Supply modulating circuit including switching circuit and wireless communication device including the supply modulating circuit

A communication circuit, including a first supply modulator configured to provide a first supply voltage; a first power amplifier configured to generate a first output signal by amplifying a first input signal corresponding to a first operation frequency band; a second power amplifier configured to generate a second output signal by amplifying a second input signal corresponding to a second operation frequency band; and a switching circuit configured to selectively provide the first supply voltage from the first supply modulator to the second power amplifier based on a first switching signal according to an operation mode.

CROSS-REFERENCE TO THE RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2019-0114960, filed on Sep. 18, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

Wireless communication devices such as smartphones, tablets and Internet of Things (IoT) devices, may use WCDMA (3G), LTE, LTE Advanced (4G), and 5G technologies for high-speed communications. As communication technology develops, high peak-to-average power ratio (PAPR) and high bandwidth of a transmit/receive signal may be required. Accordingly, when a power source of a power amplifier of a transmitting end is connected to a battery, the efficiency of the power amplifier may be lowered. To improve the power efficiency of the power amplifier at a high PAPR and a high bandwidth, average power tracking (APT) technology or envelope tracking (ET) technology is used. Chips that support the average power tracking technology and the envelope tracking technology are called supply modulators (SM).

SUMMARY

According to embodiments, a communication circuit includes a first supply modulator configured to provide a first supply voltage; a first power amplifier configured to generate a first output signal by amplifying a first input signal corresponding to a first operation frequency band; a second power amplifier configured to generate a second output signal by amplifying a second input signal corresponding to a second operation frequency band; and a switching circuit configured to selectively provide the first supply voltage from the first supply modulator to the second power amplifier based on a first switching signal according to an operation mode.

According to embodiments, communication circuit includes a plurality of supply modulators providing a plurality of supply voltages, a plurality of power amplifiers configured to generate a plurality of output signals by amplifying a plurality of input signals based on the plurality of supply voltages; and a plurality of switching components configured to provide the plurality of supply voltages to one or more of the plurality of power amplifiers based on operation frequency bands of the plurality of output signals, wherein the plurality of switching components are configured to provide the plurality of supply voltages to power amplifiers that are connected by connecting each of the plurality of supply modulators to a respective one of the plurality of power amplifiers.

According to embodiments, a wireless communication device includes a modem configured to generate a transmission signal; a supply modulating circuit configured to provide one of a first supply voltage or a second supply voltage; and a supply amplifying circuit configured to generate an output signal by amplifying an input signal generated based on the transmission signal using the one of the first supply voltage or the second supply voltage, wherein the supply modulating circuit comprises at least one switching component configured to provide the one of the first supply voltage or the second supply voltage to the supply amplifying circuit based on an operation frequency.

According to embodiments, a communication circuit includes a first supply modulator configured to provide a first supply voltage; a second supply modulator configured to provide a second supply voltage; a first power amplifier configured to generate a first output signal by amplifying a first input signal using the first supply voltage; a second power amplifier configured to generate a second output signal by amplifying a second input signal using the first supply voltage or the second supply voltage; a third power amplifier configured to generate a third output signal by amplifying a third input signal using the second supply voltage; a first switch configured to switch between the first supply modulator and the second power amplifier based on a first switching signal; and a second switch configured to switch between the second supply modulator and the second power amplifier based on a second switching signal.

According to embodiments, supply modulating circuit configured to provide a supply voltage to a supply amplifying circuit includes a first supply modulator configured to provide a first supply voltage; a second supply modulator configured to provide a second supply voltage; a first switch configured to switch between the first supply modulator and the supply amplifying circuit based on a first switching signal; and a second switch configured to switch between the second supply modulator and the supply amplifying circuit based on a second switching signal.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments relate to a supply modulating circuit and a wireless communication device, for example a supply modulating circuit including a switching circuit and a supply modulator, and a wireless communication device including the supply modulating circuit. In embodiments, a power modulating circuit may provide a supply voltage to a plurality of power amplifiers from a single supply modulator by using a switching circuit, and a wireless communication device may include the supply modulating circuit.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The embodiments described herein are all exemplary without limiting the inventive concept thereto.

FIG. 1is a block diagram illustrating an example of a wireless communication system1according to an embodiment.

Referring toFIG. 1, the wireless communication system1may include a first wireless communication device11and a second wireless communication device12. The wireless communication system1may include, an a non-limiting example, a long term evolution (LTE) system, an LTE-advance (LTE-A) system, a code division multiple access (CDMA) system, a global system for mobile communications (GSM) system, a wireless local area network (WLAN) system, a wireless fidelity (WiFi) system, a Bluetooth low energy (BLE) system, a Zigbee system, a near field communication (NFC) system, a magnetic secure transmission (MST) system, a radio frequency (RF) system, or a body area network (BAN) system.

The first wireless communication dev ice11and the second wireless communication device12may refer to various devices that can communicate with each other to transmit and receive data and/or control information. For example, the first wireless communication device11and the second wireless communication device12may be configured as either user equipment (UE) or a base station. The UE may be a fixed or mobile wireless communication device and may be referred to as terminal equipment, a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscribe station (SS), a wireless device, a handheld device, or the like. A base station (BS) may be generally referred to a fixed station that communicates with the UE and/or other base station, and may be referred to as a Node B, an evolved-Node B (eNB), a base transceiver system (BTS), or the like. In another example, the first and second wireless communication devices11and12may be configured as any one of a client and an access point (AP). The client may establish a communication link with the AP based on WiFi communication.

The first and second wireless communication devices11and12may communicate with each other by using a multiple input multiple output (MIMO) method. To this end, the first wireless communication device11may include a first antenna Ant1_1and a second antenna Ant1_2, and the second wireless communication device12may include a third antenna Ant2_1and a fourth antenna Ant2_2.

Each of the first wireless communication device11and the second wireless communication device12may operate as any one of a transmitting device and a receiving device. When the first wireless communication device11operates as a transmitting device, the second wireless communication device12may operate as a receiving device. When the second wireless communication device12operates as a transmitting device, the first wireless communication device11may operate as a receiving device.

A wireless communication network2between the first wireless communication device11and the second wireless communication device12may support communication among multiple users by sharing available network resources. For example, in the wireless communication network, information may be transferred in various methods such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). In an example, the wireless communication network2may provide multi-input multi output (MIMO) communication.

The first wireless communication device11may include a supply modulating circuit100, and the supply modulating circuit100may include a switching circuit120. When the first wireless communication device11operates as a transmitter, the supply modulating circuit100may generate modulated voltages that vary in level dynamically based on the envelope signal and the interlace signal and supply them to each of the plurality of power amplifiers. A switching circuit120may selectively supply the supply voltage generated by the supply modulating circuit100to at least some of the plurality of power amplifiers.

According to an embodiment, the switching circuit120may selectively supply the supply voltage generated by the supply modulating circuit100to at least some of the plurality of power amplifiers according to a required operation frequency, and thus, the number of power amplifiers for covering a dynamic frequency may be reduced, and many combinations of operating frequencies may be supported by a small number of power amplifiers.

FIG. 2is a block diagram illustrating an example of a wireless communication device10according to an embodiment.

Referring toFIG. 2, the wireless communication device10may include a transmitter, and may be mounted in a wireless communication system1to transmit data to an external device. The wireless communication device10may transmit a transmission signal through a plurality of frequency bands by using carrier aggregation (CA) technology. To this end, the wireless communication device10may include the plurality of power amplifiers for power amplifying a plurality of RF input signals respectively corresponding to a plurality of carriers.

The wireless communication device10may include a modem200, a supply modulating circuit, an RF block300, and a supply amplifying circuit400. The supply amplifying circuit400may include a plurality of power amplifiers PAM1through PAMn respectively corresponding to carriers.

The modem200may process a baseband signal including information to be transmitted according to a corresponding communication method. For example, the modem200may process signals to be transmitted according to a communication scheme such as orthogonal frequency division multiplexing (OFDM), orthogonal frequency division multiple access (OFDMA), wideband code multiple access (WCDMA), and high speed packet access+(HSPA +). In addition, the modem200may process a signal according to various types of communication methods to which technologies of modulating amplitude and frequency of a transmission signal are applied.

The modem200may generate a plurality of transmission signals TX1through TXn from a plurality of baseband signals including information to be transmitted on each of the plurality of carriers. In addition, the modem200may detect an envelope of the plurality of baseband signals to generate an envelope signal ENV and an interface signal IF. In an embodiment, the interface signal IF may include an operation frequency signal OF and an average power (AP) signal, and the envelope signal ENV and the AP signal may correspond to amplitude components of first through nthtransmission signals TX1through TXn. The AP signal may be provided as a reference voltage for each section to the supply modulating circuit. InFIG. 2, one AP signal is illustrated to be output. However, this is only for convenience of description. In an embodiment, a plurality of AP signals may be output as serial data or parallel data. In addition, although one envelope signal ENV is illustrated inFIG. 2, the embodiment is not limited thereto, and a plurality of envelope signals ENV may be generated. In addition, in an embodiment, the first through nthtransmission signals TX1through TXn and the plurality of envelope signals ENV may include differential signals each including a positive signal and a negative signal.

The first through nthtransmission signals TX1through TXn and the envelope signal ENV output from the modem200may be analog signals, and the AP signal may be a digital signal. The modem200may perform a digital/analog conversion on the plurality of baseband signals and digital envelope signals of the plurality of baseband signals by using a digital to analog converter (DAC), and generate the first through nthtransmission signals TX1through TXn and the envelope signal ENV, which may be analog signals. The AP signal output from the modem200may be converted into an analog signal, for example, a reference voltage, by using the DAC provided in the supply modulating circuit100. In an embodiment, the DAC provided in the modem200may operate at a relatively higher speed than the DAC provided in the supply modulating circuit100. However, the embodiment is not limited thereto, and the modem200may convert the AP signal into an analog signal and output the analog signal. The AP signal convened into an analog signal may be provided to the supply modulating circuit100as a plurality of reference voltages.

The operation frequency signal OF output from the modem200may include information about an operation frequency used for wireless communication with a receiver. In an MIMO system, the wireless communication device10may communicate with a receiver by using a plurality of operating frequencies, in which case the operation frequency signal OF may include information about the plurality of operating frequencies. InFIG. 2, an example in which the operation frequency signal OF and the AP signal are included in one interface signal IF is illustrated, but this is only an example, and the operation frequency signal OF and the AP signal may be output to the supply modulating circuit100as separate signals via different signal lines.

The RF block300may generate first through nthRF input signals RF1_in through RFn_in by up-converting each of the first through nthtransmission signals TX1through TXn based on a corresponding carrier among the plurality of carriers.

The supply amplifying circuit400may include first through nthpower amplifiers PAM1through PAMn and may generate first through nthRF output signals RF1_out through RFn_out by amplifying power of the first through nthRF input signals RF1_in through RFn_in, respectively. Each of the first through nthpower amplifiers PAM1through PAMn may amplify the power of each of the received first through nthRF input signals RF1_in through RFn_in based on the applied power voltage. The first though nthRF output signals RF1_out through RFn_out may be transmitted via respectively corresponding antennas ANT1_1through ANT1_n. InFIG. 2, an embodiment in which the supply amplifying circuit400includes three power amplifiers is illustrated, but the embodiment is only an example, and the supply amplifying circuit400may include more titan three power amplifiers.

The supply modulating circuit100may generate modulated voltages in which levels thereof are changed dynamically, based on the envelope signal ENV and the AP signal, and provide the modulated voltages to each of the first through nthpower amplifiers PAM1through PAMn as a supply voltage Vs. When a fixed level power supply voltage is applied to a power amplifier, for example, the first through nthpower amplifiers PAM1through PAMn, an efficiency of the power amplifier may be lowered. For an efficient power management of the power amplifier, the supply modulating circuit130may modulate input voltages, for example, a power provided from a battery, based on the envelope signal ENV and/or the AP signal that are generated based on amplitude components of the transmission signals, for example, the first through nthtransmission signals TX1through TXn, and may provide the modulated input voltages to the first through nthpower amplifiers PAM1through PAMn as the supply voltage Vs.

The supply modulating circuit100according to the present embodiment may include the supply modulating circuit120. The supply modulating circuit100may include a plurality of supply modulators each providing the supply voltage Vs, and the switching circuit120may selectively output the supply voltage Vs provided from the plurality of supply modulators to the first through nthpower amplifiers PAM1through PAMn based on the operation frequency.

FIG. 3is a circuit diagram illustrating an example of a communication circuit20according to an embodiment.

Referring toFIG. 3, the communication circuit20may represent one or more circuits included in a wireless communication device, for example, wireless communication device10ofFIG. 2, and may include the supply modulating circuit100and the supply amplifying circuit400. The supply modulating circuit100may include a first supply modulator111, a second supply modulator112, and the switching circuit120.

The first supply modulator111may receive the envelope signal ENV and the interface signal IF and provide a first supply voltage Vs1to the supply amplifying circuit400. In an example, the interface signal IF may include the AP signal and the operation frequency signal OF, and the first supply modulator111may determine a voltage level of the first supply voltage Vs1by using at least one of the envelope signal ENV and the AP signal.

The second supply modulator112may receive the envelope signal ENV and the interface signal IF and provide a second supply voltage Vs2to the supply amplifying circuit400. In an example, the second supply modulator112may determine a voltage level of the second supply voltage Vs2by using at least one of the envelope signal ENV and the AP signal.

According to an embodiment, the first supply modulator111may output a first switching signal Sig_S1based on the operation frequency signal OF, and the second supply modulator112may output a second switching signal Sig_S2based on the operation frequency signal OF. In an example, the operation frequency signal OF may include information corresponding to frequency bands of the RF output signals, for example, the first through third RF output signals RF1_out through RF3_out, aid the first supply modulator111and the second supply modulator112may determine the first through third power amplifiers PAM1through PAM3that receive the first and second supply voltages Vs1and Vs2, based on the operation frequency signal OF. Accordingly, the first supply modulator111may determine a logic level of the first switching signal Sig_S1, and the second supply modulator112may determine a logic level of the second switching signal Sig_S2.

The switching circuit120may include a first switch SW1that operates based on the first switching signal Sig_S1, and a second switch S2that operates based on the second switching signal Sig_S2. To this end, the first switch SW1and the second switch SW2may include switching elements such as a p-type metal oxide semiconductor (PMOS) transistor and an n-type metal oxide semiconductor (NMOS) transistor.

The first switch SW1may switch between the first supply modulator111and the second power amplifier PAM2based on the first switching signal Sig_S1. In other words, the first switch SW1may provide to the second power amplifier PAM2the first supply voltage Vs1provided from the first supply modulator111based on the first switching signal Sig_S1. The second switch SW2may switch between the second supply modulator112and the second power amplifier PAM2based on the second switching signal Sig_S2. In other words, the second switch SW2may provide to the second power amplifier PAM2the second supply voltage Vs2provided from the second supply modulator112based on the second switching signal Sig_S2.

The supply amplifying circuit400may include the first power amplifier PAM1, the second power amplifier PAM2, and the third power amplifier PAM3. In an embodiment, the first power amplifier PAM1, the second power amplifier PAM2, and the third power amplifier PAM3may be configured to amplify RF signals of different operation frequency bands, respectively. In other words, the first power amplifier PAM1may be configured to amplify the first RF input signal RF1_in of a first operation frequency band B1, the second power amplifier PAM2may be configured to amplify the second RF input signal RF2_in of a second operation frequency band B2, and the third power amplifier PAM3may be configured to amplify the third RF input signal RF3_in of a third operation frequency band B3. In an example, the first operation frequency band B1corresponding to the first power amplifier PAM1directly connected to the first supply modulator111and the third operation frequency band B3corresponding to the third power amplifier PAM3directly connected to the second supply modulator112may be main frequency bands generally used in a network.

The first power amplifier PAM1may transmit the first RF output signal RF1_out generated by amplifying the first RF input signal RF1_in via the antenna ANT to the outside, for example, to the second wireless communication device12inFIG. 1. The first power amplifier PAM1may amplify the first RF input signal RF1_in by using the first supply voltage Vs1received from the first supply modulator111. The third power amplifier PAM3may transmit the third RF output signal RF3_out generated by amplifying the third RF input signal RF1_in via the antenna ANT to the outside, for example, to the second wireless communication device12inFIG. 1. The third power amplifier PAM3may amplify the third RF input signal RF3_in by using the second supply voltage Vs2received from the second supply modulator112.

The second power amplifier PAM2may transmit the second RF output signal RF2_out generated by amplifying the second RF input signal RF2_in via the antenna ANT by using the second operation frequency band B2to the outside, for example, to the second wireless communication device12inFIG. 1. The second power amplifier PAM2may amplify the second RF input signal RF2_in by using the Fust supply voltage Vs1received from the first supply modulator111or the second supply voltage Vs2received from the second supply modulator112.

According to an embodiment, a source of a supply voltage applied to the second power amplifier PAM2may vary based on the operation of the switching circuit120. In an example, when the first switch SW1is shorted and the second switch SW2is open, the second power amplifier PAM2may receive the first supply voltage Vs1from the first supply modulator111, and when the first switch SW1is opened and the second switch SW2is shorted, the second power amplifier PAM2may receive the second supply voltage Vs2from the second supply modulator112.

According to an embodiment, the operation of the switching circuit120may be determined based on the operation frequency band in which the RF signal is transmitted. In the example of transmitting the RF signal via the first operation frequency band B1and the third operation frequency band B3, both the first switch SW1and the second switch SW2may be opened such that the first supply voltage Vs1is applied to the first power amplifier PAM1and the second supply voltage Vs2is applied to the third power amplifier PAM3. In addition, the second power amplifier PAM2may be deactivated based on a second enable signal Sig_EN2.

In the example of transmitting the RF signal via the first operation frequency band B1and the second operation frequency band B2, the first switch SW1may be opened and the second switch SW2may be shorted such that the first supply voltage Vs1is applied to the first power amplifier PAM1and the second supply voltage Vs2is applied to the second power amplifier PAM2. In addition, the third power amplifier PAM3may be deactivated based on a third enable signal Sig_EN3, and the second supply voltage Vs2may be prevented from being applied to the third power amplifier PAM3. Accordingly, the third power amplifier PAM3may be prevented from consuming power by using the second supply voltage Vs2.

In an example of transmitting a signal by using the second operation frequency band B2and the third operation frequency band B3, the first switch SW1may be shorted and the second switch SW2may be opened such that the first supply voltage Vs1is applied to the second power amplifier PAM2and the second supply voltage Vs2is applied to the third power amplifier PAM3. In addition, the first power amplifier PAM1may be deactivated based on the first enable signal Sig_EN1, and the first supply voltage Vs1may be prevented from being applied to the first power amplifier PAM1. Accordingly, the first power amplifier PAM1may be prevented from consuming power by using the first supply voltage Vs1.

In an embodiment, the first through third enable signals Sig_EN1through Sig_EN3may be output by the supply modulating circuit100. In another example, the first through third enable signals Sig_EN1through Sig_EN3may be output by a modem, for example modem200inFIG. 2, or an RF block, for example RF block300inFIG. 2).

The communication circuit20according to an embodiment may selectively apply a supply voltage to a power amplifier according to an operation frequency band and support a plurality of combinations of operation frequency bands even with a small number of power amplifiers.

InFIG. 3, the switching circuit120is illustrated as being independent of the first supply modulator111and the second supply modulator112, but in another example, the switching circuit120may include at least one of the first supply modulator111and the second supply modulator112. In an example, the first switch SW1may be included in the first supply modulator111, and the second switch SW2may be included in the second supply modulator112.

FIG. 4is a timing diagram illustrating example operations of a switching signal and an enable signal, according to an embodiment, andFIGS. 5A through 5Care diagrams illustrating examples of the communication circuit20according to an embodiment.

Referring toFIGS. 3 and 4, a first mode Mode1may indicate a mode for transmitting a signal by using the first operation frequency band B1and the third operation frequency band B3. In the first mode Mode1, the first switching signal Sig_S1and the second switching signal Sig_S2may be logic low, and accordingly, the first switch SW1and the second switch SW2may be opened. In addition, the first enable signal Sig_EN1and the third enable signal Sig_EN3may be logic high, and accordingly, the first power amplifier PAM1and the third power amplifier PAM3may be activated. The second enable signal Sig_EN2may be logic low, and accordingly, the second power amplifier PAM2may be deactivated.

Referring toFIG. 5A, in the first mode Mode1, as both the first switch SW1and the second switch SW2are opened, the first supply voltage Vs1provided by the first supply modulator111may be applied to the first power amplifier PAM1, and the second supply voltage Vs2provided by the second supply modulator112may be applied to the third power amplifier PAM3. Accordingly, the first power amplifier PAM1may generate the first RF output signal RF1_out by amplifying the first RF input signal RF1_in in the first operation frequency band B1, and the third power amplifier PAM3may generate the third RF output signal RF3_out by amplifying the third RF input signal RF3_in in the third operation frequency band B3.

Referring again toFIGS. 3 and 4, a second mode Mode2may indicate a mode for transmitting a signal by using the second operation frequency band B2and the third operation frequency band B3. In the second mode Mode2, the first switching signal Sig_S1may be logic high, and the second switching signal Sig_S2may be logic low. Accordingly, the first switch SW1may be shorted, and the second switch SW2may be opened in addition, the first enable signal Sig_EN1may be logic low, and the second enable signal Sig_EN2and the third enable signal Sig_EN3may be logic high. Accordingly, the first power amplifier PAM1may be deactivated, and the second power amplifier PAM2and the third power amplifier PAM3may be activated.

Referring toFIG. 5B, in the second mode Mode2, as the first power amplifier PAM1is deactivated and the first switch SW1is shorted, the first supply voltage Vs1provided by the first supply modulator111may be applied to the second power amplifier PAM2. In addition, as the second switch SW2is opened, the second supply voltage Vs2provided by the second supply modulator112may be applied to the third power amplifier PAM3. Accordingly, the second power amplifier PAM2may generate the second RF output signal RF2_out by amplifying the second RF input signal RF2_in in the second operation frequency band B2, and the third power amplifier PAM3may generate the third RF output signal RF1_out by amplifying the third RF input signal RF3_in in the third operation frequency band B3.

Referring again toFIGS. 3 and 4, a third mode Mode3may indicate a mode for transmitting a signal by using the first operation frequency band B1and the second operation frequency band B2. In the third mode Mode3, the first switching signal Sig_S1may be logic high, and the second switching signal Sig_S2may be logic low. Accordingly, the first switch SW1may be opened, and the second switch SW2may be shorted. In addition, the first enable signal Sig_EN1and the second enable signal Sig_EN2may be logic high, and the third enable signal Sig_EN3may be logic low. Accordingly, the first power amplifier PAM1and the second power amplifier PAM2may be activated, and the third power amplifier PAM3may be deactivated.

Referring toFIG. 5C, in the third mode Mode3, as the first switch SW1is opened, the first supply voltage Vs1provided by the first supply modulator111may be applied to the first power amplifier PAM1. In addition, as the third power amplifier PAM3is deactivated and the second switch SW2is shorted, the second supply voltage Vs2provided by the second supply modulator112may be applied to the second power amplifier PAM2. Accordingly, the first power amplifier PAM1may generate the first RF output signal RF1_out by amplifying the first RF input signal RF1_in in the first operation frequency band B1, and the second power amplifier PAM2may generate the second RF output signal RF2_out by amplifying the second RF input signal RF2_in in the second operation frequency band B2.

FIG. 6is a block diagram illustrating an example of the supply modulator110according to an embodiment. The supply modulator110ofFIG. 6may represent the first supply modulator111or the second supply modulator112inFIG. 3.

Referring toFIG. 6, the supply modulator110may include an envelope tracker110_1, an average power tracker110_2, and a switching controller110_3. The supply modulator110may provide a supply voltage according to envelope tracking (ET) or average power tracking (APT) to a power amplifier, for example, the first power amplifier PAM1through the third power amplifier PAM3inFIG. 3)

When the envelope tracking is applied, the supply voltage Vs may be generated by operating the envelope tracker110_1. The envelope tracker110_1may receive the envelope signal ENV from a modem, for example, modem200inFIG. 2, and perform the envelope tracking based on the envelope signal ENV. The envelope tracker110_1may generate the supply voltage Vs based on a result of the envelope tracking. In an example, the envelope tracker110_1may include a linear regulator and a switching regulator and may generate the supply voltage Vs by summing outputs of the linear regulator and be switching regulator.

When the envelope tracking is applied, the supply voltage Vs may be generated by operating the average power tracker110_2. The average power tracker110_2may receive the AP signal from the switching controller110_3and generate the supply voltage Vs based on the AP signal.

The switching controller110_3tray receive the interface signal IF and obtain the AP signal and the operation frequency signal OF from the interface signal IF. The switching controller110_3may output the AP signal to the AP tracker110_2and generate a switching signal Sig_S based on the operation frequency signal OF. The switching controller110_3may output the generated switching signal Sig_S to a switching circuit, for example switching circuit120inFIG. 3.

In an embodiment, the switching controller110_3may determine a center frequency required for signal transmission, based on the operation frequency signal OF, and generate the switching signal Sig_S corresponding thereto. In an embodiment, the switching controller110_3may include a switching table SWT and generate the switching signal Sig_S corresponding to a required center frequency based on the switching table SWT.

FIG. 7Aillustrates a power supply and an output waveform of a power amplifier provided with a fixed power supply voltage according to a comparative example.FIGS. 7B and 7Crespectively illustrate a power supply and an output waveform of the power amplifier provided with a varying power supply voltage based on an envelope of a transmission signal provided by a supply modulator according to an embodiment.

Referring toFIG. 7A, when the power amplifier operates by receiving a fixed power supply voltage, for example, a battery voltage as the power supply voltage, a voltage difference between an output signal RFOUTand the fixed power supply voltage may be relatively large. The voltage difference may reduce battery life and generate heat.

Referring toFIG. 7B, the average power tracking may be a technique of applying to the power amplifier a modulation voltage varying based on a peak level of the envelope at every constant transmission time interval (TTI). Referring toFIG. 7C, the envelope tracking may be a technique of instantaneously applying the modulation voltage to the power amplifier that follows a level of the envelope.

According to an embodiment, the supply modulating circuit may provide, to the power supply amplifier as the power supply voltage, a supply voltage Vs_APT which varies according to average power tracking as illustrated inFIG. 7B, or a supply voltage Vs_ET varying according to the envelope tracking as illustrated inFIG. 7C. Accordingly, by reducing the voltage difference between the output signal RFOUTof the power amplifier and the power supply voltage, energy waste may be reduced and the battery life may be increased.

The power efficiency of the power amplifier in the envelope tracking method may be higher than that in the average power tracking method, but the power efficiency of the supply modulating circuit in the average tracking method may be higher than that in the envelope tracking method. The power efficiency of the entire system, for example, the efficiency of the wireless communication device10ofFIG. 2, may be proportional to a product of the efficiency of the supply modulating circuit and the efficiencies of the first through third power amplifiers PAM1through PAM3. As a result, in a high power region where the output signal RFOUTis higher, the power efficiency of the entire system in the envelope tracking method may be higher than that in the average power tracking, and in a low power region where the output signal RFOUTis lower, the power efficiency of the entire system in the average power tracking method may be higher than that in the envelope tracking. Accordingly, the supply modulating circuit100inFIG. 2may selectively generate a supply voltage according to one of the envelope tracking method and the average power tracking method according to the level of the envelope of the transmission signal.

FIG. 8is a circuit diagram illustrating an example of the communication circuit20according to an embodiment.FIG. 8illustrates an embodiment in which supply power is selectively applied to two among four power amplifiers. Duplicate descriptions given with reference toFIG. 3are omitted.

Referring toFIG. 8, the communication circuit20may include the first supply modulator111, the second supply modulator112, the switching circuit122, and a plurality of power amplifiers PAM1through PAM4.

The switching circuit122may include the first switch SW1operating based on the first switching signal Sig_S1, the second switch S2operating based on the second switching signal Sig_S2, a third switch SW3operating based on a third switching signal Sig_S3, and a fourth switch SW4operating based on a fourth switching signal Sig_S4.

The first switch SW1may switch between the first supply modulator111and the second power amplifier PAM2based on the first switching signal Sig_S1. In other words, the first switch SW1may provide to the second power amplifier PAM2the first supply voltage Vs1provided from the first supply modulator111based on the first switching signal Sig_S1. The second switch SW2may switch between the second supply modulator112and the second power amplifier PAM2based on the second switching signal Sig_S2. In other words, the second switch SW2may provide to the second power amplifier PAM2the second supply voltage Vs2provided from the second supply modulator112based on the second switching signal Sig_S2.

The third switch SW3may switch between the first supply modulator111and the third power amplifier PAM3based on the third switching signal Sig_S3. In other words, the third switch SW3may provide to the third power amplifier PAM3the first supply voltage Vs1provided from the first supply modulator111based on the third switching signal Sig_S3. The fourth switch SW4may switch between the second supply modulator112and the third power amplifier PAM3based on the fourth switching signal Sig_S4. In other words, the fourth switch SW4may provide to the third power amplifier PAM3the second supply voltage Vs2provided from the second supply modulator112based on the fourth switching signal Sig_S4.

As an example, when the fourth switch SW4is shorted, the remaining switches SW1through SW3are opened, the first power amplifier PAM1and the third power amplifier PAM3are activated, and the second power amplifier PAM2and the fourth power amplifier PAM4are deactivated, the first power amplifier PAM1may operate by the first supply modulator111, and the third power amplifier PAM3may be operated by the second supply modulator112. Accordingly, the communication circuit20may transmit a signal by using the first operation frequency band B1and the third operation frequency band B3.

According to an embodiment, a supply voltage may be selectively applied to at least two power amplifiers among the first through fourth power amplifiers PAM1through PAM4based on the operation of the switching circuit122. The first through fourth power amplifiers PAM1through PAM4may receive transmission signals using different operation frequency bands, for example bands B1through B4, and the communication circuit20may apply the supply voltage to a power amplifier corresponding to two operation frequency bands required for signal transmission by controlling tie switching circuit122. Accordingly, since the communication circuit20according to an embodiment uses any two operation frequency bands among four operation frequency bands, a signal may be transmitted by using a total of six operation frequency band combinations, and many operation frequency band combinations may be provided by using a relatively small number of power amplifiers.

FIG. 9is a circuit diagram illustrating an example of the communication circuit20according to an embodiment.FIG. 9illustrates an embodiment in which supply power is selectively applied to three among six power amplifiers. Duplicate descriptions given with reference toFIG. 3are omitted.

Referring toFIG. 8, the communication circuit20may include the first supply modulator111, the second supply modulator112, a third supply modulator113, a switching circuit124, and a plurality of power amplifiers PAM1through PAM6.

The switching circuit124may include first through ninth switches SW1to SW9. The first switch SW1may provide to the second power amplifier PAM2the first supply voltage Vs1provided from the first supply modulator111based on the first switching signal Sig_S1. The second switch SW2may provide to the fourth power amplifier PAM4the first power voltage Vs1provided from the first supply modulator111based on the second switching signal Sig_S2. The third switch SW3may provide to the sixth power amplifier PAM6the first supply voltage Vs1provided from the first supply modulator111based on the third switching signal Sig_S3.

The fourth switch SW4may provide to the second power amplifier PAM2the second supply voltage Vs2provided from the second supply modulator112based on the fourth switching signal Sig_S4. A fifth switch SW5may provide to the fourth power amplifier PAM4the second power supply voltage Vs2provided from the second supply modulator112based on a fifth switching signal Sig_S5. A sixth switch SW6may provide to the sixth power amplifier PAM6the second supply voltage Vs2provided from the second supply modulator112based on a sixth switching signal Sig_S6.

A seventh switch SW7may provide to the second power amplifier PAM2the third power voltage Vs3provided from the third supply modulator113based on a seventh switching signal Sig_S7. An eighth switch SW8may provide to the fourth power amplifier PAM4the third power voltage Vs3provided from the third supply modulator113based on an eighth switching signal Sig_S8. A ninth switch SW9may provide to the sixth power amplifier PAM6the third power voltage Vs3provided from the third supply modulator113based on a ninth switching signal Sig_S9.

As an example, when the first switch SW1and the eighth switch SW8are shorted, the remaining switches SW2, SW3, SW4, SW5, SW6, SW7and SW9, are opened, the second power amplifier PAM2, the third power amplifier PAM3, and the fourth power amplifier PAM4are activated, and the remaining power amplifiers, PAM1, PAM5, and PAM6are deactivated, the second power amplifier PAM2may be operated by the first supply modulator111, the third power amplifier PAM3may be operated by the second supply modulator112, and the fourth power amplifier PAM4may be operated by the third supply modulator113. Accordingly, the communication circuit20may transmit a signal by using the second operation frequency band B2, the third operation frequency band B3, and the fourth operation frequency band B4.

According to an embodiment, a supply voltage may be selectively applied to at least three power amplifiers among the first through ninth power amplifiers PAM1through PAM9based on the operation of the switching circuit122. The first through ninth power amplifiers PAM1through PAM9may receive transmission signals using different operation frequency bands, for example bands B1through B9, and the communication circuit20may apply the supply voltage to a power amplifier corresponding to three operation frequency bands required for signal transmission by controlling the switching circuit122. Accordingly, since the communication circuit20according to an embodiment uses any three operation frequency bands among six operation frequency bands, a signal may be transmitted by using a total of twenty operation frequency band combinations, and many operation frequency band combinations may be provided by using a relatively small number of power amplifiers.

AlthoughFIGS. 8 and 9illustrate examples of amplifying a signal by using two supply modulators and four power amplifiers or three supply modulators and six power amplifiers, respectively, the examples are only embodiments. It may be readily understood that the present disclosure includes embodiments in which various numbers of operation frequency band combinations are provided by connecting N supply modulators to M power amplifiers, where N and M are natural numbers, using switching circuits.

In addition, although inFIGS. 8 and 9, there are power amplifiers, for example PAM1and PAM4inFIG. 8, and PAM1, PAM3, and PAM5inFIG. 9, which are directly connected to the supply modulator and the switching circuits, the embodiments are only examples. It may be understood that the present disclosure includes embodiments in which ail the power amplifiers are connected to the supply modulators via the switching circuits.

FIG. 10Ais a circuit diagram illustrating an example of the communication circuit20according to an embodiment.FIG. 10Aillustrates an example including switches that selectively connect some of the supply modulators to the power amplifiers. Duplicate descriptions given with reference toFIG. 3are omitted.

Referring toFIG. 10A, the communication circuit20may include the first supply modulator111, the second supply modulator112, the switching circuit126, and the first through third power amplifiers PAM1through PAM3, and the switching circuit126may include the first switch SW1and the second switch SW2.

The first switch SW1may provide to the second power amplifier PAM2the first supply voltage Vs1provided from the first supply modulator111based on the first switching signal Sig_S1. The second switch SW2may connect the second supply modulator112to the second power amplifier PAM2or to the third power amplifier PAM3based on the second switching signal Sig_S2. In other words, the second switch SW2may provide to the second power amplifier PAM2or the third power amplifier PAM3the second supply voltage Vs2provided from the second supply modulator112based on the second switching signal Sig_S2.

To this end, the second switch SW2may include a switching element for selectively connecting a first node a that is connected to the second power amplifier PAM2and the third power amplifier PAM3based on the second switching signal Sig_S2and a second node b that is connected to the third power amplifier PAM3to the second supply modulator112. InFIG. 10A, the second switch SW2is represented by one switching element, but the embodiment is only an example, and the second switch SW2may be implemented by one switching element or more.

FIG. 10Bis a circuit diagram illustrating an example of the communication circuit20according to an embodiment.FIG. 10billustrates an example including switches that selectively connect the supply modulators to the power amplifiers. Duplicate descriptions given with reference toFIG. 10Aare omitted.

Referring toFIG. 10B, the communication circuit20may include the first supply modulator111, the second supply modulator112, a switching circuit128, and the first through third power amplifiers PAM1through PAM3, and the switching circuit128may include the first switch SW1and the second switch SW2.

The first switch SW1may connect the first supply modulator111to the first power amplifier PAM1or the second power amplifier PAM2based on the first switching signal Sig_S1. In other words, the first switch SW1may provide the first supply voltage Vs2provided from the first supply modulator111to the first power amplifier PAM1or the second power amplifier PAM2based on the first switching signal Sig_S1.

To this end, the first switch SW1may include a switching element that, based on the first switching signal Sig_S1, selectively connects the first node a connected to the first power amplifier PAM1, and the second node b connected to the second power amplifier PAM2, to the second supply modulator112.

The second switch SW2may connect the second supply modulator112to the second power amplifier PAM2or to the third power amplifier PAM3based on the second switching signal Sig_S2. In other words, the second switch SW2may provide to the second power amplifier PAM2or the third power amplifier PAM3the second supply voltage Vs2provided from the second supply modulator112based on the second switching signal Sig_S2.

To this end, the second switch SW2may include a switching element for selectively connecting a third node c that is connected to the second power amplifier PAM2based on the second switching signal Sig_S2and a fourth node d that is connected to the third power amplifier PAM3to the second supply modulator112.

According to the embodiment ofFIG. 10B, as the first switch SW1selectively switches the first node a and the second node b, and the second switch SW2selectively switches the first node a and the second node b, the first supply modulator111may apply the first supply voltage Vs1to the first power amplifier PAM1or the second power amplifier PAM2, and the second supply modulator112may apply the second supply voltage Vs2to the second power amplifier PAM2or the third power amplifier PAM3.

FIGS. 10A and 10Billustrate examples in which switching elements for example SW1and SW2, switch between two nodes, but the embodiments are only examples, and it may be readily understood that the present disclosure includes embodiments in which the switching element selectively switches two nodes or more.

FIGS. 10A and 10Billustrate examples of amplifying a signal by using two supply modulators and three power amplifiers, but the embodiments are only examples. It may be readily understood that the present disclosure includes embodiments in which the switching elements selectively switch two nodes or more in the switching circuits126and128, and also embodiments in which N supply modulators to M power amplifiers, where N and M are natural numbers, are connected to each other by using switching circuits.

FIG. 11is a circuit diagram illustrating an example of a communication circuit20aaccording to an embodiment.FIG. 11illustrates an embodiment in which a plurality of supply modulators111aand112aand a switching controller130a, which is independent, are included in the communication circuit20a. Duplicate descriptions given with reference toFIGS. 3 and 6are omitted.

Referring toFIG. 11, the communication circuit20amay include a supply modulating circuit100aand a power amplifier circuit400a. The supply modulating circuit100may include a first supply modulator111a, a second supply modulator112a, a switching circuit120a, and a switching controller130a.

The first supply modulator111amay receive the envelope signal ENV and the AP signal and provide the first supply voltage Vs1to the supply amplifying circuit400a. The second supply modulator112amay receive the envelope signal ENV and the AP signal and provide the second supply voltage Vs2to the supply amplifying circuit400a.

The switching controller130amay receive the operation frequency signal OF and generate a switching signal Sig_S based on the operation frequency signal OF. The switching controller130amay output the generated switch ng signal Sig_S to the switching circuit120a.

In an embodiment, the switching controller130amay determine the center frequency required for signal transmission, based on the operation frequency signal OF, and generate the switching signal Sig_S corresponding thereto.

FIG. 12is a block diagram illustrating an example of a wireless communication device10baccording to an embodiment.FIG. 12illustrates an embodiment in which a switching controller210bis included in a modem200b. Duplicate descriptions given with reference toFIGS. 2 and 6are omitted.

Referring toFIG. 12, the wireless communication device10bmay include the modem200b, a supply modulating circuit100b, an RF block300b, and a supply amplifying circuit400b. The modem200bmay include the switching controller210b, and the supply modulating circuit100bmay include a switching circuit120b.

The switching controller210bmcv determine an operation frequency band required for signal transmission and generate the switching signal Sig_S based on the operation frequency band. The switching controller210bmay output the generated switching signal Sig_S to the switching circuit120b. The switching circuit120bmay selectively provide the supply voltage Vs generated by the supply modulating circuit100bbased on the switching signal Sig_S received from the switching controller210bto at least some of first through nthpower amplifiers PAM1through PAMn.

According to an embodiment, the modem200bmay determine a power amplifier to operate according to an operation frequency band and output the switching signal Sig_S to the switching circuit120bbased on the determined power amplifier.

FIG. 13is a block diagram illustrating an example of a wireless communication device10caccording to an embodiment.FIG. 13illustrates an embodiment in which a switching circuit420cis included in a supply amplifying circuit400c. Duplicate descriptions given with reference toFIGS. 2 and 12are omitted.

Referring toFIG. 13, the wireless communication device10cmay include a modem200c, a supply modulating circuit100c, in RF block300c, and the supply amplifying circuit400c. The modem200cmay include a switching controller210c, and the supply amplifying circuit400cmay include the switching circuit420c.

The switching controller210cmay output the switching signal Sig_S generated based on the operation frequency band to the switching circuit420cincluded in the supply amplifying circuit400c. The switching circuit420cmay selectively supply the supply voltage Vs provided from the supply modulating circuit100cto at least some of the first through nthpower amplifiers PAM1through PAMn based on the switching signal Sig_S that is received.

According to an embodiment, the switching circuit420cmay be included in the supply amplifying circuit400c, and the supply amplifying circuit400cmay determine a supply amplifier to operate directly based on the switching signal Sig_S.

FIG. 14is a block diagram illustrating an example of an Internet of Things (IoT) device1000, according to an embodiment.

Referring toFIG. 14, a communication circuit according to embodiments of the present disclosure may be included in the IoT device1000. The term IoT may mean a network between things using wired/wireless communication. The IoT device1000may include an accessible wired or wireless interface, and may include devices that communicate with at least one other device via a wired or wireless interface to transmit or receive data. The accessible wired or wireless interface may include a wired local area network (LAN), a wireless local area network (WLAN) such as Wi-Fi, a wireless personal area network (WPAN) such as Bluetooth, or a wireless universal serial bus (USB), Zigbee, near field communication (NFC), radio frequency identification (RFID), power line communication (PLC), or a modem communication interface that may be connected to a mobile cellular network such as 3G, 4G, and long-term evolution (LTE). The Bluetooth interface may support Bluetooth low energy (BLE).

The IoT device1000may include a communication interface1200for communicating with the outside. For example, the communication interlace1200may be a radio transceiver/receiver. The communication interface1200may include, for example, a modem communication interface connectable to a w ireless local area communication interface such as LAN, Bluetooth, Wi-fi, and Zigbee, PLC, and a mobile communication network such as 3G and LTE. The communication interface1200may include a transmitter and/or a receiver. The IoT device1000may transmit and/or receive information from an access point or a gateway via the transmitter and/or the receiver. In addition, the IoT device1000may transmit and/or receive control information or data thereof by communicating with a user device or other IoT devices.

In the present embodiment, the transmitter included in the communication interface1200may transmit a transmission signal via a plurality of frequency bands by using carrier aggregation (CA) technology. To this end, the transmitter may include a plurality of power amplifiers for power amplification of a plurality of RF input signals respectively corresponding to a plurality of carriers, and a supply modulating circuit for providing a power supply voltage to the plurality of power amplifiers. The supply modulating circuit may be implemented according to the embodiments described above with reference toFIGS. 1 through 13. The supply modulating circuit may include a switching circuit for selectively providing supply power provided from a supply modulator to the plurality of power amplifiers.

The IoT device1000may further include a processor or an application processor1100that performs operations. The IoT device1000may further include a built-in battery for internal power supply or a power supply unit that receives power from the outside. In addition, the IoT device1000may include a display1400for displaying an internal state or data. The user may control the IoT device1000via a user interface (UI) of the display1400of the IoT device1000. The IoT device1000may transmit an internal state and/or data to the outside via the transmitter, and receive a control command and/or data from the outside via the receiver.

A memory1300may store a control command code for controlling the IoT device1000, control data, or user data. The memory1300may include at least one of a volatile memory and a non-volatile memory. The nonvolatile memory may include at least one of read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable PROM (EEPROM), a flash memory, phase-change random-access memory (RAM) (PRAM), magnetic RAM (MRAM), resistive RAM (ReRAM), ferroelectric RAM (FRAM), and etc. The volatile memory may include at least one of various memories such as dynamic RAM (DRAM), static RAM (SRAM), synchronous DRAM (SDRAM), etc.

The IoT device1000may further include a storage device. The storage device may include a non-volatile medium such as a hard disk (HDD), a solid state disk (SSD), an embedded multi-media card (eMMC) and a universal flash storage (UFS). The storage device may store user information provided via an input/output unit1500and sensing information collected by using a sensor1600.

FIG. 15is a mobile terminal2000according to an embodiment.

Referring toFIG. 15, the mobile terminal2000may include an application processor2100AP, a memory2200, a display2300, and an RF module2410. In addition, the mobile terminal2000may further include various components such as a lens, a sensor, and an audio module.

The application processor2100may be implemented as a system on chip (SoC), and may include a central processing unit (CPU)2110, a RAM2120, a power management unit (PMU)2130, a memory interface2140, a display controller2150, a modem2160, and a bus2170.

The application processor2100may further include various IPs. The application processor2100may be referred to as a ModAP, is functions of a modem chip are integrated therein.

The CPU2110may control overall operations of the application processor2100and the mobile terminal2000. The CPU2110may control the operation of each element of the application processor2100. In an embodiment, the CPU2110may be implemented as a multi-core. The multi-core may include a computing component including two or more independent cores.

RAM2120may temporarily store programs, data, or instructions. For example, the programs and/or data stored in the memory2200may be temporarily stored in the RAM2120according to the control or booting codes of the CPU2110. The RAM2120may be implemented with DRAM or SRAM.

The PMU2130may manage power of each component of the application processor2100. The PMU2130may also determine an operation status of each component of the application processor2100and control an operation thereof.

The memory interface2140may control an overall operation of a memory2200, and may control data exchange between each component of the application processor2100and the memory2200. The memory interface2140may write data to the memory2200or read data from the memory2200at a request of the CPU2110.

The display controller2150may transmit image data to be displayed on the display2300to the display2300. The display2300may be implemented as a flat panel display or a flexible display such as a liquid crystal display (LCD) and an organic light emitting diode (OLED).

The modem2160may, for wireless communication, modulate the data to be transmitted to suit a wireless environment, and recover data that has been received. The modem2160may perform digital communication with the RF module2410.

The RF module2410may convert a high frequency signal received via an antenna into a low frequency signal, and transmit the convened low frequency signal to the modem2160. In addition, the RF module2410may convert the low frequency signal received from the modem2160into a high frequency signal, and transmit the converted high frequency signal to the outside of the mobile terminal2000via an antenna. In addition, the RF module2410may amplify or filter signals.

In the present embodiment, the RF module2410may transmit a transmission signal via a plurality of frequency bands by using the CA technology. To this end, the RF module2410may include a plurality of power amplifiers for power amplification of a plurality of RF input signals respectively corresponding to a plurality of carriers, and a supply modulator for providing a power supply voltage to the plurality of power amplifiers. The supply modulator may be implemented according to the embodiments described above with reference toFIGS. 1 through 13. The supply modulating circuit may include a switching circuit for selectively providing supply power provided from a supply modulator to the plurality of power amplifiers.