HF FILTER MODULE WITH IMPROVED EXPANDABILITY

Abstract

The invention relates to an HF module, the filter functionality of which can easily be expanded and which has good electrical properties. For this purpose, the module comprises two filter units with a respective HF filter and a switch having two possible switching states. The two filter units are connected in parallel.

Claims

1. An HF module (M) comprising two filter units (FE), of which each comprises a first HF filter (HF-F) with an input (I) and an output (O), a first switch (SW1) with two possible switching states, wherein in each filter unit (FE), the first switch (SW1) is connected to the input (I) or the output (O) of the first HF filter (HF-F), and the two filter units (FE) are connected in parallel.

2. The HF module according to the preceding claim, wherein to at least one filter unit (FE), the following applies: the filter unit (FE) comprises a second switch (SW2) with two possible switching states, the first switch (SW1) is connected to the input (I), the second switch (SW2) is connected to the output (O).

3. The HF module according to one of the preceding claims, wherein to at least one filter unit (FE), the following applies: the filter unit (FE) comprises a second filter (HF-F) with an input (I) and an output (O), the second filter (HF-F) is connected in parallel to the first filter (HF-F), the filter unit (FE) implements a duplexer.

4. The HF module according to the preceding claim, wherein to at least one filter unit (FE), the following applies: the filter unit (FE) comprises a third switch (SW3) with two possible switching states, the third switch (SW3) is connected to the input (I) of the second filter (HF-F).

5. The HF module according to one of the preceding claims, wherein to the filter unit (FE), the following applies: each switch (SW) has three connectors (A1, A2, A3), each switch (SW) is connected with a first connector (A1) to an HF filter (HF-F) of the filter unit (FE).

6. The HF module according to the preceding claim, wherein to at least one filter unit (FE), the following applies: each switch (SW) is connected with a second connector (A2) to a terminating impedance (Z).

7. The HF module according to one of the two preceding claims, wherein to at least one filter unit (FE), the following applies: each switch (SW) is connected with a third connector (A3) to a signal bus (SIGS).

8. The HF module according to one of the preceding claims, wherein to at least one filter unit (FE), the following applies: the filter unit (FE) comprises a control circuit (STS) in order to control the switching states of the switches (SW).

9. The HF module according to one of the preceding claims, wherein to at least one filter unit (FE), the following applies: the third connector (A3) of the first switch (SW1) is connected to a transmission amplifier (PA).

10. The HF module according to one of the 8 preceding claims, wherein to at least one filter unit (FE), the following applies: the third connector (A3) of the second switch (SW2) is connected to an antenna connector (ANT).

11. The HF module according to one of the 7 preceding claims, wherein to at least one filter unit (FE), the following applies: the third connector (A3) of the third switch (SW3) is connected to a receiving amplifier (LNA).

12. The HF module according to one of the preceding claims, furthermore comprising one or more filter units (FE).

13. The HF module according to one of the preceding claims, wherein all filter units (FE) have the same circuit topology, the HF filters (HF-F) of the filter units (FE) are band-pass filters, and the band-pass filters of the filter units (FE) comprise different bandwidths and/or center frequencies.

14. Use of an HF module according to one of the preceding claims in a mobile radio device or a mobile radio unit.

Description

[0036] Shown are:

[0037] FIG. 1: the principal structure of the module,

[0038] FIG. 2: the naming of the inputs and outputs of the circuit components of a filter unit,

[0039] FIG. 3: the schematic structure of a filter unit with two switches and an HF filter,

[0040] FIG. 4: the schematic structure of a filter unit with three switches and two HF filters,

[0041] FIG. 5: a summary overview of a module with a filter unit with a control circuit,

[0042] FIG. 6: a possible connection of terminating impedances within a filter unit,

[0043] FIG. 7: an overview of a module with a filter unit with an HF filter, two switches, and a control circuit,

[0044] FIG. 8: an overview of a module with a filter unit with two HF filters, three switches, and a control circuit,

[0045] FIG. 9: the diagram of the easy expandability by adding additional filter units in order to be able to cover additional frequency bands, wherein the filter units are connected to an amplifier via a common signal bus,

[0046] FIG. 10: the easy expandability, in which all filter units are connected to a low-noise amplifier via a common signal bus,

[0047] FIG. 11: the easy expandability in the case of filter units that are designed as duplexers,

[0048] FIG. 12: a possible physical realization by stacked filter units,

[0049] FIG. 13: an alternative possible realization by filter units arranged next to one another.

[0050] FIG. 1 shows the fundamental diagram, according to which an HF module M with its filter units FE1, FE2 is realized. Within the module M, the first filter unit FE1 and the second filter unit FE2 are connected in parallel. Each of the two filter units has a first switch SW1 and a first HF filter HF-F. The two first switches have a signal input and allow for two possible switching states. In respectively one of the two switching states, the signal input of the respectively first switch is connected to the respectively (first) HF filter HF-F.

[0051] By adding identical or similar filter units, the module can be adapted without much effort and in particular without a big change of the fundamental circuit topology to a plurality of frequency bands. If the carrier aggregation is to be used, a combination of different HF filters can in particular be activated via the switch position of the first switches. The circuit complexity is reduced compared to conventional HF modules, because only double switches are required. The extensive circuit complexity of multi-switches is eliminated.

[0052] FIG. 2 illustrates the naming of different connectors: The HF filter is connected via an input I to the switch SW, namely via its first connector A1. The third connector A3 of the switch SW implements a signal input of the filter unit FE. Via a second connector A2 of the switch SW, the switch SW can be connected to a terminating impedance.

[0053] FIG. 3 illustrates the naming of the connectors of the second switch SW2: Via the first connector A1 of the second switch SW2, the second switch SW2 is connected to the HF filter. Via the third connector A3 of the second switch SW2, the filter unit FE can be connected to its output. Via a second connector A2 of the second switch SW2, the switch can be connected to a terminating impedance.

[0054] The signal direction of the switches and filters shown in FIGS. 2 and 3 can also be reversed so that a signal can be routed from the second switch SW2 via the filter to the first switch SW1.

[0055] FIG. 4 illustrates the naming of the connectors of the third switch. The first connector A1 of the third switch SW3 is thus connected to the second filter. Via the third connector A3 of the third switch SW3, the filter unit FE can be connected to a signal bus provided for the connection to the third switch SW3. Via the second connector A2, the third switch SW3 can be connected to ground via a terminating impedance.

[0056] It thus applies to all three switches SW1, SW2, SW3 of a filter unit FE, that the first connector is respectively provided for the connection to a filter. The second connectors A2 can be provided for the connection to a terminating impedance. The third connectors can be provided for the connection with one of the three possible signal buses.

[0057] FIG. 5 shows an embodiment, in which the HF module M comprises a filter unit FE, in which the switch position of the first switch SW1 is controlled by a control circuit STS.

[0058] The control circuit STS can in this case receive control signals of an external circuit environment and convert them into corresponding action signals for the switch SW1.

[0059] FIG. 6 shows an embodiment of a filter unit FE with three switches, two HF filters, and three terminating impedances Z. The second connector A2 of the three switches SW1, SW2, SW3 is respectively connected to ground via a terminating impedance Z.

[0060] FIG. 7 shows an embodiment of a filter unit FE in an HF module M, in which a control circuit STS controls the switching states of the two switches SW1, SW2.

[0061] FIG. 8 shows an embodiment of a filter unit FE of an HF module M, in which a control circuit STS controls the switching states of all three switches SW1, SW2, SW3. The two HF filters HF can in this case constitute the two filters of a duplexer so that only three switches are required since the common output of the duplexer is routed via the second switch SW2.

[0062] FIG. 9 shows how the module can be expanded by adding additional filter units FE. On the input side is a signal bus SIGS, which is connected to a power amplifier PA in the specific example. There is a second signal bus SIGS, which is connected to an antenna. Via the respective switches of the filter units, which can be switched via a respective control line STL, each of the filters of the filter units can be activated individually in order to open appropriate signal paths for HF signals from the amplifier to the antenna. Since only double switches are required respectively and the complexity of multi-switches is eliminated, the signal quality is improved. In a required expansion, the new construction of the respective multi-switch, via which individual filters are connected to the amplifier, is also eliminated. The amplifier PA can in this case be an MMMB-PA.

[0063] FIG. 10 shows a situation, analog to FIG. 9, for received signals.

[0064] FIG. 11 shows a situation, which is analog to FIGS. 9 and 10 and in which each filter unit FE comprises two filters of a duplexer and three double switches, wherein the switching states of the three switches are controlled by a control circuit.

[0065] A signal bus is connected to a power amplifier PA. A signal bus is connected to an antenna. Another signal bus (not shown for the sake of clarity) would be connected, on the one hand, to the respective receiving filters of the duplexers and, on the other hand, to a receiving amplifier.

[0066] FIG. 12 illustrates how different filter units having the same topology can be stacked on top of one another on a carrier substrate TS in order to produce a compact structural element with smallest space requirement by means of 3D integration. Two or possibly three commonly used signal buses can be realized by vias, which are routed through all filter units FE.

[0067] FIG. 13 shows an alternative possibility of the integration of the filter units FE on a carrier substrate TS. In this case, the different filter units FE are arranged next to one another on the carrier substrate TS and connected, for example, via through-connections to two or possibly three signal buses SIGS, which can be arranged on the top side or in metallization layers within a multi-layered carrier substrate TS.

[0068] In doing so, the HF module is not limited to the embodiments described above or shown in the figures, which embodiments are only of an exemplary nature. Modules, which comprise additional filter units, or filter units, which comprise additional filters and/or switches, also constitute possible embodiments.

Reference List

[0069] A1: First switch connector [0070] A2: Second switch connector [0071] A3: Third switch connector [0072] ANT: Antenna [0073] FE, FE1, FE2: Filter unit [0074] HF-F: HF filter [0075] I: Filter input [0076] LNA: Low-noise amplifier [0077] M: HF module [0078] O: Filter output [0079] PA: Power amplifier [0080] SIGS: Signal bus [0081] STS: Control circuit [0082] SW, SW1, SW2, SW3: Switch [0083] TS: Carrier substrate [0084] Z: Terminating impedance