WO2022039640A1

WO2022039640A1 - Power combiner for amplifier arrangement

Info

Publication number: WO2022039640A1
Application number: PCT/SE2020/050799
Authority: WO
Inventors: Mingquan Bao; David Gustafsson; Kristoffer ANDERSSON
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2022-02-24
Also published as: EP4200980A4; EP4200980A1

Abstract

There is provided a power combiner for an amplifier arrangement. The power combiner is configured to combine an input power signal, as provided to the power combiner through outputs of power cells of the amplifier arrangement, to an output power signal of the amplifier arrangement. The power combiner comprises serially galvanically connected, and electromagnetically coupled, transmission lines arranged to combine all the outputs of power cells to, at an output of the power combiner, produce the output power signal.

Description

POWER COMBINER FOR AMPLIFIER ARRANGEMENT

TECHNICAL FIELD

Embodiments presented herein relate to a power combiner for an amplifier arrangement. Embodiments further relate to an amplifier arrangement comprising such a power combiner. Embodiments further relate to a radio transceiver device comprising such an amplifier arrangement.

BACKGROUND

In general terms, an electronic amplifier is an electronic device used to increase the magnitude of voltage/current/power of an input signal. It takes in a weak electrical signal/ waveform and reproduces a similar stronger waveform at the output by using an external direct current (DC) power source. A power amplifier (PA) is an electronic amplifier designed to increase the magnitude of power of a given input signal. The power of the input signal is increased to a level high enough to drive loads of output devices like speakers, headphones, antennas, etc.

As a non-limiting illustrative example, in a fifth generation (5G) telecommunication system designed for millimeter-wave frequencies, a variety of frequencies are utilized. For example, the frequency ranges 24.25 to 27.5 GHz, 27.5 to 29.5 GHz, 37 GHz to 40 GHz, etc. might be utilized in a 5G telecommunication system. A broadband PA as utilized in components of the 5G telecommunication system should be able to operate in such a wide frequency range, as well as be able to deliver large output power for good coverage of the 5G telecommunication system. Furthermore, in a 5G telecommunication system implementing multi-input and multi-output (MIMO) communication, multiple transceivers, each comprising PAs, should fit in a limited space. Therefore, the size of the chip in which the PA is implemented should be small, and thus the PA itself should have a small footprint on the chip.

A broadband PA with large output power is often realized by combining the output from several power cells. The outputs of the power cells are combined in a power combiner. One way to realize a power combiner is by means of transformers. A power combiner based on transformers has loss associated with the coupling between the windings on the primary side and the secondary side. At mm-wave frequencies these losses are higher due to a low quality factor. Another way to realize a power combiner is by means of transmission lines. One drawback with such a power combiner is the large chip area needed for realization.

Hence, there is still a need for improved amplifier arrangements in general and power combiners for amplifier arrangements in particular.

SUMMARY

An object of embodiments herein is to provide power combiners and amplifier arrangements addressing the issues noted above.

According to a first aspect there is presented a power combiner for an amplifier arrangement. The power combiner is configured to combine an input power signal, as provided to the power combiner through outputs of power cells of the amplifier arrangement, to an output power signal of the amplifier arrangement. The power combiner comprises serially galvanically connected, and electromagnetically coupled, transmission lines arranged to combine all the outputs of power cells to, at an output of the power combiner, produce the output power signal.

According to a second aspect there is presented an amplifier arrangement for amplifying an input power signal to an output power signal. The amplifier arrangement comprises an input network and power cells. Each power cell has an input and an output. The amplifier arrangement comprises a power divider having an input and outputs. The input of the power divider is configured to receive the input power signal. Each output of the power divider is connected to a respective input of the power cells. The amplifier arrangement comprises a power combiner according to the first aspect. The transmission lines are arranged to combine all the outputs of all the power cells to, at the output of the power combiner, produce the output power signal.

According to a third aspect there is presented an amplifier arrangement for amplifying an input power signal to an output power signal. The amplifier arrangement comprises. The amplifier arrangement comprises an input network and power cells. Each power cell has an input and an output. The amplifier arrangement comprises a power divider having an input and outputs. The input of the power divider is configured to receive the input power signal. Each output of the power divider is connected to a respective input of the power cells. The amplifier arrangement comprises a power combiner. The power combiner comprises serially galvanically connected, and electromagnetically coupled, transmission lines configured to combine all the outputs of the power cells to, at an output of the power combiner, produce the output power signal.

According to a fourth aspect there is provided a radio transceiver device. The radio transceiver device comprises at least one amplifier arrangement according to any of the second aspect and the third aspect.

Advantageously these aspects provide power combiners and amplifier arrangements not suffering from the issues noted above or at least where the above issued have been mitigated or reduced.

Advantageously, the proposed power combiner enables the transmission lines to be arranged either in a side-by-side configuration, or in an on-top-of each other configuration, or in a mixed side-by-side and on-top-of each other configuration, and thus, the proposed power combiner is compact, compared with conventional distributed amplifiers.

Advantageously, in the proposed power combiner, the transmission lines are connected in series and, consequently, the outputs of the transmission lines are galvanically connected with the output port of the amplifier arrangement. Comparing to a conventional power combiner where outputs of power cells are combined through a transformer, the proposed power combiner has lower losses due to a direct galvanic connection.

Advantageously, in the proposed power combiner, the width and/or length of the transmission lines, as well as the separation between transmission lines, are selectable parameters for impedance matching in the design.

Advantageously, since all transmission lines in the proposed power combiner are directly connected, the drain/collector of any transistor in the power cells can share a single direct current (DC) supply.

Advantageously, the proposed power combiner is capable of operating at a wide bandwidth, and thus suitable for applications in a wideband telecommunication system. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, module, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 schematically illustrates a reference power combiner with transmission lines

Fig. 2 schematically illustrates a power combiner with transmission lines according to embodiments;

Fig. 3 schematically illustrates a coupled pair of transmission lines and the equivalent circuit.

Figs. 4, 5, io schematically illustrate amplifier arrangements according to embodiments;

Figs. 6, 7, and 8 schematically illustrate power combiners according to embodiments;

Fig. 9 schematically illustrate an amplifier arrangement with a reference power combiner;

Figs. 11-14 illustrate results; and

Fig. 15 schematically illustrates a radio transceiver device according to an embodiment. DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

As noted above, there is still a need for improved amplifier arrangements in general and power combiners for amplifier arrangements in particular.

The embodiments disclosed herein therefore relate to power combiners and amplifier arrangements addressing the issues noted above.

A conventional distributed amplifier has a power combiner which consists of several transmission lines (TLs) connecting power cells, as shown in Fig. 1. The transmission lines thus have no mutual electromagnetic (EM) coupling. As will be further disclosed below, in the herein proposed power combiner, the transmission lines could be arranged either side-by-side or on-top-of each other, as shown in Fig. 2. Consequently, the transmission lines become electromagnetically coupled. This also reduces the required chip area, as compared to the power combiner of Fig. 1.

The EM coupling between TLs introduces a mutual inductance, M. For two coupled transmission lines TL₁₀ and TL₁₁ the mutual inductance becomes

where k is coupling coefficient, L₁₀ and are the self-inductance of the two transmission lines TL₁₀ and TL₁₁, respectively. When two transmission lines are connected in the way shown in Fig. 3(a), which schematically shows a coupled pair of transmission lines (represented by inductors) with mutual inductance M, the following equations for the current, I, and voltages V₁, V₂, V₃ of the coupled transmission lines TL₁₀ and TL₁₁ are obtained as:

and

From equations (la), (lb) and (2) follow that:

The proposed way of connecting TL₁₀ and TL₁₁ forces the currents flowing in two coupled lines in the same direction, thus, the mutual inductance M is larger than zero. The value of the mutual inductance M is determined by the separation of two transmission lines. The equivalent circuit of Fig. 3(a) is shown in Fig. 3(b), where the impedance is given by:

Comparing equations (3) and (4),

Thus, the coupled TL pair can be represented by an inductor with an equivalent inductance L_eq. For EM coupled TLs, the equivalent inductance for each TL is thus equal to the self-inductance plus the mutual inductances from different coupled lines. Due to M being positive- valued, for the same equivalent inductance, EM coupled TLs could be shorter than TLs without EM coupling. As will be disclosed next, EM coupled TLs could be used to build a compact power combiner.

Fig. 4 schematically illustrates an amplifier arrangement 100 for amplifying an input power signal P_in to an output power signal P_out comprising a power combiner 120 according to an embodiment.

The power combiner 120 is configured to combine an input power signal P_in, as having been amplified by power cells 106 of the amplifier arrangement 100 and provided to the power combiner 120 through outputs of the power cells 106, to an output power signal P_out of the amplifier arrangement 100. In general terms, when combining the signals, the characteristics of the power combiner 120 have a direct impact on the impedance presented to each power cell 106, and it therefore also impacts the amplification, energy efficiency, distortion, and bandwidth of each power cell 106.

The power combiner 120 comprises serially galvanically connected, and electromagnetically coupled, transmission lines 108 arranged to combine all the outputs of power cells 106 to, at an output of the power combiner 120, produce the output power signal P_out.

With continued reference to Fig. 4, the amplifier arrangement 100 further comprises an input network 110 and the power cells 106. Each power cell 106 has an input and an output. The amplifier arrangement 100 further comprises a power divider 102 having an input and outputs. The input of the power divider 102 is configured to receive the input power signal P_in. Each output of the power divider 102 is connected to a respective input of the power cells 106. As disclosed above, the transmission lines 108 of the power combiner 120 are arranged to combine all the outputs of all the power cells 106 to, at the output of the power combiner 120, produce the output power signal P_out.

Embodiments relating to further details of the power combiner 120 as well as the amplifier arrangement 100 will now be disclosed.

As is the case in Fig. 4, one of the transmission lines 108 might be connected between the output of one of power cells 106 and the output of the power combiner 120. In some aspects, the transmission line connected to the output provides an impedance transformation. That is, in some embodiments, the transmission line connected to the output of the power combiner 120 is configured to provide an impedance transformation. The impedance transformation might either be a step-up impedance transform or a step-down impedance transform.

As is the case in Fig. 4, in some examples, the outputs of the power cells 106 is connected separately between two neighbouring transmission lines 108. That is, in some embodiments, each pair of neighbouring transmission lines 108 is separated by a junction, and the output of each power cell 106 is connected to a respective one of the junctions between two neighboring transmission lines 108 (except for power cell AN connected with transmission line TL_N). With continued reference to Fig. 4, the input network 110 might further comprise a power divider 102 having an input and outputs. The input of the power divider 102 is configured to receive the input power signal P_in, and each output of the power divider 102 is connected to a respective input of the power cells 106. In some embodiments (as for example in below referenced Fig. 10), the power divider 102 further comprises transmission lines, and the outputs of the power divider 102 are junctions between neighbouring transmission lines of the power divider 102. In some embodiments, the transmission lines of the power divider 102 are serially galvanically connected, and electromagnetically coupled, transmission lines TLin (n = o, 1, ..., N), to build a compact power divider 102.

As in Fig. 4, in some examples the input signal is divided in N ways, and each way has a delay line Di (i = 1, 2, ..., IV). That is, the power divider 102 might further comprise phase delay lines 104. The phase delay lines might drive each power cell 106 with a proper phase. In some embodiments the input of each power cell 106 is thus connected to one output of the power divider 102 via a respective phase delay line 104 to drive each power cell 106 in terms of phase and amplitude. Consequently, the outputs from the power cells 106 are added constructively at the output of the power divider 102.

There could be different examples of power cells 106. In some examples, each power cell 106 is an amplifier. Non-limiting examples of amplifiers are power amplifiers with a single transistor, or a cascode amplifier, or a multi-stage cascaded amplifier. In other examples each power cell 106 is a transistor. In some examples there are as many power cells 106 as there are transmission lines 108 in the power combiner 120.

Fig. 5 shows the amplifier arrangement in Fig. 4 where the power combiner 120 is represented by a circuit diagram and where the coupled transmission lines are represented by coupled inductors. As shown in Fig. 5, the coupled TLs form multi-coil coupled inductors. In particular, in some embodiments, all the transmission lines 108 collectively form a multi-turn spiral structure. However, this does not imply that the power combiner 120 in itself is a transformer, merely that the coupled TLs form a multi-turn spiral, where one terminal of a TL is connected with one terminal of another TL. The separation between the transmission lines 108 might be defined by an impedance matching criterion for the power combiner 120. That is, in some embodiments, the transmission lines 108 in each pair of neighboring transmission lines 108 are separated by a distance defined by an impedance matching criterion for the power combiner 120.

In some examples the impedance transformation ratio of the transmission lines 108 is optimized. In particular, in some embodiments each pair of neighboring transmission lines 108 exhibit a difference of impedance of those two transmission lines given by separation distance between the two transmission lines 108 of that pair, as well as length and width of each transmission line, and the impedance difference for each of the pairs of neighboring transmission lines 108 is selected according to an impedance matching criterion for the power cells 106 connected to the two transmission lines 108 of that pair.

In some aspects, the layout of the power combiner 120 with coupled transmission lines 108 is similar to a spiral inductor with two or more terminals. Such a power combiner 120 is illustrated in Fig. 6. Fig. 6 shows the layout of a power combiner with three coupled transmission lines. It has three input ports T_in1, T_in2, T_in3, and one output port Tout where bridges connect the inner transmission lines with outside terminals T_in1, T_in2. That is, in some examples, the transmission lines 108 are arranged in either a squared or hexagonal or octagonal or circular spiral, and parallel sides of the spiral form the transmission lines 108. The spiral structure allows the transmission lines 108 to be connected in series. In this respect, a spiral inductor has only terminals Tim and Tout. The power combiner 120 has two extra terminals Tim and T_in3 which connect to the outer transmission line and middle transmission line, respectively. Those coupled transmission lines can be arranged in the same or different metal layer(s). In Fig. 6 the arc lines represent the bridges that connect the inner transmission lines to the outside terminal.

There could be different arrangements of the transmission lines 108 of the power combiner. For example, the serially galvanically connected, and electromagnetically coupled, transmission lines 108 arranged in a side-by-side configuration, in an on- top-of each other configuration, or in a mixed side-by-side and on-top-of each other configuration. In some embodiments the power combiner 120 is implemented in a technology (such as integrated circuit technology, printed circuit board technology, etc.) having at least one metal layer, and at least two of the transmission lines 108 are arranged in one and the same metal layer. Such a power combiner 120 is illustrated in Fig. 7(a) and Fig. 7(b). In some examples, the transmission lines 108 are connected via bridges or bonding wires. In further detail, Fig. 7(a) and Fig. 7(b) show a top view and perspective view of the power combiner 12, respectively, and where all transmission lines TL₁, TL₂, and TL₃ are in the same metal layer. Bridges connect the inner transmission lines with outside terminals T_in1, T_in2. Each terminal T_in1, T_in2, T_in3 is connected to a respective power cell (not shown) and terminal Tout is connected to the output of the amplifier arrangement (not shown).

In some embodiments the power combiner 120 is implemented in a technology (such as integrated circuit technology, printed circuit board technology, etc.) having at least two metal layers, and at least two of the transmission lines 108 are arranged in different ones of the metal layers. Such a power combiner 120 is illustrated in Fig. 8(a) and Fig. 8(b). Further, in case there are three or more transmission lines 108, some of the transmission lines 108 might be arranged in one and the same metal layer whereas other of the transmission lines 108 might be arranged in different ones of the metal layers. In further detail, Fig. 8(a) and Fig. 8(b) show a top view and perspective view of the power combiner 120, respectively. Each terminal Tim, Tim, Tm₃ is connected to a respective power cell (not shown) and terminal Tout is connected to the output of the amplifier arrangement (not shown). Transmission lines TL₂ and TL₁ are laid side-by-side, and they are edge coupled. TL₂ and TL₃ are connected by a via near terminal Tin₃. Most part of TL₂ is located underneath of TL₃. Thus, TL₂ and TL₃ are broad-side coupled, usually resulting in a larger coupling coefficient than correspondingly edge coupled TL₂ and TL₁. The coupling coefficient of TL₂ and TL₃ are determined by the (vertical) separation between the top metal layer and the sub- top metal layer, as well as the separation in the horizontal plane (i.e., metal layer plane). If three metal layers are available, the transmission lines could all be laid in different metal layers. But in principle, transmission lines can be laid in arbitrary number of metal layers. However, the characteristic impedance of each transmission line, and the coupling coefficients between transmission lines differ when the transmission line are laid in different metal layers. A comparison will now be made between an amplifier arrangement having a reference power combiner (e.g. with transmission lines arranged as in Fig. 1) and an amplifier arrangement comprising the herein disclosed power combiner 120 (e.g. with transmission lines arranged as in Fig. 2). Two 24-40 GHz amplifier arrangements utilizing such power combiners with three transmission lines in the power combiner were designed in a 60 nm GaN technology.

The schematic of the reference distributed amplifier arrangement 900 is shown in Fig. 9. The power cells consist of single transistors (Q₁, Q₂, and Q₃). The drains of Q₁, Q₂, and Q₃ are connected via transmission lines TL₁ and TL₂, while transmission line TL₃ and transistor C₄ form an impedance matching network and DC component decoupling for the output port. The transmission lines do not have any intentional EM coupling. Each of transmission lines might be of different width and/or length to provide an optimal load for the power cells. To reduce the chip area, transmission line TL₁ and transmission line TL₃ are folded. The power combiner consumes a chip area of 0.87 mm by 0.26 mm = 0.226 mm².

The schematic of an amplifier arrangement 100 with the proposed power combiner is shown in Fig. 10. The transmission lines TL₁, TL₂ and TL₃ of the power combiner are laid side-by-side in one and the same metal layer. In the design, the length and/or width of each transmission line, as well as the separation between the transmission lines can be optimized, to get a large output power and power added efficiency with a broad bandwidth. The drains of transistors Q₁, Q₂ and Q₃ (where each transistors Q₁, Q₂, and Q₃ represent a power cell) are connected by transmission lines TL₁ and TL₂. Transmission line TL₃ and capacitor C₄ are used for impedance matching and DC component decoupling for the output port. The gates of the transistors Q₁, Q₂ and Q₃ are connected with transmission lines TLin (n = o, 1, 2, 3) via a respective capacitor Cn (n = 1, 2, 3). A gate resistor R_g is inserted between the transistor's gate and the gate bias to block the leakage of the radio frequency (RF) signal. The drain supplier, VDD, is connected with TL₁ via a RF chock. The size, in terms of chip area, of the power combiner of the PA shown in Fig. 10 is about 0.054 mm². The reference power combiner of Fig. 9 thus consumes 4.2 times as much chip area. If multi-metal layers are available, for instance, using a silicon technology (such as CMOS or BiCMOS), the coupled transmission line can be laid in different layers. The size of the power combiner can then be further reduced. Additionally, the proposed power combiner can also be realized by laying TL₃ in the top metal layer and TL₂ and TL₁ in the subtop metal layer, as in Fig. 8.

The performance of the two amplifier arrangements will now be compared.

For the amplifier arrangement 900 with a reference power amplifier, Fig. 11 plots the simulated gain as a function of the output power at frequencies 24 GHz, 29.6G Hz, 34.6 GHz, and 40 GHz. From 24 GHz to 40 GHz, small signal gain is varied from 6.9 dB to 7.7 dB. The maximum output power of the amplifier arrangement is around 34.8 dBm. The gain decreases no more than 2.2 dB as output power reaches the maximum. The power-added efficiency (PAE) versus output power for the amplifier arrangement with a reference power amplifier is shown in Fig. 12. The maximum PAE is varied between 31% to 37% in the frequency range from 24 to 40 GHz.

For the amplifier arrangement 100 with the proposed power amplifier, Fig. 13 plots simulated gain versus output power at frequencies 24 GHz, 29.6G Hz, 34.6 GHz, and 40 GHz. The small signal gain of the is varied between 7.0 dB to 7.7 dB at different frequencies. The maximum output power is around 34.2 dBm. The gain decreases no more than 2.6 dB when the output power reaches the maximum. The PAEs of the amplifier arrangement with the proposed power amplifier are plotted in Fig. 14 at frequencies 24GHz, 34.6GHz, 39.3GHz, and 40GHz. The maximum PAEs varies between 28.3 % to 32.2 % at different frequencies.

It can thus be concluded that, with the benefit of a more compact design, the performance of the amplifier arrangement with the proposed power amplifier is only slightly worse than the amplifier arrangement with a reference power amplifier but requires significantly less chip area for implementation.

The herein disclosed power amplifier arrangement 100 might be provided either as a standalone arrangement, or as part of a further device or arrangement. In particular, as illustrated in Fig. 15, in some aspects there is provided a radio transceiver device 1500 comprising at least one power amplifier arrangement 100 as herein disclosed. The radio transceiver 1500 might in turn be part of a radio base station (such as a radio access network node, base transceiver station, node B (NB), evolved node B (eNB), gNB, access point or transmission and reception point (TRP)). The radio transceiver 1500 might alternatively be part of a portable wireless device (such as mobile station, mobile phone, handset, wireless local loop phone, user equipment (UE), smartphone, laptop computer, tablet computer, modem, wireless sensor, network equipped vehicle, or Internet of Things (loT) device).

The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

Claims

1. A power combiner (120) for an amplifier arrangement (100), wherein: the power combiner (120) is configured to combine an input power signal provided to the power combiner (120) through outputs of power cells (106) of the amplifier arrangement (100), to an output power signal (Pout) of the amplifier arrangement (100); and wherein: the power combiner (120) comprises serially galvanically connected, and electromagnetically coupled, transmission lines (108) arranged to combine all the outputs of power cells (106) to, at an output of the power combiner (120), produce the output power signal (Pout).

2. The power combiner (120) according to claim 1, wherein each power cell (106) is an amplifier.

3. The power combiner (120) according to claim 1, wherein there are as many power cells (106) as there are transmission lines (108).

4. The power combiner (120) according to claim 1, wherein all the transmission lines (108) collectively form a multi-turn spiral structure.

5. The power combiner (120) according to claim 1, wherein the transmission lines (108) are arranged in either a squared or hexagonal or octagonal or circular spiral, and wherein parallel sides of the spiral form the transmission lines (108).

6. The power combiner (120) according to claim 1, wherein the power combiner (120) is implemented in a technology having at least one metal layer, and wherein at least two of the transmission lines (108) are arranged in one and the same metal layer.

7. The power combiner (120) according to claim 1, wherein the power combiner (120) is implemented in a technology having at least two metal layers, and wherein at least two of the transmission lines (108) are arranged in different ones of the metal layers.

8. The power combiner (120) according to claim 1, wherein the transmission lines (108) in each pair of neighboring transmission lines (108) are separated by a distance defined by an impedance matching criterion for the power combiner (120).

9. The power combiner (120) according to claim 1, wherein each pair of two neighboring transmission lines (108) exhibit a difference of impedance of the two transmission lines given by separation distance between the two transmission lines (108) of the pair as well as length and width of each transmission line of the pair, and wherein the impedance difference for each of the pairs of neighboring transmission lines (108) is selected according to an impedance matching criterion for the power cells (106) connected to the two transmission lines (108) of that pair of two neighboring transmission lines (108).

10. The power combiner (120) according to claim 1, wherein one of the transmission lines (108) is connected between the output of one of power cells (106) and the output of the power combiner (120).

11. The power combiner (120) according to claim 10, wherein the transmission line connected to the output of the power combiner (120) is configured to provide an impedance transformation.

12. The power combiner (120) according to claim 1, wherein each pair of neighboring transmission lines (108) is separated by a junction, and wherein the output of each power cell (106) is connected to a respective one of the junctions between two neighboring transmission lines (108).

13. An amplifier arrangement (100) for amplifying an input power signal (Pin) to an output power signal (Pout), the amplifier arrangement (100) comprising: an input network (110) and power cells (106), each power cell (106) having an input and an output, and a power divider (102) having an input and outputs, wherein the input of the power divider (102) is configured to receive the input power signal (Pin), and wherein each output of the power divider (102) is connected to a respective input of the power cells (106); and a power combiner (120) according to claim 1, and wherein the transmission lines (108) are arranged to combine all the outputs of all the power cells (106) to, at the output of the power combiner (120), produce the output power signal (Pout).

14. An amplifier arrangement (100) for amplifying an input power signal (Pin) to an output power signal (Pout), the amplifier arrangement (100) comprising: an input network (110) and power cells (106), each power cell (106) having an input and an output, and a power divider (102) having an input and outputs, wherein the input of the power divider (102) is configured to receive the input power signal (Pin), and wherein each output of the power divider (102) is connected to a respective input of the power cells (106); and a power combiner (120) comprising serially galvanically connected, and electromagnetically coupled, transmission lines (108) configured to combine all the outputs of the power cells (106) to, at an output of the power combiner (120), produce the output power signal (Pout).

15. The amplifier arrangement (100) according to claim 13 or 14, wherein the input network (110) further comprises a power divider (102) having an input and outputs, wherein the input of the power divider (102) is configured to receive the input power signal (Pin), and wherein each output of the power divider (102) is connected to a respective input of the power cells (106).

16. The amplifier arrangement (100) according to claim 15, wherein the power divider (102) further comprises phase delay lines (104), and wherein the input of each power cell (106) is connected to one output of the power divider (102) via a respective phase delay line (104) to drive each power cell (106) in terms of phase and amplitude.

17. The amplifier arrangement (100) according to claim 15, wherein the power divider (102) further comprises transmission lines, and wherein the outputs of the power divider (102) are junctions between neighbouring transmission lines of the power divider (102).

18. The amplifier arrangement (100) according to any of claims 13 to 17, wherein each power cell (106) is an amplifier.

19. A radio transceiver device (1500) comprising at least one amplifier arrangement (100) according to any of claims claims 13 to 18.