Transmitter device, transceiver, radio communication system and method

Abstract

The invention relates in particular to a transmitter device (1), in particular for radio communication, comprising: at least two antenna elements (31, 32), spaced apart by a defined distance; and a differential output amplifier (20), having a first output (21) coupled to a first antenna element (31) of the at least two antenna elements (31, 32), and a second inverted output (22) coupled to a second antenna element (32) of the at least two antenna elements (31, 32). A first transmission line element (50) is arranged between at least one of the first output (21) and the second output (22) and a respective one of the at least two antenna elements (31, 32), and is configured such that signals applied to respective input taps (310, 320) of the at least two antenna elements (31, 32) are substantially in phase with each other.

Description

Technical Field

[0001] The invention relates to a transmitter device, in particular for radio communication, and a transceiver having the transmitter device. The invention also relates to a radio communication system and a method for radio communication. Background Art

[0002] 5G base stations are using beamforming technology to send radio signals to user equipment UE, and also receive radio signals from such UE. Beamforming technology is also used in defense and satellite applications. The basic principle of beamforming is to combine signals in an antenna array to electronically focus the beam, which then concentrates the power in the desired direction - without physical antenna movement.

[0003] Beamforming can be used for multiple-input / multiple-output MIMO communications. A two-dimensional beamforming combination (elevation / azimuth) enables a base station to send radio signals in relatively narrow beams within certain horizontal and vertical angles.

[0004] To perform beamforming, an antenna array system (AAS) is used. To achieve high output power, each antenna or subarray is typically connected to a power amplifier (PA). In addition to the antenna array, modern complementary metal oxide semiconductor (CMOS) technology provides a high level of integration and low production cost. However, advanced CMOS technology nodes show limitations on the supply voltage and the available voltage margin level. This limits the achievable power of each power stage in the power amplifier of the transmitter. The combination of two power stages with a differential topology boosts the output power by an ideal 3dB to alleviate this problem. The differential topology in the power amplifier also provides a virtual ground and, therefore, improves PA stability compared to single-ended designs that are sensitive to ground return path parasitics.

[0005] Although the transmitter is designed differentially, single-ended antennas are usually used in AAS to limit the size of the antenna in the system. The antenna array is usually implemented on a printed circuit board PCB. Therefore, differential to single-ended conversion is required between the transmitter and the antenna. However, current solutions usually have various disadvantages, including but not limited to the decrease of overall Tx output power and phase imbalance. Summary of the invention

[0006] The object of the present disclosure is to mitigate, alleviate or eliminate one or more of the above-mentioned defects and shortcomings in the prior art and to at least solve the above-mentioned problems. This object is solved by the subject matter of the independent claims.

[0007] According to some aspects, there is provided a transmitter apparatus, in particular for radio communication, comprising:

[0008] - at least two antenna elements, spaced apart by a defined distance;

[0009] a differential output amplifier having a first output coupled to a first antenna element of the at least two antenna elements and a second inverting output coupled to a second antenna element of the at least two antenna elements;

[0010] - a first transmission line element arranged between at least one of the first output and the second output and a respective one of the at least two antenna elements;

[0011] - wherein the first transmission line element is configured such that signals applied to respective inputs of the at least two antenna elements are substantially in phase with each other.

[0012] The proposed radio transmitter device performs differential to single-ended conversion by introducing a 180° phase shift on one of the differential paths of the differential amplifier in the transmitter using a low-loss transmission line and connecting each differential path to an antenna forming a 2x1 subarray. The transmission line elements may include no or only very small power losses. The signal combination is then performed over the air.

[0013] Therefore, no additional and lossy conversion element similar to a balun is required.By careful design of the first transmission line element, the amplitude mismatch between the first antenna element and the second antenna element is negligible and does not negatively impact most applications.

[0014] In some aspects, the first transmission line element can be arranged on a substrate on which the antenna element is also arranged. Such a substrate can include, for example, a PCB. Arranging the first transmission line element and the first and second antenna elements on the substrate can reduce space and can enable a more simplified production method with fewer steps involved.

[0015] According to some other aspects, the first transmission line element is configured to cause a phase shift of substantially 180° or an odd multiple of 180° of the signal, in particular to cause a phase shift of substantially 180° or an odd multiple of 180° of the center frequency of the signal applied to the first transmission line element. The inventors have recognized that ensuring that the phases of the two signals are in phase with each other at the input of the respective antenna elements is sufficient to perform a differential to single-ended conversion when the signals are combined in the air. Therefore, different phase shift elements can be used as long as the above requirements are met. Therefore, this approach provides greater flexibility in producing larger antenna element arrays.

[0016] According to some other aspects, at least two antenna elements have a center-to-center distance substantially equal to half of the center frequency wavelength of the signals applied to the at least two antenna elements in air. Similarly, the first transmission line element may include an electrical length corresponding to substantially half of the center frequency wavelength of the signals applied to the first transmission line element. Thus, each subarray may be optimized for a respective center frequency.

[0017] Some other aspects relate to a transmitter apparatus having several antenna elements. Such a transmitter apparatus may include:

[0018] - a plurality of antenna elements n in number, in particular arranged in a single row or column, wherein n is an even number greater than 2; and

[0019] wherein each of the second ones of the antenna elements are each coupled to a second output of the differential output amplifier;

[0020] - one or more second transmission line elements arranged between the second output and each of said antenna elements except the second antenna element such that signals applied to said second antenna element and respective inputs of even-numbered antenna elements are in phase.

[0021] The additional antenna elements in the transmitter arrangement as proposed above may be suitable for covering various 5G and other user scenarios where different beam steering requirements must be met. In addition to this aspect, the proposed solution can further reduce the number of power amplifiers used in such an arrangement.

[0022] A similar aspect relates to a transmitter apparatus further comprising a plurality of antenna element pairs, wherein

[0023] - a first antenna element of a pair of antenna elements is coupled to the first antenna element or the first antenna element of a preceding pair of antenna elements via a respective first one of the second transmission lines; and

[0024] - a second antenna element of a pair of antenna elements is coupled to said second antenna element or to the second antenna element of a preceding pair of antenna elements via a respective second one of the second transmission lines; and

[0025] - wherein the second transmission line element is configured to cause signals applied to respective inputs of the pair of antenna elements to be in phase.

[0026] Various designs of the first transmission line element and / or one or more second transmission line elements are possible based on actual needs and requirements. For example, the transmission line element may include at least one of the following:

[0027] - a coplanar waveguide CWG arranged on a substrate;

[0028] - a microstrip arranged on a substrate;

[0029] -Substrate integrated waveguides;

[0030] - a double belt arranged on a substrate;

[0031] - a stripline arranged in a substrate;

[0032] - fin lines arranged in the substrate;

[0033] - a slot line arranged on a substrate; and

[0034] - One or more lumped elements arranged on a PCB substrate.

[0035] According to some aspects, the first transmission line element and / or one or more second transmission line elements include an inductor element and two capacitors arranged in the signal path to form a π-configuration.Alternatively, a T-section or lumped / distributed transmission line on a substrate may be used for phase shifting of the signal.

[0036] In this regard, it may be appropriate in some aspects if the first transmission line element and / or one or more of the second transmission line elements include an adjustment input for adjusting the phase shift of a signal applied thereto. Likewise, in the case of lumped elements, some of the elements may be electrically or mechanically adjustable. Such adjustment functionality may support compensation for imbalance or other distortion that may otherwise result from mismatches during differential to single-ended conversion.

[0037] Some aspects relate to the arrangement of various elements on a common substrate. In some aspects, the first transmission line element and / or the second transmission line element and at least two antenna elements are arranged on or in a common substrate. Generally, the antenna elements and the transmission line elements and in some aspects also the transmitter can be arranged on or in a common substrate. The substrate can include a printed circuit board of suitable materials. This provides a space-efficient and highly integrated board with all key elements assembled in a single production line. Therefore, the board can be optimally designed and produced for the intended purpose with all necessary components.

[0038] Several combinations and alternatives of this arrangement are possible. According to some other aspects, the differential output amplifier is arranged in a semiconductor body in a package, wherein the package is arranged on a common substrate with at least two antenna elements. According to some aspects, the first transmission line element is arranged in one of the semiconductor body and the package.

[0039] According to some aspects, the transmitter includes an impedance match configured to match the impedance of the first output and the second output of the differential output amplifier to the impedance of the corresponding inputs of at least two antenna elements. This will improve the matching with the corresponding elements and reduce power losses due to reflections and mismatches. In this regard, the impedance matching element may include one of the following:

[0040] - a transmission line transformer arranged between the first transmission line element and / or one or more second transmission line elements and the corresponding antenna element, or coupled to the output of the differential power amplifier;

[0041] - a matching network, in particular an adjustable matching network coupled to the output of the differential output amplifier.

[0042] A second aspect of the present disclosure relates to a transceiver comprising a transmitter arrangement as previously disclosed. It also comprises:

[0043] - a differential input amplifier for amplifying signals received by at least two antenna elements,

[0044] - wherein each of the antenna elements is coupled to a respective input of a differential input amplifier; and

[0045] A transmit / receive-switch (or TRx-switch) arranged in the signal path between the respective differential input amplifier and the differential output amplifier and the at least two antenna elements.

[0046] The proposed transceiver can be used to transmit and receive signals via a single-ended antenna and perform differential to single-ended conversion or single-ended to differential conversion of the corresponding signals. Thus, the same antenna array can be used to transmit and receive signals, especially time division duplex signals. The differential signal at the receiver can be amplified and will be less affected by certain distortions than a single-ended signal.

[0047] In some aspects, the transceiver may include a matching network in the signal path between the TRx-switch and the differential input amplifier. The matching network may be an adjustable matching network. Such a network may match impedance mismatches in the respective transmitter and receiver paths. Specifically, impedance mismatches between antenna elements and amplifiers of the receiver or transmitter paths may be optimized separately. An adjustable matching network configured to adjust the impedance in the respective paths may enable the transceiver to react to time-dependent distortions caused by weather or other influences, such as a user or object close to the antenna.

[0048] In some other aspects, the differential input amplifier and the differential output amplifier are arranged in a common semiconductor body, thereby reducing the size of the arrangement.The differential input amplifier and the differential output amplifier may both be arranged on the same substrate as the antenna element.

[0049] A third aspect of the present disclosure shows a radio communication system comprising a plurality of transceivers or transmitters according to any one of the preceding claims, wherein at least two antenna elements of the plurality of transceivers or transmitters are arranged on a common substrate forming an antenna element array. This will provide a highly integrated front end of a base station BS or UE.

[0050] In some aspects, at least two antenna elements are arranged in a substantially vertical direction relative to the position of the common substrate. Arranging the antenna elements in a vertical direction will reduce the impact on the beam during beam steering in the horizontal direction. This may be appropriate when the beam steering is mainly performed in the horizontal direction (i.e., along the azimuth).

[0051] In one aspect, an antenna element of a first transceiver or transmitter is spaced apart from an adjacent antenna element of a second transceiver or transmitter by a distance corresponding to a distance between at least two antenna elements of the first transceiver or transmitter or the second transceiver or transmitter. The structure may form an XxY matrix of antenna elements, wherein two or more adjacent antenna elements are coupled to a differential amplifier. The total number of amplifiers in the array is reduced.

[0052] A fourth aspect of the present disclosure shows a method for radio communication, comprising the following steps:

[0053] - amplifying a differential signal having a first component and a second antiphase component;

[0054] - shifting the phase of one of the amplified first component and the amplified second antiphase component;

[0055] - applying the phase-shifted amplified first component or the phase-shifted amplified second antiphase component to the second antenna element;

[0056] - applying the other of the amplified first component or the amplified second antiphase component to the first antenna element;

[0057] - wherein shifting the phase comprises: shifting the phase so that the phase of the amplified phase-shifted component at the second antenna element is in phase with the phase of the amplified component at the first antenna element.

[0058] The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the present disclosure only by way of illustration. Those skilled in the art will understand that changes and modifications can be made within the scope of the present disclosure based on the guidance in the detailed description.

[0059] Therefore, it should be understood that the disclosure disclosed herein is not limited to the specific components of the described devices or the steps of the described methods, because such devices and methods can be changed. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting. It should be noted that, as used in the specification and the appended claims, unless the context clearly dictates otherwise, the articles "a", "an", "the" and "said" are intended to indicate the presence of one or more elements. Thus, for example, reference to "a unit" or "the unit" may include several devices, etc. In addition, the words "comprising", "including", "containing" and similar expressions do not exclude other elements or steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The above will become apparent from the following more particular description of example embodiments as illustrated in the accompanying drawings, in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily drawn to scale, emphasis instead being placed upon illustrating the example embodiments.

[0061] Figure 1 A transmitter arrangement using a balun for differential to single-ended conversion is shown;

[0062] Figure 2A The proposed transmitter device having some aspects of the present disclosure is shown;

[0063] Figure 2B Shows Figure 2A Alternatives to the proposed transmitter arrangement;

[0064] Figure 3 A second exemplary embodiment of a transmitter apparatus according to some aspects of the present disclosure is shown;

[0065] Figure 4 A third exemplary embodiment of a transmitter apparatus according to some aspects of the present disclosure is shown;

[0066] Figure 5 A fourth exemplary embodiment of a transmitter apparatus according to some aspects of the present disclosure is shown;

[0067] Figure 6 A first exemplary embodiment of a transceiver according to some aspects of the present disclosure is shown;

[0068] Figure 7 A second exemplary embodiment of a transceiver in Tx mode according to some aspects of the present disclosure is shown;

[0069] Figure 8 FIG. 1 shows an example of an Rx mode according to some aspects of the present disclosure. Figure 7An exemplary embodiment of a transceiver of;

[0070] Fig. 9 A third exemplary embodiment of a transceiver according to some aspects of the present disclosure is shown;

[0071] Fig.10 A fourth exemplary embodiment of a transceiver according to some aspects of the present disclosure is shown;

[0072] Fig.11 An exemplary embodiment of grouping antenna elements into sub-arrays according to some aspects of the present disclosure is shown;

[0073] Fig.12 is a schematic diagram of the AAS radiation plane and beam angle θ diagram;

[0074] Fig.13 Some simulation results of a radiation pattern of a transmitter having a first beam angle θ according to some aspects of the present disclosure are shown;

[0075] Fig.14 Some simulation results of a radiation pattern of a transmitter having a second beam angle θ according to some aspects of the present disclosure are shown;

[0076] Fig.15 shows several beam directions and beam steering angles depending on various sizes of antenna subarrays according to some aspects of the present disclosure;

[0077] Fig.16 An exemplary embodiment implementing some aspects of the present disclosure is shown;

[0078] Fig.17 Several possibilities for the implementation of a phase shifting element 50 in a transmitter arrangement are shown;

[0079] Fig.18 An exemplary method for radio communications is shown. DETAILED DESCRIPTION

[0080] Aspects of the present disclosure will be described more fully below with reference to the accompanying drawings. However, the devices, transceivers, systems, and methods disclosed herein may be implemented in a variety of different forms and should not be construed as limited to the aspects set forth herein. Throughout the drawings, similar reference numerals in the drawings represent similar elements.

[0081] The terms used herein are only for describing specific aspects of the present disclosure and are not intended to limit the present 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.

[0082] Some of the example embodiments presented herein relate to transmitter devices with improved differential to single-ended conversion, transceivers, and radio communication systems having such transmitters or transceivers.As part of the development of the example embodiments presented herein, a problem will first be identified and discussed.

[0083] As discussed previously, 5G base stations are using beamforming techniques that are also known in various defense and satellite applications. For beamforming, an antenna array system (AAS) is usually used, and the signal to be transmitted is split, amplified, and distributed among the individual antennas. The power amplifier used to amplify the signal is usually implemented in CMOS technology because it allows high integration and low-cost production. However, advanced CMOS technology nodes show limitations on the supply voltage and available voltage margin levels. This limits the achievable power of each power stage in the power amplifier of the transmitter. The combination of two power stages with a differential topology boosts the output power by an ideal 3dB to alleviate this problem. The differential topology in the power amplifier also provides a virtual ground and therefore improves PA stability compared to single-ended designs that are sensitive to ground return path parasitics.

[0084] Although the transmitter is designed differentially, the antenna array system is concentrating on single-ended antenna to limit the size of the antenna in the system. Therefore, a differential to single-ended conversion is required between the transmitter and the antenna.

[0085] Figure 1 A classic antenna array system 2 having an on-chip differential transmitter device 100 connected to a single-ended patch antenna element 3 implemented on a PCB is shown, with differential to single-ended conversion provided by an on-chip balun. The device includes a differential amplifier for each antenna element. The conversion is typically implemented on a chip with a balun coupled between each amplifier and the corresponding antenna element. The balun can also provide impedance transformation for impedance matching between the antenna elements and the TRx output. The antenna elements 3 are typically spaced apart by a distance of approximately half a wavelength (λ / 2) to reduce side lobes in the radiation pattern.

[0086] However, the use of baluns increases losses in the radio frequency (RF) path. These losses cause a decrease in overall Tx output power and efficiency. As deep submicron CMOS technology nodes shrink and operating frequencies increase, the losses caused by on-chip baluns are increasing. At the same time, supply voltage limitations on advanced CMOS technologies are reducing the achievable output power in Tx. In addition to the losses caused, in some instances, phase and amplitude imbalances can also appear in the balun branches. Therefore, there is no guarantee that the two differential sections will have an exact 180° phase difference and the same amplitude in all cases. In addition, on-chip baluns have a larger footprint, and advanced technology nodes have a higher price per square millimeter.

[0087] To overcome these and other problems, the inventors proposed a solution to perform differential to single-ended conversion by introducing a 180° phase shift on one of the differential paths of the transmitter with a low-loss transmission line element. Each differential path is connected to one antenna, forming a 2x1 subarray. Therefore, no on-chip balun is required, and the signal power combining is performed in the air. Compared with conventional solutions, the proposed architecture can be easily implemented on a PCB to achieve high integration and provide high power efficiency.

[0088] Figure 2A and Figure 2B An overview of the proposed solution in an antenna array system 2 is presented. The transmitter device 1 comprises a differential output amplifier 20 arranged in a chip in a package. The package is arranged on a PCB substrate 10. The transmitter device also comprises two antenna elements 31 and 32, which are also arranged on the PCB substrate. Figure 2A As shown, the distance between the adjacent edges of the two antenna elements 31 and 32 is set to the distance of the signal to be transmitted. Figure 2B In the example, a setup distance of half the wavelength of the center frequency is measured between the center points of the individual antenna elements.

[0089] Return to reference Figure 2A , the transmitter arrangement is part of a larger antenna array 2. Individual antenna elements 31, 32, 35 and 36 are paired together to form element pairs 30 and are placed adjacent to each other, wherein the two elements are separated by a distance of approximately half a wavelength as mentioned above.

[0090] According to the proposed principle, each of the output terminals of the differential amplifier is coupled to a corresponding one of the antenna elements. Specifically, the non-inverting output 21 is connected to the antenna element 31 and the inverting output 22 is connected to the antenna element 32 (see also Figure 2B ). The connections between the outputs of the individual differential amplifiers and the antenna element pairs are arranged so that, except for the first transmission line segment 50, the electrical lengths of both the reverse path and the non-reverse path are equal to each other. This aspect is illustrated by the conductor element 51a, which indicates that due to the length of the connection, the phase of the signal is offset and losses may also occur. The factor xλ in the transmission line from the amplifier to the antenna elements represents the electrical length of the distribution transmission line. They can be equal or different for each antenna pair. For the sake of simplicity, it is assumed that the transmission line is designed so that the signal amplifier of the differential output amplifier 20 will have an additional phase offset of 180° to one of the antenna elements.

[0091] According to this disclosure and reference Figure 2A, a phase shift element 50 is introduced in the inverting path between the inverting output 22 of the differential output amplifier 20 and the antenna element 32. The phase shift element 50 is configured to make the phases of the signals applied at the inputs of the antenna elements 31 and 32 equal. In other words, the phase shift element 50 is configured to make the signals applied to the respective inputs of the antenna elements 31, 32 in phase.

[0092] Likewise, and now with reference to Figure 2B , the phase shift element 50 may also be arranged on the substrate 10 between the non-inverting output 21 and the input tap 310 of the antenna element 31. The phase shift element 50 is configured to make the signals provided by the differential output amplifier 20 at the input taps 310 and 320 in phase.

[0093] Thus, the phase shifting element 50 can not only be used to correct for phase mismatches due to, for example, different electrical lengths between different paths (e.g., the elements xλ may be different), but can actually shift the phase of the signal in one of the paths to match the phase of the corresponding other path at the antenna element.

[0094] For the sake of simplicity, it is assumed that the transmission lines 51a connecting the output terminals to the differential amplifier and the various antenna elements are equal, resulting in the same phase shift and loss. Therefore, without the phase shift element 50, the signals at the input of the antenna elements will have a phase shift of 180° from each other.

[0095] Then, Figure 3 The principle of the proposed transmitter device is presented. The on-chip differential output amplifier 20 is connected to two on-PCB antennas (here patch antenna elements) 31 and 32 with a center-to-center distance of half the wavelength of the center frequency. By definition, the differential amplifier of the transmitter output has two paths. The first path at the non-inverting output 21 is defined as the path with a 0° phase, and the path at the inverting output 22 is defined as the path with a 180° phase. The path with a 0° phase is directly connected to the corresponding antenna in a route from the semiconductor body 12 through the package 11 to the PCB. This routing on the RF path can have low losses.

[0096] The λ / 2 transmission line is arranged on the PCB substrate in a path with a 180° phase. The transmission line introduces a phase shift of 180°. Therefore, at the output of the transmission line on the antenna side, the phase becomes 0°. Therefore, both signals on the antenna side have a 0° phase. Because the two signals are in phase, the recombination of the two paths will be performed in the air. It should be noted that the phase shift caused by element 50 can be substantially 180° or an odd multiple thereof. Therefore, a phase shift of (180°+360°*z) (z is a natural number) will be sufficient. The phase shift is considered to be at the center frequency of the signal applied thereto.

[0097] Compared to the classic differential to single-ended on-chip combination with a balun, no additional losses are introduced on either RF path at the chip. A λ / 2 transmission line is implemented on the PCB on the corresponding RF path, introducing low losses related to the additional routing to the antenna on this path. The combination of the signals takes place in the air, which makes it lossless in principle.

[0098] The example table below shows the estimated losses for a coplanar waveguide transmission line routed on a PCB.

[0099]

[0100]

[0101] While the losses in a typical balun are about 1dB at 30GHz, they tend to increase as advanced CMOS technology nodes shrink and frequency increases because of increased resistance due to skin effect and smaller trace widths at high frequencies. The losses caused by the balun at the output of the transmitter chain are significant because it reduces overall system efficiency.

[0102] In the proposed solution with the implementation of the phase-shifting element (e.g. as an additional transmission line on the PCB), low losses (0.28 dB at 30 GHz) are achieved regardless of the technology used for the chip, and since the losses are only present at one side of the differential output signal, the losses will be effectively divided by 2, corresponding to a loss of 0.14 dB at 30 GHz. Furthermore, as shown in the table above, the losses in the λ / 2 transmission line will decrease when the frequency increases. Thus, efficiency gains can be achieved at the system level. For highly integrated solutions, in this case meaning many transmitters or transceivers connected to an antenna array, the reduced losses will provide greater flexibility in placing the power amplifier relative to the antenna to relax the cooling constraints of the system and reduce the overall power consumption.

[0103] Reference now Figure 3 , Figure 4 and Figure 5, various aspects of the implementation of a phase shifting element 50 in a transmitter device are shown. The phase shifting element 50 may be implemented using various methods depending on requirements, space and design preferences. Fig.17 Several possibilities are shown. For example, the phase shift element 50 can be implemented as a microstrip, dual strip or slot line by etching or milling the transmission line directly onto the PCB substrate. A similar approach can be taken using a CWG with a ground plane on the opposite side of the PCB substrate. For a stripline or finline solution, the conductive element is arranged within the surrounding dielectric. Other embodiments or combinations thereof are also possible.

[0104] about Figure 3 In the transmitter device of FIG. 1 , the phase shift element 50 is arranged on the PCB substrate 10 , resulting in a 180° phase shift of the signal at the output terminal 22 (ie, inverting the signal). Figure 4 In the embodiment, the phase shifting element 50 is implemented as a transmission line within the package 11. One terminal 501 of the element 50 is connected to the inverting output 22, and the other terminal 502 is connected to the package connector (not shown) and coupled to the input tap 320 of the antenna element 32. The package 11 is arranged on a PCB substrate. This solution is suitable when the connections or transmission lines on the PCB substrate between the package connector taps and the corresponding antenna elements are equal in electrical length. In both embodiments, the center-to-center distance of the antenna elements is half the wavelength of the center frequency of the signal to be transmitted.

[0105] Figure 5 Yet another solution of a phase shifting element 50 using lumped elements is shown in FIG. The phase shifting element is implemented in the semiconductor body 12 itself, which also includes the differential output amplifier 20. The phase shifting element 50 forms a transmission line in a double π configuration, but other network configurations (e.g., a T network) are possible. The network includes two inductive elements 504 and 506 arranged in the signal path, with a capacitor connected to each tap and coupled to ground. Unlike Figure 3 and Figure 4 In the implementation of the transmitter arrangement in , a design choice is made so that the antenna elements 31 and 32 are spaced apart by half the wavelength of the center frequency from edge to edge of the antenna elements.

[0106] Figure 6Another embodiment envisioning several aspects of the proposed principles in a fully differential transceiver TRx 1a is shown. The differential TRx 1a comprises a differential output amplifier 20, a differential input amplifier 24, and a differential transmit / receive switch TRx-switch 23. For the purposes of this disclosure, the differential output amplifier 20 may also be referred to as a differential transmitter amplifier 20 to distinguish this amplifier in the transmitter path from the amplifier in the receiver path. Similarly, the differential input amplifier may be referred to as a differential receiver amplifier. The differential transceiver is arranged in a semiconductor body 12a or chip 12a, which is integrated in a package arranged on a PCB substrate.

[0107] Switch 23 is used to switch between two modes:

[0108] - Tx mode, in which the signal flows from the differential output amplifier 20 to the antenna elements 31 , 32 for transmission.

[0109] - Rx mode, in which the signal flows from the antenna element to the differential input amplifier 24 to amplify the received signal.

[0110] Similar to the transmitter arrangement according to the proposed principle, a phase shift element 50 is arranged in one of the signal paths to ensure that the amplified signal to be transmitted in Tx mode is in phase at the antenna elements. In Rx mode, the phase shift element will shift the phase in one signal path so that the signals received via antenna elements 31 and 32 are out of phase at the input / output taps of the TRx-switch 23. This approach provides a solution for time division duplex TDD applications compliant with the 5G standard. Full TRx integration means that a differential switch and a differential Rx amplifier are connected to 2 antennas, similar to Tx.

[0111] Figure 7 and Figure 8 The signal flows of the transceiver in Tx and Rx modes are shown respectively. During transmission, i.e. when Tx is on, the receiver amplifier is off. The TRx-switch 23 is placed in Tx mode and couples the differential output amplifier 20 to the antenna element. As previously described, the RF path with 0° phase extends from the output 21 through the TRx-switch 23, the package 11, the PCB substrate 10 to the corresponding antenna element 31 without phase offset (in practice there will of course be a phase offset, but we define this path as a reference and only the phase offset difference between the two paths is important).

[0112] The signal on the RF path with a 180° phase extends from the inverting output 22 through the TRx-switch without a phase shift. The phase shift element 50 implemented as a transmission line element on the PCB causes a 180° phase shift. As a result, the phase at the input of the antenna element becomes 0° at the antenna element 31. Then, the two signals at the antenna element are in phase, and therefore, the signals will constructively combine in the air.

[0113] Figure 8 The signal flow during Rx mode is shown. In Rx mode, the differential output amplifier 20 is turned off or put into low power mode. The TRx-switch 23 is in the Rx position. The signal is received at both antenna elements and will be in phase at the antennas. One of the RF paths (e.g., the path with element 31) does not cause an additional phase shift, and the antenna is directly connected to the TRx-switch 23 via the package 11 and towards the corresponding 0° input of the differential input amplifier 24.

[0114] Another RF path comprises a λ / 2 transmission line on the PCB, configured to cause a 180° phase shift. Thus, the signal will be shifted by 180° at the output of the phase shift element. The phase shift element is then coupled to the corresponding 180° input of the differential input amplifier 24 through the package via the TRx-switch 23. The signal at the input terminal of the differential input amplifier 24 has a phase difference of 180° and, therefore, can be processed in a differential amplifier operation. Compared to the classical solution of including a balun at the input of the receiver amplifier, the phase shift element 50 presents low losses.

[0115] Fig. 9 and Fig.10 Another aspect shown takes into account potential impedance mismatches. Such mismatches may exist between the antenna and the differential transmitter amplifier, causing some reflection of the signal to be transmitted, reducing the overall strength of the transmitted signal. Traditionally, when a balun is used, in addition to the differential to single-ended conversion, the balun can also achieve impedance transformation. Fig. 9 Different approaches are presented, wherein a transmission line transformer TLT 54 on a PCB is arranged in a corresponding path to perform impedance transformation on the PCB, maintaining a low loss advantage for the transmission line routing on the PCB. The arrangement on the PCB substrate can allow the design of the TLT to match the antenna element. In addition to the TLT, other elements for impedance adjustment may also be suitable. The TLT may also be placed at the other side of the phase shifter 50.

[0116] Fig.10A flexible solution is shown, in which adjustable matching networks 25 and 26 are arranged within the semiconductor body 12. Such on-chip impedance transformation can also be used, since the Tx part of the transceiver is typically designed for a low impedance output, while the Rx is typically designed for a higher input impedance. Therefore, both networks 25 and 26 are located between the TRx-switch and the corresponding differential amplifiers 20 and 24. The matching network includes an adjustment input (not shown) to flexibly adjust the impedance mismatch. For this purpose, corresponding feedback can be provided, in which the reflected power is determined and the network is adjusted accordingly. The adjustable matching network can compensate for temporary mismatches caused, for example, by weather or other conditions at the location of the BS or UE. In order to reduce the chip area and sacrifice some flexibility, a single adjustable matching network can also be used at the antenna port of the TRx switch.

[0117] Reference now Fig.16 In addition to the aforementioned solutions, the transmitter arrangement as well as the transceiver is not limited to a 2x1 subarray with two antenna elements. Instead, the transmitter or transceiver may be connected to several antenna elements which typically form a single row or column. Fig.16 An exemplary embodiment for implementing some aspects of the present disclosure is shown. The transmitter device includes a differential output amplifier 20 and a plurality of antenna elements even arranged in a 1xn column. In the exemplary embodiment, a total of 4 antenna elements 31, 32, 33 and 34 are provided. The antenna elements are located on a PCB substrate so that the respective centers of adjacent elements are spaced apart by half the wavelength of the center frequency λ / 2. The antenna elements are coupled to the output of the differential output amplifier 20 in an alternating manner. That is, each first antenna element is connected to the non-inverting output 21, and each second antenna element is coupled to the inverting output 22. As in various other embodiments, the phase shift element 50 is positioned as a transmission line on the PCB between the antenna element 32 and the inverting output 22. Due to the different distances between the elements and the output of the differential output amplifier 20, the arrangement of antenna elements in such columns or rows results in different electrical lengths of the individual elements. In order to compensate for this difference, additional transmission line elements 51 and 52 are located between the additional elements and the output amplifier. More specifically, elements 33 and 34 can form another antenna pair, in which one antenna receives a 0° signal and the other receives a 180° signal. Antenna element 33 is connected to transmission line element 51 to element 31 and output 21, and antenna element 34 is connected to antenna element 32 and phase shifting element 50 via transmission line element 52. Both transmission line elements are configured to adjust the phase of the respective signals applied at their inputs so that all signals applied to the antenna elements are in phase.

[0118] Return to reference Fig.11, which shows an arrangement in an antenna system of a transmitter or transceiver device according to some aspects of the present disclosure. In a conventional 1x1 subarray, each antenna is connected to a transceiver and the antennas are separated by a distance of λ / 2 to reduce side lobes. Therefore, there is a phase offset between adjacent antenna elements. In the proposed solution, multiple 2x1 subarrays or more generally nx1 subarrays are provided, where n is the number of antenna elements belonging to the same subarray. A single transceiver is connected to the antenna elements of each subarray, transmitting and receiving the same signal. Compared to a 1x1 antenna array, when the beam angle θ is non-zero (see Fig.12 ), this results in higher power in the side lobes. Fig.12 As shown in Figure 1, θ is the angle of the beam to the orthogonal plane of the antenna. The angle θ is determined by the phase shift of the AAS. control.

[0119] Regarding the signal strength in the side lobes and the behavior of the subarray according to the proposed principle, Fig.13 and Fig.14 Some simulation results are shown. Fig.13 The simulation results for a beam angle θ of 0° are shown. The first figure shows the simulation results for a 1x1 array in a conventional array. The following figures present the results for a 2x1 subarray according to some aspects of the proposed principles. It is clear that for a beam direction of θ=0, i.e. the main lobe is orthogonal to the antenna plane, the signal strength in the side lobe is several dB smaller than the main lobe. Both subarrays show the same radiation pattern with low sidelobe power because for this beam direction all antenna array elements operate in phase. Fig.14 The simulation results for a beam direction angle θ = 10° are shown. In this case, the radiation patterns of the two arrays are different. The main lobe is offset as expected. However, in the 2x1 subarray, the sidelobes centered at -50° show about -10dB of power relative to the mainlobe, while in the 1x1 subarray, all sidelobe powers remain low. As a result, the 2x1 subarray sends more power in the sidelobes, and for this beam direction, the radiation pattern will be higher than the 1x1 subarray at about -50°.

[0120] These behaviors, visible in simulation results, may limit the achievable beam steering angles when the transmitter is connected to two or more antenna elements as shown in the various embodiments. For example, for a 2x1 subarray, Fig.13 and Fig.14Simulations indicate that a suitable maximum beam angle range is in the range of [-10; +10]°. It corresponds to a total beam steering angle of 20°. The range can be extended to approximately [-15; +15]° corresponding to a maximum beam steering of 30°, but will result in a loss of approximately 0.7 dB. In the case where the antennas in the subarray form a single row or column, the beam steering angle limitation affects only one of the two directions. For a horizontal arrangement of the subarrays, the beam steering angle is limited in the horizontal direction, and for a vertical arrangement of the subarrays, the beam steering angle is limited in the vertical direction. The corresponding other directions of the beam steering angle are substantially unaffected.

[0121] However, this limitation is not critical for typical 5G AAS scenarios. Fig.15 Several use cases of AAS in 5G scenarios are shown. The figure above shows the so-called "Dense Urban High-Rise" scenario for dense and vertical cities with an expected communication range between 200m and 500m. Due to the dense area, a vertical angle of 30° is required. 2x1 subarrays are used for a total array featuring 4 vertical subarrays and 8 horizontal subarrays.

[0122] In the case of the "Urban Low-Rise" scenario depicted in the middle figure, corresponding to many cities around the world, the expected range is between 500m and 1km, and a vertical angle of 15°. A 4x1 subarray for an AAS featuring 2 vertical subarrays and 8 horizontal subarrays can be used in these areas.

[0123] at last, Fig.15 The bottommost figure corresponds to the "suburban and rural" scenario, and a range of more than 1 km with a vertical beam angle of 8° is considered sufficient. An 8x1 subarray may be used in an AAS featuring 1 vertical subarray and 8 horizontal subarrays.

[0124] The proposed transceiver with a minimum subarray size of 2x1 is Fig.16 The 20° beam steering that can be achieved by the proposed solution makes it suitable for "urban low-rise" and "suburban and rural" 5G scenarios. For dense urban high-rise areas, a beam steering of 30° for "dense urban high-rise" is required. Although the present disclosure can achieve such a beam steering angle, as described in Fig.13 and Fig.14 As discussed, some losses in the radiation pattern are expected. However, due to the short transmission range for this scenario, the additional losses are not significant.

[0125] Various scenarios indicate that significant savings can be made while meeting 5G standard requirements. Using nx1 subarrays (where n is 2, 4, or 8) requires fewer power amplifiers for the transmitter and enables highly integrated transceivers. Overall power consumption is reduced while maintaining signal quality. Already existing antenna elements can be reused, reducing development time and production costs.

[0126] Fig.18 An exemplary method for radio communication is shown. In step S1, a differential signal having a first component and a second antiphase component is amplified. The amplified component corresponds to the signal to be transmitted. For differential to single-ended conversion in the air according to the proposed principle, the phase of one of the amplified components is now phase-shifted in step S2. In a subsequent step S3, the phase-shifted component of the amplified first component and the second antiphase component is applied to the second antenna element. Similarly, the other (non-phase-shifted) component of the amplified first component or the second antiphase component is applied to the first antenna element.

[0127] In step S5, a phase shift is performed in such a way that the phase of the amplified phase-shifted component at the second antenna element is in phase with the phase of the amplified component at the first antenna element. In other words, a phase shift of one of the components is done so that the two components are in phase at the antenna element. The signal components are then combined in the air.

[0128] Those skilled in the art will appreciate that the present disclosure is not limited to the preferred embodiments described above. Those skilled in the art will also appreciate that modifications and changes may be made within the scope of the appended claims. Additionally, those skilled in the art, in practicing the present disclosure for which protection is sought, may understand and implement changes to the disclosed embodiments based on a study of the drawings, the specification, and the appended claims.

[0129] Reference List

[0130] 1 Transmitter device

[0131] 2 Antenna Array System AAS

[0132] 3 Antenna elements

[0133] 10 PCB substrate

[0134] 11 Packaging

[0135] 12 Semiconductor body, chip

[0136] 20 Differential Output Amplifier

[0137] 21 Inverting output

[0138] 22 Non-inverting output

[0139] 23 TRx-Switch

[0140] 24 Differential Input Amplifier

[0141] 25, 26 Matching Network

[0142] 30 subarrays

[0143] 31, 32 Antenna elements

[0144] 33, 34 Antenna elements

[0145] 35, 36 Antenna elements

[0146] 50 Phase shift element

[0147] 51, 52 Transmission line elements

[0148] 51a Wire element

[0149] 54 Impedance matching elements

[0150] 100 Transmitter Device

[0151] 310, 320 Input tap

[0152] 501, 502 Terminal.

Claims

1. A transmitter device (1), comprising: - at least two antenna elements (31, 32), spaced apart by a defined distance; - a differential output amplifier (20) having a first output (21) coupled to a first antenna element (31) of the at least two antenna elements (31, 32), and a second inverted output (22) coupled to a second antenna element (32) of the at least two antenna elements (31, 32); - a first transmission line element (50) arranged between at least one of the first output (21) and the second inverted output (22) and a corresponding one of the at least two antenna elements (31, 32), the first transmission line element (50) being configured such that signals applied to the corresponding input taps (310, 320) of the at least two antenna elements (31, 32) are substantially in phase with each other.

2. The transmitter device (1) according to claim 1, wherein the transmitter device (1) is used for radio communication.

3. The transmitter device (1) according to claim 1 or 2, wherein: The first transmission line element (50) is configured to cause a phase shift of a signal of substantially 180° or an odd multiple of 180°.

4. The transmitter device (1) according to claim 1 or 2, wherein: The first transmission line element (50) is configured to cause a phase shift of substantially 180° or an odd multiple of 180° of a center frequency of the signal applied to the first transmission line element (50).

5. The transmitter device (1) according to claim 1 or 2, wherein: The at least two antenna elements (31, 32) have a center-to-center distance substantially equal to half (λ / 2) of a center frequency wavelength in air of a signal applied to the at least two antenna elements (31, 32).

6. The transmitter device (1) according to claim 1 or 2, wherein: The first transmission line element (50) includes an electrical length corresponding to substantially half (λ / 2) of a center frequency wavelength in air of a signal applied to the first transmission line element (50).

7. The transmitter device (1) according to claim 1, further comprising: - a plurality of antenna elements (31, 32, 33, 34) having a number n, wherein n is an even number greater than 2; and wherein each second antenna element (32, 34) of the plurality of antenna elements (n) is coupled to a second inverting output (22) of the differential output amplifier (20); - one or more second transmission line elements (52) arranged between the second inverted output (22) and each second antenna element (34) of the plurality of antenna elements (n) except the second antenna element (32), so that the signals applied to the corresponding input taps (310, 340) of the second antenna element (32) and the even-numbered antenna elements (34) are in phase.

8. The transmitter device (1) according to claim 7, wherein the plurality of antenna elements (31, 32, 33, 34) having a number n are arranged in a single row or a single column.

9. The transmitter device (1) according to claim 1, further comprising: - A plurality of antenna element pairs, wherein o a first antenna element of a pair of antenna elements coupled to the first antenna element or the first antenna element of a preceding pair of antenna elements via a respective first one (51) of the second transmission line elements; as well as o a second antenna element in a pair of antenna elements coupled to said second antenna element or to a second antenna element in a preceding pair of antenna elements via a respective second one of the second transmission line elements (52); - wherein a first and a second of the second transmission line elements are configured such that signals applied to respective input taps (310, 340) of the pair of antenna elements are in phase.

10. The transmitter device (1) according to claim 7 or 8, wherein: The first transmission line element and / or the second transmission line element (50, 51, 52) comprises at least one of the following: - a coplanar waveguide CWG arranged on a substrate (10); - a microstrip arranged on the substrate (10); - Substrate integrated waveguide; - a double belt arranged on said substrate (10); - a stripline arranged in said substrate (10); - a fin line arranged in the substrate (10); - a slot line arranged on the substrate (10); - One or more lumped elements arranged on a PCB substrate.

11. The transmitter device (1) according to claim 7 or 8, wherein: The first transmission line element and / or the second transmission line element (50, 51, 52) comprises an inductor element (504, 506) arranged in a signal path, and two capacitors (503, 505) to form -Configuration or T-section.

12. The transmitter device (1) according to claim 7 or 8, wherein: The first transmission line element and / or the second transmission line element (50, 51, 52) comprises an adjustment input for adjusting a phase shift of a signal applied to the first transmission line element and / or the second transmission line element (50, 51, 52).

13. The transmitter device (1) according to claim 7 or 8, wherein: The first transmission line element and / or the second transmission line element (50, 51, 52) and the at least two antenna elements (31, 32) are arranged on or in a common substrate (10).

14. The transmitter device (1) according to any one of claims 1 to 2 and 7 to 8, wherein: The differential output amplifier (20) is arranged in a semiconductor body (12) in a package (11), and the package (11) is arranged on a common substrate (10) together with the at least two antenna elements (31, 32).

15. The transmitter device (1) according to claim 14, wherein The first transmission line element (50) is arranged in one of the semiconductor body (12) and the package (11).

16. The transmitter device (1) according to any one of claims 1 to 2, 7 to 8 and 15, further comprising: An impedance matching element (25, 54) is configured to match the impedance of the first output and the second output (21, 22) of the differential output amplifier (20) with the impedance of the corresponding input taps (310, 320) of the at least two antenna elements (31, 32).

17. The transmitter device (1) according to claim 16, wherein The impedance matching element (25, 54) includes one of the following: - a transmission line transformer (54) arranged between the first transmission line element and / or one or more second transmission line elements (50) and the respective antenna element; - A matching network (25) coupled to the output of the differential output amplifier (20).

18. The transmitter device (1) according to claim 17, wherein the matching network (25) is an adjustable matching network.

19. A transceiver (1a) comprising the transmitter device (1) according to any one of claims 1 to 18, and further comprising: - a differential input amplifier (24) for amplifying signals received by the at least two antenna elements (31, 32), wherein each of the antenna elements (31, 32) is coupled to a respective input (+, -) of the differential input amplifier (31, 32); - a transmitter and receiver switch (23) arranged in the signal path between the respective differential input amplifier and differential output amplifier (20, 24) and the at least two antenna elements (31, 32).

20. The transceiver (1a) according to claim 19, further comprising a matching network (26) arranged in the signal path between the transmitter and receiver switch (23) and the differential input amplifier (24).

21. The transceiver (1a) of claim 20, wherein the matching network (26) is an adjustable matching network.

22. The transceiver (1a) according to claim 19 or 20, wherein The differential input amplifier (24) and the differential output amplifier (20) are arranged in a common semiconductor body (12a).

23. A radio communication system (60) comprising a plurality of transceivers according to any one of claims 19 to 22 or a plurality of transmitter devices according to any one of claims 1 to 18, wherein: The at least two antenna elements (31, 32) of the transceiver or transmitter device are arranged on a common substrate (2) forming an array of antenna elements.

24. The radio communication system (60) according to claim 23, wherein: The at least two antenna elements (31, 32) are arranged in a substantially vertical direction relative to the position of the common substrate.

25. The radio communication system (60) according to claim 23 or 24, wherein: An antenna element (31, 32) of a first transceiver or transmitter device is spaced apart from an adjacent antenna element (35, 36) of a second transceiver or transmitter device by a distance corresponding to the distance between the at least two antenna elements (31, 32) of the first transceiver or transmitter device or the second transceiver or transmitter device.

26. A method for radio communication, comprising the steps of: - amplifying (S1) a differential signal having a first component and a second antiphase component; - shifting (S2) the phase of one of the amplified first component and the amplified second antiphase component; - applying (S3) the phase shifted component in the amplified first component and the amplified second antiphase component to a second antenna element; - applying (S4) the other of the amplified first component or the amplified second antiphase component to a first antenna element; - wherein shifting the phase comprises: shifting the phase (S5) so that the phase of the amplified phase-shifted component at the second antenna element is in phase with the phase of the amplified component at the first antenna element.

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