary section 106, 107; 146, 147; 206, 207 comes to the primary local characteristic impedance Zo

[0119] With the above limitations, a good tuning sensitivity can be achieved whereas greater impedance changes could lead to decreased overall VSWR-levels of an array antenna or other component connected to the impedance matching arrangement 100, 200, at least in some frequency ranges.

[0120] Each dielectric part 104, 105 can be completely made of a dielectric material, but some parts such as a handle part 121, 122 may be made of another material. A handle part 221, 222 may be partly made of a dielectric material, and partly made of another material.

[0121] To remain in position after movement, each dielectric part 104, 105 may according to some aspects, be equipped with certain latching or locking mechanisms such as screws 241, 242 or similar, as schematically indicated in Figure 11. A friction lock may alternatively be sufficient. To move the dielectric parts 104, 105, a handle part 121, 122; 221, 222 may be used as described above. Alternatively, as schematically indicated in Figure 11 , motor means 243, 244, such as for example stepper motors, may be adapted to move the dielectric parts 104, 105. In this case, handle parts that are formed for being grasped by fingers are not necessary. The motor means 243, 244 enable a more or less automatic tuning procedure to be performed.

[0122] According to some aspects, the electrical length of each primary section 108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c is 0,027-0,267 wavelengths, where the wavelength corresponds to a center frequency in a frequency band of operation. According to some aspects, the electrical length of each secondary section 106, 107; 146, 147; 206, 207 is 0,027-0,133 wavelengths, where the wavelength corresponds to a center frequency in a frequency band of operation.

[0123] This means that for an example where the first primary section 108a has a length of 15mm, the second primary section 108b has a length of 30mm and the third primary section 108c has a length of 15mm, the first and third primary sections 108a, 108c have a length of 0,04 wavelengths at 800MHz and 0,1 wavelengths at 2000MHz. The second primary section 108b has a length of 0,08 wavelengths at 800MHz and 0,2 wavelengths at 2000MHz.

[0124] Furthermore, if the first secondary section 106 and the second secondary section 107 each have a length of 15mm, they have a length of 0,04 wavelengths at 800MHz and 0,1 wavelengths at 2000MHz.

[0125] In an illustrated use example of the impedance matching arrangement 100 according to the first example, both dielectric parts 104, 105 are moved 8 mm in each direction independently of each other with a step of 4 mm, which results in 25 different combinations. The resulting calculated impedances of one port 101 when the other port 102 is terminated with a load having an impedance equal to the primary characteristic impedance, here 50Q, over the frequency range of 1400-2700 MHz are displayed in Figure 13 that shows a simulated impedance for an impedance matching arrangement 100, 200 illustrated in Smith chart. The span of + / - 8 mm is chosen as a good compromise between sensitivity and influence, providing a range that is easy to handle manually.

[0126] In Figure 13, a circle 600 is drawn, representing all possible impedances which correspond to a VSWR level of 1.5 (RL= 14 dB) with all impedances within the circle showing lower VSWR levels (< 1.5). It is demonstrated that every one of the 25 combinations yields VSWR levels lower than 1.5 for every frequency in the range of 1400-2700 MHz, which is especially well visible in the magnified view of the same instance and circle 600 in Figure 14.

[0127] As shown in Figure 1 and Figure 2, the present disclosure also relates to a linear array antenna 300, 400 as discussed initially. The linear array antenna 300, 400 comprises a plurality of linearly arranged antenna elements 301, 401, at least one antenna port 302, 402, 403 and a distribution network 304, 404 that is adapted to transfer signals between the antenna elements 301, 401 and said antenna port 302, 402, 403. The distribution network 304, 404 comprises at least one impedance matching arrangement 100, 200 as described herein.

[0128] According to some aspects, the distribution network 304, 404 comprises at least one component in the form of a phase shifter 305, 405, a filter 406, or a bias-T 407. In Figure 1, there is a phase shifter 305, and in Figure 2 there are is a phase shifter 405, a filter 406 and bias-Ts 407.

[0129] At least one impedance matching arrangement 100, 200 is positioned between said antenna port 302, 402, 403 and one of said components 305; 405, 406, 407, between two of said components 305; 405, 406, 407, and / or between one of said components 305; 405, 406, 407, and at least one antenna element 301, 401. In Figure 1, the impedance matching arrangement 100 (indicated by a box with solid lines) is positioned between said antenna port 302 and the phase shifter 305, and in Figure 2, an impedance matching arrangement 100 (indicated by a box with solid lines) is positioned between the phase shifter 405 and the filter 406. In both Figure 1 and Figure 2, two optional impedance matching arrangements 100 (indicated by respective boxes with dashed lines) are shown positioned between the phase shifter 305, 405 and corresponding antenna elements 301 , 401.

[0130] The component configurations and impedance matching arrangement positions disclosed in Figure 1 and Figure 2 are of course only examples, a multitude of alternatives exists.

[0131] As shown in Figure 3, the present disclosure also relates to a two-dimensional array antenna 500 comprising at least one row 510, 511 of linear array antennas 300, 400 according to the above, each row 510 comprising two or more linear array antennas 300, 400.

[0132] With reference to Figure 16, the present disclosure also relates to a network node 800 comprising an array antenna 801, 802, 803 that is constituted by the two-dimensional array antenna 500 and / or the linear array antenna 300, 400 as described herein. In this example, the network node 800 comprises three array antennas 801, 802, 803 where each one is constituted by the two-dimensional array antenna 500 and / or the linear array antenna 300, 400 as described herein. The network node 800 may for example be constituted by a base station or similar.

[0133] When measuring a whole array antenna 500, a poor VSWR violating a minimum required VSWR level of 1.5 is detected in certain frequency ranges, see the dotted trace 701 in Figure 15 that shows simulations of how the antenna impedance can be tuned by means of the impedance matching arrangement 100, 200, illustrated as VSWR. With the help of one or more impedance matching arrangements 100, 200 according to the present disclosure, it is now possible to improve the VSWR levels to a state where the required levels are reached over the whole desired frequency range. The improved VSWR levels are represented by the black trace 702 in Figure 15. In this case the level at lower frequencies could be improved significantly. At the same time, in some frequency ranges (especially at 1900 - 2300 MHz) VSWR levels are increasing, however, but are kept well within specified limits, representing a certain trade-off. Typically, array antennas failing to achieve the minimum required RLA / SWR- levels, usually even only in some sections of the desired frequency range, are still already close to these requirements yet not fulfilling the requirements though. As the deviations are moderate, the impedance matching arrangement 100, 200 only needs to confer a limited influence as illustrated in Figure 15.

[0134] Aside from improving the matching of components and VSWR-levels by changing positions of the dielectric part 104, 105; 204, 205, the relative position of the impedance matching arrangement 100, 200 (distance, cable length etc.) to other components in an array antenna 500 is influencing the matching as well, as phase relations between components are changed. To keep the antenna radiation pattern unchanged, hence keeping the array antenna 500 working as planned, it is necessary to maintain the correct phase relations within the signal paths. Changing positions of the dielectric parts 104, 105; 204, 205 only induces a completely negligible change of the transmission phase of the impedance matching arrangement 100, 200 itself, producing no recognizable impact on the antenna pattern at all. As a conclusion, according to the present disclosure, an impedance matching arrangement 100, 200 is provided which can be easily integrated into the signal path at various or even multiple positions between sub-components. The impedance matching arrangement 100, 200 enables stepless adjustability to enable improvement of overall antenna-RL / VSWR- levels, making it possible to fulfil requirements without the need for re- designing sub- components or other complex and time- consuming adjustments or development processes.

[0135] The impedance matching arrangement 100, 200 is a simple assembly, consisting of only very few parts. The interfaces can be individually configured to be compatible to the respective antenna technology and design. With these it is easily integrable into desirable positions of an antenna signal path with standard production processes.

[0136] A simple adjustment mechanism allows stepless variations manually, without the help of additional tools or software. This tuning enables live monitoring and assessment aiming for optimization of performance of an antenna, such as an array antenna. If the performance is improved through design changes or other advancements in the lifecycle of the connected component, such as the array antenna 500, the impedance matching arrangement 100, 200 can easily be omitted retrospectively.

[0137] Simple integration allows for subsequent implementation in existing antennas and other components facing RL-problems while it is also possible to integrate the impedance matching arrangement 100, 200 in the design process of an array antenna 500 from the start. It may then be omitted afterwards in case it is actually not needed.

[0138] The adjustment / tuning of an array antenna can be done simply by shifting positions of the integrated dielectric parts 104, 105; 204, 205 manually, without the need for extra tools or software, during the usual VS R-measurement of the array antenna. The optimum RL / VSWR- levels can be determined intuitively while changing dielectric part positions of the impedance matching arrangement 100, 200 in their respective range. Optimum settings may then be applied in further array antennas of the same type.

[0139] Re-design of sub-components and antenna elements, changing of transmission line and cable lengths and other complicated tuning efforts can be avoided. This will save resources and time, and therefore cost.

[0140] In the above, adjustment and / or tuning of antennas and in particular array antennas have been addressed, but of course the impedance matching arrangement 100, 200 can be applied for adjustment / tuning of other components that need impedance adjustment / tuning.

[0141] The present disclosure is not limited to the description above, but may vary freely within the scope of the appended claims. For example, the local characteristic impedances Zo, Zi, Z2 may be defined by means of different dielectric carrier materials 130, 230 instead of different conductor shapes as exemplified above. Combinations are of course possible.

Claims

CLAIMS1. An impedance matching arrangement (100, 200) comprising: a first port (101, 201), a second port (102, 202), a transmission line (103, 109; 203, 228) configured to guide electromagnetic waves between the first and second ports (101, 102; 201, 202), and a movably attached dielectric part (104, 105; 204, 205),where the transmission line is formed by a first conductor (103, 203) and a second conductor (109, 228), where the transmission line (103, 109; 203, 228) comprises a primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) and a secondary section, (106, 107; 146, 147; 206, 207) and wherethe dielectric part (104, 105; 204, 205) comprises a dielectric material arranged adjacent to the first conductor (103, 203) and / or the second conductor (109, 228) of a part of the transmission line (103, 109; 203, 228) and arranged movable along the transmission line (103, 109; 203, 228), where, in absence of the dielectric part (104, 105; 204, 205), the primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) has a primary local characteristic impedance (Zo) and the secondary section (106, 107; 146, 147; 206, 207) has a secondary local characteristic impedance (Zi, Z2) different from the primary local characteristic impedance (Zo).

2. The impedance matching arrangement (100, 200) according to claim 1, wherein the dielectric part (104, 105; 204, 205) is arranged to selectively affect wave propagation conditions for a part of the transmission line (103, 109; 203, 228) depending on the position of the dielectric part along the transmission line (103, 109; 203, 228).

3. The impedance matching arrangement (100, 200) according to any one of the claims 1 or 2, wherein the impedance matching arrangement (100, 200) is configured such that a local characteristic impedance (Z'1, Z'2) of the secondary section (106, 107; 146, 147; 206, 207) is more similar to the primary local characteristic impedance (Zo) when the dielectric part (104, 105; 204, 205) is positioned mainly along the secondary section (106, 107; 146, 147; 206, 207) as compared to when the dielectric part (104, 105; 204, 205) is positioned mainly along the primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c).

4. The impedance matching arrangement (100, 200) according to any one of the previous claims, wherein, in the primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c), a corresponding section (108a, 108b, 108c; 208a, 208b, 208c) of the first conductor (103, 203) and a corresponding section (148a, 148b, 148c) of the second conductor (109, 228) have respective first shapes, and where, in the secondary section (106, 107; 146, 147; 206, 207), the shape of a corresponding section (106, 107; 146, 147; 206, 207) of the first conductor (103, 203) and / or the second conductor (109, 228) is different than in the primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) of the transmission line (103, 109; 203, 228).

5. The impedance matching arrangement (100, 200) according to claim 4, wherein the first shape of the first conductor (103) corresponds to a first conductor width (wi), and where, in the secondary section (106, 107; 146, 147; 206, 207), the shape of first conductor (103) corresponds to a reduction of conductor width (W2, W3) of the transmission line (103) in relation to the first conductor width (wi).

6. The impedance matching arrangement (100, 200) according to any one of the previous claims, further being configured such that when said dielectric part (104, 105; 204, 205) is positioned mainly along said secondary section (106, 107; 146, 147; 206, 207), in presence of the dielectric part (104, 105; 204, 205), the local characteristic impedance (Z'i, Z'2) of the secondary section (106, 107; 146, 147; 206, 207) is less than 10%, preferably 5%, more preferably 2%, larger or smaller than the primary local characteristic impedance (Zo).

7. The impedance matching arrangement (100, 200) according to any one of the previous claims, further comprising a plurality of primary sections (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c), wherein each primary section of the plurality of primary sections, in absence of any dielectric part (104, 105; 204, 205), has the primary local characteristic impedance (Zo).

8. The impedance matching arrangement (100, 200) according to any one of the previous claims, further comprising a plurality of secondary sections (106, 107; 146, 147; 206, 207), and a respective movably attached dielectric part (104, 105; 204, 205) for each secondary section (106, 107; 146, 147; 206, 207) of the plurality of secondary sections, wherein each dielectric part (104, 105; 204, 205) comprises a respective dielectric material arranged adjacent to the first conductor (103, 203) and / or the second conductor (109, 228) of a respective part of the transmission line (103, 109; 203, 228) and arranged movable along the transmission line (103, 109; 203, 228), and wherein each secondary section of the plurality of secondary sections, in absence of any dielectric part (104, 105; 204, 205), has a respective local characteristic impedance (Z1, Z2) different from the primary local characteristic impedance (Zo).

9. The impedance matching arrangement (100, 200) according to claim 8 when dependent on claim 7, wherein every other section is a primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) and every other section is a secondary section (106, 107; 146, 147; 206, 207), where there is a primary section adjacent each of the first and the second ports (101, 102; 201, 202).

10. The impedance matching arrangement (100, 200) according to any one of the previous claims, wherein, in absence of any dielectric part (104, 105), the primary local characteristic impedance (Zo) has a magnitude that is between 5-25 %, preferably 5-15%, smaller than each secondary local characteristic impedance (Z1, Z2).

11. The impedance matching arrangement (100, 200) according to any one of the previous claims, wherein each dielectric material (104, 105; 204, 205) is arranged between the first conductor (103, 203) and the second conductor (109, 228).

12. The impedance matching arrangement (100, 200) according to any one of the previous claims, wherein each dielectric material (104, 105; 204, 205) is in contact with the first conductor (103, 203) and / or the second conductor (109, 228).

13. The impedance matching arrangement (100, 200) according to any one of the previous claims, wherein the electrical length of each primary section (108a, 108b, 108c; 148a, 148b, 148c; 208a, 208b, 208c) is 0,027-0,267 wavelengths, where the wavelength corresponds to a center frequency in a frequency band of operation.

14. The impedance matching arrangement (100, 200) according to any one of the previous claims, wherein the electrical length of each secondary section (106, 107; 146, 147; 206, 207) is 0,027-0,133 wavelengths, where the wavelength corresponds to a center frequency in a frequency band of operation.

15. The impedance matching arrangement (100) according to any one of the previous claims, wherein each port (101, 102; 201, 202) comprises a radio frequency, RF, connector (110, 111; 210, 211).

16. The impedance matching arrangement (100) according to claim 15, wherein each RF connector (110) comprises a contact pin (112) that is adapted to be received in a corresponding slot (113) in the first conductor (103).

17. The impedance matching arrangement (100) according to any one of the previous claims, wherein the first conductor (103) is constituted by a metal sheet part.

18. The impedance matching arrangement (100, 200) according to any one of the claims 1-16, wherein the first conductor (103' 203) is formed as a metal conductor (103' 203) that runs on a dielectric carrier material (130, 230).

19. The impedance matching arrangement (100) according to claim 18, wherein there is a metal conductor (103') on opposite sides of the dielectric carrier material (130), where the metal conductors (103') are electrically connected by means of vias (116).

20. The impedance matching arrangement (100) according to any one of the previous claims, further comprising a housing (109), where the first conductor (103) extends in the housing (109) that constitutes the second conductor (109), and where each dielectric part (104, 105) is movably attached to the housing (109).

21. The impedance matching arrangement (100) according to claim 20, wherein the housing (109) comprises a first wall part (114) and a second wall part (115) that extend opposite each other, the first conductor (103) extending between the wall parts (114, 115), each wall part (114, 115) having a corresponding first edge (116, 117) and a corresponding second edge (118, 119), opposite the first edge (116, 117), where each dielectric part (104, 105) comprises a handle part (121, 122) and snap-fit engagement means (123, 124), where each handle part (121, 122) is adapted to slide on the first edges (116, 117) and where the snap-fit engagement means (123, 124) are adapted to be in locking engagement with, and slide on, the second edges (118, 119).

22. The impedance matching arrangement (200) according to claim 18, wherein the dielectric carrier material (230) comprises a first main side (225) and a second main side (226), where the first main side (225) comprises the first conductor (203) and the second main side (226) comprises the second conductor that is constituted by a metal ground plane (228), the dielectric carrier material (230) further comprising a slot (227) that runs mainly along the transmission line (203), where each dielectric part (204, 205) comprises a handle part (221, 222) and snap-fit engagement means (223, 224), where each handle part (221, 222) is adapted to slide along the slot (227) on the first main side (225) and where each snap-fit engagement means (223, 224) are adapted to be in locking engagement with, and slide on, the second main side (226) via the aperture (227).

23. The impedance matching arrangement (100) according to any one of the previous claims, further comprising motor means (243, 244) adapted to move each dielectric part (104, 105).

24. A linear array antenna (300, 400) comprising a plurality of linearly arranged antenna elements (301, 401), at least one antenna port (302, 402, 403) and a distribution network (304, 404) that is adapted to transfer signals between the antenna elements (301, 401) and said antenna port (302, 402, 403), wherein the distribution network (304, 404) comprises at least one impedance matching arrangement (100, 200) according to any one of the previous claims.

25. The linear array antenna (300, 400) according to claim 24, wherein the distribution network (304, 404) comprises at least one component in the form of- a phase shifter (305, 405),- a filter (406), or- a bias-T (407),where at least one impedance matching arrangement (100, 200) is positioned- between said antenna port (302, 402, 403) and one of said components (305; 405, 406, 407),- between two of said components (305; 405, 406, 407), and / or- between one of said components (305; 405, 406, 407), and at least one antenna element (301, 401).

26. A two-dimensional array antenna (500) comprising at least one row (510, 511) of linear array antennas (300, 400) according to any one of the claims 24 or 25, each row (510) comprising two or more linear array antennas (300, 400).

27. A network node (800) comprising an array antenna (801, 802, 803) that is constituted by the two-dimensional array antenna (500) according to claims 26 and / or the linear array antenna (300, 400) according to any one of the claims 24 or 25.

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