A compact filter module

Abstract

The present disclosure relates to a filter module (100, 200, 300) comprising a printed circuit board (110, 210, 310), PCB, and at least two filter arrangements (120, 121; 220, 221; 320, 321). The PCB has a first main side (111) and a second main side (112) and comprises at least two antenna ports (201, 202, 203, 204; 301, 302) arranged along a first PCB edge (213, 313) and at least four radio ports (231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334) arranged along a second PCB edge (214, 314), opposite the first PCB edge (213, 313), where the main sides (111, 112) at least partly run between the PCB edges (213, 214; 313, 314). A first filter arrangement (120, 220, 320) is mounted to the first main side (111) and connected between at least one antenna port (201, 202; 301) and at least one radio port (231, 232, 233, 234; 331, 332), and a second filter arrangement (121, 221, 321) is mounted to the second main side (112) and connected between at least one antenna port 203, 204; 302) and at least one radio port (235, 236, 237, 238; 333, 334). Each filter arrangement (220, 221; 320, 322) comprises at least one corresponding receiver, RX, filter (240, 241, 242, 243; 340, 341).

Description

[0001] TITLE

[0002] A compact filter module

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to a filter module comprising a printed circuit board (PCB) and at least two filter arrangements. The PCB has a first main side and a second main side and comprises at least two antenna ports and at least four radio ports. The filter module can for example be used in array antenna systems.

[0005] BACKGROUND

[0006] Massive MIMO (Multiple Input Multiple Output) antennas systems require a large number of receiver and transmitter modules, so-called transceiver (TRX) modules, is needed; today up to 256 TRX modules and possibly more in the future. In FDD (Frequency Division Duplex), duplexfilters are required to separate reception (Rx) and transmission (TX). In TDD (Time Division Duplex), TX output filters are required to filter out disturbing spectral emissions of TX amplifiers and to suppress disturbing out of band signals for Rx amplifiers. The output of the TX filters is connected to antenna elements, normally dual polarized antenna elements.

[0007] Today, separate antenna modules and TRX Modules are placed in separate modules. Both modules can be integrated in one housing, but at least the TX power amplifiers need additional heat sinks which typically are located at an antenna rear side. To connect the antenna with the TRX modules, separate cables or interfaces are needed, which contributes to increase size and weight of the antenna system .

[0008] There is a large number of filters in each antenna system, and coaxial connections as well as shielding require very tight tolerances, especially the coaxial connections between the amplifier PCB and the filter modules. Furthermore, the weight of the casted filters with the used filter technology is relatively high.

[0009] US2021 / 0336659 Al discloses an implementation where filters modules are stacked behind an antenna module, where filter modules cover one TRX chain. There is, however, a need for an improved module arrangement which contributes to decreased size and weight of the antenna system.

[0010] SUMMARY

[0011] It is an object of the present disclosure to provide an improved module arrangement which contributes to decreased size and weight of the antenna system. This object is obtained by means of a filter module comprising a printed circuit board (PCB) and at least two filter arrangements. The PCB has a first main side and a second main side and comprises at least two antenna ports arranged along a first PCB edge and at least four radio ports arranged along a second PCB edge, opposite the first PCB edge, where the main sides at least partly run between the PCB edges. A first filter arrangement is mounted to the first main side and connected between at least one antenna port and at least one radio port, and a second filter arrangement is mounted to the second main side and connected between at least one antenna port and at least one radio port. Each filter arrangement comprises at least one corresponding receiver (RX) filter.

[0012] This means that a filter module is provided, where an efficient sandwich mounting arrangement is used. The antenna ports and radio ports are arranged from the PCB edges, enabling easy mounting of each filter module. The filter module is capable of serving a plurality of TRX paths

[0013] According to some aspects, the first filter arrangement is constituted by a first comb-line filter arrangement, and where the second filter arrangement is constituted by a second comb-line filter arrangement.

[0014] Using comb-line filters provides a small and flat design technology for the filter module, saving size, cost and weight. Comb-line filters are as such previously well-known, and can easily be adapted for the use described herein.

[0015] According to some aspects, each filter arrangement comprises an electrically conducting combline foil that is sandwiched between opposing electrically conducting cover parts, a first cover part, being adjacent a corresponding main side, and a second cover part.

[0016] In this manner, the comb-line filter arrangement can be manufactured in a versatile, well-known and reliable manner, enabling filter characteristics to be easily updated or changed.

[0017] According to some aspects, each first cover part comprises through connections for filter connections that enable the combline foil to be electrically connected to the PCB.

[0018] In this manner, one or more filter modules can easily be mounted since a filter module may comprise a plurality of TRX chains and can be manufactured and tested separately. Shielding is provided by the cover parts, which also cover the PCB.

[0019] According to some aspects, each second cover part comprises filter tuning elements. This provides filter tuning means that are easily accessible for a user. According to some aspects, the PCB comprises at least two low-noise amplifier (LNA) arrangements, where each LNA arrangement is connected between a corresponding radio port and a corresponding RX filter.

[0020] The short distance between the antenna ports, filters and the LNAs provides an enhanced performance of noise figure and sensitivity.

[0021] According to some aspects, the PCB comprises at least one switch assembly connected between, on one hand, two corresponding radio ports constituted by an RX port and a transmitter (TX) port, and, on the other hand, a corresponding RX filter. Each switch assembly is adapted to alternatingly switch between the corresponding RX port and the corresponding TX port such that Time Division Multiple Access (TDMA) is enabled.

[0022] According to some aspects, each filter arrangement comprises at least one corresponding transmitter (TX) filter connected between a corresponding radio port, constituted by a TX port and a corresponding antenna port.

[0023] This means that the filter module can be applied for both FDMA and TDMA applications.

[0024] According to some aspects, each filter arrangement comprises at least one corresponding pre-filter connected between, on one hand, a corresponding RX filter and corresponding TX filter, and, on the other hand, a corresponding antenna port.

[0025] According to some aspects, at least a subset of the ports comprises contact pins that are soldered to the PCB. This provides an uncomplicated type of connectors that enable an efficient mounting of the filter modules.

[0026] This object is also obtained by means of array antenna systems that are associated with the above advantages.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure will now be described more in detail with reference to the appended drawings, where:

[0029] Figure 1A shows a schematic exploded perspective view of a filter module;

[0030] Figure IB shows a schematic exploded side view of a filter module; Figure 2 shows a schematic view of a first example filter module and antenna elements;

[0031] Figure 3 shows a schematic view of a second example filter module and antenna elements;

[0032] Figure 4 shows a side view of the first example filter module and antenna elements, where the filter module is mounted to a radio module; and

[0033] Figure 5 shows a schematic exploded perspective view of an array antenna system;

[0034] DETAILED DESCRIPTION

[0035] 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.

[0036] The terminology used herein is for describing aspects of the disclosure only and is not intended to limit the invention. 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.

[0037] As shown in Figure 1A and Figure IB, there is a filter module 100 comprising a printed circuit board 110 (PCB), and at least two filters arrangements 120, 121, in this example there is a first filter arrangement 120 and a second filter arrangement 121. With reference also Figure 2, that illustrates a first example, the PCB 110 has a first main side 111 and a second main side 112 and comprises at least two antenna ports 201, 202, 203, 204 arranged along a first PCB edge 213, in this example a first antenna port 201, a second antenna port 202, a third antenna port 203, and a fourth antenna port 204.

[0038] The PCB 110 comprises at least four radio ports 231, 232, 233, 234, 235, 236, 237, 238 arranged along a second PCB edge 214, opposite the first PCB edge 213, where the main sides 111, 112 at least partly run between the PCB edges 213, 214. In this example there is a first radio port 231, a second radio port 232, a third radio port 233, a fourth radio port 234, a fifth radio port 235, a sixth radio port 236, a seventh radio port 237, and an eighth radio port 238.

[0039] According to the present disclosure, a first filter arrangement 120, 220 is mounted to the first main side 111 and connected between at least one antenna port 201, 202 and at least one radio port 231, 232, 233, 234, and a second filter arrangement 121, 221 is mounted to the second main side 112 and connected between at least one antenna port 203, 204 and at least one radio port 235, 236, 237, 238. Each filter arrangement 220, 221 comprises at least one corresponding receiver (RX) filter 240, 241, 242, 243.

[0040] This means that a filter module which can serve a plurality of TRX paths is provided, where an efficient sandwich mounting arrangement is used. The antenna ports 201, 202, 203, 204 and radio ports 231, 232, 233, 234, 235, 236, 237, 238 are arranged from the PCB edges 231, 214, enabling easy mounting of each filter module 200.

[0041] The filter arrangement 120, 220 according to the present disclosure saves size, cost and weight. The short distance between the antenna ports 201, 202, 203, 204, filters 240, 241, 242, 243 and low noise amplifiers (LNAs), in case LNAs are integrated on the PCB 210, provides an enhanced performance of noise figure and sensitivity. Examples of how LNAs can be incorporated will be described later.

[0042] In this example that illustrates Time Division Multiple Access (TDMA), the first filter arrangement 220 is connected between, on one hand, the first antenna port 201 and the second antenna port 202, and on the other hand the first radio port 231, the second radio port 232, the third radio port 233, and the fourth radio port 234. Furthermore, the second filter arrangement 221 is connected between, on one hand, the third antenna port 203, and the fourth antenna port 204, and on the other hand the fifth radio port 235, the sixth radio port 236, the seventh radio port 237, and the eighth radio port 238.

[0043] The antenna ports 201, 202; 203, 204 are adapted to be connected to corresponding antenna devices 271, 272; 273, 274 such that the first antenna port 201 is adapted to be connected to a first antenna device 271, the second antenna port 202 is adapted to be connected to a first antenna device 272, the third antenna port 203 is adapted to be connected to a third antenna device 273, and the fourth antenna port 204 is adapted to be connected to a fourth antenna device 274. As an example, the first antenna port 201 and the second antenna port 202 are adapted to be connected to corresponding antenna devices 271, 272 of a first polarization, for example +45°, and the third antenna port 203 and the fourth antenna port 204 are adapted to be connected to corresponding antenna devices 273, 274 of a second polarization that is orthogonal to the first polarization, for example -45°. The antenna devices 271, 272, 273, 274 can of course be combined such that dual polarized antenna devices are formed in a well-known manner.

[0044] According to some aspects, the PCB 210 comprises at least one switch assembly 260, 261, 262, 263 connected between, on one hand, two corresponding radio ports constituted by an RX port 231, 233, 236, 238 and a transmitter (TX) port 232, 234, 235, 237, and, on the other hand, a corresponding RX filter 240, 241, 242, 243. Each switch assembly 260, 261, 262, 263 is adapted to alternatingly switch between the corresponding RX port 231, 233, 236, 238 and the corresponding TX port 232, 234, 235, 237 such that TDMA is enabled.

[0045] In this example, there is a first switch assembly 260 connected between, on one hand, the first radio port 231 that is an RX port, and the second radio port 232 that is a TX port, and, on the other hand, a first RX filter 240. There is a second switch assembly 261 connected between, on one hand, the third radio port 233 that is an RX port, and the fourth radio port 234 that is a TX port, and, on the other hand, a second RX filter 241. There is a third switch assembly 262 connected between, on one hand, the fifth radio port 235 that is an RX port, and the sixth radio port 236 that is a TX port, and, on the other hand, a third RX filter 242. There is a fourth switch assembly 263 connected between, on one hand, the seventh radio port 237 that is an RX port, and the eighth radio port 238 that is a TX port, and, on the other hand, a fourth RX filter 242.

[0046] Since both RX ports 231, 233, 235, 237 and TX ports 232, 234, 236, 238 are connected to the RX filters 240, 241, 242, 243 alternatingly, the RX filters 240, 241, 242, 243 works as TX filters as well in this example. Thus, in this context, an RX filter at least works as an RX filter.

[0047] Traditionally, microwave radios and radars are using waveguide filters due to the low losses where such waveguide filters often are manufactured of milled or cast aluminum that is surface-treated with silver, gold or copper to lower the insertion losses. These filters often have ports that are perpendicular to the rest of the waveguide structures which results in H- or E-bends in the design to connect the waveguide ports.

[0048] According to some aspects, the first filter arrangement 120, 220, 320 is constituted by a first combline filter arrangement, and where the second filter arrangement 121, 221, 321 is constituted by a second comb-line filter arrangement.

[0049] Using comb-line filters provides a small and flat design technology for the filter module 100, 200. The comb-line filter can according to some aspects be constituted by an interdigital filter. Combline filters are as such previously well-known, and can easily be adapted for the use described herein.

[0050] According to some aspects, as illustrated in Figure 1A and Figure IB, each filter arrangement 120, 121 comprises an electrically conducting combline foil 122, 125 that is sandwiched between opposing electrically conducting cover parts 123, 124; 126, 127, a first cover part 123, 126, being adjacent a corresponding main side 111, 112 and a second cover part 124, 127. The foil 122, 125 can be formed in one metal such as for example copper, aluminum or brass, that can be metalized with for example silver or gold. The foil 122, 125 can also be in the form of a metal pattern that is formed on a PCB part, for example by means of etching. The foil 122, 125 can be manufactured by means of for example etching, stamping or laser-cutting a sheet metal. The foil 122, 125 should have such a thickness that it is sufficiently mechanically stable where it is fitted, and can be constituted of a metallic sheet. According to some aspects, the thickness may vary in a range from 0,6mm to 2mm.

[0051] In this manner, the comb-line filter arrangement can be manufactured in a versatile, well-known and reliable manner, enabling filter characteristics to be easily updated or changed. For a frequency division duplex (FDD) duplex filter, typically 5 inner conductors in the form of stubs are required for every RX and / or TX band, therefore 8-10 stubs are required for one chain. Dependent on the size, four parallel chains can be integrated in one module.

[0052] According to some aspects, each first cover part 123, 126 comprises through connections 117A,117B; 118A, 118B for filter connections 115A,115B; 116A, 116B that enable the combline foil 122, 125 to be electrically connected to the PCB 110. In this manner, one or more filter modules 100 can easily be mounted since a filter module 100 may comprise a plurality of TRX chains and can be manufactured and tested separately. Mounting of a plurality of filter modules will be described later.

[0053] Shielding is provided by the cover parts 123, 124; 126, 127, which also cover the PCB 110.

[0054] According to some aspects, each second cover part 124, 127 comprises filter tuning elements 119. This provides filter tuning means that are easily accessible for a user.

[0055] Other types of flat waveguide filters are also conceivable, for example coupled cavity resonators, quarter wavelength resonators, or direct cavity resonators, alternatively based on resonating band gap structures are conceivable.

[0056] According to some aspects, as shown in Figure 2, the PCB 210, 310 comprises at least two low- noise amplifier, LNA, arrangements 250, 251, 252, 253, where each LNA arrangement 250, 251, 252, 253 is connected between a corresponding radio port 231, 233, 236, 238; 331, 333 and a corresponding RX filter 240, 241, 242, 243; 340, 341. The short distance between the antenna ports, filters and the LNAs provides an enhanced performance of noise figure and sensitivity. In this example, there is a first LNA arrangement 250 connected between the first radio port 231 and the first RX filter 240, a second LNA arrangement 251 connected between the third radio port 233 and the second RX filter 241, a third LNA arrangement 252 connected between the fifth radio port 235 and the third RX filter 242, and a fourth LNA arrangement 253 connected between the seventh radio port 237 and the fourth RX filter 243. The LNA arrangements 250, 251, 252, 253 are here connected to the RX filters 240, 241, 242, 243 via corresponding switch arrangements 260, 261, 262, 263. The LNA arrangements 250, 251, 252, 253 can according to some aspects be implemented on the PCB 210.

[0057] As indicated with dashed lines in Figure 2, the filter module 200 may comprise further filter arrangements 220’, 221’, further antenna ports 201’, 203’ adapted to be connected to corresponding antenna devices 271’, 273’, and corresponding components (not shown) which are implemented in the same manner as those previously described herein.

[0058] According to some aspects, with reference to Figure 3 that illustrates a second example, each filter arrangement 320, 321 comprises at least one corresponding transmitter (TX) filter 344, 345 connected between a corresponding radio port, constituted by a TX port 332, 334 and a corresponding antenna port 301, 302.

[0059] In this example that illustrates Frequency Division Multiple Access (FDMA), there is a first filter arrangement 320 that is connected between, on one hand, a first antenna port 301, and on the other hand a first radio port 331 and a second radio port 332. Furthermore, there is a second filter arrangement 321 that is connected between, on one hand, a second antenna port 302, and on the other hand a third radio port 333 and a fourth radio port 334.

[0060] Furthermore, the first filter arrangement 320 comprises a first RX filter 340 and a first TX filter 344 where the first RX filter 340 is connected between the first radio port 331 that is constituted by a first RX port, and the first antenna port 301, and the first TX filter 344 is connected between the second radio port 332 that is constituted by a first TX port, and the first antenna port 301. Correspondingly, the second filter arrangement 321 comprises a second RX filter 341 and a second TX filter 345 where the first RX filter 341 is connected between the third radio port 333 that is constituted by a second RX port, and the second antenna port 302, and the second TX filter 345 is connected between the fourth radio port 334 that is constituted by a second TX port, and the second antenna port 301.

[0061] This means that the present disclosure is applicable for FDMA as well as TDMA, where the filter arrangements 320, 321 here can be constituted by diplexer arrangements. The antenna ports 301, 302 are adapted to be connected to corresponding antenna devices 371, 372 such that the first antenna port 301 is adapted to be connected to a first antenna device 371 , and the second antenna port 302 is adapted to be connected to a second antenna device 372. As an example, the first antenna port 301 is adapted to be connected to a corresponding antenna device 371 of a first polarization, for example +45°, and the second antenna port 302 is adapted to be connected to a corresponding antenna device 372 of a second polarization that is orthogonal to the first polarization, for example -45°.

[0062] According to some aspects, each filter arrangement 320, 321 comprises at least one corresponding pre-filter 346, 348 connected between, on one hand, a corresponding RX filter 340, 341 and corresponding TX filter 344, 345, and, on the other hand, a corresponding antenna port 301, 302.

[0063] In this example, there is a first pre-filter 346 connected between, on one hand, the first RX filter 340 and the first TX filter 344, and, on the other hand, the first antenna port 301. Furthermore, there is a second pre-filter 347 connected between, on one hand, the second RX filter 341 and the second TX filter 345, and, on the other hand, the second antenna port 302.

[0064] As in the first example, there is a PCB 310 where the antenna ports 301, 302 are arranged along a first PCB edge 313 and where the radio ports 331, 332, 333, 334 are arranged along a second PCB edge 314, opposite the first PCB edge 313.

[0065] Also, according to some aspects, there is a first LNA arrangement 350 connected between the first radio port 331 and the first RX filter 340 and aa second LNA arrangement 351 connected between the third radio port 333 and the second RX filter 341. The LNA arrangements 350, 351 can according to some aspects be implemented on the PCB 310.

[0066] As indicated with dashed lines in Figure 3, the filter module 300 may comprise further filter arrangements 320’, 321’, further antenna ports 301’ adapted to be connected to corresponding antenna devices 371’, and corresponding components (not shown) which are implemented in the same manner as those previously described herein.

[0067] The filter arrangements 320, 321 are according to some aspects realized in the same manner as exemplified for the first example.

[0068] Above, two examples of filter modules 200, 300 have been described. These are only uncomplicated examples illustrating possible implementations. Many other types of filter modules with other port constellations and other number of ports are of course conceivable. Generally, a filter module 100, 200, 300 comprises a PCB 110, 210, 310, and at least two filter arrangements 120, 121; 220, 221; 320, 321, where one filter arrangement may comprise one or more several filters.

[0069] The PCB comprises at least two antenna ports 201, 202, 203, 204; 301, 302 and at least four radio ports 231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334 arranged along the opposing PCB edges 213, 214; 313, 314.

[0070] One filter arrangement 120, 220, 320 is mounted to the first main side 111 of the PCB and is connected between at least one antenna port 201, 202; 301 and at least one radio port 231, 232, 233, 234; 331, 332, and a second filter arrangement 121, 221, 321 is mounted to the second main side 112 of the PCB and is connected between at least one antenna port 203, 204; 302 and at least one radio port 235, 236, 237, 238; 333, 334. Each filter arrangement 220, 221; 320, 322 comprises at least one corresponding receiver, RX, filter 240, 241, 242, 243; 340, 341.

[0071] With reference to Figure 1A, Figure IB, Figure 4 and Figure 5, the present disclosure also relates to an array antenna system 500 comprising a plurality of antenna devices 271, 272, 273, 274; 371, 372, two or more filter modules 200, 300 as described herein, and at least one radio module 400A, 400B, where the antenna ports 201, 202, 203, 204; 301, 302 are connected to the antenna devices 271, 272, 273, 274; 371, 372, and where the radio ports 231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334 are connected to the radio module 400A, 400B.

[0072] In Figure 4, the filter modules are here exemplified by the TDMA filter module 200 according to the first example, but of course the array antenna system 500 can comprise any filter modules as described herein. Interfaces to the antenna devices 271, 272, 273, 274; 371, 372 and possible distribution / feeding network is simplified by means of the filter modules according to the present disclosure, since no cables are needed and the interfaces can be supported by the PCB 110 itself. The interface, that can be constituted by the ports, can be realized by pin contacts.

[0073] The antenna devices may be of any sort, for example single antenna elements or array antennas that can be linear or two-dimensional, each array antenna comprising a plurality of antenna elements that may be dual polarized as discussed above. Generally, the antenna devices 271, 272, 273, 274; 371, 372 comprise a first antenna device group 271, 272; 371 and a second antenna device group 273, 274; 372, where the first antenna device group 271, 272; 371 comprises antenna devices adapted for a first polarization Pl and where the second antenna device group 273, 274; 372 comprises antenna devices adapted for a second polarization P2 that is orthogonal to the first polarization Pl. In this context, orthogonal does not mean mathematically exact, but relates to what is practical obtainable within this field of technology. The antenna elements may be realized in any suitable technology such as patch antennas, slot antennas, dipole antennas, etc.

[0074] The radio module 400A, 400B may for example comprise TX power amplifier arrangements and also LNA arrangements in case the filter modules do not comprise LNA arrangements. The radio module 400A, 400B may for example comprise further radio components that may part of the other required signal processing.

[0075] The filter modules 200 are placed between an antenna unit 571 compromising the radiating antenna devices 271, 272, 273, 274; 371, 372 and the active signal processing radio module 400A, 400B. The thermal flow will transport dissipated heat from the filter modules 200 as well as the radio module 400A, 400B to a cooling fin arrangement 580 that is positioned such that the radio module 400A, 400B is sandwiched between the cooling fin arrangement 580 and the filter modules 200. A set of filter modules 200, a radio module 400A, 400B and a cooling fin arrangement 580 may form a radio unit 581, in the example the array antenna system 500 comprises two such radio units 581, 582.

[0076] According to some aspects, the antenna elements lie in an antenna aperture plane 470, where the main sides 111, 112 of each PCB 110 run perpendicular to the antenna aperture plane 470. In this way, the filter modules 200 are mounted in an efficient manner, allowing air to circulate and enables easy mounting of the filter modules 200 to the antenna devices and to the radio module 400A, 400B.

[0077] The radio module 400A, 400B is here illustrated to comprise a first layer part 400A and a second layer part 400B where the first layer part 400A comprises through-holes 195 for the ports 231 as shown in Figure IB, where the ports may be in the form of pin connectors 231 that mate with corresponding pin connectors 196 that are comprised in the second layer part 400B, where the second layer part also may comprise all necessary components.

[0078] The first layer part 400A may only constitute a cover or base plate for the second layer part 400B, fixing the second layer part 400B mechanically, and also containing the connectors to which the pins 231 from the filter modules 100 are connected. Other connector arrangements such as coaxial arrangements or interleaved pin-ground-pin connections between the signal pins and the ground are also conceivable.

[0079] This is of course only an example; the radio module may be constituted by one or several layer parts. Other types of connectors are of course conceivable, for example having connectors formed on the PCB 110 as an etched line.

[0080] The present disclosure is not limited to the examples above, but may vary freely within the scope of the appended claims. For example, the filter modules 100 at least comprise filters, ports and connections, but may comprise several other parts such as switch arrangements and LNAs as described above. The filter modules 100 may also comprise further components such as SAW / FBAR (surface acoustic wave / thin-film bulk acoustic resonator) filters that normally relocated after the first amplifier stage - as they can have higher attenuation. When higher amplification is needed, these filters can be distributed between the different amplifier stages where the first amplifier stage is the most sensitive as this will influence the noise figure, and the following amplifier stage may be less sensitive.

[0081] According to some aspects, at least a subset of the ports 201, 202, 203, 204; 301, 302; 231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334 comprise contact pins that are soldered to the PCB 110, 210, 310. This provides an uncomplicated type of connectors that enable an efficient mounting of the filter modules 100, 200, 300.

Claims

CLAIMS1. A filter module (100, 200, 300) comprising a printed circuit board (110, 210, 310), PCB, and at least two filter arrangements (120, 121; 220, 221; 320, 321), where the PCB has a first main side (111) and a second main side (112) and comprises at least two antenna ports (201, 202, 203, 204; 301, 302) arranged along a first PCB edge (213, 313) and at least four radio ports (231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334) arranged along a second PCB edge (214, 314), opposite the first PCB edge (213, 313), where the main sides (111, 112) at least partly run between the PCB edges (213, 214; 313, 314), wherein a first filter arrangement (120, 220, 320) is mounted to the first main side (111) and connected between at least one antenna port (201, 202; 301) and at least one radio port (231, 232, 233, 234; 331, 332), and a second filter arrangement (121, 221, 321) is mounted to the second main side (112) and connected between at least one antenna port 203, 204; 302) and at least one radio port (235, 236, 237, 238; 333, 334), where each filter arrangement (220, 221; 320, 322) comprises at least one corresponding receiver, RX, filter (240, 241, 242, 243; 340, 341).

2. The filter module (100, 200, 300) according to claim 1, wherein the first filter arrangement (120, 220, 320) is constituted by a first comb-line filter arrangement, and where the second filter arrangement (121, 221, 321) is constituted by a second comb-line filter arrangement.

3. The filter module (100) according to claim 2, wherein each filter arrangement (120, 121) comprises an electrically conducting combline foil (122, 125) that is sandwiched between opposing electrically conducting cover parts (123, 124; 126, 127), a first cover part (123, 126), being adjacent a corresponding main side (111, 112) and a second cover part (124, 127).

4. The filter module (100) according to claim 3, wherein each first cover part (123, 126) comprises through connections (117A,117B; 118A, 118B) for filter connections (115A,115B; 116A, 116B) that enable the combline foil (122, 125) to be electrically connected to the PCB (110).

5. The filter module (100) according to any one of the claims 3 or 4, wherein each second cover part (124, 127) comprises filter tuning elements (119).

6. The filter module (200, 300) according to any one of the previous claims, wherein the PCB (210, 310) comprises at least two low-noise amplifier, LNA, arrangements (250, 251, 252, 253; 350, 351), where each LNA arrangement (250, 251, 252, 253; 350, 351) is connected between a corresponding radio port (231, 233, 236, 238; 331, 333) and a corresponding RX filter (240, 241, 242, 243; 340, 341).

7. The filter module (200) according to any one of the previous claims, wherein the PCB (210, 310) comprises at least one switch assembly (260, 261, 262, 263) connected between, on one hand, two corresponding radio ports constituted by an RX port (231, 233, 236, 238) and a transmitter, TX, port (232, 234, 235, 237), and, on the other hand, a corresponding RX filter (240, 241, 242, 243), each switch assembly (260, 261, 262, 263) being adapted to altematingly switch between the corresponding RX port (231, 233, 236, 238) and the corresponding TX port (232, 234, 235, 237) such that Time Division Multiple Access, TDMA, is enabled.

8. The filter module (300) according to any one of the claims 1-6, wherein each filter arrangement (320, 321) comprises at least one corresponding transmitter, TX, filter (344, 345) connected between a corresponding radio port, constituted by a TX port (332, 334) and a corresponding antenna port (301, 302).

9. The filter module (300) according to claim 8, wherein each filter arrangement (320, 321) comprises at least one corresponding pre-filter (346, 348) connected between, on one hand, a corresponding RX filter (340, 341) and corresponding TX filter (344, 345), and, on the other hand, a corresponding antenna port (301, 302).

10. The filter module (100, 200, 300) according to any one of the previous claims, wherein at least a subset of the ports (201, 202, 203, 204; 301, 302; 231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334) comprise contact pins that are soldered to the PCB (110, 210, 310).

11. An array antenna system (500) comprising a plurality of antenna devices (271, 272, 273, 274; 371, 372), two or more filter modules (200, 300) according to any one of the previous claims, and at least one radio module (400A, 400B), where the antenna ports (201, 202, 203, 204; 301, 302) are connected to the antenna devices (271, 272, 273, 274; 371, 372), and where the radio ports (231, 232, 233, 234, 235, 236, 237, 238; 331, 332, 333, 334) are connected to the radio module (400A, 400B).

12. The array antenna system (500) according to claim 11, wherein the antenna elements lie in an antenna aperture plane (470), where the main sides (111, 112) of each PCB (110) run perpendicular to the antenna aperture plane (470).

13. The array antenna system (500) according to any one of the claims 11 or 12, wherein the antenna devices (271, 272, 273, 274; 371, 372) comprise a first antenna device group (271, 272; 371) and a second antenna device group (273, 274; 372), where the first antenna device group (271, 272; 371) comprises antenna devices adapted for a first polarization (Pl) and where thesecond antenna device group (273, 274; 372) comprises antenna devices adapted for a second polarization (P2) that is orthogonal to the first polarization (Pl).

14. The array antenna system (500) according to any one of the claims 11-13, wherein the antenna system (500) comprises a cooling fin arrangement (580) that is positioned such that the radio module (400A, 400B) is sandwiched between the cooling fin arrangement (580) and the filter modules (200).

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