High-frequency assembly having an impedance matching filter

Abstract

To provide a high frequency assembly with an impedance matching filter that can improve efficiency.SOLUTION: A high frequency assembly 10 includes a signal source 20 in the form of a semiconductor amplifier output 22, an impedance matching filter 30, and a high frequency waveguide 50. The impedance matching filter 30 is connected to the semiconductor amplifier output 22 on the input side and to the high frequency waveguide 50 on the output side. The impedance matching filter 30 has an impedance value on the input side different from that on the output side, is matched to the semiconductor amplifier output 22 on the input side, and is matched to the high frequency waveguide 50 on the output side.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This description relates to high-frequency technology. In particular, this description relates to a high-frequency assembly having an impedance matching filter disposed between two components having different impedances. Further, this description relates to an antenna device having one or more such high-frequency assemblies, where the high-frequency assembly can be used, for example, as part of a communication device or a data transmission link, particularly a satellite transmission link or a satellite wireless transmission link. Finally, but importantly, this description relates to a satellite having such an antenna device.

Background Art

[0002] Systems in the field of high-frequency technology are used to transmit signals and data from a transmitting station to a receiving station. High-frequency technology is preferably used when it is necessary to transmit data over long distances (up to several hundred kilometers or several thousand kilometers).

[0003] Before the signal is sent to the air interface (e.g., an antenna), it may need to be processed, amplified, adjusted, etc. High-frequency technology is used, for example, for amplifying, synthesizing, and filtering communication signals in communication satellites.

[0004] High-frequency systems are often composed of individual modules (such as low-noise amplifiers, also called LNAs, filters, couplers, isolators, preamps, power amplifiers, etc.) connected to each other. For the connection between two directly connected modules, matching is often required. Power matching is usually achieved by matching the impedances of the modules connected to each other.

[0005] (Patent Document 1) and (Patent Document 2) describe signal transmission units employed in the high-frequency band and particularly find use in communication satellites.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be addressed can be considered to be improving the efficiency of the high-frequency assembly.

Means for Solving the Problems

[0008] This problem is solved by the subject matter of the independent claims. Further embodiments will become apparent from the dependent claims and also from the following description.

[0009] According to one aspect, a high-frequency assembly, also referred to as an RF assembly, is identified. The RF assembly has a signal source, an impedance matching filter, and a high-frequency waveguide also referred to as an RF waveguide. The signal source has a semiconductor amplifier output section. The impedance matching filter has a first interface and a second interface. The first interface is communicatively coupled to the signal source such that a high-frequency signal, an RF signal, can be transmitted from the signal source to the impedance matching filter. The second interface is communicatively coupled to the RF waveguide such that an RF signal can be transmitted from the impedance matching filter to the RF waveguide. The first impedance value at the first interface corresponds to the impedance value at the semiconductor amplifier output section (this optimal impedance of the output section of the semiconductor amplifier is generally evaluated complexly, i.e., consisting of magnitude and phase). The second impedance value at the second interface corresponds to the impedance value in the RF waveguide. The first impedance value and the second impedance value have different values.

[0010] In other words, the impedance matching filter has an impedance value on the input side (at the interface to the semiconductor amplifier output section) that is different from the impedance value on the output side (at the interface to the RF waveguide), and is designed on the input side so that the optimal impedance for the desired operating conditions (maximum efficiency, maximum gain, maximum linearity, maximum output) is presented to the semiconductor amplifier output section, and is matched to the high-frequency waveguide on the output side, where power matching for optimal efficiency in particular is mentioned. As a result, in addition to its filter function, the impedance matching filter also performs matching for individually connected components, eliminating the need for a separate matching circuit between the semiconductor amplifier output section and the high-frequency waveguide. Similarly, since the filter has a hollow waveguide output section, a dedicated hollow waveguide joint is not required. Furthermore, since the impedance matching filter has capacitive input coupling, a dedicated blocking capacitor for DC blocking (to remove the DC component from the RF signal) can be omitted.

[0011] The semiconductor amplifier output section is a semiconductor component, such as a transistor, that outputs an RF signal supplied to the impedance matching filter.

[0012] The impedance matching filter has two functions. The first function is that the impedance matching filter satisfies the function of a frequency filter and functions, for example, as a band filter. The second function is that the impedance matching filter is matched to the impedance of the semiconductor amplifier output section at its first interface and to the impedance of the RF waveguide at its second interface. This matching is preferably power matching, that is, the impedance value of the first interface corresponds to the impedance value of the amplifier output section, and the impedance value of the second interface corresponds to the impedance value of the RF waveguide.

[0013] As a result, the power loss as a result of the required impedance matching is reduced. This is because an impedance matching filter using hollow waveguide technology has significantly lower losses than, for example, a microstrip matching structure implemented in a power amplification substrate or a PCB. Furthermore, this structure of the RF assembly makes it possible to omit a separate matching circuit. Rather, the matching is performed by the impedance matching filter. The number of components is reduced, thereby reducing both the energy demand and the heat load. Overall, the power effect (as the ratio of the output power to the input power for the RF assembly) is improved by the structure described herein. The impedance values considered herein are preferably complex values and are each related to the magnitude and phase at each respective position of the RF assembly. Furthermore, the filter is designed to enable compensation for structures (such as wire bonds, microstrip lines) required for the mechanical connection between the filter and the amplifier.

[0014] Each communication coupling between the first interface and the signal source and between the second interface and the RF waveguide is configured such that these two couplings can transmit electrical and / or electromagnetic signals. This does not necessarily assume that there is a DC electrical conductivity connection between the components described above. Rather, signals, particularly high-frequency signals, can be transmitted via capacitive coupling. Capacitive coupling makes it possible to omit a dedicated blocking capacitor in the RF path and thus also reduces the RF losses caused by that portion due to the capacitor.

[0015] According to one embodiment, the semiconductor amplifier output has an impedance value lower than that of the RF waveguide.

[0016] The semiconductor amplifier output is, for example, in the form of a transistor and typically has an actual impedance value of 10 to 30 ohms. In contrast, an RF waveguide in the form of a coaxial line or a hollow waveguide typically has an actual impedance value of about 50 ohms or more.

[0017] The impedance matching filter achieves matching between these components having different impedance values.

[0018] According to a further embodiment, the impedance matching filter is configured as a hollow waveguide having at least one resonator and / or at least one window.

[0019] The impedance matching filter is preferably configured using hollow waveguide technology. Thus, it is characterized by high efficiency or low loss, and as a result, the power efficiency of the RF assembly as a whole becomes better.

[0020] The resonator and / or window are components of the impedance matching filter, and their structure and configuration affect the filter function and characteristic impedance of the impedance matching filter.

[0021] According to a further embodiment, the impedance matching filter has a plurality of resonators and / or a plurality of windows arranged side by side along the signal propagation direction in the impedance matching filter.

[0022] The plurality of resonators and / or windows arranged side by side and spaced apart from each other provide impedance matching of the impedance matching filter and also serve to perform the filter function.

[0023] Preferably, the windows are arranged between two resonators arranged side by side respectively, and the windows correspond to the cross-sectional constrictions of the impedance matching filter.

[0024] According to a further embodiment, the plurality of resonators arranged side by side along the signal propagation direction are different from each other in terms of their geometric shapes along the signal propagation direction.

[0025] This means that the resonators have different extents and / or shapes. As an example, resonators arranged side by side may have different heights, materials, thicknesses, and / or shapes. This achieves the matching of the amplifier output part on the one hand and the impedance value of the RF waveguide on the other hand.

[0026] The resonators are configured such that at least two resonators have different geometric shapes. However, it is also conceivable that each resonator has a geometric shape (size, shape, etc.) that appears only once in the impedance matching filter.

[0027] According to a further embodiment, the impedance matching filter is configured as a hollow waveguide having one ridge or no ridge.

[0028] According to a further embodiment, the one ridge has a plurality of ridge sections, and the ridge sections have different geometric shapes.

[0029] The ridge sections are arranged side by side in the signal propagation direction. In particular, the ridges are arranged so as to be directly adjacent to each other. The ridge sections have, for example, different heights and / or widths. The plurality of differently configured ridge sections arranged side by side provide impedance matching of the impedance matching filter because the differently configured ridge sections have impedances of different characteristics.

[0030] According to a further embodiment, the RF assembly further has a base plate, the semiconductor amplifier output part is arranged on the base plate, and is DC-coupled to the transmission path on the base plate via one or more lines. The transmission path is positioned opposite the first interface and has a capacitive coupling element arranged to capacitively couple a high-frequency signal to the first interface.

[0031] The capacitive coupling element is DC-isolated from the first interface and is spaced apart from the first interface by a gap. High-frequency signals in the multi-GHz frequency range are supplied from the semiconductor amplifier output section to the transmission path and the capacitive coupling element. Due to the high frequencies, these signals are capacitively supplied from the capacitive coupling element to the first interface of the impedance matching filter, i.e., without a DC connection.

[0032] The semiconductor amplifier output section is DC-isolated from the impedance matching filter, and the DC component of the RF signal or the DC present in the transmission path and / or the coupling element is prevented from being transmitted from the transmission path or the capacitive coupling element to the impedance matching filter.

[0033] Normally, the base plate is a circuit board or a PCB (abbreviation for printed circuit board).

[0034] According to a further embodiment, the RF assembly further has a power supply, which is DC-coupled to the transmission path and is embodied to send an energy supply in the form of DC, DC, to the transmission path and to provide the energy supply to the semiconductor amplifier output section via the one or more lines.

[0035] The DC power is absorbed as operating energy by the semiconductor amplifier output section, for example, a transistor. This involves DC. The DC is transmitted via the same transmission path as the RF signal.

[0036] According to a further embodiment, the power supply has a DC filter configured to be non-transmissive for high-frequency signals on the transmission path.

[0037] The DC filter is configured as, for example, a low-pass filter. As a result, the DC filter allows the passage of DC signals and is non-transmissive with respect to high-frequency signals. The DC filter is non-transmissive with respect to the RF signal on the transmission path, that is, the useful signal output by the semiconductor amplifier output section. As a result, the DC energy supply does not significantly affect the impedance value of the semiconductor amplifier output section and the behavior with respect to the high-frequency signal.

[0038] According to a further embodiment, the RF assembly has a plurality of semiconductor amplifier output sections capacitively coupled to a first interface of the impedance matching filter.

[0039] In this embodiment, the plurality of semiconductor amplifier output sections are coupled to one impedance matching filter. Accordingly, the power supplied to the impedance matching filter is increased. The combination or increase of power is implemented on the input side of the impedance matching filter in this variant.

[0040] According to a further embodiment, the RF assembly has a plurality of impedance matching filters, each of which is coupled to at least one semiconductor amplifier output section, and the plurality of impedance matching filters are coupled to a single RF waveguide.

[0041] As an alternative to or in addition to the previous embodiments, the combination of powers is carried out in this embodiment at the output side of the impedance matching filter. This embodiment also serves to increase the output power. The plurality of impedance matching filters are connected at the output side, i.e., to the same RF waveguide at their respective second interfaces. It is also conceivable to first connect the respective second interfaces to each other and then connect the common output of the plurality of impedance matching filters to a single RF waveguide. Alternatively, each second interface is individually coupled to an RF waveguide. Two or more impedance matching filters on the output side can be connected to a so-called 3 dB coupler and connected to an RF waveguide.

[0042] According to a further embodiment, the RF waveguide is a hollow waveguide, a ridged hollow waveguide or a coaxial conductor.

[0043] According to a further aspect, an antenna device is specified. The antenna device has an antenna and a plurality of RF assemblies as described herein. The plurality of RF assemblies are connected to the antenna for transmitting a useful signal to the antenna.

[0044] According to a further aspect, a communication satellite having the antenna device described herein is specified.

[0045] The antenna device is, for example, part of a data transmission link within a communication satellite. The communication satellite is a spacecraft provided for use in an orbit of the earth and includes a communication station for transmitting and receiving data or signals. Further, the communication satellite can also include a unit for processing data. The RF assembly can preferably be used in the signal processing path of the communication station of the communication satellite.

[0046] In connection with this description, that is, in connection with RF assemblies, antenna devices, and communication satellites, high frequencies are to be understood as meaning a frequency range above 1 GHz (gigahertz, 1 × 10E9 hertz). Such a frequency range is used, for example, in satellite wireless transmission links. Such satellite wireless transmission links can be, for example, Ka-band transmission links in the frequency range of 17.7 - 21.2 GHz for the downlink and 27.5 - 31 GHz for the uplink, Ku-band or X-band implementations in the ranges of approximately 11 and 7 GHz respectively, or L-band (approximately 1.5 GHz), S-band (approximately 2.5 GHz), or C-band (approximately 4 GHz) implementations.

[0047] The semiconductor amplifier output section can be a component of an amplifier connected upstream of the antenna. As an example, a high-power transistor amplifier can be used as the amplifier. A high-power transistor amplifier may also be called a solid-state power amplifier (SSPA). This type of amplifier is used as an alternative or addition to the so-called traveling-wave tube amplifier at high frequencies. SSPAs are available in various power classes and very high frequency bands. As an example, SSPAs can be used in the following frequency bands: C-, X-, Ku-, Ka-, and Q-bands.

[0048] Hereinafter, exemplary embodiments of the present invention will be discussed in detail with reference to the accompanying drawings. The figures are schematic and not drawn to scale. The same reference signs refer to the same or similar elements.

Brief Description of the Drawings

[0049]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 8

Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0050] FIG. 1 shows a schematic diagram of an RF assembly 10. The RF assembly 10 has a signal source 20. The signal source 20 outputs a signal that follows a signal transmission path. The signal transmission path extends from left to right in the figure of FIG. 1. In this example, the RF signal is first output from the signal source 20, passes through the first line 23 and the second line 24, and reaches the transmission path 25 and the capacitive coupling element 26. From the capacitive coupling element 26, the RF signal is capacitively, that is, wirelessly, supplied to the first interface 31 of the impedance matching filter 30. The RF signal propagates through the impedance matching filter 30 to the second interface 39, from where the RF signal is supplied to the RF waveguide 50.

[0051] The power supply 60 is, for example, in the form of a DC supply and is connected to the transmission path 25 via a connection line 62. The DC energy supply is sent from the power supply 60 to the transmission path 25, and from there it is sent to the semiconductor amplifier output part 22 via the first line 23 and the second line 24. Therefore, both the RF signal and the energy supply for the semiconductor amplifier output part 22 are transmitted via the first line 23 and the second line 24. The power supply 60 also has a DC filter (DC filter) 61. The DC filter 61 has a function of passing DC and not passing high-frequency signals or generally attenuating high-frequency signals.

[0052] The signal source 20 is a power amplifier, which is composed of, for example, an amplifier unit 21 and a semiconductor amplifier output section 22. The semiconductor amplifier output section 22 is, for example, a transistor that outputs the signal amplified by the amplifier unit 21. In this regard, the semiconductor amplifier output section 22 can be provided in an integrated manner with the amplifier unit 21 or separately therefrom.

[0053] In this example, the signal source 20 is a high-frequency power amplifier module. High-frequency power amplifier modules are often used in satellite communications. They are used at remote stations to raise the transmission signal to the required power level so that, for example, a signal level that can still be received on Earth can be obtained. Conventionally, for this purpose, vacuum tube amplifiers have been used, especially at higher frequencies above 6 GHz. These amplifiers have outstanding characteristics, especially high efficiency (as measured by low DC energy consumption relative to the available RF output power) with good linearity (low distortion of the signal). In particular, for use in so-called active antennas, i.e., electrically controlled antennas, semiconductor-based amplifiers, however, have significant advantages, especially in terms of size and cost. In the case of active antennas, since each antenna element requires a dedicated amplifier, a large number of low-power amplifiers are needed. However, high linearity is also required together with very high power efficiency. However, conventional semiconductor-based amplifiers generally have several drawbacks here. This not only results in high energy consumption but also high heat generation. This can make the thermal design of the antenna more complex or even impossible. These drawbacks are overcome by the configuration of the RF assembly proposed here for use in active antennas. High efficiency is also desired for other amplifier applications, and it goes without saying that this RF assembly can also be easily used for other power amplifier applications (such as gateway amplifiers, channel amplifiers, etc.).

[0054] Components integrated using GaN or GaAs technology can be used for the amplifier unit 21 and the semiconductor amplifier output section 22 of the signal source 20.

[0055] The RF assembly described herein can be used, for example, in an active antenna module in the band of 17.8 - 20.2 GHz (in the Ka band). However, it can be sent to other amplifier applications and frequencies without problem, provided that suitable transistors are available (for example, Ku band 10.7 - 12.7 GHz, Q band 37.5 - 42.5 GHz). The RF assembly can be configured to meet the linearity requirement (given by 17 dB NPR (noise power ratio)) and the efficiency requirement of more than 30% (for the output stage, given by a maximum total antenna power of about 600 W for a plurality of amplifier paths) for a given dimension of about 7×3 mm^2 for each amplifier channel.

[0056] The signal source 20 is connected to the transmission path 25 by two lines 23, 24, and as a result, an electromagnetic signal is inductively transmitted from the amplifier output section 22 to the transmission path 25. The transmission path 25 is, for example, a conductor track on a circuit board. The transmission path 25 transitions to the capacitive coupling element 26. The capacitive coupling element 26 is, for example, directly connected to the transmission path 25, or these two elements are part of the same conductor track on the circuit board.

[0057] Individual transistors using GaN (or GaAs) technology are used as the semiconductor of the amplifier output section 22, especially without an integrated matching and stabilization network. In particular, the matching at the output of the transistor is generated by a hollow waveguide structure (i.e., the impedance matching filter 30). Two variants are considered here. The first variant is shown in FIGS. 4 - 6 and has a filter with a resonator and a window, and the second variant is shown in FIG. 8 and has a raised hollow waveguide.

[0058] The input coupling of the impedance matching filter to the hollow waveguide structure is carried out as directly as possible. A short piece of a PCB / ceramic substrate or, alternatively, a coaxial structure is considered for this purpose. The DC supply of the transistor functioning as the amplifier output is supplied either via the filter (in which case, a blocking using a capacitor, which is conventional otherwise, is positioned at the input of the filter) or is blocked using a capacitor. As a result, the input coupling of the RF signal to the hollow waveguide structure of the impedance matching filter is capacitive, so that no further DC barrier is needed for the RF lines (first line 23, second line 24).

[0059] The impedance matching filter 30 is coupled to the RF waveguide 50 by a coupling unit 40. The coupling unit 40 can be, for example, a flange or other connection part.

[0060] The impedance matching filter 30 is fabricated using hollow waveguide technology and has the function of filtering the signal output by the amplifier output unit 22, performing matching for the amplifier output unit 22 on the one hand, and also performing matching for the RF waveguide 50 on the other hand. As a result of this structure, the number of components required for the matching circuit is reduced, thereby improving the efficiency of the RF assembly 10 and providing high linearity. In particular, in the case of a semiconductor amplifier, it is possible to omit the matching network usually used at the output of the amplifier. Such a matching network usually results in high losses, thereby reducing the efficiency of the amplifier.

[0061] These drawbacks are avoided by the impedance matching filter 30 being configured using hollow waveguide technology and a capacitive junction being used as a DC part barrier between the amplifier output and the impedance matching filter.

[0062] Figure 2 shows an exemplary connection of a plurality of signal sources 20 to a single impedance matching filter 30. Any number of signal sources (determined in advance by requirements regarding available structural space and signal levels) can be connected to the impedance matching filter, and the connection between the signal source 20 and the impedance matching filter 30 is configured as configured in FIG. 1 with reference to the transmission path 25 and the capacitive coupling element 26.

[0063] The circuit of FIG. 2 serves to obtain a higher power level. However, it is also conceivable to connect a plurality of impedance matching filters 30 to each other on the output side to increase the output power level.

[0064] Figure 3 shows a detailed view of the semiconductor amplifier output section 22 connected to the transmission path 25 by two lines. The semiconductor amplifier output section 22 is disposed on the base plate 28. A connection line 62 for the DC supply of the semiconductor amplifier output section 22 is connected to the transmission path 25. The transmission path 25 transitions to the capacitive coupling element 26. The RF signal is output from the semiconductor amplifier output section 22 to the transmission path 25 and then propagates in the direction of the capacitive coupling element 26, from where the RF signal is capacitively supplied to the impedance matching filter. Only the resonator 32 of the impedance matching filter is shown in FIG. 3. A gap can be recognized between the resonator 32 and the capacitive coupling element 26.

[0065] The DC supply for the semiconductor amplifier output section 22 is supplied to the corresponding transistor as the drain voltage and is implemented via a PCB integrated filter in combination with, for example, discrete capacitors. Alternatively, the filter can be realized by a lambda / 4 line with parallel capacitors. In this example, the drain voltage can be connected to the transmission path 25 and also to any other area of the line to the filter.

[0066] FIG. 4 shows a larger portion of the RF assembly, and the RF assembly shown in FIG. 4 corresponds to the RF assembly from FIG. 3 in terms of its structure. FIG. 4 shows a power supply 60 that makes electrical energy available to the semiconductor amplifier output section 22. The semiconductor amplifier output section 22 outputs an RF signal via a transmission path and a capacitive coupling element, and the RF signal propagates through the impedance matching filter 30 along the signal propagation direction 36. The impedance matching filter 30 has a plurality of resonators 32 (in the example of FIG. 4, these are cylindrical pedestals) arranged side by side in the signal propagation direction 36, and windows 34 (cross-section constrictions) between the resonators.

[0067] In the deformation modes shown in FIGS. 3 and 4, the matching is provided by a cavity filter structure within an impedance matching filter configured as a hollow waveguide. In principle, all known filter topologies and filter types (rectangular / circular hollow waveguide filters, coaxial filters, dielectric filters) are suitable for this. As an example, a four-circuit coaxial filter is shown.

[0068] The impedance matching filter 30 is detuned in the development process so as to provide a desired matching according to magnitude and phase at the first interface 31 for the transistor of the semiconductor amplifier output section 22. This matching can be determined, for example, by so-called load-pull measurement or simulation. As a result, although the impedance matching filter cannot be used as an individual filter, when it is operated at the output section of the transistor of the semiconductor amplifier output section 22, the latter can be operated at its optimum operating point (for example, the best efficiency for power matching). In addition to generating the matching required for the semiconductor amplifier output section, the impedance matching filter 30 combined with the transistor of the semiconductor amplifier output section 22 also has a frequency-selective effect. For this reason, a dedicated output filter can be dispensed with. For this reason, since there is no need to consider additional filter losses, the efficiency is improved. The number of circuits and topology of the impedance matching filter depend on the requirements for the output filter, and the filter can be used regardless of the presence or absence of transmission zeros and group delay equalization. The typical number of circuits is from 1 circuit to 14 circuits or more (it is likely to be 4 circuits to 12 circuits in actual applications). The input coupling of the RF signal to the impedance matching filter is capacitively performed via a PCB, ceramic or coaxial structure (for example, via an internal conductor discretely made of an insulator material). The PCB or ceramic has the advantages of easy manufacturing and high cost efficiency, and the coaxial structure realizes the highest efficiency (low loss).

[0069] In principle, inductive input coupling to the impedance matching filter is of course also conceivable, but in such a case, a dedicated DC block (for example, a capacitor or a PCB structure) is required.

[0070] In the example shown, the connection of the transistor of the semiconductor amplifier output section to the input coupling structure leading to the impedance matching filter is formed by band wires (the first line 23, the second line 24, see FIG. 3). The transistor of the semiconductor amplifier output section can be directly placed in the notch of the PCB on the housing or spacer, but it is also possible to place it directly on the PCB or ceramic. The transistor can be (conductively) adhesively joined or soldered, where silver sintering or similar connection techniques are equally conceivable.

[0071] FIG. 5 shows an RF assembly having a plurality of paths or branches. Through the input interface 18, the signal is sent to the base plate 28, where the signal is processed and / or amplified. A plurality of impedance matching filters 22A, 22B, 22C, 22D output the signal to the path of the impedance matching filter 30 respectively.

[0072] FIG. 6 shows a cross-sectional view of a single path from FIG. 5. The power supply 60, the signal source 20 and the impedance matching filter 30 are shown together with the signal propagation direction 36. In the impedance matching filter 30, the four resonators 32A, 32B, 32C, 32D are arranged side by side and spaced apart from each other in the signal propagation direction 36. It is obvious that the resonators have different heights. However, in addition to different heights, the resonators can also deviate from each other in other characteristics, such as shape, diameter, etc. This deviation is used to achieve the targeted detuning of the impedance matching filter so that the input impedance and the output impedance deviate from each other in a state where the power is matched to the semiconductor amplifier output section on the input side and to the RF waveguide on the output side.

[0073] FIG. 7 shows a schematic diagram of the communication satellite 1. The high-frequency assembly 10 is arranged on the communication satellite 1. The high-frequency assembly 10 can be a part of the signal transmission path of the communication satellite. As an example, the high-frequency assembly 10 can output the signal to the transmission unit 2 in the form of an antenna.

[0074] The high-frequency assembly described in this specification is particularly suitable for connections related to signals to an antenna of a transistor amplifier or generally a semiconductor amplifier (SSPA).

[0075] FIG. 8 shows an RF assembly 10 having an impedance matching filter using a ridged hollow waveguide technique. For the general structure and function of the RF assembly 10, reference is made to the description of FIGS. 1-7 above.

[0076] In a variant of FIG. 8, the impedance matching filter uses a hollow waveguide having ridges 80 for matching. The ridges 80 are divided into a plurality of ridge sections 80A, 80B, 80C, 80D. The ridges 80 have different configurations in the ridge sections. From a functional point of view, this corresponds to resonators of different configurations as shown, for example, in FIG. 6.

[0077] The base plate 28 supports the semiconductor amplifier output part 22 and is covered by a cover 75.

[0078] In a variant of FIG. 8, the supply of direct current for the operation of the semiconductor amplifier output part and the capacitive coupling to the impedance matching filter are carried out as described above. The RF signal is coupled to the ridged hollow waveguide of the impedance matching filter via a slot 71 in the PCB, and in the waveguide, ridge sections having a plurality of mutually different configurations are arranged (corresponding to line sections having different characteristic impedances), providing corresponding matching of the input and output side impedances of the impedance matching filter.

[0079] Finally, FIG. 9 shows an antenna device 100 having a plurality of RF assemblies 10 connected to an antenna 2. This antenna device 100 can be used, for example, in a communication satellite.

[0080] It is additionally pointed out that "including" or "having" does not exclude other elements or steps, and "a" or "one" does not exclude a plurality. Further, it is pointed out that features or steps described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of the other above exemplary embodiments. Reference signs in the claims should not be regarded as limiting.

Explanation of Signs

[0081] 1 Communication satellite 2 Antenna 10 High-frequency assembly 18 Input interface 20 Signal source 21 Amplification unit 22 Semiconductor amplifier output section 23 First line 24 Second line 25 Transmission path 26 Capacitive coupling element 28 Base plate 30 Impedance matching filter 31 First interface 32 Resonator 34 Window 36 Signal propagation direction 39 Second interface 40 Coupling unit 50 High-frequency waveguide 60 Power supply 61 DC filter 62 Connection line 71 Coupling slot 75 Cover 80 Protrusion 80A, 80B, 80C Protrusion sections 100 Antenna device

Claims

1. An RF assembly (10), comprising: a signal source (20) having a semiconductor amplifier output section (22); an impedance matching filter (30) having a first interface (31) and a second interface (39); an RF waveguide (50); and the first interface (31) is communicatively coupled to the signal source (20) such that an RF signal can be transmitted from the signal source (20) to the impedance matching filter (30); the second interface (39) is communicatively coupled to the RF waveguide (50) such that an RF signal can be transmitted from the impedance matching filter (30) to the RF waveguide (50); a first impedance value at the first interface (31) corresponds to an impedance value at the semiconductor amplifier output section (22); a second impedance value at the second interface (39) corresponds to an impedance value at the RF waveguide (50); the first impedance value and the second impedance value have different values; further comprising a base plate (28); the semiconductor amplifier output section (22) is disposed on the base plate (28) and is DC-coupled to a transmission path (25) on the base plate (28) via one or more lines (23, 24); the transmission path (25) is positioned opposite the first interface (31) and has a capacitive coupling element (26) disposed for capacitively coupling an RF signal to the first interface (31); the RF assembly (10).

2. The RF assembly (10) according to claim 1, wherein the semiconductor amplifier output section (22) has an impedance value lower than that of the RF waveguide (50).

3. The RF assembly (10) according to claim 1, wherein the impedance matching filter (30) is configured as a hollow waveguide having at least one resonator (32) and / or at least one window (34).

4. The RF assembly (10) according to claim 3, wherein the impedance matching filter (30) has a plurality of resonators (32) and / or a plurality of windows (34) arranged side by side along a signal propagation direction (36) in the impedance matching filter (30).

5. The plurality of resonators (32) arranged side by side along the signal propagation direction (36) are different from each other with respect to their geometric shapes along the signal propagation direction (36), the RF assembly (10) according to claim 4.

6. The impedance matching filter (30) is configured as a hollow waveguide having one ridge (80), the RF assembly (10) according to claim 1.

7. The one ridge (80) has a plurality of ridge sections (80A, 80B, 80C) having different geometric shapes, the RF assembly (10) according to claim 6.

8. Further comprising a power supply (60), the power supply (60) being directly coupled to the transmission path (25) and sending an energy supply in the form of direct current, DC, to the transmission path, and the energy supply being provided to the semiconductor amplifier output through the one or more lines (23, 24), the RF assembly (10) according to claim 1.

9. The power supply (60) has a DC filter (61) configured to be non-transmissive with respect to the RF signal on the transmission path (25), the RF assembly (10) according to claim 8.

10. Having a plurality of semiconductor amplifier output parts (22A, 22B, 22C, 22D) capacitively coupled to the first interface (31) of the impedance matching filter, the RF assembly (10) according to claim 1.

11. A plurality of impedance matching filters (30), each of which is coupled to at least one semiconductor amplifier output (22), having a plurality of impedance matching filters (30), The plurality of impedance matching filters (30) are coupled to a single RF waveguide (50), the RF assembly (10) according to claim 1.

12. The RF waveguide (50) is a hollow waveguide, a ridged hollow waveguide or a coaxial conductor, the RF assembly (10) according to claim 1.

13. An antenna device (100), An antenna (2), A plurality of RF assemblies (10) according to any one of claims 1 to 12, and Having, the plurality of RF assemblies (10) being connected to the antenna for transmitting a useful signal to the antenna, an antenna device (100).

14. A communication satellite (1) having the antenna device (100) according to claim 13.

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