Radio frequency switch circuit

Abstract

A radio frequency (RF) switching circuit is provided that transmits a signal input through a first input port and a second input port to an output port. The RF switching circuit includes: a first series switch transmitting the signal input through the first input port; a first parallel switch connected to the first input port; a first attenuation circuit connected between the first parallel switch and ground, and attenuating the signal transmitted from the first input port to the output port; a detector detecting an amplitude of a signal transmitted to the output port and generating a first control signal based on the detected amplitude of the signal; and a switch control circuit controlling the first series switch, the first parallel switch, and the first attenuation circuit using the first control signal and the second control signal to select a signal path between the first input port and the output port.

Description

Technical Field

[0001] The following description relates to a radio frequency (RF) switching circuit. Background Art

[0002] As the expansion of the fifth generation network in the wireless communication system increases, the long term evolution (LTE) network, the second generation network and the fifth generation network are being integrated into a single mobile phone system. As radio frequency (RF) components of various frequency bands are integrated, the demand for RF switches that implement the path of selecting RF signals is also increasing. The RF switch can select the signal of the input frequency band and output the selected signal to the power amplifier.

[0003] Generally, a power amplifier may have an operating range of signal amplitude, and if a signal exceeding the operating range is input, the power amplifier may be damaged. To prevent such damage, an overvoltage protection (OVP) circuit or an overcurrent protection (OCP) circuit may be added inside the power amplifier.

[0004] The above information is presented as background information only to help understand the present disclosure. The above description should not be interpreted as these contents belonging to the prior art of the present disclosure. Summary of the invention

[0005] This summary is provided to introduce selected concepts in a simplified form, and these concepts are further described in the following detailed description. This summary is neither intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0006] In one general aspect, a radio frequency (RF) switching circuit is configured to transmit a first signal input through a first input port to an output port, and is configured to transmit a second signal input through a second input port to the output port, the RF switching circuit comprising: a first series switch configured to transmit the first signal input through the first input port to the output port; a first parallel switch connected to the first input port; a first attenuation circuit connected between the first parallel switch and ground and configured to attenuate the first signal transmitted from the first input port to the output port; a detector configured to detect an amplitude of one of the first signal and the second signal transmitted to the output port and generate a first control signal based on the amplitude of the detected signal; and a switch control circuit configured to control the first series switch, the first parallel switch, and the first attenuation circuit based on the first control signal and the second control signal to select a first signal path between the first input port and the output port.

[0007] The first attenuation circuit may include: a first switch connected between the first parallel switch and the ground; and a first resistor connected between the first parallel switch and the ground, wherein the switch control circuit may be configured to determine the on operation or off operation of the first series switch, the first parallel switch and the first switch based on the first control signal and the second control signal.

[0008] The RF switch circuit may also include: a second series switch configured to transmit the second signal input through the second input port to the output port; a second parallel switch connected to the second input port; and a second attenuation circuit connected between the second parallel switch and the ground and configured to attenuate the second signal transmitted from the second input port to the output port, wherein the switch control circuit is configured to select the first signal path between the first input port and the output port or the second signal path between the second input port and the output port based on the second control signal, and control the second series switch, the second parallel switch and the second attenuation circuit based on the first control signal and the second control signal.

[0009] The second attenuation circuit may include: a second switch connected between the second parallel switch and the ground; and a second resistor connected between the second parallel switch and the ground, wherein the switch control circuit may be configured to determine the on operation or off operation of the second series switch, the second parallel switch and the second switch based on the first control signal and the second control signal.

[0010] The detector may include: a reference voltage selector configured to select a reference voltage based on the second control signal; and a comparator configured to compare a first voltage corresponding to the amplitude of the first signal or the second signal transmitted to the output port with the reference voltage, and generate the first control signal to have a first value when the first voltage is less than the reference voltage, and generate the first control signal to have a second value when the first voltage is greater than or equal to the reference voltage.

[0011] The second control signal may have a first value indicating selection of a signal path between the first input port and the output port and a second value indicating selection of a signal path between the second input port and the output port, and the reference voltage selector may be configured to store different reference voltages corresponding to the first value of the second control signal and the second value of the second control signal, respectively, and provide the selected reference voltage corresponding to the first value or the second value of the input second control signal to the comparator.

[0012] When the second control signal has a first value and the first control signal has a second value, the switch control circuit can be configured to control the first series switch to be in an on state, control the second series switch to be in an off state, control the first parallel switch, the second parallel switch and the second switch to be in an on state, and control the first switch to be in an off state.

[0013] When the second control signal has a second value and the first control signal has a second value, the switch control circuit can be configured to control the second series switch to be in an on state, control the first series switch to be in an off state, control the first parallel switch, the second parallel switch and the first switch to be in an on state, and control the second switch to be in an off state.

[0014] When the second control signal has a first value and the first control signal has a first value, the switch control circuit can be configured to control the first series switch to be in an on state, control the second series switch to be in an off state, control the first parallel switch to be in an off state, and control the second parallel switch and the second switch to be in an on state.

[0015] When the second control signal has a second value and the first control signal has a first value, the switch control circuit can be configured to control the second series switch to be in an on state, control the first series switch to be in an off state, control the second parallel switch to be in an off state, and control the first parallel switch and the first switch to be in an on state.

[0016] In one general aspect, a radio frequency (RF) switch circuit includes: a first input port configured to receive a first signal; a second input port configured to receive a second signal; an output port; a first switch section configured to transmit the first signal to the output port; a second switch section configured to transmit the second signal to the output port; a first attenuation circuit configured to attenuate the first signal transmitted to the output port; a second attenuation circuit configured to attenuate the second signal transmitted to the output port; a detector configured to detect an amplitude of one of the first signal and the second signal transmitted to the output port and generate a first control signal based on the amplitude of the detected signal; and a switch control circuit configured to control the first switch section, the second switch section, the first attenuation circuit, and the second attenuation circuit based on the first control signal and the second control signal to select one of a first signal path between the first input port and the output port and a second signal path between the second input port and the output port.

[0017] The first switch section may include: a first series switch connected between the first input port and the output port; and a first parallel switch connected between the first input port and the ground, the second switch section may include: a second series switch connected between the second input port and the output port; and a second parallel switch connected between the second input port and the ground, the first attenuation circuit may include: a first switch connected between the first parallel switch and the ground; and a first resistor connected between the first parallel switch and the ground, and the second attenuation circuit may include: a second switch connected between the second parallel switch and the ground; and a second resistor connected between the second parallel switch and the ground.

[0018] The detector may include: a reference voltage selector configured to select a reference voltage based on the second control signal; and a comparator configured to generate the first control signal to have a first value when a first voltage corresponding to an amplitude of the first signal and the second signal transmitted to the output port is less than the reference voltage, and to generate the first control signal to have a second value when the first voltage is greater than or equal to the reference voltage.

[0019] The second control signal may have a first value for selecting the first signal path and a second value for selecting the second signal path, and the reference voltage selector may be configured to select a first reference voltage when the second control signal has a first value, and may be configured to select a second reference voltage when the second control signal has a second value different from the first value, and provide the selected first reference voltage or the second reference voltage to the comparator.

[0020] The switch control circuit can be configured to control the on-operation or off-operation of the first series switch and the second series switch based on the value of the second control signal, and to control the on-operation or off-operation of the first parallel switch, the second parallel switch, the first switch and the second switch based on the value of the first control signal and the value of the second control signal, the second control signal can have a first value for selecting the first signal path and a second value for selecting the second signal path, and the first control signal can have a first value and a second value different from the first value based on the amplitude of the signal transmitted to the output port.

[0021] In one general aspect, a radio frequency (RF) switch circuit includes: a first input port; a second input port; an output port; a first switch section including a first series switch and a first parallel switch and configured to receive a first signal from the first input port; a second switch section including a second series switch and a second parallel switch and configured to receive a second signal from the second input port; a first attenuation circuit connected between the first switch section and ground and including a first switch and a resistor connected in parallel with the first switch; a second attenuation circuit connected between the second switch section and the ground and including a second switch and a resistor connected in parallel with the second switch; and a switch control circuit configured to control the first series switch, the first parallel switch, the second series switch, the second parallel switch, the first attenuation circuit, and the second attenuation circuit based on a first control signal, and select one of a first signal path between the first input port and the output port and a second signal path between the second input port and the output port based on a second control signal, wherein the first control signal is determined based on an amplitude of a signal transmitted to the output port.

[0022] Other features and aspects will be readily apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A diagram illustrating an example of an RF switch circuit in accordance with one or more embodiments.

[0024] Figure 2 Shows Figure 1 FIG. 1 is a diagram of an example of a first attenuation circuit 130 shown.

[0025] Figure 3 Shows Figure 1 FIG. 1 is a diagram of an example of a second attenuation circuit 140 shown.

[0026] Figure 4 is a diagram illustrating a method of controlling a switch based on a control signal VC0 and a control signal VC1 by a switch control circuit according to one or more embodiments.

[0027] Figure 5 It is shown Figure 1 Diagram of the detector shown.

[0028] Figure 6 is a graph showing attenuation of an RF signal output when the control signal VC0 is 1 and the control signal VC1 is 0.

[0029] Figure 7 is a graph showing attenuation of an RF signal output when the control signal VC0 is 1 and the control signal VC1 is 1.

[0030] Throughout the drawings and detailed description, like reference numerals refer to like elements unless otherwise described. The drawings may not be drawn to scale, and the relative size, proportion, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0031] Hereinafter, although examples of the present disclosure will be described in detail with reference to the accompanying drawings, it should be noted that the examples are not limited thereto.

[0032] The following specific embodiments are provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be readily understood after understanding the present disclosure. For example, the order of operations described herein is merely an example and is not limited to the order set forth herein, but changes may be made that will be readily understood after understanding the present disclosure, except for operations that must occur in a particular order. In addition, descriptions of features known in the art may be omitted for increased clarity and brevity.

[0033] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be readily understood after understanding the present disclosure.

[0034] Throughout the specification, when an element such as a layer, a region, or a substrate is described as being “on”, “connected to”, or “coupled to” another element, the element may be directly “on”, “connected to”, or “coupled to” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, or “directly coupled to” another element, there are no other elements present between them.

[0035] As used herein, the term "and / or" includes any one of the associated listed items or any combination of any two or more items. Similarly, "at least one of..." includes any one of the associated listed items or any combination of any two or more items.

[0036] Although terms such as "first", "second", and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, first component, first region, first layer, or first portion referred to may also be referred to as the second member, second component, second region, second layer, or second portion.

[0037] For ease of description, spatially relative terms such as "above", "above", "below", "below", etc. may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "above" relative to another element will be "below" or "below" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0038] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, singular expressions (e.g., "a", "an", and "the") are also intended to include plural expressions. The terms "include", "comprise", and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0039] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0040] Here, it should be noted that use of the term "may" with respect to examples (e.g., with respect to what an example may include or implement) means that there is at least one example that includes or implements such features, but is not limited to all examples including or implementing such features.

[0041] The features of the examples described herein may be combined in various ways that will be readily understood after understanding the present disclosure. In addition, although the examples described herein have various configurations, other configurations that will be readily understood after understanding the present disclosure are feasible.

[0042] Throughout the specification, by way of example only, radio frequency (RF) signals may have formats according to, but not limited to, the following protocols: Wi-Fi (IEEE 802.11 series, etc.), WiMAX (IEEE 802.16 series, etc.), IEEE 802.20, Long Term Evolution (LTE), Evolution-Data Optimized (Ev-DO), High Speed ​​Packet Access + (HSPA+), High Speed ​​Downlink Packet Access + (HSDPA+), High Speed ​​Uplink Packet Access + (HSUPA+), Enhanced Data Rates for GSM Evolution (EDGE), Global System for Mobile Communications (GSM), Global Positioning System (GPS), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Digital Enhanced Cordless Telecommunications (DECT), Bluetooth, third generation mobile communication technology (3G), fourth generation mobile communication technology (4G), fifth generation mobile communication technology (5G), and any other wireless protocols and wired protocols specified after the above protocols.

[0043] One or more examples may provide an RF switching circuit that prevents a signal of excessive magnitude exceeding an operating range of the power amplifier from being delivered to the power amplifier.

[0044] Figure 1 A diagram illustrating an example of an RF switch circuit in accordance with one or more embodiments.

[0045] Reference Figure 1 The RF switch circuit 100 includes a first port P1, a second port P2, a third port P3, a control port C1, a first switch section 110, a second switch section 120, a first attenuation circuit 130, a second attenuation circuit 140, a detector 150 and a switch control circuit 160.

[0046] In an example, the first port P1 and the second port P2 may be input ports. RF signals of different frequency bands may be input to the first port P1 and the second port P2, respectively. In an example, an RF signal of a communication method based on a second generation communication system may be input to the first port P1, and an RF signal of a communication method based on a third generation or fourth generation communication system may be input to the second port P2.

[0047] In an example, the third port P3 may be an output port. An RF signal input through the first port P1 or the second port P2 may be output through the third port P3. In an example, a power amplifier may be connected to the third port P3.

[0048] The first switch unit 110 may include a series switch SE1 and a parallel switch SH1. The series switch SE1 may be connected between the first port P1 and the third port P3. The parallel switch SH1 may be connected between the first port P1 and the ground. The series switch SE1 and the parallel switch SH1 may operate complementarily. When the series switch SE1 is turned on, the parallel switch SH1 may be turned off, and when the series switch SE1 is turned off, the parallel switch SH1 may be turned on.

[0049] The second switch unit 120 may include a series switch SE2 and a parallel switch SH2. The series switch SE2 may be connected between the second port P2 and the third port P3. The parallel switch SH2 may be connected between the second port P2 and the ground. The series switch SE2 and the parallel switch SH2 may operate complementarily. When the series switch SE2 is turned on, the parallel switch SH2 may be turned off, and when the series switch SE2 is turned off, the parallel switch SH2 may be turned on.

[0050] The series switch SE1, the series switch SE2, the parallel switch SH1, and the parallel switch SH2 may be turned on or off based on a control signal output from the switch control circuit 160. When the series switch SE1 is turned on, a signal path between the first port P1 and the third port P3 may be selected, and an RF signal input through the first port P1 may be delivered to the power amplifier through the third port P3. When the series switch SE2 is turned on, a signal path between the second port P2 and the third port P3 may be selected, and an RF signal input through the second port P2 may be delivered to the power amplifier through the third port P3.

[0051] When the series switch SE1 is turned on and the series switch SE2 is turned off, the RF switch circuit 100 transmits the RF signal input through the first port P1 to the third port P3. At this time, in order to increase the isolation of the RF signal between the second port P2 and the third port P3, the parallel switch SH1 may be turned off and the parallel switch SH2 may be turned on.

[0052] When the series switch SE2 is turned on and the series switch SE1 is turned off, the RF switch circuit 100 transmits the RF signal input through the second port P2 to the third port P3. At this time, in order to increase the isolation of the RF signal between the first port P1 and the third port P3, the parallel switch SH2 may be turned off and the parallel switch SH1 may be turned on.

[0053] The first attenuation circuit 130 may be connected between the parallel switch SH1 and the ground. The first attenuation circuit 130 may operate under the control of the switch control circuit 160 and attenuate the amplitude of the RF signal transmitted from the first port P1 to the third port P3 during operation.

[0054] The second attenuation circuit 140 may be connected between the parallel switch SH2 and the ground. The second attenuation circuit 140 may operate under the control of the switch control circuit 160, and may attenuate the amplitude of the RF signal transmitted from the second port P2 to the third port P3 during operation.

[0055] The detector 150 may detect the amplitude of the RF signal transmitted to the third port P3. The detector 150 may generate a control signal VC0 based on the amplitude of the RF signal transmitted to the third port P3. In an example, the detector 150 may output 1 as the control signal VC0 when the amplitude of the RF signal is greater than or equal to a predetermined level (e.g., a predetermined reference value), and output 0 as the control signal VC0 when the amplitude of the RF signal is less than a predetermined level (e.g., a predetermined reference value). The detector 150 may output the control signal VC0 to the switch control circuit 160.

[0056] The switch control circuit 160 can control the series switch SE1 and the parallel switch SH1 of the first switch unit 110, the series switch SE2 and the parallel switch SH2 of the second switch unit 120, the first attenuation circuit 130 and the second attenuation circuit 140 based on the control signal VC0 output from the detector 150 and the control signal VC1 input through the control port C1.

[0057] The control signal VC1 may be a signal for selecting one of a signal path between the first port P1 and the third port P3 and a signal path between the second port P2 and the third port P3 .

[0058] In the example, there are a first port P1 and a second port P2 shown as input ports, and RF signals of different frequency bands can be input to the first port P1 and the second port P2. At this time, the RF signal input through the first port P1 or the second port P2 can be transmitted to the third port P3 according to the control signal VC1. In the example, when the control signal VC1 is 0, the RF signal input through the first port P1 can be selected and transmitted to the third port P3. If the control signal VC1 is 1, the RF signal input through the second port P2 can be selected and transmitted to the third port P3. Although Figure 1 Only two input ports P1 and P2 are shown in FIG, but this is merely an example, and fewer or more ports may be implemented based on the intended operation.

[0059] Figure 2 It is shown Figure 1 FIG. 1 is a diagram of an example of a first attenuation circuit 130 shown.

[0060] Reference Figure 2 , the first attenuation circuit 130 may include a switch SA1 and a resistor R1.

[0061] Switch SA1 may be connected between shunt switch SH1 and ground.

[0062] The resistor R1 may be connected between the parallel switch SH1 and the ground. That is, the resistor R1 may be connected between both ends of the switch SA1.

[0063] The switch SA1 can be turned on or off according to the control of the switch control circuit 160 .

[0064] In an example, when the series switch SE1 is turned on, the parallel switch SH1 is turned on, and the switch SA1 is turned off under the control of the switch control circuit 160, the RF signal input through the first port P1 may be transferred to the third port P3 through the series switch SE1, and at the same time may be transferred to the ground through the parallel switch SH1 and the resistor R1. Therefore, since the RF signal input through the first port P1 is divided into two paths, the amplitude of the RF signal transmitted to the third port P3 may be attenuated.

[0065] Figure 3 It is shown Figure 1 FIG. 1 is a diagram of an example of a second attenuation circuit 140 shown.

[0066] Reference Figure 3 , the second attenuation circuit 140 may include a switch SA2 and a resistor R2.

[0067] Switch SA2 may be connected between shunt switch SH2 and ground.

[0068] The resistor R2 may be connected between the parallel switch SH2 and the ground. That is, the resistor R2 may be connected between both ends of the switch SA2.

[0069] The switch SA2 may be turned on or off according to the control of the switch control circuit 160 .

[0070] In an example, when the series switch SE2 is turned on, the parallel switch SH2 is turned on, and the switch SA2 is turned off under the control of the switch control circuit 160, the RF signal input through the second port P2 may be transferred to the third port P3 through the series switch SE2, and at the same time may be transferred to the ground through the parallel switch SH2 and the resistor R2. Therefore, since the RF signal input through the second port P2 is divided into two paths, the amplitude of the RF signal transmitted to the third port P3 may be attenuated.

[0071] Figure 2 The first attenuation circuit 130 and Figure 3 The second attenuation circuit 140 shown is only an example, and Figure 1 The illustrated first attenuation circuit 130 and second attenuation circuit 140 may be composed of a combination of a resistor, an inductor, and a capacitor instead of the resistors R1 and R2.

[0072] Figure 4 is a diagram illustrating a method of controlling a switch based on a control signal VC0 and a control signal VC1 by a switch control circuit according to one or more embodiments.

[0073] Reference Figure 4 , when the control signal VC1 is 0, the signal path between the first port P1 and the third port P3 may be selected. That is, the RF signal input through the first port P1 may be selected and transmitted to the third port P3.

[0074] If the control signal VC1 is 1, a signal path between the second port P2 and the third port P3 may be selected. That is, an RF signal input through the second port P2 may be selected and transmitted to the third port P3.

[0075] If the amplitude of the RF signal output through the third port P3 is greater than or equal to a predetermined reference value, the detector 150 may output 1 as the control signal VC0, and if the amplitude of the RF signal output through the third port P3 is less than the predetermined reference value, the detector 150 may output 0 as the control signal VC0.

[0076] The switch control circuit 160 may use the control signal VC0 and the control signal VC1 to determine the on or off state of the series switch SE1 and the parallel switch SH1 of the first switch unit 110 , the series switch SE2 and the parallel switch SH2 of the second switch unit 120 , the switch SA1 of the first attenuation circuit 130 , and the switch SA2 of the second attenuation circuit 140 .

[0077] The switch control circuit 160 may determine whether to attenuate the amplitude of the RF signal output through the third port P3 according to the control signal VC0. If the control signal VC0 is 1, the switch control circuit 160 may determine to attenuate the amplitude of the RF signal output through the third port P3. In the example, if the control signal VC0 is 0, the amplitude of the RF signal output through the third port P3 does not need to be attenuated.

[0078] The switch control circuit 160 may control the on state or off state of the series switch SE1 of the first switch section 110 and the series switch SE2 of the second switch section 120 based on the control signal VC1. If the control signal VC0 is 0 (i.e., if the amplitude of the RF signal output through the third port P3 is less than a predetermined reference value), the switch control circuit 160 may control the on state or off state of the parallel switch SH1 of the first switch section 110, the parallel switch SH2 of the second switch section 120, the switch SA1 of the first attenuation circuit 130, and the switch SA2 of the second attenuation circuit 140 based on the control signal VC1.

[0079] If the control signal VC0 is 0 and the control signal VC1 is 0, the switch control circuit 160 may set the series switch SE1 of the first switch section 110 to the on state, the parallel switch SH1 of the first switch section 110 to the off state, the series switch SE2 of the second switch section 120 to the off state, and the parallel switch SH2 of the second switch section 120 to the on state. Therefore, since the parallel switch SH1 is in the off state and the control signal VC0 is 0, the switch control circuit 160 may set the switch SA1 of the first attenuation circuit 130 to any state. In addition, since the parallel switch SH2 is in the on state and the control signal VC0 is 0, the switch control circuit 160 may set the switch SA2 of the second attenuation circuit 140 to the on state, so that the isolation of the RF signal between the second port P2 and the third port P3 may be increased.

[0080] If the control signal VC1 is 1 and the control signal VC0 is 0, the switch control circuit 160 may set the series switch SE2 of the second switch section 120 to the on state, the parallel switch SH2 to the off state, the series switch SE1 of the first switch section 110 to the off state, and the parallel switch SH1 to the on state. Therefore, since the parallel switch SH2 is off and the control signal VC0 is 0, the switch control circuit 160 may set the switch SA2 of the second attenuation circuit 140 to any state. In addition, since the parallel switch SH1 is in the on state and the control signal VC0 is 0, the switch control circuit 160 may set the switch SA1 of the first attenuation circuit 130 to the on state. Thus, the isolation of the RF signal between the first port P1 and the third port P3 may be increased.

[0081] Therefore, if the control signal VC0 is 0, the switch control circuit 160 may determine the on state or off state of the series switch SE1 and the parallel switch SH1 of the first switch section 110 and the series switch SE2 and the parallel switch SH2 of the second switch section 120 based on the control signal VC1. However, if the control signal VC0 is 1, an operation of attenuating the amplitude of the RF signal is required. If the control signal VC0 is 1 and the control signal VC1 is 0, the attenuation operation of the first attenuation circuit 130 is required, and if the control signal VC0 is 1 and the control signal VC1 is 1, the attenuation operation of the second attenuation circuit 140 is required.

[0082] If the control signal VC0 is 1 (i.e., if the amplitude of the RF signal output through the third port P3 is greater than or equal to a predetermined reference value), the switch control circuit 160 can control the on state or off state of the parallel switch SH1 of the first switch unit 110, the parallel switch SH2 of the second switch unit 120, the switch SA1 of the first attenuation circuit 130, and the switch SA2 of the second attenuation circuit 140 based on the control signal VC0 and the control signal VC1.

[0083] If the control signal VC0 is 1, the switch control circuit 160 may determine the on state or off state of the series switch SE1 of the first switch section 110 and the series switch SE2 of the second switch section 120 based on the control signal VC1. If the control signal VC1 is 0, the switch control circuit 160 may set the series switch SE1 of the first switch section 110 to the on state and the series switch SE2 of the second switch section 120 to the off state. Therefore, if the control signal VC0 is 1, since the attenuation operation of the first attenuation circuit 130 is required, the switch control circuit 160 may set the parallel switch SH1 of the first switch section 110 to the on state and the switch SA1 of the first attenuation circuit 130 to the off state. Since the attenuation operation of the second attenuation circuit 140 is not required, the switch control circuit 160 may set the parallel switch SH2 of the second switch section 120 to the on state and the switch SA2 of the second attenuation circuit 140 to the on state based on the control signal VC1, so that the isolation of the RF signal between the second port P2 and the third port P3 can be increased.

[0084] In addition, if the control signal VC1 is 1, the switch control circuit 160 may set the series switch SE2 of the second switch section 120 to the on state, and set the series switch SE1 of the first switch section 110 to the off state. Therefore, if the control signal VC0 is 1, since the attenuation operation of the second attenuation circuit 140 is required, the switch control circuit 160 may set the parallel switch SH2 of the second switch section 120 to the on state, and set the switch SA2 of the second attenuation circuit 140 to the off state. Since the attenuation operation of the first attenuation circuit 130 is not required, the switch control circuit 160 may set the parallel switch SH1 of the first switch section 110 to the on state and the switch SA1 of the first attenuation circuit 130 to the on state based on the control signal VC1, so that the isolation of the RF signal between the first port P1 and the third port P3 can be increased.

[0085] Figure 5 It is shown Figure 1 A diagram of an example of a detector is shown.

[0086] Reference Figure 5 , the detector 150 may include a diode D1 , a resistor R3 , a capacitor C1 , a variable gain amplifier (VGA) 152 , a reference voltage selector 154 , and a comparator 156 .

[0087] The RF signal output through the third port P3 may be rectified and converted into a direct current (DC) voltage signal through a diode D1 , a resistor R3 , and a capacitor C1 .

[0088] A DC voltage signal for the RF signal output through the third port P3 may be transmitted to the VGA 152 .

[0089] The VGA 152 may amplify the DC voltage signal to a desired amplitude and output the amplified signal to the comparator 156 .

[0090] The reference voltage selector 154 may select a reference voltage VREF based on the control signal VC1. The reference voltage VREF may be a voltage used as a reference for comparison with a voltage input to the comparator 156.

[0091] RF signals of different frequency bands may be input to the first port P1 and the second port P2, respectively. For example, the second generation communication system, the third generation communication system, the fourth generation communication system, and the fifth generation communication system may use different frequency bands and have different RF signal amplitudes and different modulation schemes according to the communication method. Therefore, the comparator 156 should use different reference voltages according to the type of the input RF signal. The reference voltage selector 154 may select the reference voltage VREF according to the value of the control signal VC1, and provide the selected reference voltage VREF to the comparator 156.

[0092] As an example of a method for selecting the reference voltage VREF in the reference voltage selector 154, the reference voltage selector 154 may store the reference voltages VREF corresponding to the values ​​of the control signal VC1, respectively, and select the reference voltage VREF corresponding to the value of the control signal VC1. The reference voltage selector 154 may store the reference voltages VREF corresponding to the values ​​of the control signal VC1 as a table in the form of Table 1.

[0093] Table 1:

[0094]

[0095] In Table 1, it is shown that an RF signal according to a communication method of a second generation communication system can be input through the first port P1, and an RF signal according to a communication method of a third generation communication system or a fourth generation communication system can be input through the second port P2. VC1=0 may indicate that a signal path between the first port P1 and the third port P3 is selected, and VC1=1 may indicate that a signal path between the second port P2 and the third port P3 is selected.

[0096] Therefore, the reference voltage VREF used in the comparator 156 may be selected by the reference voltage selector 154 to have different values ​​according to the control signal VC1 .

[0097] The comparator 156 may compare the voltage output from the VGA 152 with the reference voltage VREF, and generate a control signal VC0 based on the comparison result. In an example, if the voltage output from the VGA 152 (i.e., the voltage corresponding to the amplitude of the RF signal output through the third port P3) is less than the reference voltage VREF, the comparator 156 may output the control signal VC0 having a value of 0. In addition, if the voltage corresponding to the amplitude of the RF signal output through the third port P3 is greater than or equal to the reference voltage VREF, the comparator 156 may output the control signal VC0 having a value of 1.

[0098] The comparator 156 may output the control signal VC0 to the switch control circuit 160 .

[0099] Figure 6 is a graph showing attenuation of an RF signal output when the control signal VC0 is 1 and the control signal VC1 is 0.

[0100] Reference Figure 6 , if the control signal VC1 is 0 and the control signal VC0 is 1, the series switch SE1 of the first switch section 110 may be turned on, the series switch SE2 of the second switch section 120 may be turned off, the parallel switch SH1 of the first switch section 110 may be turned on, and the switch SA1 of the first attenuation circuit 130 may be turned off. Then, the RF signal input to the first port P1 may be divided into a path S610 toward the third port P3 through the series switch SE1 and a path S620 toward the ground through the parallel switch SH1 and the resistor R1. At this time, the ratio of the RF signal input to the first port P1 to be divided into the two paths S610 and S620 may be determined by the impedance of the first attenuation circuit 130. In an example, the impedance of the first attenuation circuit 130 may correspond to the resistance value of the resistor R1. Thus, the amplitude of the RF signal transmitted from the first port P1 to the third port P3 may be attenuated according to the resistance value of the resistor R1.

[0101] In addition, when the control signal VC1 is 0 and the control signal VC0 is 1, the parallel switch SH2 of the second switch section 120 may be turned on, and the switch SA2 of the second attenuation circuit 140 may be turned on. That is, if the first switch section 110 performs a signal transmission operation, the second switch section 120 may be turned off. At this time, the parallel switch SH2 of the second switch section 120 and the switch SA2 of the second attenuation circuit 140 may be turned on, and the RF signal of the second port P2 may be transmitted to the path S630 toward the ground through the parallel switch SH2 of the second switch section 120 and the switch SA2 of the second attenuation circuit 140. Therefore, the isolation of the RF signal between the second port P2 and the third port P3 may be increased.

[0102] Figure 7is a graph showing attenuation of an RF signal output when the control signal VC0 is 1 and the control signal VC1 is 1.

[0103] Reference Figure 7 , if the control signal VC1 is 1 and the control signal VC0 is 1, the series switch SE2 of the second switch section 120 may be turned on, the series switch SE1 of the first switch section 110 may be turned off, the parallel switch SH2 of the second switch section 120 may be turned on, and the switch SA2 of the second attenuation circuit 140 may be turned off. Then, the RF signal input to the second port P2 may be divided into a path S710 toward the third port P3 through the series switch SE2 and a path S720 toward the ground through the parallel switch SH2 and the resistor R2. At this time, the ratio of the RF signal input to the second port P2 to be divided into the two paths S710 and S720 may be determined by the impedance of the second attenuation circuit 140. In an example, the impedance of the second attenuation circuit 140 may correspond to the resistance value of the resistor R2. Thus, the amplitude of the RF signal transmitted from the second port P2 to the third port P3 may be attenuated according to the resistance value of the resistor R2.

[0104] In addition, if the control signal VC1 is 1 and the control signal VC0 is 1, the parallel switch SH1 of the first switch section 110 may be turned on, and the switch SA1 of the first attenuation circuit 130 may be turned on. That is, if the second switch section 120 performs a signal transmission operation, the first switch section 110 may be turned off. At this time, the parallel switch SH1 of the first switch section 110 and the switch SA1 of the first attenuation circuit 130 may be turned on, and the RF signal of the first port P1 may be transmitted to the path S730 toward the ground through the parallel switch SH1 of the first switch section 110 and the switch SA1 of the first attenuation circuit 130. Therefore, the isolation of the RF signal between the first port P1 and the third port P3 may be increased.

[0105] According to at least one example, since a signal having a specific amplitude or greater can be attenuated and input to the power amplifier, an overvoltage protection (OVP) or overcurrent protection (OCP) circuit inside the power amplifier can be removed, and the performance of the power amplifier can be improved by removing the OVP or OCP circuit.

[0106] Although specific examples have been shown and described above, it will be readily understood after understanding the present disclosure that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein will be understood only as descriptive, and not for limiting purposes. The description of the features or aspects in each example will be considered applicable to similar features or aspects in other examples. If the described techniques are performed in a different order, and / or if the components in the described system, architecture, device, or circuit are combined in a different manner and / or replaced or supplemented by other components or their equivalents, the components in the described system, architecture, device, or circuit can be obtained. Appropriate results can be obtained. Therefore, the scope of the present disclosure is not limited by specific embodiments, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents will be interpreted as included in the present disclosure.

Claims

1. A radio frequency switch circuit, the radio frequency switch circuit being configured to transmit a first signal input through a first input port to an output port, and being configured to transmit a second signal input through a second input port to the output port, the radio frequency switch circuit include: a first series switch configured to transmit the first signal input through the first input port to the output port; a first parallel switch connected to the first input port; a first attenuation circuit connected between the first parallel switch and ground and configured to attenuate the first signal transmitted from the first input port to the output port; a detector configured to detect an amplitude of one of the first signal and the second signal transmitted to the output port, and to generate a first control signal based on the amplitude of the detected signal; as well as The switch control circuit is configured to control the first series switch, the first parallel switch, and the first attenuation circuit based on the first control signal and the second control signal to select a first signal path between the first input port and the output port.

2. The radio frequency switching circuit according to claim 1, in, The first attenuation circuit comprises: A first switch connected between the first parallel switch and the ground; and a first resistor connected between the first parallel switch and the ground, The switch control circuit is configured to determine an on operation or an off operation of the first series switch, the first parallel switch, and the first switch based on the first control signal and the second control signal.

3. The radio frequency switch circuit according to claim 2, wherein the radio frequency switch circuit further comprises: include: a second series switch configured to transmit the second signal input through the second input port to the output port; a second parallel switch connected to the second input port; as well as a second attenuation circuit connected between the second parallel switch and the ground and configured to attenuate the second signal transmitted from the second input port to the output port, Wherein, the switch control circuit is configured to select the first signal path between the first input port and the output port or the second signal path between the second input port and the output port based on the second control signal, and to control the second series switch, the second parallel switch and the second attenuation circuit based on the first control signal and the second control signal.

4. The radio frequency switching circuit according to claim 3, in, The second attenuation circuit comprises: a second switch connected between the second parallel switch and the ground; and a second resistor connected between the second parallel switch and the ground, The switch control circuit is configured to determine an on operation or an off operation of the second series switch, the second parallel switch, and the second switch based on the first control signal and the second control signal.

5. The radio frequency switch circuit according to claim 4, in, The detector comprises: a reference voltage selector configured to select a reference voltage based on the second control signal; and A comparator is configured to compare a first voltage corresponding to the amplitude of the first signal or the second signal transmitted to the output port with the reference voltage, and to generate the first control signal to have a first value when the first voltage is less than the reference voltage, and to generate the first control signal to have a second value when the first voltage is greater than or equal to the reference voltage.

6. The radio frequency switching circuit according to claim 5, in, The second control signal has a first value indicating selection of a signal path between the first input port and the output port and a second value indicating selection of a signal path between the second input port and the output port, and The reference voltage selector is configured to store different reference voltages corresponding to a first value of the second control signal and a second value of the second control signal, respectively, and provide the selected reference voltage corresponding to the first value or the second value of the input second control signal to the comparator.

7. The radio frequency switching circuit according to claim 6, in, When the second control signal has a first value and the first control signal has a second value, the switch control circuit is configured to control the first series switch to be in an on state, control the second series switch to be in an off state, control the first parallel switch, the second parallel switch and the second switch to be in an on state, and control the first switch to be in an off state.

8. The radio frequency switch circuit according to claim 6, in, When the second control signal has a second value and the first control signal has a second value, the switch control circuit is configured to control the second series switch to be in an on state, control the first series switch to be in an off state, control the first parallel switch, the second parallel switch and the first switch to be in an on state, and control the second switch to be in an off state.

9. The radio frequency switch circuit according to claim 6, in, When the second control signal has a first value and the first control signal has a first value, the switch control circuit is configured to control the first series switch to be in an on state, control the second series switch to be in an off state, control the first parallel switch to be in an off state, and control the second parallel switch and the second switch to be in an on state.

10. The radio frequency switch circuit according to claim 6, in, When the second control signal has a second value and the first control signal has a first value, the switch control circuit is configured to control the second series switch to be in an on state, control the first series switch to be in an off state, control the second parallel switch to be in an off state, and control the first parallel switch and the first switch to be in an on state.

11. A radio frequency switching circuit, include: A first input port configured to receive a first signal; A second input port configured to receive a second signal; Output port; a first switch unit configured to transmit the first signal to the output port; a second switch section configured to transmit the second signal to the output port; a first attenuation circuit configured to attenuate the first signal transmitted to the output port; a second attenuation circuit configured to attenuate the second signal transmitted to the output port; a detector configured to detect an amplitude of one of the first signal and the second signal transmitted to the output port, and to generate a first control signal based on the amplitude of the detected signal; as well as A switch control circuit is configured to control the first switch unit, the second switch unit, the first attenuation circuit and the second attenuation circuit based on the first control signal and the second control signal to select one of a first signal path between the first input port and the output port and a second signal path between the second input port and the output port.

12. The radio frequency switch circuit according to claim 11, in, The first switch unit includes: A first series switch connected between the first input port and the output port; and a first parallel switch connected between the first input port and ground, The second switch unit includes: A second series switch connected between the second input port and the output port; and a second parallel switch connected between the second input port and the ground, The first attenuation circuit comprises: A first switch connected between the first parallel switch and the ground; and a first resistor connected between the first parallel switch and the ground, and The second attenuation circuit comprises: a second switch connected between the second parallel switch and the ground; and A second resistor is connected between the second parallel switch and the ground.

13. The radio frequency switch circuit according to claim 12, in, The detector comprises: a reference voltage selector configured to select a reference voltage based on the second control signal; and A comparator is configured to generate the first control signal to have a first value when a first voltage corresponding to the amplitude of the one of the first signal and the second signal transmitted to the output port is less than the reference voltage, and to generate the first control signal to have a second value when the first voltage is greater than or equal to the reference voltage.

14. The radio frequency switch circuit according to claim 13, in, The second control signal has a first value for selecting the first signal path and a second value for selecting the second signal path, and The reference voltage selector is configured to select a first reference voltage when the second control signal has a first value, and is configured to select a second reference voltage when the second control signal has a second value different from the first value, and provides the selected first reference voltage or the second reference voltage to the comparator.

15. The radio frequency switch circuit according to claim 12, in, The switch control circuit is configured to control the on operation or off operation of the first series switch and the second series switch based on the value of the second control signal, and control the on operation or off operation of the first parallel switch, the second parallel switch, the first switch, and the second switch based on the value of the first control signal and the value of the second control signal, The second control signal has a first value for selecting the first signal path and a second value for selecting the second signal path, and The first control signal has a first value and a second value different from the first value based on the amplitude of the signal transmitted to the output port.

16. A radio frequency switching circuit, include: First input port; The second input port; Output port; a first switch section including a first series switch and a first parallel switch, and configured to receive a first signal from the first input port; a second switch section including a second series switch and a second parallel switch and configured to receive a second signal from the second input port; a first attenuation circuit connected between the first switch section and ground and including a first switch and a resistor connected in parallel with the first switch; a second attenuation circuit connected between the second switch section and ground and including a second switch and a resistor connected in parallel with the second switch; as well as a switch control circuit configured to control the first series switch, the first parallel switch, the second series switch, the second parallel switch, the first attenuation circuit, and the second attenuation circuit based on a first control signal, and select one of a first signal path between the first input port and the output port and a second signal path between the second input port and the output port based on a second control signal, The first control signal is determined based on the amplitude of the signal transmitted to the output port.

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