Power supply modulator providing multiple level supply voltages and method of operation thereof

Abstract

The power modulator includes a multi-level voltage generator configured to generate a plurality of power voltages having different voltage levels; a switch array including a plurality of switches respectively corresponding to the plurality of power voltages and outputting one of the plurality of power voltages by activating a connection of one of the plurality of switches; and a switch controller configured to control the connection of each of the plurality of switches, and in response to receiving a level control signal to switch the connection from a first switch to a second switch, activate a connection of at least one third switch distinguished from the first switch and the second switch during a time period corresponding to a frequency to be attenuated between disconnecting the first switch and connecting the second switch.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0004929, filed with the Korean Intellectual Property Office on January 13, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to a power modulator, and more specifically, to a power modulator that outputs a multi-level power voltage. Background Technology

[0004] In wireless communication devices such as smartphones, tablets, and Internet of Things (IoT) devices, communication technologies such as Wideband Code Division Multiple Access (WCDMA), 3G, LTE, LTE-Advanced 4G, or NR 5G are used for high-speed communication. However, with the development of communication technologies, high peak-to-average power ratio (PAPR) and high bandwidth are used for transmitting / receiving signals. Therefore, when the power amplifier used for the transmitter is connected to a battery, the efficiency of the power amplifier is reduced. Accordingly, in order to track the power efficiency of the power amplifier under high PAPR and high bandwidth, average power tracking (APT) or envelope tracking (ET) techniques can be used. Chips or components that support such APT and ET are called supply modulators (SMs). Summary of the Invention

[0005] This disclosure relates to power modulators, and more specifically, to power modulators with minimized noise and methods of operation thereof.

[0006] According to embodiments of the present disclosure, a power modulator is provided, comprising: a multilevel voltage generator configured to generate a plurality of power supply voltages having different voltage levels; a switch array including a plurality of switches corresponding to the plurality of power supply voltages, each switch being switchably connected to an output terminal; and a switch controller configured to receive a level control signal indicating that the connection to the output terminal is switched from a first switch to a second switch, and to connect at least one third switch to the output terminal during a time period corresponding to a frequency to be attenuated between disconnecting the first switch and connecting the second switch.

[0007] According to another embodiment of this disclosure, a wireless communication device is provided, comprising: a power modulator configured to output any one of a plurality of power supply voltages of different voltage levels, and, when the power supply voltage changes from a first voltage level to a second voltage level, outputting a power supply voltage of at least one third voltage level different from the first voltage level and the second voltage level during a time period corresponding to a frequency to be attenuated between the change from the first voltage level to the second voltage level; and a communication processor configured to control the power modulator and determine at least one of the frequency and time period to be attenuated.

[0008] According to another embodiment of this disclosure, a method of operating a wireless communication device for amplifying the power of a communication signal based on a power supply voltage of multiple levels is provided, comprising: determining a transition delay time based on a frequency to be attenuated when the power supply voltage transitions from a first level to a second level among multiple levels; outputting a power supply voltage of at least one of a third level that is different from the first level and the second level during the transition delay time between the transition from the first level to the second level; and amplifying the power of the communication signal based on the power supply voltage. Attached Figure Description

[0009] Embodiments of this disclosure will become clearer from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 This is a block diagram of a wireless communication device according to an embodiment;

[0011] Figure 2 This is a circuit diagram of the power modulator according to an embodiment;

[0012] Figure 3 This is a circuit diagram of a multilevel voltage generator according to an embodiment;

[0013] Figure 4 This is a graph illustrating an example of discretely generating multi-level output voltages based on envelope tracking results;

[0014] Figure 5 This is a graph illustrating an example of a power modulator generating a level difference transition voltage in a comparative embodiment.

[0015] Figure 6A and Figure 6B This is a graph illustrating an example of a power modulator generating a level difference transition voltage according to an embodiment.

[0016] Figure 7 It is a block diagram of the transfer function according to an embodiment, wherein noise components of a specific frequency are attenuated by the power supply voltage output by the power supply modulator during the delay time period;

[0017] Figure 8 This is a graph illustrating an example of a power modulator generating a switching voltage with two level differences according to an embodiment.

[0018] Figure 9 This is a graph illustrating an example of a power modulator generating three level differences for switching voltages according to an embodiment.

[0019] Figures 10A to 10D It is a graph illustrating the frequency characteristics of the power supply voltage output by the power supply modulator according to the present invention.

[0020] Figure 11 This is a table showing the time delay of the power supply voltage at the third level output by the power modulator according to an embodiment.

[0021] Figure 12 It is a tabular diagram used to determine the frequency characteristics of each band for the frequency to be attenuated by the power modulator conceived in this invention;

[0022] Figure 13 This is a circuit diagram illustrating an example of a power modulator of the present disclosure supplying power voltage to multiple power amplifiers.

[0023] Figure 14 The diagram is based on Figure 13 Examples of multiple power supply voltage curves; and

[0024] Figure 15 This is a block diagram of a wireless communication device including the power modulator disclosed herein. Detailed Implementation

[0025] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0026] Figure 1 The illustration shows a wireless communication device according to an embodiment.

[0027] refer to Figure 1 According to an embodiment, the wireless communication device 10 may include a communication processor (CP) 100, a radio frequency integrated circuit (RFIC) 200, a power modulator 300, a duplexer 400, a power amplifier (PA) 500, and an antenna ANT.

[0028] The communication processor 100 may include an envelope tracking (ET) processor 110, a transmit (TX) processor 120, and a receive (RX) processor 130. The communication processor 100 can process baseband signals, such as in-phase (I) and quadrature (Q) signals, including information to be transmitted via the transmit processor 120, according to a certain communication method. Furthermore, the communication processor 100 can process baseband signals received via the receive processor 130 according to a certain communication method.

[0029] For example, the communication processor 100 can process the signal to be transmitted or received according to a communication method such as Orthogonal Frequency Division Multiplexing (OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Wideband Code Division Multiple Access (WCDMA), or High-Speed ​​Packet Access+ (HSPA+). Furthermore, the communication processor 100 can process the baseband signal according to various types of communication methods (e.g., various communication methods in which techniques for modulating or demodulating the amplitude and / or frequency of the baseband signal are applied).

[0030] The communication processor 100 can extract the envelope of the baseband signal through the envelope tracking processor 110 and generate a digital envelope signal D_ENV based on the extracted envelope. The extracted envelope can correspond to the amplitude components of the baseband signal (e.g., the amplitudes of the I and Q signals).

[0031] The envelope tracking processor 110, transmitting processor 120, and receiving processor 130 of the communication processor 100 can each be configured with different modules to output signals. However, the envelope tracking processor 110, transmitting processor 120, and receiving processor 130 of this disclosure are not limited thereto, and can be configured as a single module to perform different functions.

[0032] The communication processor 100 can generate a transmit signal TX as an analog signal by performing digital-to-analog conversion on each baseband signal using a plurality of digital-to-analog converters provided therein. The communication processor 100 can receive a receive signal RX as an analog signal from the RFIC 200. The communication processor 100 can extract the baseband signal as a digital signal by performing analog-to-digital conversion on the receive signal RX by an analog-to-digital converter (ADC) provided therein. The transmit signal TX and the receive signal RX can be differential signals including positive and negative signals.

[0033] RFIC 200 can generate an RF input signal RF_IN by up-converting the transmit signal TX, and / or can generate a receive signal RX by down-converting the RF receive signal RF_R. More specifically, RFIC 200 may include a transmit circuit 210 for up-conversion, a receive circuit 220 for down-conversion, and a local oscillator LO.

[0034] The transmitting circuit 210 may include a first baseband filter 213, a first mixer 212, and a first amplifier 211. For example, the first baseband filter 213 may include a low-pass filter. The first baseband filter 213 may filter the transmit signal TX received from the communication processor 100 and provide it to the first mixer 212. Furthermore, the first mixer 212 may perform up-conversion of the transmit signal TX from the baseband to a higher frequency band using a frequency signal provided by the local oscillator LO. Through such up-conversion, the transmit signal TX may be provided to the first amplifier 211 as an RF input signal RF_IN, and the first amplifier 211 may primarily amplify the RF input signal RF_IN and provide it to the power amplifier 500.

[0035] The power amplifier 500 can receive a power supply voltage from the power modulator 300 and can generate an RF output signal RF_OUT by amplifying the power of the RF input signal RF_IN based on the received power supply voltage. Furthermore, the power amplifier PA can provide the generated RF output signal RF_OUT to the duplexer 400. According to an embodiment, the power supply voltage output from the power modulator can be any of a plurality of discrete levels, but is not limited thereto.

[0036] The receiving circuit 220 may include a second baseband filter 223, a second mixer 222, and a second amplifier 221. The second amplifier 221 may be, for example, a low-noise amplifier including a low-pass filter. The second amplifier 221 may amplify the RF received signal RF_R provided from the duplexer 400 and provide it to the second mixer 222. Additionally, the second mixer 222 may perform down-conversion of the RF received signal RF_R from the high-frequency band to the baseband using a frequency signal provided by the local oscillator LO. Through this down-conversion, the RF received signal RF_R may be provided as a received signal RX to the second baseband filter 223, and the second baseband filter 223 may filter the received signal RX and provide it to the communication processor 100.

[0037] For reference, the wireless communication device 10 may use carrier aggregation (CA) to transmit and receive signals over multiple frequency bands. Furthermore, the wireless communication device 10 may include multiple power amplifiers for amplifying the power of multiple RF input signals, each corresponding to a multiple carrier. However, in this embodiment, for ease of description, a single power amplifier 500 will be used as an example, but the device is not limited thereto.

[0038] When a fixed-level supply voltage is applied to the power amplifier 500, the power efficiency of the power amplifier 500 may decrease. According to an embodiment, the power modulator 300 can generate a modulated output voltage whose level changes dynamically based on the digital envelope signal D_ENV, and can provide the modulated output voltage as a supply voltage to the power amplifier 500. Therefore, for effective power management of the power amplifier 500, the power modulator 300 can modulate the input voltage based on the digital envelope signal D_ENV, and can provide the modulated voltage as a supply voltage to the power amplifier 500.

[0039] According to an embodiment, when transitioning the power supply voltage level from a first voltage level to a second voltage level, the power supply modulator 300 can attenuate noise at that specific frequency by outputting a third voltage level that differs from the first and second voltage levels during a time period in which the specific frequency is attenuated. On the other hand, in the power supply modulator according to a comparative embodiment, noise may be generated during the transition of the power supply voltage level from a first voltage level having discrete levels to a second voltage level, and signal loss may occur even in frequency bands outside the specific frequency during the attenuation of noise through a low-pass filter. A further detailed description of the power supply modulator 300 can be described below.

[0040] The duplexer 400 can be connected to the antenna ANT to separate the transmit frequency and the receive frequency. More specifically, the duplexer 400 can separate the RF output signal RF_OUT provided from the power amplifier 500 for each frequency band and provide the RF output signal RF_OUT to the corresponding antenna ANT. Furthermore, the duplexer 400 can provide the external signal RF_R received from the antenna ANT to the second amplifier 221 of the receiver circuit 220 of the RFIC 200. For example, the duplexer 400 may include a front-end module with an integrated duplexer (FEMiD).

[0041] In an alternative embodiment, the wireless communication device 10 may be equipped with a switching structure capable of separating a transmit frequency such as RF_OUT and a receive frequency such as RF_R, instead of the duplexer 400. Furthermore, the wireless communication device 10 may be provided with a structure consisting of the duplexer 400 and a switch to separate the transmit and receive frequencies. However, for ease of illustration, in this embodiment, as a non-limiting example, the wireless communication device 10 is provided with a duplexer 400 capable of separating the transmit and receive frequencies.

[0042] The antenna ANT can transmit an RF output signal RF_OUT, which is divided by the duplexer 400, to the outside, or it can provide the RF received signal RF_R received from the outside to the duplexer 400. The antenna ANT can include, but is not limited to, an array antenna.

[0043] The communication processor 100, power modulator 300, RFIC 200, duplexer 400, and power amplifier 500 can be individually implemented as ICs, chips, or modules. Furthermore, the communication processor 100, power modulator 300, RFIC 200, power amplifier 500, and duplexer 400 can be mounted together on a printed circuit board (PCB). However, this disclosure is not limited thereto, and in some embodiments, at least some of the communication processor 100, power modulator 300, RFIC 200, duplexer 400, and power amplifier 500 can be implemented as a single communication chip.

[0044] also, Figure 1 The illustrated wireless communication device 10 can be included in a wireless communication system using a cellular network (such as 5G, LTE, LTE-Advanced, etc.), or it can be included in a wireless local area network (WLAN) system or any other wireless communication system. Although Figure 1 The configuration of the wireless communication device 10 shown is provided as an illustrative embodiment, but this disclosure is not limited thereto, and the wireless communication device 10 may be configured differently according to communication protocols and / or communication methods.

[0045] Figure 2 The illustration shows a power modulator (SM) according to an embodiment. The power modulator can be used as... Figure 1 Power modulators in communication equipment, but not limited to these.

[0046] refer to Figure 2 According to the embodiment, the power modulator 300a may include a multilevel voltage generator 310, a switch array 320, a switch (SW) controller 330, a discrete level (DL) controller 340, and a filter circuit 350.

[0047] The multilevel voltage generator 310 can be controlled by a main controller to output multiple voltage levels V1 to VN, where N is a natural number of 2 or greater. For example, the multilevel voltage generator 310 can increase or decrease the input voltage (e.g., the power supply voltage in VIN supplied from a battery) based on multiple reference output voltage signals to generate and output multiple voltage levels V1 to VN. See also... Figure 3 The method of outputting multiple voltages by the multilevel voltage generator 310 is described in more detail.

[0048] Multiple reference output voltage signals can be provided from the envelope tracking processor 110. The communication processor 100 can calculate the reference output voltage value based on the output power of the power amplifier 500, generate multiple reference output voltage signals based on the calculated reference output voltage value, and provide the multiple reference output voltage signals to the multilevel voltage generator 310.

[0049] Furthermore, the connection between the multilevel voltage generator 310 and the power amplifier 500 can be selectively opened and closed by the switch array 320. In other words, any one of the multiple different voltage levels V1 to VN generated and output by the multilevel voltage generator 310 (e.g., V1 to VN generated and output in a time-division manner) can be selected by the opening / closing operation of the switch array 320, and the selected voltage can be supplied to the power amplifier 500.

[0050] Furthermore, the output of the multilevel voltage generator 310 may include multiple capacitors C1 to CN (N being a natural number of 2 or greater) corresponding to multiple different voltage levels V1 to VN, and the connection between the multiple capacitors C1 to CN and the power amplifier 500 can be individually opened and closed by multiple switches S1 to SN (where N is a natural number of 2 or greater) in the switch array 320. However, the multiple capacitors C1 to CN may be provided outside the multilevel voltage generator 310 rather than inside, without limitation. For ease of illustration, in this embodiment, it will be described as an example where the multiple capacitors C1 to CN are included in the multilevel voltage generator 310.

[0051] The switch array 320 may include multiple switches S1 to SN (where N is a natural number of 2 or greater) corresponding to multiple different voltage levels V1 to VN output from the multi-level voltage generator 310. Furthermore, the opening / closing operations of the multiple switches S1 to SN in the switch array 320 can be controlled by a switch control signal SW provided from the switch controller 330. Therefore, the switch array 320 can select one of the multiple different voltage levels V1 to VN based on the switch control signal SW and provide it to the power amplifier 500.

[0052] According to an embodiment, each switch in the switch array 320 is connected to a respective output terminal for outputting multiple voltages from the multilevel voltage generator 310, and the activation of any one of the multiple switches can be determined based on the switch control signal SW of the switch controller 330. For example, when a switch control signal SW is received to activate switch S3 in the third column of the switch array 320, a third-level voltage V3 can be output.

[0053] The discrete level (DL) controller 340 can be controlled by the envelope tracking processor 110, and the discrete level controller 340 can generate a level control signal ENV_LV including envelope level information based on a digital envelope signal D_ENV provided from an external source. More specifically, the discrete level controller 340 can receive the digital envelope signal D_ENV from the communication processor 100, and can generate and output a level control signal ENV_LV that includes a portion of the envelope level information based on the received digital envelope signal D_ENV. Furthermore, the output level control signal ENV_LV can be provided to the switch controller 330.

[0054] The switch controller 330 can receive a level control signal ENV_LV from the discrete level controller 340 and control the opening / closing operations of multiple switches S1 to SN based on the received level control signal ENV_LV. Therefore, the switch controller 330 can generate a switch control signal SW for controlling the opening / closing operations of the switch array 320 and provide the generated switch control signal SW to the switch array 320. Furthermore, the switch controller 330 can be controlled by an envelope tracking processor 110, etc.

[0055] The filter circuit 350 can eliminate noise by filtering the power supply voltage ET output from the multi-level voltage generator 310. For example, the filter circuit 350 may include a low-pass filter formed by a combination of inductors and capacitors. The filter circuit 350 can provide the power amplifier 500 with a low-frequency power supply voltage LP_ET from which high-frequency noise of the power supply voltage has been eliminated.

[0056] In addition to the above configuration, the power modulator 300a according to the embodiment may also include an additional capacitor, an oscillator, a bandgap reference circuit, etc.

[0057] More specifically, an additional capacitor can be connected near the output of the power modulator 300a and can eliminate parasitic capacitance and high-frequency noise that may be present in the circuitry of the power modulator 300a. An oscillator can be included in a circuit using an NMOS structure (e.g., a gate-boosted NMOS structure) to adjust the characteristics of switches S1 to SN. A bandgap reference circuit is a circuit that can supply a reference voltage or reference current during each component's operation and can be substantially unaffected by process, voltage, and temperature changes.

[0058] Thus, the power modulator 300a can have the above-described configuration and characteristics. Furthermore, based on the above configuration and characteristics, the power modulator 300a can provide any of a plurality of power supply voltage levels to the power amplifier 500 via the tracking envelope.

[0059] The power modulator according to the comparative embodiment can generate any one of multiple power supply voltage levels and can supply discrete power supply voltages, similar to a continuous envelope, to the power amplifier depending on whether a switch corresponding to each level is open or closed. In this case, a power modulator that outputs one of the multiple power supply voltage levels may cause the output voltage to switch rapidly and thus output high levels of noise. Since this noise characteristic may degrade the performance of frequency division duplex (FDD) communication systems, the power modulator can generate a noise-cancelled power supply voltage. According to the comparative embodiment, the power modulator can use a passive filter with high attenuation characteristics to cancel noise, and when noise is canceled by such a passive filter, large power losses may occur in the power supply voltage.

[0060] In contrast, according to an embodiment, the power modulator 300a can output a power supply voltage of at least a third level that differs from the first and second levels during at least a delay period before the power supply voltage transitions from a first level to a second level. Therefore, the power modulator 300a of this disclosure can generate a power supply voltage with low noise characteristics without significant power loss.

[0061] Figure 3 A multilevel voltage generator according to an embodiment is illustrated. The multilevel voltage generator can be used as... Figure 1 and Figure 2 Multilevel voltage generators in communication equipment, but not limited to this.

[0062] The multilevel voltage generator 310 may include, for example, a single inductor multiple output (SIMO) DC-DC converter or a SIMO buck-boost converter.

[0063] More in detail, Figure 3 The multilevel voltage generator 310 can have a structure in which the output current of the switching regulator (SR) in the SIMO DC-DC converter or SIMO buck-boost converter is supplied to each output in a time-division manner through a single inductor L'.

[0064] SIMO controller 312 can monitor the difference between each of the output voltages V1 to VN and each of the corresponding reference output voltage signals VREF1 to VREFN, and can determine, based on the monitoring results, which of the switches S1M, S2M, ..., SNM should be turned on to connect the inductor L' to each of the output voltages V1 to VN. SIMO controller 312 can determine the switch input SW_SIMO of SR connected to the side of inductor L' based on information about the difference between each of the output voltages V1 to VN and each of the corresponding reference output voltage signals VREF1 to VREFN.

[0065] according to Figure 3 The multilevel voltage generator 310 of one embodiment uses an inductor to generate multiple output voltages, but is not limited thereto. The multilevel voltage generator 310 may include multiple embodiments for outputting multiple levels of power supply voltage to multiple output terminals by reducing or increasing the input voltage.

[0066] Figure 4 The illustration shows an example of generating discrete multilevel output voltages based on envelope tracking results.

[0067] refer to Figure 4 The power modulator 300a of this disclosure can output a power supply voltage of any one of a plurality of discrete levels based on the voltage level of the envelope. The communication processor 100 can track the envelope RF_OUT_ENV of the transmitted signal RF_OUT, and the power modulator 300a can determine the level of the power supply voltage supplied to the power amplifier 500 based on the voltage level of the tracked envelope RF_OUT_ENV.

[0068] According to a comparative embodiment, the analog power modulator can output a continuous power supply voltage ET based on the voltage level of the envelope RF_OUT_ENV. The analog power modulator combines a linear amplifier and a switching amplifier in parallel to achieve good linearity. For analog power modulators with this structure, significantly improving efficiency may be impractical due to structural limitations, and / or acceleration may be impractical due to process limitations.

[0069] On the other hand, compared to the analog power modulator of the comparative embodiment, the power modulator 300a of this disclosure can output discrete-level power supply voltages ET, and can output multiple levels of power supply voltages ET with a simple structure. Noise voltage may be generated due to the sudden voltage change during the transition of the power supply voltage ET from a first level to a second level.

[0070] According to an embodiment, when a transmitted signal and / or received signal are amplified in power amplifier 500, interference may occur in the transmitted signal and / or received signal due to noise in the power supply voltage ET. To mitigate this interference, noise at a specific frequency corresponding to the frequency of the transmitted signal and / or received signal can be attenuated. For example, when the frequency of the transmitted signal and / or received signal is 30MHz, power supply modulator 300a can output a third-level power supply voltage during a delay period corresponding to 30MHz to eliminate 30MHz noise. An embodiment of power supply modulator 300a eliminating noise at a specific frequency based on a voltage level difference will be described below.

[0071] Figure 5 The illustration shows an example of a power modulator 300a generating a level-difference transition voltage, and... Figure 6A and Figure 6B An example is illustrated in which the power modulator 300a according to an embodiment generates a transition voltage with essentially one level difference.

[0072] refer to Figure 5 The difference between the first level of the power supply voltage before the transition and the second level of the power supply voltage after the transition is one level, and the power supply modulator according to the comparative embodiment can discontinuously increase or decrease the power supply voltage from the first level to the second level. In this case, the power supply modulator according to the comparative example generates a noise signal with a large voltage level by rapidly increasing or decreasing the power supply voltage. The power supply voltage levels, which will be further described below, may include discretely divided levels.

[0073] According to an embodiment, the power modulator 300a can provide a power voltage to the power amplifier 500 that amplifies the transmitted / received signal, thereby attenuating noise signals of a specific frequency. The power modulator 300a can eliminate noise signals of a specific frequency by generating a third level power voltage that is distinct from the first and second levels over a certain period of time.

[0074] refer to Figure 6A From the first level V K The power supply voltage is increased to the second level V. K+1 Before the power supply voltage, the power modulator 300a can output the third level V for a certain period of time. K-1 The power supply voltage. According to the embodiment, the power modulator 300a can operate at the third output level V. K-1 The difference between the power supply voltage delay time and the output first level V during the delay time period. K Or the second level V K+1 The power supply voltage.

[0075] according to Figure 6AWhen the first level V K Second level V K+1 When the difference between them is one level, the power supply modulator 300a can output the third level V. K-1 The power supply voltage reaches a certain level before or after a certain period of time, at which time the second level V is output. K+1 The power supply voltage. That is, when the power supply voltage is changed from the first level V... K Increase to the second level V K+1 At that time, the power modulator 300a can output the second level V during the first delay time period T1. K+1 The power supply voltage, and can output the third level V during the second delay time period T2. K-1 The power supply voltage. After the second delay period T2, the voltage of the power modulator 300a is output through the second level V. K+1 By adding a level, a power supply voltage can be output where noise at a specific frequency is attenuated due to the delay time period. The power supply modulator 300a disclosed herein can output a third level V for each specific frequency during different delay time periods. K-1 The power supply voltage is used to attenuate noise at a specific frequency, but is not limited to this.

[0076] according to Figure 6A When the power supply voltage is changed from the second level V K+1 Reduce to the first level V K At that time, the power modulator 300a can output the third level V during the third delay time period T3. K-1 The power supply voltage, and can output the second level V during the fourth delay time period T4. K+1 The power supply voltage. After the fourth delay period T4, the voltage of the power modulator 300a is output through the first level V. K It can reduce the voltage by one level and output a power supply voltage in which noise at a specific frequency is attenuated due to the delay time period, but is not limited to this.

[0077] according to Figure 6B In one embodiment, the power modulator 300a can be coupled with... Figure 6A Different methods are used to increase or decrease the power supply voltage from the first level to the second level. Repeated descriptions can be omitted.

[0078] according to Figure 6B When the first level V K Second level V K+1 When the difference between them is one level, the power supply modulator 300a can output the third level V. K+2 The power supply voltage reaches the first level V before or after a certain period of time. K The power supply voltage. That is, when the power supply voltage is changed from the first level V...K Increase to the second level V K+1 At that time, the power modulator 300a can output the third level V during the first delay time period T1. K+2 The power supply voltage, and can output the first level V during the second delay time period T2. K The power supply voltage. After the second delay period T2, the voltage of the power modulator 300a is output through the second level V. K+1 By adding a level, a power supply voltage can be output where noise at a specific frequency is attenuated due to the delay time period. The power supply modulator 300a disclosed herein can output a third level V for each specific frequency during different delay time periods. K+2 The power supply voltage is adjusted to attenuate noise at specific frequencies.

[0079] according to Figure 6B When the power supply voltage is changed from the second level V K+1 Reduce to the first level V K At that time, the power modulator 300a can output the first level V during the third delay time period T3. K The power supply voltage, and can output the third level V during the fourth delay time period T4. K+2 The power supply voltage. After the fourth delay period T4, the voltage of the power modulator 300a is output through the first level V. K It can reduce the voltage by one level and output a power supply voltage in which noise at a specific frequency is attenuated due to the delay time period, but is not limited to this.

[0080] Figure 6A The diagram illustrates the third level V of the power supply voltage output by the power modulator 300a. K-1 Less than the first level V K Second level V K+1 In this situation, Figure 6B The third level V is shown K+2 Greater than the first level V K Second level V K+1 The situation where the power modulator 300a can operate at a voltage lower than the first level V. K Second level V K+1 When the power supply voltage is output at a certain level, the power modulator 300a of this disclosure can be adjusted according to the specified level. Figure 6A Output power supply voltage, and when the power modulator 300a can output a voltage greater than the first level V. K Second level V K+1 When the power supply voltage is output at a certain level, it can be based on... Figure 6B Output power supply voltage, but not limited to this.

[0081] Figure 7The illustration shows the Z-transform transfer function according to an embodiment, wherein noise components at a specific frequency are attenuated by the power supply voltage output by the power supply modulator 300a during the delay time period.

[0082] When a third-level power supply voltage is output during at least one delay period, the power supply voltage output from the power modulator 300a can be output after attenuating a specific frequency through a finite impulse response (FIR) filter. The transfer function of the FIR filter used to filter the power supply voltage can be shown in Equation 1 below.

[0083] [Equation 1]

[0084] H(z) = K1 + K2 * Z -m1 +K3*Z -m1-m2

[0085] Here, K l K2 and K3 (where K l K1, K2, and K3 (where K1, K2, and K3 are real numbers) can correspond to the level difference of the switching power supply voltage, and ml and m2 (where ml and m2 are natural numbers) as exponents of the Z term can correspond to the length of the delay time period. For example, when there are multiple delay time periods, the ratio between the delay time periods can be the ratio of m1 and m2 (where m1 and m2 can each be the exponent of a constant term).

[0086] Furthermore, m1 and m2 can correspond to the number of delayed time periods activated during the transition from the first level to the second level. When a delayed time period exists, the transfer function of the FIR filter can be shown in Equation 2 below.

[0087] [Equation 2]

[0088] H(z) = K1 + K2 * Z -m1

[0089] For example, refer to Figure 6A When transitioning from the first level to the second level, the power modulator 300a can achieve the following during the first delay time T: l During this period, a second-level power supply voltage is output, and a third-level power supply voltage can be output during the second delay time period T2. Therefore, according to Figure 6A The power modulator 300a has filtering characteristics according to Equation 1. In the transfer function of Equation 1, the constant term represents the transition from the first level to the first delay time T. l The characteristics at the second level, Z -m1 The term represents the characteristic when transitioning from the second level of the first delay time period T1 to the third level of the second delay time period T2, and Z -m1-m2The term represents the characteristic when transitioning from the third level to the second level during the second delay time period T2.

[0090] refer to Figure 6A The first delay time period T l The length of the second delay time period T2 can be twice the length of the second delay time period T2. Therefore, the difference between the exponents 0 and ml, which are constant terms, can be twice the difference between m1 and m2. For example, when m1 is 2, m2 can be 1. K1, K2, and K3 can correspond to the difference in voltage levels before the transition. For example, K1 can be 1 because it is the difference between the second level and the first level, K2 is -2 because it is the difference between the third level and the second level, and K3 can be 2 because it is the difference between the second level and the third level. Therefore, according to Figure 6A The transfer function can be as shown in Equation 3 below.

[0091] [Equation 3]

[0092] H(z) = 1 - 2*Z -2 +2*Z -3

[0093] Similarly, having Figure 6B The transfer function of the power modulator 300a during the delay period can be shown in Equation 4 below.

[0094] [Equation 4]

[0095] H(z) = 2 - 2*Z -1 +1*Z -3

[0096] In this case, the length of the delay period can vary depending on the frequency to be attenuated, which will refer to... Figure 11 Describe it.

[0097] Figure 8 An example is illustrated in which the power modulator 300a according to an embodiment generates a switching voltage with a difference between two levels.

[0098] refer to Figure 8 When the difference between the first level of the power supply voltage before the conversion and the second level of the power supply voltage after the conversion is 2 levels, the power modulator 300a can output a voltage equal to the first level V. K Second level V K+2 The third level V of the difference K+1 The power supply voltage reaches a certain level for a certain period of time. According to an embodiment, the power modulator 300a can modulate the first level V... K Second level V K+2 The intermediate level between them is set to the third level V. K+1To output the power supply voltage. Compared to the case where a level different from the intermediate level is set to the third level, when the first level V is used... K Second level V K+2 The intermediate level between them is used as the third level V. K+1 When outputting the power supply voltage, charging and discharging losses caused by the capacitors connected to the corresponding switches in the switch array can be minimized.

[0099] According to an embodiment, the power modulator 300a can output a third level V during the delay period. K+1 The power supply voltage provides the power amplifier 500, which amplifies the transmitting and / or receiving signals, with the noise signal attenuated from its frequency. (Reference) Figure 8 When the power supply voltage is changed from the first level V K Increase to the second level V K+2 At that time, the power supply modulator 300a can output as the first level V during a first delay time T1 before outputting the second level power supply voltage. K Second level V K+2 The third level V between the intermediate levels K+1 The power supply voltage. Therefore, the power supply modulator 300a can output a power supply voltage that is delayed by a certain time period, and the delayed power supply voltage can be obtained through... Figure 7 The FIR filter is used to filter specific frequency components of the power supply voltage to obtain the power supply voltage.

[0100] refer to Figure 7 The power modulator 300a modulates the power supply voltage from the first level V. K Increase or decrease to the second level V K+2 The process can have a delay period. Therefore, the output Figure 8 The power supply modulator 300a, which supplies the power supply voltage, can have filtering characteristics according to the transfer function in Equation 2. For example, according to... Figure 8 The transfer function can be as shown in Equation 5 below.

[0101] [Equation 5]

[0102] H(z) = 1 / 2 + 1 / 2 * Z -1

[0103] The power modulator 300a with the filtering characteristics of Equation 5 can attenuate a frequency component during the process of switching the power supply voltage through the difference between two levels, and the delay time can be adjusted according to the frequency to be attenuated.

[0104] Figure 9 An example of a power modulator 300a according to an embodiment generating a three-level differential switching voltage is illustrated.

[0105] refer to Figure 9 When the first level V of the power supply voltage before the transition K-1 and the second level V of the transformed power supply voltage K+2 When the difference between them is three levels, the power modulator 300a can output the same level as the first level V. K-1 Second level V K+2 The third level of the power supply voltage is differentiated for a certain period of time. According to an embodiment, the power modulator 300a can modulate the first level V... K-1 Second level V K+2 Multiple intermediate levels are set as the third level V. K and V K+1 To output the power supply voltage. When multiple intermediate levels are used as the third level V K and V K+1 When outputting, there may be multiple delay periods.

[0106] According to an embodiment, the power modulator 300a can output multiple third levels V during multiple delay time periods. K and V K+1 The power supply voltage provides the power amplifier 500, which amplifies the transmitting and / or receiving signals, with the noise signal attenuated from its frequency. (Reference) Figure 9 When the power supply voltage is changed from the first level V K-1 Increase to the second level V K+2 At that time, the power modulator 300a can output the second level V. K+2 The third level V is output during the first delay period T1 and the second delay period T2 before the power supply voltage. K and V K+1 The power supply voltage. Therefore, the power supply modulator 300a can output a power supply voltage delayed by a first delay time period T1 and a second delay time period T2, and the delayed power supply voltage can be obtained through... Figure 7 The FIR filter is used to filter specific frequency components of the power supply voltage to obtain the power supply voltage.

[0107] refer to Figure 7 The power modulator 300a modulates the power supply voltage from the first level V. K-1 Increase or decrease to the second level V K+2 The process can have two delay periods. Therefore, the output Figure 9 The power supply modulator 300a, which supplies power to the specified voltage, can have filtering characteristics according to the transfer function in Equation 1. For example, according to... Figure 9 The transfer function can be as shown in Equation 6 below.

[0108] [Equation 6]

[0109] H(z) = 1 / 3 + 1 / 3 * Z -1 +1 / 3*Z -2

[0110] The power modulator 300a with the filtering characteristics of Equation 6 can attenuate the frequency component corresponding to the frequency to be attenuated during the process of switching the power supply voltage through three levels, and the delay time can be adjusted according to the frequency to be attenuated.

[0111] Figures 10A to 10D The diagram illustrates the frequency characteristics of the power supply voltage output by the power supply modulator 300a according to the present disclosure.

[0112] More in detail, Figure 10A It could be a graph showing the frequency response of the power supply voltage when the power supply modulator 300a outputs the power supply voltage according to the third level of Figure 6 and transitions the power supply voltage through a level change. Figure 10B This can be shown when the power modulator 300a outputs according to... Figure 8 The third level of the power supply voltage and the frequency characteristic curve of the power supply voltage when the power supply voltage is changed through an even number of levels including two levels. Figure 10C and Figure 10D It could be a graph showing the frequency characteristics of the power supply voltage when the power supply voltage is switched by 3 levels and 5 levels respectively.

[0113] The power modulator 300a disclosed herein may have FIR filter characteristics, wherein a specific frequency output is attenuated by outputting a third-level power supply voltage during at least one delay time period. The filtering characteristics performed by the power modulator 300a can be determined by the number and length of the delay time periods, the difference between the first and third levels, and transfer functions such as Equations 1 to 6. In this case, the frequency at which the absolute value of the transfer function is minimized can be the frequency to be attenuated.

[0114] Figure 11 The illustration shows the time delay period of the power supply voltage at the third level output by the power modulator 300a according to an embodiment.

[0115] refer to Figure 11 The power modulator 300a can output a third-level power supply voltage during different delay periods according to the frequency to be attenuated. The delay period can be the same as the frequency f to be attenuated. NT It is inversely proportional, and the frequency f to be attenuated can be determined based on the difference between the first and second levels. NT According to the embodiment, the frequency f to be attenuated NT It can be the frequency at the point where the absolute value of the transfer function is minimum.

[0116] The power modulator 300a disclosed herein can output a third-level power supply voltage during a delay period inversely proportional to the frequency to be attenuated. For example, when the difference (Δlevel) between the first and second levels is two levels and the frequency to be attenuated is approximately 30 MHz, the delay period can be approximately 16.67 ns. In this case, when the frequency to be attenuated is changed to approximately 45 MHz, the delay period can be changed to approximately 11.11 ns.

[0117] Figure 12 The illustration shows the frequency characteristics of each band used to determine the frequency to be attenuated by the power modulator 300a of this disclosure.

[0118] Wireless communication devices, including the power modulator 300a, can determine the frequency to be attenuated based on the frequency band to be transmitted / received. (Reference) Figure 12 The frequency to be attenuated in this disclosure can correspond to the duplex interval frequency. The duplex interval frequency can be the difference between the uplink frequency and the downlink frequency. More specifically, the duplex interval frequency can be the difference between the minimum value of the uplink frequency band and the minimum value of the downlink frequency band, or the difference between the maximum value of the uplink frequency band and the maximum value of the downlink frequency band.

[0119] refer to Figure 12 When a wireless communication device transmits and receives signals through a channel corresponding to the fifth band index (Band IDX), the frequency to be attenuated can be set to approximately 45MHz. The channel corresponding to each band index can be referred to as a communication channel allocated to a pre-defined frequency band in the communication protocol. (Reference) Figure 11 When the power modulator 300a transitions the power supply voltage from a first level to a second level differing by one level, the first delay time T1 can be approximately 2.07 ns, and the second delay time T2 can be approximately 4.14 ns. The memory of the wireless communication device can store... Figure 11 and Figure 12 The table is provided, but the wireless communication device disclosed herein is not limited thereto. The corresponding data is stored in memory. Figure 12 The indexed duplex interval frequencies can be calculated by the processor of the wireless communication device based on the delay time period for each duplex interval frequency.

[0120] Figure 13 The illustration shows an example of the power modulator 300b of this disclosure supplying power supply voltage to multiple power amplifiers, and Figure 14 The diagram illustrates the following: Figure 13 Examples of multiple power supply voltages.

[0121] refer to Figure 13A multilevel voltage generator 310 can generate multiple levels of power supply voltages ET1 and ET2, and a power modulator 300b can supply power voltages to different power amplifiers PA1 and PA2 through multiple switch arrays 320a and 320b. More specifically, in Figure 13 In the case of the power modulator 300b, power supply voltages ET1 and ET2 can be supplied to multiple power amplifiers respectively (in Figure 1 In the case of multiple power amplifiers (e.g., a first power amplifier and a second power amplifier).

[0122] Therefore, in Figure 13 In the case of power modulator 300b, the number of switch arrays 320a, 320b, switch controllers 330a, 330b, discrete level controllers 340a, 340b, and filter circuits 350a, 350b can be greater than that of the power modulator 300b. Figure 2 The number of power modulators 300a is greater than that of the power modulator 300b. Furthermore, in the power modulator 300b, the output capacitors C1 to CN connected to the multilevel voltage generator 310 are respectively connected to both sides of the first power amplifier PA1 and the second power amplifier PA2. Therefore, the output capacitors C1 to CN of the multilevel voltage generator 310 can be shared in the generation operation of each of the first power supply voltage ET1 and the second power supply voltage ET2. Thus, the communication processor 100 can jointly generate a reference output voltage signal for each of the first power supply voltage ET1 and the second power supply voltage ET2, and provide this reference output voltage signal to the multilevel voltage generator 310.

[0123] Thus, in this embodiment, even when generating power supply voltages ET1 and ET2 for multiple power amplifiers, the number of output capacitors, which occupy a large proportion of the circuit area, is the same as when generating power supply voltage for a single power amplifier. Therefore, the increase in circuit area can be minimized.

[0124] refer to Figure 13 and Figure 14 The first discrete-level controller 340a and the second discrete-level controller 340b can receive different digital envelope signals through the envelope tracking processor 110 to provide different level control signals ENV_LV1 and ENV_LV2 to the switch controllers 330a and 330b, respectively. The first switch controller 330a and the second switch controller 330b can generate a first switch control signal SW1 and a second switch control signal SW2, respectively, for controlling the opening / closing operations of the first switch array 320a and the second switch array 320b. Therefore, the first switch array 320a and the second switch array 320b can provide multi-level power supply voltages with different waveforms to the first power amplifier PA1 and the second power amplifier PA2.

[0125] Figure 15 The illustration shows a wireless communication device 2000 that includes a power modulator of the present disclosure.

[0126] refer to Figure 15 The wireless communication device 2000 may include an application processor (hereinafter referred to as AP) 2100, a memory 2200, a display 2300, and an RF module 2410. In addition, the wireless communication device 2000 may also include various components such as a lens, a sensor, and an audio module.

[0127] AP 2100 can be implemented as a System-on-Chip (SoC) and may include a Central Processing Unit (CPU) 2110, Random Access Memory (RAM) 2120, Power Management Unit (PMU) 2130, Memory Interface (I / F) 2140, Display Controller (DCON) 2150, Communication Processor 2160, and System Bus 2170. AP 2100 may also include various intellectual property (IP). AP 2100 may be referred to as ModAP because it integrates the functionality of the communication processor chip.

[0128] The CPU 2110 can control the operation of the AP 2100 and the wireless communication device 2000. The CPU 2110 can control the operation of each component of the AP 2100. Furthermore, the CPU 2110 can be implemented as a multi-core processor. A multi-core processor is a computing component with two or more independent cores.

[0129] RAM 2120 can temporarily store programs, data, or instructions. For example, programs and / or data stored in memory 2200 can be temporarily stored in RAM 2120 under the control of CPU 2110 or boot code. RAM 2120 can be implemented as dynamic random access memory (DRAM) or static RAM (SRAM).

[0130] The PMU 2130 can manage the power of each component of the AP 2100. The PMU 2130 can also determine the operating status of each component of the AP 2100 and control the operation of that component.

[0131] The memory I / F 2140 can control the operation of the memory 2200 and can control the data exchange between each component of the AP 2100 and the memory 2200. The memory I / F 2140 can write data to or read data from the memory 2200 upon request from the CPU 2110.

[0132] The DCON 2150 can send image data to the display 2300 to be displayed on the display 2300. The display 2300 can be implemented as a flat panel display, such as a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, or a flexible display.

[0133] For wireless communication, the communication processor 2160 can appropriately modulate the data to be transmitted and recover the received data according to the wireless environment. The communication processor 2160 can perform digital communication with the RF module 2410.

[0134] For reference, see above. Figure 1 The described communication processor 100 can be implemented in the communication processor 2160.

[0135] RF module 2410 can convert high-frequency signals received through the antenna into low-frequency signals and send the low-frequency signals to communication processor 2160. Additionally, RF module 2410 can convert low-frequency signals received from communication processor 2160 into high-frequency signals and send the high-frequency signals to the outside of wireless communication device 2000 through the antenna. Furthermore, RF module 2410 can amplify or filter signals.

[0136] For reference, the above-mentioned implementation can be achieved in RF module 2410. Figure 1 The RFIC 200, power modulator 300, duplexer 400, power amplifier 500, and antenna ANT are described. Therefore, the above references... Figures 4 to 15 The described power modulator can also be implemented in RF module 2410.

[0137] For example, in wireless communication device 2000, while supporting broadband communication, the power consumption of communication can be reduced.

[0138] Although the present disclosure has been specifically shown and described by way of example with reference to embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure as set forth in the appended claims.

Claims

1. A power modulator comprising: a multi-level voltage generator configured to generate a plurality of power voltages having different voltage levels; a switch array including a plurality of switches respectively corresponding to the plurality of power voltages, each switch being switchably connected to an output terminal; and a switch controller configured to receive a level control signal indicating a switch of a connection to the output terminal from a first switch to a second switch, and to connect at least one third switch to the output terminal during a time period corresponding to a frequency to be attenuated between a disconnection of the first switch and a connection of the second switch. The frequency to be attenuated corresponds to a frequency of a transmission / reception signal of a power amplifier to which the power voltage is supplied.

2. The power modulator of claim 1, wherein, When the frequency to be attenuated is changed, the switch controller activates the connection of the at least one of the third switches for a time period which is inversely proportional to the changed frequency to be attenuated.

3. The power modulator of claim 1, wherein, The switch controller activates the connection of the at least one of the third switches during different time periods according to a difference between a voltage corresponding to a first level of the first switch and a voltage corresponding to a second level of the second switch.

4. The power modulator of claim 1, wherein, When the difference between the first level and the second level is an odd level, the switch controller sequentially activates connections of a plurality of third switches corresponding to a plurality of voltage levels between the first level and the second level.

5. The power modulator of claim 4, wherein, When the difference between the first level and the second level is an even level, the switch controller activates a connection of a third switch corresponding to an intermediate level between the first level and the second level.

6. The power modulator of claim 4, wherein, 7.The power modulator of claim 1, further comprising: a filter circuit configured to remove noise of the power voltage output from the switch array. The filter circuit is activated when a frequency division duplex (FDD) operation is performed, and is deactivated when a time division duplex (TDD) operation is performed.

8. The power modulator of claim 7, wherein, 9.A wireless communication device comprising: a power modulator configured to output one of a plurality of power voltages having different voltage levels, and when the power voltage is changed from a first voltage level to a second voltage level, to output a power voltage of at least one third voltage level which is distinguished from the first voltage level and the second voltage level during a time period corresponding to a frequency to be attenuated between the change from the first voltage level to the second voltage level; and a communication processor configured to control the power modulator and to determine at least one of the frequency to be attenuated and the time period. The communication processor determines the time period according to the frequency to be attenuated, the frequency to be attenuated corresponding to a frequency of a transmission / reception signal of a power amplifier to which the power voltage is supplied.

10. The wireless communication device of claim 9, wherein, The power modulator further includes a switch array including a plurality of switches corresponding to each voltage level, and outputs any one of the plurality of power voltages by activating a connection of any one of the plurality of switches.

11. The wireless communication device of claim 9, wherein, ​ 12. The wireless communication device of claim 11, wherein, The power supply modulator outputs the third voltage level of power supply voltage during a time period inversely proportional to the changed frequency to be attenuated when the frequency to be attenuated is changed.

13. The wireless communication device of claim 11, wherein, The power supply modulator outputs the third voltage level of power supply voltage during different time periods according to a difference between the first voltage level and the second voltage level.

14. The wireless communication device of claim 13, wherein, The power supply modulator outputs a plurality of third voltage levels between the first voltage level and the second voltage level when the difference between the first voltage level and the second voltage level is an odd level.

15. The wireless communication device of claim 13, wherein, The power supply modulator outputs an intermediate level between the first voltage level and the second voltage level as the third voltage level when the difference between the first voltage level and the second voltage level is an even level.

16. An operating method of a wireless communication device for amplifying power of a communication signal based on a plurality of levels of power supply voltage, the operating method comprising: determining a transition delay time based on a frequency to be attenuated when the power supply voltage is transitioning from a first level to a second level among the plurality of levels; outputting a power supply voltage of at least one third level distinguished from the first level and the second level during the transition delay time between the transition from the first level to the second level; and amplifying power of a communication signal based on the output power supply voltage. Determining the transition delay time includes:

17. The method of operating of claim 16, wherein, determining the frequency to be attenuated corresponding to a frequency of a communication signal; and determining a time period inversely proportional to the frequency to be attenuated as the transition delay time. Determining the transition delay time includes:

18. The operating method of claim 16, wherein, determining the transition delay time based on a voltage difference between the first level and the second level. Outputting the third level of power supply voltage includes:

19. The operating method of claim 18, wherein, outputting a plurality of voltage levels between the first level and the second level as the third level of power supply voltage when the voltage difference between the first level and the second level is an odd level. Outputting the third level of power supply voltage includes:

20. The operating method of claim 18, wherein, outputting a voltage level corresponding to an intermediate level between the first level and the second level as the third level of power supply voltage when the voltage difference between the first level and the second level is an even level. ​

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