Phase shifter

Abstract

Provided is a phase shifter comprising: a switching unit which switches a transmission path of a signal (hereinafter, referred to as an "input signal") input through an input terminal so that the input signal is selectively transmitted to an output terminal through different paths; and a transformer which outputs the signal switched through the switching unit through the output terminal by coupling the switching unit and the output terminal.

Description

phase shifter

[0001] The present invention relates to a phase shifter.

[0002] A phase shifter is a component that changes or controls the phase of an electrical signal, and is essential for implementing beam-forming or phased-array technology.

[0003] These phase shifters must consider various design factors, such as low insertion loss and phase error, as well as the desired phase shift value within the application bandwidth. In particular, for communication technologies beyond 5G, which operate at high frequencies (e.g., 20 GHz) and require wide bandwidths, wideband operation of the phase shifter is required.

[0004] Meanwhile, among the various units that make up the phase shifter, the 180-degree phase shifter is the unit that shows the greatest phase error and loss.

[0005] Figures 1 and 2 illustrate circuit diagrams of a conventional filter-type 180-degree phase shifter.

[0006] In the case of Fig. 1, two circuits for 90-degree phase shift are connected in series to implement a 180-degree phase shifter.

[0007] In this circuit structure, a single circuit for a 90-degree phase shift may be relatively simple and easy to implement compared to the 180-degree phase shift illustrated in Fig. 2, but since it must be implemented as two combined structures to implement a 180-degree phase shift, the loss is bound to be greater than that of implementing it as a single structure.

[0008] In the case of Fig. 2, a 180-degree phase shifter implemented as a single circuit is illustrated.

[0009] In the case of a single circuit structure for such a 180-degree phase shift, it has the advantages of lower loss and wider bandwidth compared to the structure in which two 90-degree phase shift circuits are combined as illustrated in Fig. 1, but it is difficult to implement because the structure is relatively complex.

[0010] However, it is a self-evident fact that the bandwidth of the 180-degree phase shifter illustrated in Fig. 2 is relatively wide compared to the structure illustrated in Fig. 1, while the existing filter-type phase shifter exhibits narrowband operation characteristics.

[0011] Meanwhile, beamforming or phased array systems require numerous RF components, including phase shifters, which inevitably leads to high manufacturing costs. Therefore, complementary metal-oxide semiconductor (CMOS) technology is being utilized to minimize implementation costs.

[0012] This manufacturing process using CMOS technology is a very advantageous technology for implementing RF circuits on a single chip at low cost, but it is insufficient to demonstrate sufficient performance compared to other manufacturing processes that entail high manufacturing costs, such as compound processes.

[0013] Accordingly, various attempts have been made recently to improve the performance of beam forming or phased array systems using CMOS technology.

[0014] [Teacher's Technical Literature]

[0015] [Patent Document]

[0016] (Patent Document 1) Korean Patent Publication No. 10-1988901 (Registration Date: June 7, 2019)

[0017] The present invention was conceived to solve the above-described problems and to achieve miniaturization while ensuring excellent performance.

[0018] In order to achieve this purpose, a phase shifter according to one embodiment of the present invention includes: a switching unit that switches a transmission path of an input signal (hereinafter referred to as an “input signal”) input through an input terminal so that the signal is selectively transmitted to an output terminal through a different path; and a transformer that couples between the switching unit and the output terminal so that the signal switched through the switching unit is output through the output terminal; wherein the switching unit includes: a first switch that is disposed between the input terminal and the transformer and selectively connects between the input terminal and the transformer so that the input signal is transmitted to the transformer through a first path among the transmission paths; And a second switch disposed between the input terminal and the transformer, selectively connecting the input terminal and the transformer so that the input signal is transmitted to the transformer through a second path among the transmission paths; wherein the transformer may include a first inductor having one end connected to the first switch and the other end connected to ground to receive a signal transmitted through the first path; a second inductor having one end connected to the second switch and the other end connected to ground to receive a signal transmitted through the second path; and a third inductor magnetically coupled with the first inductor or the second inductor to output a signal input to the first inductor or the second inductor to the output terminal.

[0019] Here, when the first switch is short-circuited and the second switch is open, the first coupling signal, which is a signal induced to have the same phase as the input signal, is output through the output terminal connected to the third inductor, and when the first switch is open and the second switch is short-circuited, the second coupling signal, which is a signal induced to have a phase difference of 180 degrees from the input signal, is output through the output terminal connected to the third inductor.

[0020] At this time, at least one of the first switch and the second switch may be provided as an N-type MOSFET.

[0021] And, the third inductor can form a mutual inductance of polarity with at least one of the first inductor and the second inductor.

[0022] Meanwhile, the phase shifter proposed by the present invention further includes a matching unit for impedance matching, and the matching unit may be configured to include at least one of a first matching network electrically connected between the input terminal and the switching unit; and a second matching network electrically connected between the transformer and the output terminal.

[0023] In addition, the phase shifter proposed by the present invention may further include passive elements electrically connected between the switching unit and the transformer, and arranged in the first path and the second path, respectively.

[0024] In addition, the transformer is formed by being integrated into a single chip through a complementary metal-oxide semiconductor (CMOS) process, and the transformer includes: a first layer in which at least a portion of the first winding for implementing the first inductor (hereinafter referred to as the '1-1 part') and at least a portion of the second winding for implementing the second inductor (hereinafter referred to as the '2-1 part') are arranged to face each other; a second layer in which the third winding for implementing the third inductor is vertically magnetically coupled with the 1-1 part and the 2-1 part constituting the first layer; And a third layer laminated on top of the second layer so that the remaining part of the first winding (hereinafter referred to as the '1-2 part') and the remaining part of the second winding (hereinafter referred to as the '2-2 part') are arranged to face each other, but are vertically magnetically coupled to the third winding; In the first winding, the 1-1 part and the 1-2 part are electrically connected, and a first through-hole is provided in the connection part (hereinafter referred to as the 'first connection part') so that the third winding passes through it, and in the second winding, the 2-1 part and the 2-2 part are electrically connected, and a second through-hole is provided in the connection part (hereinafter referred to as the 'second connection part') so that the third winding passes through it.

[0025] At this time, the first inductor and the second inductor have the same inductance value, but the winding directions of the first inductor and the second inductor may be different.

[0026] And, either of the first layer and the third layer may be provided as a top metal layer.

[0027] As described above, according to the present invention, the following effects can be obtained.

[0028] First, by adding simple circuitry and modifying the transformer's structure, wideband operation can be achieved while minimizing loss and phase error. In other words, excellent phase shifter performance can be guaranteed.

[0029] Second, the size of the transformer itself can be reduced by allowing the inductors that make up the transformer to utilize mutual inductance while achieving phase shift by inverting the phase using the inherent characteristics of the transformer.

[0030] Third, by proposing a miniaturized phase shifter that guarantees excellent performance, it can contribute to reducing manufacturing costs when used in the semiconductor field where area directly affects cost.

[0031] Fourth, the transformer and phase shifter including the transformer proposed by the present invention can significantly improve the gain loss and phase error of the RF pre-stage of beamforming and phased array systems compared to conventional systems, and can greatly improve communication quality and performance, thereby contributing greatly to the development of the wireless communication industry.

[0032] Figures 1 and 2 are drawings to explain a conventional phase shifter.

[0033] Figures 3a to 3c are drawings illustrating a phase shifter according to one embodiment of the present invention.

[0034] Figures 4a and 4b illustrate various application examples of a phase shifter according to one embodiment of the present invention.

[0035] FIGS. 5a and 5b are examples for explaining the wideband operating characteristics of a phase shifter according to one embodiment of the present invention.

[0036] Figure 6 is a drawing to explain a comparative example contrasting with the present invention.

[0037] Figures 7a and 7b illustrate the structure when the center tap transformer illustrated in Figure 6 is implemented on a substrate.

[0038] Figures 8a to 8d are drawings illustrating an embodiment of a transformer applied to a phase shifter proposed by the present invention.

[0039] A preferred embodiment of the present invention will be described in more detail with reference to the attached drawings, but technical parts already known will be omitted or compressed for the sake of brevity.

[0040] It should be noted that references in this specification to “one” or “an” embodiment of the invention are not necessarily to the same embodiment, but rather mean at least one.

[0041] In the examples below, the terms first, second, etc. are not used in a limiting sense, but are used for the purpose of distinguishing one component from another.

[0042] In the examples below, singular expressions include plural expressions unless the context clearly indicates a different meaning.

[0043] In the examples below, terms such as “include” or “have” mean that a feature or component described in the specification is present, and do not preclude the possibility that one or more other features or components may be added.

[0044] Each configuration shown in the drawing is arbitrarily shown for convenience of explanation, and therefore the present invention is not necessarily limited to what is shown.

[0045] <Explanation of phase transition>

[0046] FIG. 3 is a diagram illustrating a phase shifter according to one embodiment of the present invention, FIG. 3a is a circuit diagram illustrating a phase shifter according to one embodiment of the present invention, and FIG. 3b and FIG. 3c are examples illustrating the operation of the phase shifter illustrated in FIG. 3a.

[0047] Referring to FIGS. 3a to 3c, a phase shifter (100) according to one embodiment of the present invention is configured to include an input terminal (110), a switching unit (120), a transformer (130), and an output terminal (140).

[0048] A signal (e.g., an RF signal) is input to the input terminal (110).

[0049] The switching unit (120) is configured to switch the transmission path of the input signal so that the signal (hereinafter referred to as the 'input signal') input through the input terminal (110) is selectively transmitted to the output terminal (140) described later through different paths.

[0050] The switching unit (120) includes a first switch (121) and a second switch (122).

[0051] The first switch (121) is placed between the input terminal (110) and the transformer (130) to be described later, and selectively connects the input terminal (110) and the transformer (130) so that the input signal is transmitted to the transformer (130) through the first path (r1) among the transmission paths.

[0052] The second switch (122) is placed between the input terminal (110) and the transformer (130) to selectively connect the input terminal (110) and the transformer (130) so that the input signal is transmitted to the transformer (130) through the second path (r2) among the transmission paths.

[0053] At this time, at least one of the first switch (121) and the second switch (122) may be provided as an N-type MOSFET.

[0054] More specifically, since a P-type MOSFET may be inappropriate for use in a phase shifter due to its slow carrier transfer speed, it may be desirable for both the first switch (121) and the second switch (122) to be formed of an N-type MOSFET.

[0055] That is, the phase shifter (100) proposed by the present invention transmits an input signal input to the input terminal (110) to the transformer (130) through the first path (r1) or the second path (r2) depending on the short / open (e.g., on / off) of the first switch (121) and the second switch (122).

[0056] The transformer (130) couples between the switching unit (120) and the output terminal (140), thereby outputting a signal transmitted along the transmission path switched through the switching unit (120) through the output terminal.

[0057] This transformer (130) includes a first inductor (L1), a second inductor (L2), and a third inductor (L3).

[0058] The first inductor (L1) has one end connected to the first switch (121) and the other end connected to ground, and receives a signal transmitted through the first path (r1).

[0059] The second inductor (L2) has one end connected to the second switch (122) and the other end connected to ground, and receives a signal transmitted through the second path (r2).

[0060] The third inductor (L3) is magnetically coupled with the first inductor (L1) or the second inductor (L2), and outputs the signal input to the first inductor (L1) or the second inductor (L2) to the output terminal (140).

[0061] At this time, one end of the third inductor (L3) is connected to ground, and the other end is connected to the output terminal (140).

[0062] Here, the first inductor (L1) and the second inductor (L2) have the same inductance value, but the winding directions of the first inductor (L1) and the second inductor (L2) may be different.

[0063] And, the third inductor (L3) forms a mutual inductance of polarity with at least one of the first inductor (L1) and the second inductor (L2).

[0064] For reference, by forming a mutual inductance of polarity between the first inductor (L1) and the third inductor (L3) or between the second inductor (L2) and the third inductor (L3), the mutual inductance of polarity can be utilized to obtain the inductance value required as a configuration of the transformer (130). Accordingly, the physical size of the inductors (the first inductor (L1), the second inductor (L2), and the third inductor (L3)) required to obtain the required inductance value is reduced. This can contribute to miniaturization of the phase shifter.

[0065] Hereinafter, the operation of the phase shifter (100) proposed by the present invention will be described with reference to FIGS. 3b to 3c.

[0066] For reference, the first switch (121) and the second switch (122) function as switches to shift the phase of the input signal by 0° or 180°. Depending on each switch, the induction direction of the third inductor (L3) of the transformer (130) changes, thereby causing a phase delay.

[0067] First, referring to FIG. 3b, when the first switch (121) is short-circuited by the control voltage and the second switch (122) is open, the current flowing through the first inductor (L1) among the two primary inductors (e.g., the first inductor (L1) and the second inductor (L2)) of the transformer (130) generates an induced current in the output direction from the ground of the secondary inductor (e.g., the third inductor (L3)) of the transformer (130), i.e., toward the output terminal (140).

[0068] At this time, the phase shifter (100) can operate so that the first coupling signal, which is a signal induced to have the same phase (0°) as the input signal, is output through the output terminal (140) electrically connected to the third inductor (L3).

[0069] Next, referring to FIG. 3c, when the first switch (121) is opened by the control voltage and the second switch (122) is short-circuited, the current flowing into the second inductor (L2) among the two primary inductors of the transformer (130) generates an induced current toward the ground direction at the output of the secondary inductor of the transformer (130), i.e., the third inductor (L3).

[0070] At this time, the phase shifter (100) can operate so that the second coupling signal, which is a signal induced to have an inverse phase (180°) with the input signal, is output through the output terminal (140) that is electrically connected to the third inductor (L3).

[0071] For reference, the control voltage can be controlled by a processor (not shown) electrically connected to the phase shifter (100).

[0072] For example, when a first control signal (e.g., 1) is transmitted to the first switch (121) or the second switch (122) by the processor, the first switch (121) or the second switch (122) operates in a short circuit, i.e., an on state.

[0073] As another example, when a second control signal (e.g., 0) is transmitted to the first switch (121) or the second switch (122) by the processor, the first switch (121) or the second switch (122) is opened, i.e., operates in an off state.

[0074] In conclusion, the phase of the output signal output through the output terminal (140) according to the operation of the switching unit (120) is output in the same phase (0°) or opposite phase (180°) as the input signal due to the change in the induced current of the third inductor (L3) provided on the output terminal (140) side.

[0075] Ideally, since the path where the switch is in the off state does not carry current, the inductor (e.g., the first inductor or the second inductor) electrically connected to that path does not affect the transformer (130), and only the inductor (e.g., the first inductor or the second inductor) connected to the path where the switch is in the on state maintains polarity with the third inductor (L3).

[0076] Hereinafter, various application examples of a phase shifter according to an embodiment of the present invention will be described with reference to FIG. 4.

[0077] FIG. 4 is a diagram illustrating a phase shifter according to one embodiment of the present invention, and FIG. 4a illustrates a circuit diagram of a phase shifter further including a matching unit (150), and FIG. 4b illustrates a circuit diagram of a phase shifter further including a passive element (160).

[0078] First, referring to FIG. 4a, a phase shifter (100) according to one embodiment of the present invention may further include a matching unit (150) for impedance matching.

[0079] Since this matching unit (150) can perform not only impedance matching (e.g., 50 ohm) but also wideband matching, it can contribute to the wideband operation of the phase shifter (100) proposed by the present invention.

[0080] The matching unit (150) may include at least one of the first matching network (151) and the second matching network (152).

[0081] That is, the matching unit (151) can be designed to include only one matching network, i.e., the first matching network (151) or the second matching network (152), or it can be designed to include all of the above-mentioned matching networks.

[0082] At this time, the first matching network (151) is electrically connected between the input terminal (110) and the switching unit (120).

[0083] And, the second matching network (152) is electrically connected between the transformer (130) and the output terminal (140).

[0084] For reference, the first matching network (151) and the second matching network (152) may be combined circuits by connecting passive elements such as capacitors and inductors in series / parallel.

[0085] Next, referring to FIG. 4b, a phase shifter (100) according to one embodiment of the present invention includes passive elements (L) such as an inductor and a capacitor to facilitate implementation of a transformer (130) as well as impedance matching. α ) may be included.

[0086] These passive components are electrically connected between the switching unit (120) and the transformer (130), and can be placed in the first path (r1) and the second path (r2), respectively.

[0087] For reference, as illustrated in Fig. 4b, two inductors (L α ) is additionally configured, the inductance of each of the two inductors can be substantially the same.

[0088] In addition, depending on the implementation, passive components such as capacitors (C1, C2) may be additionally connected between the input terminal (110) and the switching unit (120) or between the transformer (130) and the output terminal (140).

[0089] The addition of a passive element in this phase shifter (100) facilitates the implementation of wideband operation using a transformer (130), and the primary inductor of the transformer (130) is configured to be fully transferred to the secondary inductor, thereby minimizing insertion loss.

[0090] Additionally, the phase error can be minimized because the phase is changed by 180° by changing the direction of the induced current in the secondary inductor.

[0091] Hereinafter, with reference to FIG. 5, it will be explained that the phase shifter (100) proposed by the present invention performs a wideband operation compared to a conventional filter-type phase shifter.

[0092] FIG. 5 is an example to explain the wideband operating characteristics of the present invention, and more specifically, FIG. 5a is an example of a reflection coefficient according to a frequency change in a conventional filter-type phase shifter, and FIG. 5b is an example of a reflection coefficient according to a frequency change in a phase shifter using a transformer proposed by the present invention.

[0093] Referring to Fig. 5a, it can be confirmed that a conventional phase shifter with a filter structure composed of an inductor and a capacitor operates in a narrowband manner. In other words, it is difficult to perform wideband operation.

[0094] On the other hand, referring to FIG. 5b, it can be confirmed that a wideband operation is performed compared to a conventional phase shifter by applying the transformer proposed by the present invention.

[0095] This is because mutual inductance is formed between the inductors configured in the transformer, and one more pole is added compared to the transfer function between the two ports in a conventional phase shifter.

[0096] That is, the present invention is designed to perform wideband operation.

[0097] Separately, the differences between the conventional filter-type phase shifter and the present invention are further described. In the case of the conventional filter-type phase shifter, since the delay is adjusted by utilizing the characteristics of the delay element, process validation is difficult, and it is difficult to achieve the target phase shift even with a slight process error of the delay element. Furthermore, since the design requires impedance matching, the design difficulty is inevitably high.

[0098] On the other hand, the present invention utilizes the essential characteristics of a transformer, so it has the advantage of being insensitive to process errors and easy to validate.

[0099] <Description of Transformers>

[0100] FIGS. 6 and 7 are illustrated to explain comparative examples in contrast to the present invention, and FIG. 8 is illustrated to explain an embodiment of a transformer applied to a phase shifter proposed by the present invention.

[0101] For reference, the transformer applied to the phase shifter proposed by the present invention is formed and integrated into a single chip through a complementary metal-oxide semiconductor (CMOS) process. The transformer proposed by the present invention is designed to be specialized for 180° phase shift.

[0102] Hereinafter, with reference to FIGS. 6 to 8, the usefulness of the present invention will be described while discussing comparative examples and embodiments utilizing a transformer.

[0103] <Explanation of comparative examples>

[0104] Fig. 6 is a circuit diagram for explaining a comparative example of a phase shifter utilizing a transformer. Figs. 7a to 7d are examples for explaining the structure when a center-tap transformer is implemented on a substrate in the circuit diagram of Fig. 6.

[0105] First, referring to FIG. 6, the phase shifter (PS) of the comparative example is composed of a first switch (M1), a second switch (M2), and a center-tap transformer (CT).

[0106] As for the first switch (M1) and the second switch (M2), since they perform the same role as the configuration mentioned above, the description of their functions will be omitted.

[0107] The center-tapped transformer (CT) is electrically connected to the switches mentioned above and has a primary inductor (L). a , Lb ), secondary inductor (L c , L d ) and center tap capacitor (C s2 ) can be configured.

[0108] At this time, if the first switch (M1) is on and the second switch (M2) is off, the input signal input through the input terminal of the phase shifter (PS) is connected to the inductor (L) connected to the first stage of the primary inductor. a ) is transmitted to the primary inductor (L a ) and a magnetically coupled secondary inductor (L c , L d ) is output to the output terminal through a coupling signal of the same phase (0°).

[0109] And, when the first switch (M1) is off and the second switch (M2) is on, the input signal input through the input terminal of the phase shifter (Ps) is connected to the inductor (L) connected to the second stage of the primary inductor. b ) is transmitted to the primary inductor (L b ) and a magnetically coupled secondary inductor (L c , L d ) is output to the output terminal through a coupling signal of reverse phase (180°).

[0110] Fig. 7a is a plan view of a center-tapped transformer, Fig. 7b illustrates a primary inductor that operates when outputting a coupling signal in phase with an input signal, Fig. 7c illustrates a primary inductor that operates when outputting a coupling signal that is opposite in phase to an input signal, and Fig. 7d illustrates a secondary inductor that operates when outputting a coupling signal provided by coupling with the primary inductor.

[0111] As a comparative example, the phase shifter (PS) presented in the present invention can be implemented in a stacked shape with the primary and secondary inductors constituting the center-tapped transformer (CT) in order to reduce the circuit size, as in the idea proposed in the present invention.

[0112] However, in the case of the center-tapped transformer (CT) included in the phase shifter (PS), the terminal through which the signal (current) flows when the operation changes for phase shifting flows to the center-tapped transformer (Cs2), and only half of the center-tapped transformer (CT) can contribute to the operation for signal transmission. In other words, since only half of the entire center-tapped transformer (CT) is used to output each phase, not only is there a basic loss, but the center-tapped transformer (CT) cannot be used efficiently.

[0113] In addition, in order to implement the desired inductance value at the target frequency by utilizing only half of the center-tapped transformer (CT), the size of the transformer (130) proposed by the present invention cannot but be larger.

[0114] <Description of the embodiment>

[0115] Hereinafter, the structure of the transformer (130) proposed by the present invention will be described with reference to FIG. 8. However, since the transformer (130) is intended to perform the functions of the first inductor (L1), the second inductor (L2), and the third inductor (L3) described above, its operation may be partially replaced with the description of the functions and operations of the first inductor (L1), the second inductor (L2), and the third inductor (L3) described above.

[0116] FIG. 8 is a diagram illustrating an embodiment of a transformer applied to a phase shifter proposed by the present invention.

[0117] Fig. 8a is a plan view of a transformer, Fig. 8b illustrates a first inductor that operates when outputting a first coupling signal that is in phase with an input signal, Fig. 8c illustrates a second inductor that operates when outputting a second coupling signal that is in phase with an input signal, and Fig. 8d illustrates a third inductor that operates when outputting a coupling signal provided by being coupled with a first inductor or a second inductor.

[0118] Referring to FIGS. 8a to 8d, the transformer (130) proposed by the present invention may include a first layer (131), a second layer (132), and a third layer (133).

[0119] The first layer (131) includes at least a part of the first winding (hereinafter referred to as 'part 1-1 (P)') for implementing the first inductor (L1). 1-1 ) and at least a part of the second winding (hereinafter referred to as 'Part 2-1 (P)') for implementing the second inductor (L2) 2-1 ) are arranged opposite to each other.

[0120] The second layer (132) is the 1-1 part (P) that constitutes the first layer (131) and the third winding for implementing the third inductor (L3). 1-1 ) and Part 2-1 (P 2-1 ) is laminated on the first layer (131) so as to be vertically magnetically coupled.

[0121] The third layer (133) is the remaining part of the first winding (hereinafter referred to as 'Part 1-2 (P 1-2 ) is the remaining part of the second winding (hereinafter referred to as 'Part 2-2 (P 2-2 ) are arranged to face each other, but are stacked on top of the second layer (132) so as to be vertically magnetically coupled to the third winding.

[0122] At this time, the 1-1 part (P) of the 1st winding 1-1 ) and Part 1-2 (P 1-2 ) is electrically connected, and a first through hole (H1) is formed so that a third winding passes through the connection portion (hereinafter referred to as the ‘first connection portion (CP1)’).

[0123] In addition, in the second winding, part 2-1 (P 2-1 ) and Part 2-2 (P 2-2 ) is electrically connected, and a second through hole (H2) is formed so that the third winding passes through a connecting portion (hereinafter referred to as “second connecting portion (CP2)”) positioned opposite to the first connecting portion (CP1).

[0124] To be more specific, the first winding can be provided on the first layer (131) and the third layer (133) to implement the first inductor (L1). At this time, the first winding has one end (E1) and the other end (E2) extending upward, and can receive an input signal through the one end (E1). In addition, the other end (E2) of the first winding is connected to the ground (GND).

[0125] A second winding may be provided on the first layer (131) and the third layer (133) to implement a second inductor (L2). At this time, the second winding has one end (E3) and the other end (E4) extending downward, and an input signal can be received through the one end (E3). In addition, the other end (E4) of the first winding is connected to ground (GND).

[0126] A third winding may be provided on the second layer (132) to implement a third inductor (L3). At this time, the third winding may output a first coupling signal or a second coupling signal through both ends (E5, E6) extended to the right.

[0127] At this time, the third winding and the first or second winding can be magnetically coupled, forming a mutual inductance of polarity. In this case, the actual inductance of the inductors provided in each layer increases, enabling the designer or manufacturer to design or manufacture the first, second, and third windings in a miniaturized manner. This can contribute to miniaturizing the transformer (130).

[0128] Meanwhile, either the first layer (131) or the third layer (133) may be provided as a top metal layer. More specifically, the first and second windings provided in the third layer (133) may be provided as a top metal layer.

[0129] The top metal layer refers to M9 among the nine metal layers (M1 to M9) used in the CMOS process. It is thicker and has a wider cross-sectional area than other metal layers, resulting in superior power transfer efficiency.

[0130] More specifically, by providing at least some of the first and second windings configured in the third layer (133) as a top metal layer, it can contribute to increasing the signal transmission efficiency between the primary inductor (e.g., the first inductor (L1) or the second inductor (L2)) and the secondary inductor (e.g., the third inductor (L3)).

[0131] For reference, in the implementation examples of the inductors illustrated in FIGS. 8b to 8d, there appears to be some difference in the thickness of the windings for implementing each inductor. However, since this is only one embodiment, the thickness of the windings for implementing each inductor may be the same or different, depending on the implementation to achieve the desired inductance value.

[0132] When comparing the comparative example mentioned above with this embodiment, when the transformer proposed by the present invention is applied to a phase shifter rather than using a center-tapped transformer, the ratio of mutual inductance to self-inductance is bound to be higher.

[0133] This suggests that the present invention can be implemented in a smaller size if the transformer proposed by the present invention and the center-tap transformer presented in the comparative example are implemented to have the same inductance value.

[0134] As described above, the specific description of the present invention has been made by way of embodiments with reference to the drawings, but since the above-described embodiments have only described preferred examples of the present invention, the present invention should not be understood as being limited to the above-described embodiments, and the scope of the rights of the present invention should be understood by the claims described below and their equivalents.

Claims

1. A switching unit that switches the transmission path of the input signal so that the signal input through the input terminal (hereinafter referred to as the “input signal”) is selectively transmitted to the output terminal through different paths; and A transformer that couples between the switching unit and the output terminal and outputs a signal switched through the switching unit through the output terminal; The above switching unit, A first switch is arranged between the input terminal and the transformer, and selectively connects the input terminal and the transformer so that the input signal is transmitted to the transformer through a first path among the transmission paths; and A second switch is disposed between the input terminal and the transformer, and selectively connects the input terminal and the transformer so that the input signal is transmitted to the transformer through a second path among the transmission paths; The above transformer is, A first inductor, one end of which is connected to the first switch and the other end is connected to ground, and which receives a signal transmitted through the first path; A second inductor having one end connected to the second switch and the other end connected to ground to receive a signal transmitted through the second path; and A third inductor magnetically coupled to the first inductor or the second inductor and outputting a signal input to the first inductor or the second inductor to the output terminal; characterized in that it includes: Phase transition.

2. In paragraph 1, When the first switch is short-circuited and the second switch is open, a first coupling signal, which is a signal induced to have the same phase as the input signal, is output through the output terminal connected to the third inductor. When the first switch is open and the second switch is short-circuited, the second coupling signal, which is a signal induced to have a phase difference of 180 degrees from the input signal, is output through the output terminal connected to the third inductor. Phase transition.

3. In paragraph 1, Characterized in that at least one of the first switch and the second switch is provided as an N-type MOSFET. Phase transition.

4. In paragraph 1, The third inductor is characterized in that it forms a mutual inductance of polarity with at least one of the first inductor and the second inductor. Phase transition.

5. In paragraph 1, Further including a matching section for impedance matching; The matching unit is configured to include at least one of a first matching network electrically connected between the input terminal and the switching unit; and a second matching network electrically connected between the transformer and the output terminal. Phase transition.

6. In paragraph 1 or paragraph 5, It is characterized by further including passive elements electrically connected between the switching unit and the transformer, and arranged in the first path and the second path respectively; Phase transition.

7. In any one of paragraphs 1 to 4, The above transformer is formed by integration into a single chip through a complementary metal-oxide semiconductor (CMOS) process. The above transformer is, A first layer in which at least a portion of the first winding for implementing the first inductor (hereinafter referred to as “part 1-1”) and at least a portion of the second winding for implementing the second inductor (hereinafter referred to as “part 2-1”) are arranged to face each other; A second layer stacked on top of the first layer so that the third winding for implementing the third inductor is vertically magnetically coupled with the first-1 part and the second-1 part constituting the first layer; and A third layer is laminated on top of the second layer so that the remaining part of the first winding (hereinafter referred to as the '1-2 part') and the remaining part of the second winding (hereinafter referred to as the '2-2 part') are arranged to face each other, but are vertically magnetically coupled to the third winding; In the above first winding, the first-1 part and the first-2 part are electrically connected, and a first through-hole is provided in the connecting portion (hereinafter referred to as the 'first connecting portion') so that the third winding passes through it. In the second winding, the second-1 part and the second-2 part are electrically connected, and a second through hole is provided so that the third winding passes through a connecting part (hereinafter referred to as the 'second connecting part') arranged to face the first connecting part. Phase transition.

8. In paragraph 7, The first inductor and the second inductor have the same inductance value, but the winding directions of the first inductor and the second inductor are different. Phase transition.

9. In paragraph 7, Characterized in that one of the first layer and the third layer is a top metal layer. Phase transition.

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