JP5458726B2 - Portable terminal, transmission circuit, and transmission power control method - Google Patents

Description

  The present invention relates to a mobile terminal, a transmission circuit, and a transmission power control method, and in particular, a mobile terminal, a transmission circuit, and transmission power that can control the maximum transmission power uniformly without depending on an antenna load. It relates to a control method.

  The base station, which is a component of the wireless communication system, controls power to output the minimum transmission power necessary for communication to the mobile phone in order to avoid interference with other mobile phones. Send a signal. When the mobile phone receives a power control signal from the base station, the mobile phone controls a power amplifier (power amplifier) of the transmission system circuit and outputs a desired transmission power.

  However, the load on the antenna changes depending on whether the user holds the mobile phone by hand or whether the user places the mobile phone on the desk. As a result, the load impedance of the transmission system circuit of the mobile phone fluctuates. Therefore, in order to keep the transmission power constant without depending on the load of the antenna of the mobile terminal, a line from the antenna to the output of the power amplifier (Power Amplifier) so that the reflected wave from the antenna does not enter the detection circuit It is necessary to ensure isolation. In order to ensure isolation, it is necessary to use an isolator on the line from the antenna to the output of the power amplifier, or to use a coupler having high directivity.

  In addition, the following technique is known as a technique for obtaining the transmission characteristics of the transmission circuit (see, for example, Patent Document 1). According to the technique proposed in Patent Document 1, a matching circuit is provided between the terminal terminal of the isolator provided in the subsequent stage of the power amplifier and the ground, and the transmission output power and current consumption values of the transmission circuit are displayed on a monitor by a personal computer. Then, by adjusting the circuit constants of the matching circuit so that the values of the transmission output power and current consumption displayed on the monitor become desired values, and adjusting the impedance viewed from the input terminal of the isolator to the subsequent circuit side, Match the output impedance of the power amplifier with the input impedance of the isolator. Thus, desired transmission characteristics can be obtained without increasing the power loss of the circuit in the transmission circuit.

JP 2005-303468 A

  However, in a state where the isolation of the isolator and the directivity of the coupler are low, the reflected wave component is added to the detection power due to the influence of the antenna load. As a result, the maximum transmission power changes according to changes in the antenna load.

  The present invention has been made in view of such a situation, and provides a mobile terminal, a transmission circuit, and a transmission power control method capable of controlling the maximum transmission power to be constant without depending on an antenna load. For the purpose.

  In order to solve the above-described problem, the portable terminal of the present invention includes a generation unit that generates a high-frequency signal, a power amplification unit that amplifies the power of the high-frequency signal generated by the generation unit to a predetermined transmission power level, An antenna that radiates a high-frequency signal after amplification, a first output terminal, a second output terminal, and a third output terminal. The high-frequency signal after power amplification is transmitted to the antenna through the first output terminal. A coupler that outputs a signal in a direction and branches a part of the high-frequency signal through the second output terminal and the third output terminal, and a first output from the coupler through the second output terminal. A detector for detecting the signal and the second signal output from the coupler via the third output terminal and converting the detected signal into a power value; a voltage value based on the first signal converted by the detector; The first converted by the detector The output voltage from the power amplifying unit is calculated based on the voltage value based on the signal, and the power of the high-frequency signal reaches a predetermined transmission power level based on the calculated output voltage from the power amplifying unit. And a control unit that controls the power amplification unit.

  In order to solve the above-described problem, the transmission circuit of the present invention includes a generation unit that generates a high-frequency signal, a power amplification unit that amplifies the power of the high-frequency signal generated by the generation unit to a predetermined transmission power level, In a transmission circuit of a portable terminal, comprising: an antenna that radiates an amplified high-frequency signal; and a control unit that controls the power amplification unit so that the power of the high-frequency signal reaches a predetermined transmission power level. 2 and a third output terminal, and outputs a high-frequency signal after power amplification to the direction of the antenna through the first output terminal, and branches a part of the high-frequency signal to the second A coupler that outputs via an output terminal and a third output terminal, a first signal that the coupler outputs via a second output terminal, and a second that the coupler outputs via a third output terminal Signal and Each by detecting, characterized in that it comprises a detection unit for converting the power value.

  In order to solve the above-described problem, the transmission power control method of the present invention generates a high-frequency signal, amplifies the power of the generated high-frequency signal to a predetermined transmission power level, and radiates the high-frequency signal after power amplification. And outputting the high-frequency signal after power amplification in the direction of the antenna, branching part of the high-frequency signal, and outputting the first signal and the second signal in the first direction and the second direction, respectively, The first signal and the second signal are each detected and converted into a power value. Based on the voltage value based on the converted first signal and the voltage value based on the second signal converted by the detection unit. Then, the output voltage after power amplification is calculated, and control is performed so that the power of the high-frequency signal reaches a predetermined transmission power level based on the calculated output voltage after power amplification.

  According to the present invention, the maximum transmission power can be controlled to be constant without depending on the antenna load.

(A) and (B) are external views showing the configuration of the external appearance of a mobile phone applicable as a mobile terminal according to the present invention. The block diagram which shows the internal structure of the mobile telephone applicable to the portable terminal which concerns on this invention. The figure which shows the detailed circuit structure of the transmission system circuit of a mobile telephone. The figure which shows the structure of a coupler. The figure which shows the structure of a 1st stripline and a 2nd stripline. The figure which shows the equivalent circuit of a coupler. 4 is a flowchart for explaining a maximum transmission power control process in the mobile phone of FIG. 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an external configuration of a mobile phone 1 applicable as a mobile terminal according to the present invention. 1A shows a configuration of an external appearance when the mobile phone 1 is opened at about 180 degrees, and FIG. 1B is a side view when the mobile phone 1 is opened. It shows the structure of the appearance.

  As shown in FIGS. 1A and 1B, the mobile phone 1 has a first casing 12 and a second casing 13 hinged to each other with a hinge 11 at the center as a boundary. 11 is formed so as to be foldable in the direction of arrow X. A transmitting / receiving antenna (antenna 31 in FIG. 2 to be described later) is provided at a predetermined position inside the mobile phone 1, and radio waves are transmitted to and from a base station (not shown) via the built-in antenna. Send and receive.

  The first casing 12 is provided with operation keys 14 such as numeric keys “0” to “9”, a calling key, a redial key, an end / power key, a clear key, and an e-mail key on the surface. Various instructions can be input using the operation keys 14.

  The first casing 12 is provided with a cross key and a confirmation key at the top as the operation keys 14, and the cursor is moved in the vertical and horizontal directions when the user operates the cross key in the vertical and horizontal directions. be able to. Specifically, various operations such as a phone book list and an e-mail scrolling operation displayed on the main display 17 provided in the second housing 13, a simple homepage page turning operation, and an image sending operation are performed. Run.

  Various functions can be confirmed by pressing the confirmation key. For example, in the first housing 12, a desired phone number is selected from a plurality of phone numbers in the phone book list displayed on the main display 17 in response to the operation of the cross key by the user, and the confirmation key is the first key. When pressed in the inner direction of the housing 12, the selected telephone number is confirmed and a calling process is performed on the telephone number.

  Further, the first casing 12 is provided with an e-mail key on the left side of the cross key and the confirmation key. When the e-mail key is pressed in the inner direction of the first casing 12, the mail You can call the send / receive function. A browser key is provided on the right side of the cross key and the confirmation key. When the browser key is pressed in the direction toward the inside of the first housing 12, it is possible to browse the data on the Web page.

  The first casing 12 is provided with a microphone 15 below the operation keys 14, and the microphone 15 collects the user's voice during a call. Further, the first casing 12 is provided with a side key 16 for operating the mobile phone 1. The first casing 12 has a battery pack (not shown) inserted on the back side. When the call end / power key is turned on, power is supplied from the battery pack to each circuit unit. Start in a possible state.

  On the other hand, the second housing 13 is provided with a main display 17 on the front side thereof, such as a radio wave reception state, a remaining battery level, a destination name registered as a telephone directory, a telephone number, and a transmission history. In addition, the contents of e-mail, a simple homepage, an image captured by a CCD (Charge Coupled Device) camera (CCD camera 20 in FIG. 2 described later), content received from an external content server (not shown), a memory card (described later) The contents stored in the memory card 46) of FIG. 2 can be displayed. In addition, a receiver (receiver) 18 is provided at a predetermined position on the upper part of the main display 17 so that the user can make a voice call. Note that a speaker (speaker 50 in FIG. 2) as an audio output unit other than the receiver 18 is also provided at a predetermined position of the mobile phone 1. Magnetic sensors 19 a, 19 b, 19 c, and 19 d for detecting the state of the mobile phone 1 are provided at predetermined positions inside the first housing 12 and the second housing 13.

  FIG. 2 shows an internal configuration of the mobile phone 1 applicable to the mobile terminal according to the present invention. A radio signal transmitted from a base station (not shown) is received by an antenna 31 and then input to a receiving circuit (RX) 33 via a duplexer (DUP) 32. The receiving circuit 33 mixes the received radio signal with the local oscillation signal output from the frequency synthesizer (SYN) 34 and converts the frequency into an intermediate frequency signal (down-conversion). Then, the reception circuit 33 orthogonally demodulates the down-converted intermediate frequency signal and outputs a reception baseband signal. The frequency of the local oscillation signal generated from the frequency synthesizer 34 is instructed by a control signal SYC output from the control unit 41.

  The reception baseband signal from the reception circuit 33 is input to the CDMA signal processing unit 36. The CDMA signal processing unit 36 includes a RAKE receiver (not shown). In this RAKE receiver, a plurality of paths included in the received baseband signal are despread with each spreading code (that is, the same spreading code as that of the spread received signal). Then, the signals of the respective paths subjected to the despreading process are subjected to coherent Rake synthesis after the phase is adjusted. The data sequence after Rake combining is subjected to deinterleaving and channel decoding (error correction decoding), and then binary data determination is performed. Thereby, received packet data of a predetermined transmission format is obtained. This received packet data is input to the compression / decompression processor 37.

  The compression / decompression processing unit 37 is configured by a DSP (Digital Signal Processor) or the like, and the received packet data output from the CDMA signal processing unit 36 is separated for each medium by a demultiplexing unit (not shown). Each data is decrypted. For example, in the call mode, audio data corresponding to call voice included in the received packet data is decoded by a speech codec. Also, if the received packet data includes moving image data, such as the videophone mode, this moving image data is decoded by a video codec. Further, if the received packet data is a download content, the download content is decompressed, and then the decompressed download content is output to the control unit 41.

  The digital audio signal obtained by the decoding process is supplied to the PCM codec 38. The PCM codec 38 PCM-decodes the digital audio signal output from the compression / decompression processor 37 and outputs the analog audio data signal after PCM decoding to the reception amplifier 39. The analog audio signal is amplified by the reception amplifier 39 and then output from the receiver 18.

  The digital moving image signal decoded by the video codec by the compression / decompression processing unit 37 is input to the control unit 41. The control unit 41 displays a moving image based on the digital moving image signal output from the compression / decompression processing unit 37 on the main display 17 via a video RAM (for example, a VRAM) (not shown). The control unit 41 can display not only the received moving image data but also the moving image data captured by the CCD camera 20 on the main display 17 via a video RAM (not shown).

  Further, when the received packet data is an electronic mail, the compression / decompression processing unit 37 supplies the electronic mail to the control unit 41. The control unit 41 stores the electronic mail supplied from the compression / decompression processing unit 37 in the storage unit 42. Then, the control unit 41 reads out the electronic mail stored in the storage unit 42 in accordance with the operation of the operation key 14 as an input unit by the user, and displays the read electronic mail on the main display 17.

  On the other hand, in the call mode, the voice signal (analog audio signal) of the speaker (user) input to the microphone 15 is amplified to an appropriate level by the transmission amplifier 40 and then PCM encoded by the PCM codec 38. The digital audio signal after the PCM encoding is input to the compression / decompression processing unit 37. The moving image signal output from the CCD camera 20 is digitized by the control unit 41 and input to the compression / decompression processing unit 37. Further, an electronic mail which is text data created by the control unit 41 is also input to the compression / decompression processing unit 37.

  The compression / decompression processor 37 compresses and encodes the digital audio signal output from the PCM codec 38 in a format corresponding to a predetermined transmission data rate. Thereby, audio data is generated. The compression / decompression processing unit 37 compresses and encodes the digital moving image signal output from the control unit 41 to generate moving image data. Then, the compression / decompression processing unit 37 multiplexes these audio data and moving image data by a demultiplexing unit (not shown) according to a predetermined transmission format and then packetizes them, and the packetized transmission packet data is transmitted to the CDMA signal processing unit 36. Output to. Note that the compression / decompression processing unit 37 also multiplexes the e-mail into the transmission packet data even when the e-mail is output from the control unit 41.

  The CDMA signal processing unit 36 performs spread spectrum processing on the transmission packet data output from the compression / decompression processing unit 37 using a spreading code assigned to the transmission channel, and transmits the output signal after the spread spectrum processing to the transmission circuit ( TX) 35. The transmission circuit 35 modulates the signal after the spread spectrum processing using a digital modulation method such as a QPSK (Quadrature Phase Shift Keying) method. The transmission circuit 35 combines the digitally modulated transmission signal with a local oscillation signal generated from the frequency synthesizer 34 and frequency-converts (up-converts) the signal into a radio signal. Then, the transmission circuit 35 amplifies the radio signal generated by this up-conversion with high frequency so that the transmission power level instructed by the control unit 41 is obtained. The radio signal amplified by the high frequency is supplied to the antenna 31 via the duplexer 32 and transmitted from the antenna 31 to a base station (not shown).

  Note that the reception circuit 33, the frequency synthesizer 34, the transmission circuit 35, and the CDMA signal processing unit 36 of the mobile phone 1 constitute a one-chip RFIC 51.

  The mobile phone 1 also includes an external memory interface 45. The external memory interface 45 has a slot into which the memory card 46 can be attached and detached. The memory card 46 is a type of flash memory card typified by a NAND flash memory card or a NOR flash memory card, and can write and read various data such as images, sounds and music via a 10-pin terminal. It has become. Further, the mobile phone 1 is provided with a clock circuit (timer) 47 for measuring the current accurate current time.

  The control unit 41 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU is loaded into the RAM from the program stored in the ROM or the storage unit 42. In addition to executing various processes according to various application programs including an operating system (OS), the mobile phone 1 is comprehensively controlled by generating various control signals and supplying them to each unit. The RAM appropriately stores data necessary for the CPU to execute various processes.

  The storage unit 42 includes, for example, a flash memory element that is an electrically rewritable and erasable nonvolatile memory, an HDD (Hard Disc Drive), and the like, and various application programs executed by the UI processing CPU of the control unit 41. And various data groups are stored. The power supply circuit 44 generates a predetermined operating power supply voltage Vcc based on the output of the battery 43 and supplies it to each circuit unit.

  FIG. 3 shows a detailed circuit configuration of the transmission system circuit of the mobile phone 1. As shown in FIG. 3, the transmission signal from the RFIC 51 is input to the power amplifier (PA) 61. The power amplifier 61 amplifies the transmission signal (high frequency signal) from the RFIC 51 to a predetermined transmission level. The transmission signal after power amplification is radiated as an electromagnetic wave from the antenna 31 via the coupler 62, the duplexer 32, and the antenna switch 63. The coupler 62 branches a part of the transmission signal amplified by the power amplifier 61 to the RFIC 51 or the phase shift circuit 64.

  FIG. 4 shows the configuration of the coupler 62. As shown in FIG. 4, the coupler 62 includes a substrate on which a ground layer 81, a first prepreg (first dielectric layer) 82, a core material 83, and a second prepreg (second dielectric layer) 84 are stacked. . A first strip line 85 is formed between the second prepreg 84 and the core material 83, and a second strip line 86 is formed between the core material 83 and the first prepreg 82. FIG. 5 shows the configuration of the first stripline and the second stripline. As shown in FIG. 5, via holes 87 are formed at both ends of the first strip line 85 and the second strip line 86. Via holes 87 for movement are also formed in the core material 83, the first prepreg 82, and the second prepreg 84. By filling metal in the via hole 87, the first strip line 85, the second strip line 86, and other circuit elements of the transmission system circuit formed on the upper surface of the second prepreg 84 are connected. The second strip line 86 is connected to the ground layer 81 via a via hole 87 for conduction and a resistor.

  FIG. 6 shows an equivalent circuit of the coupler 62. As shown in FIG. 6, the coupler 62 includes a second output terminal 92 connected to the RFIC 51 in addition to an input terminal 90 connected to the power amplifier 61 side and a first output terminal 91 connected to the duplexer 32 side. It has a termination terminal 94 and a third output terminal 95 connected to the phase shift circuit 64. The terminal terminal 94 of the coupler 62 is grounded (grounded) via a resistor 93.

  Returning to FIG. 3, the duplexer 32 is a filter element that separates the frequency range of the transmission signal output from the antenna 31 and the reception signal input from the antenna 31. The antenna switch 63 is provided between the antenna 31 and the duplexer 32. The phase shift circuit 64 reverses the phase of the transmission signal from the third output terminal 95 of the coupler 62. The detection circuit 65 converts the transmission signal (RF signal) from the third output terminal 95 of the coupler 62 whose phase has been reversed to a voltage value, and outputs the converted signal to the control unit 41.

  On the other hand, the transmission signal from the second output terminal 92 of the coupler 62 is input to the RFIC 51. The RFIC 51 converts the transmission signal from the second output terminal 92 of the coupler 62 into a voltage value using a detection circuit in the RFIC 51, and outputs the converted signal to the control unit 41.

  When the mobile phone 1 according to the present embodiment monitors the detected power for the traveling wave from the power amplifier 61 to the antenna 31, the coupling port of the coupler 62 is also used to simultaneously monitor the reflected wave from the antenna 31 to the power amplifier 61. In addition to the second output terminal 92, the third output terminal 95 is used. The concept of the maximum transmission power control method using transmission signals from the second output terminal 92 and the third output terminal 95 will be described below.

Here, the output power of the power amplifier 61 is P ₀ [dBm], the coupling (coupling coefficient) to the second output terminal 92 as the coupling port of the coupler 62 is C ₁ [dB], and the second of the coupler 62 I ₁ [dB] is isolated from the output terminal 92, and RL [dB] is the return loss when the antenna 31 side is viewed from the power amplifier 61. Note that coupling _{C 1} and the isolation _{I 1} of the coupler 62 is a known value. At this time, the traveling wave pi1 [mW] and the reflected wave pr1 [mW] entering the second output terminal 92 as the coupling port of the coupler 62 are represented by the numbers [1] and [2].

The transmission signal p1 [mW] from the second output terminal 92 of the coupler 62 is a composite component of the traveling wave pi1 and the reflected wave Pr1, and is represented by p1 = pi1 + pr1. Therefore, the transmission signal p1 from the second output terminal 92 of the coupler 62 is represented by the number [3].

On the other hand, the coupling (coupling coefficient) to the third output terminal 95 as the termination side port of the coupler 62 is C ₂ [dB], and the isolation of the coupler 62 to the third output terminal 95 is I ₂ [dB]. ]. Note that coupling _{C 2} and the isolation _{I 2} of coupler 62 is a known value. At this time, the traveling wave pi2 [mW] and the reflected wave pr2 [mW] entering the third output terminal 95 as the terminator side port of the coupler 62 are represented by the numbers [4] and [5].

The transmission signal p2 [mW] from the third output terminal 95 of the coupler 62 is a composite component of the traveling wave pi2 and the reflected wave pr2, and is represented by p2 [mW] = pi2 + pr2. Accordingly, the transmission signal P2 from the third output terminal 95 of the coupler 62 is represented by the number [6].

As described above, by using the transmission signal p1 from the second output terminal 92 and the transmission signal p2 from the third output terminal 95, the traveling wave component as the value of the detection power used for controlling the maximum transmission power is used. (Ie, the value for p ₀ [mW]) only. As a result, it is possible to prevent the reflected wave component from being added to the detected power. Hereinafter, the maximum transmission power control process using this method will be described.

  With reference to the flowchart of FIG. 7, the maximum transmission power control process in the mobile phone 1 of FIG. 3 will be described.

  In step S1, the power amplifier 61 amplifies the transmission signal from the RFIC 51 to a predetermined transmission level under the control of the control unit 41. In step S <b> 2, the power amplifier 61 outputs the transmission signal after power amplification to the coupler 62. In step S <b> 3, the coupler 62 outputs the transmission signal P <b> 2 from the third output terminal 95 of the coupler 62 to the phase shift circuit 64. In step S <b> 4, the phase shift circuit 64 reverses the transmission of the transmission signal from the third output terminal 95 of the coupler 62. Thereby, the reflected wave Pr1 can be canceled in a circuit. The phase shift circuit 64 outputs the transmission signal from the third output terminal 95 of the coupler 62 whose phase shift is reversed to the detection circuit 65. In step S <b> 5, the detection circuit 65 converts the transmission signal (RF signal) from the third output terminal 95 of the coupler 62 whose phase has been reversed to a voltage value, and converts the converted signal to the control unit 41. Output to.

Next, in step S <b> 6, the coupler 62 outputs the transmission signal P <b> 1 from the second output terminal 92 of the coupler 62 to the RFIC 51. In step S <b> 7, the RFIC 51 converts the transmission signal from the second output terminal 92 of the coupler 62 into a voltage value using the detection circuit in the RFIC 51, and outputs the converted signal to the control unit 41. In step S8, the control unit 41 uses the voltage value based on the transmission signal P1 from the second output terminal 92 of the coupler 62 and the voltage value based on the transmission signal P2 from the third output terminal 95 of the coupler 62. Thus, the output power p ₀ [mW] from the power amplifier 61 is calculated by the above [Equation 9].

In step S <b> 9, the control unit 41 uses the calculated output power p ₀ [mW] from the power amplifier 61 to control the output power of the power amplifier 61 used when transmitting a transmission signal via the antenna 31. To do. As a result, in a state where the coupler's directivity is low, the maximum transmission power can be controlled to be constant without depending on the antenna load, and high accuracy and great transmission power control that is not affected by the antenna load can be achieved. Can be realized.

  In particular, the performance of the coupler 62 depends on the physical characteristics at the time of manufacture, but the performance of each individual coupler is not always sufficient. Further, when the coupler 62 is incorporated in the transmission system circuit of the mobile phone 1, the performance expected to be possessed by the coupler may not be exhibited to the maximum extent. Therefore, when the coupler 62 is used to ensure isolation in the line from the antenna to the output of the power amplifier, not only the maximum transmission power changes in accordance with the change in the antenna load, but also the physical property of the coupler. Characteristic affects transmission power control. In the embodiment of the present invention, even when the coupler 62 is used to ensure isolation in the line from the antenna to the output of the power amplifier, at least the reflected wave component is generated according to the change in the load of the antenna. Since it is possible to prevent the detection power from being added, one factor that adversely affects the maximum transmission power control of the mobile phone 1 can be eliminated.

  The processing related to the transmission signal P2 from the third output terminal 95 of the coupler 62 in steps S3 to S5 and the processing related to the transmission signal P1 from the second output terminal 92 of the coupler 62 in steps S6 to S7. The order may be changed. Further, the present invention can be applied to the mobile phone 1 including an isolator in addition to the coupler 62.

  3 and 7, the phase shift circuit 64 is used, but the reflected wave pr1 may be canceled numerically without using the phase shift circuit 64.

  Furthermore, the series of processes described in the embodiment of the present invention can be executed by software, but can also be executed by hardware.

  In the embodiment of the present invention, the steps of the flowchart show an example of processing that is performed in time series in the order described. However, even if they are not necessarily processed in time series, they are executed in parallel or individually. The processing to be performed is also included.

  DESCRIPTION OF SYMBOLS 1 ... Mobile phone, 11 ... Hinge part, 12 ... 1st housing | casing, 13 ... 2nd housing | casing, 14 ... Operation key, 15 ... Microphone, 16 ... Side key, 17 ... Main display, 18 ... Receiver, 19a Thru 19d ... magnetic sensor, 20 ... CCD camera, 21 ... sub-display, 31 ... antenna, 32 ... duplexer, 33 ... receiving circuit (RX), 34 ... frequency synthesizer (SYN), 35 ... transmitting circuit (TX), 36 ... CDMA signal processing unit, 37: compression / decompression processing unit, 38: PCM codec, 39: receiving amplifier, 40 ... transmitting amplifier, 41 ... control unit, 42 ... storage unit, 43 ... battery, 44 ... power supply circuit, 45 ... external Memory interface 46 ... Memory card 47 ... Timer circuit 50 ... Speaker 51 ... RFIC 61 ... Power amplifier 62 ... Coupler 63 ... A Tenor switch, 64 ... phase shift circuit, 65 ... detector circuit, 90 ... input terminal, 91 ... first output terminal, 92 ... second output terminal, 93 ... resistor, 94 ... termination terminal, 95 ... third output Terminal.

Claims (6)

A generator for generating a high-frequency signal;
A power amplifying unit for amplifying the power of the high-frequency signal generated by the generating means to a predetermined transmission power level;
An antenna that radiates the high-frequency signal after power amplification;
A first output terminal, a second output terminal, and a third output terminal, wherein the high-frequency signal after the power amplification is output to the antenna through the first output terminal; A coupler that branches a part of a high-frequency signal and outputs the branched signal through the second output terminal and the third output terminal, respectively .
The generation unit detects a first signal output from the coupler through the second output terminal , converts the first signal into a power value,
A detection wave circuit for converting the power value by detecting a second signal before Symbol coupler output through the third output terminal,
Based on the voltage value based on the first signal converted by the generation unit and the voltage value based on the second signal converted by the detection circuit , an output voltage from the power amplification unit is calculated. , based on the output voltage from the calculated said power amplifier, and a control unit for power of the high frequency signal to control the power amplifier so as to reach said predetermined transmission power level, and further comprising a Mobile terminal. A phase shift circuit that reverses the phase of the second signal output from the coupler through the third output terminal;
The mobile terminal according to claim 1, wherein the detection circuit detects the second signal that has been reversed in phase by the phase shift circuit and converts the second signal into a power value.   The control unit uses a value related to coupling of the coupler and a value related to isolation based on a voltage value based on the first signal and a voltage value based on the second signal, and outputs from the power amplification unit. The mobile terminal according to claim 1, wherein an output voltage is calculated.   The control unit uses a value related to coupling and a value related to isolation of the coupler based on a voltage value based on the first signal and a voltage value based on the second signal, and a reflected wave flowing backward from the antenna The mobile terminal according to claim 3, wherein an output voltage from the power amplification unit is calculated so as to remove a component. A generation unit that generates a high-frequency signal; a power amplification unit that amplifies the power of the high-frequency signal generated by the generation unit to a predetermined transmission power level; an antenna that radiates the high-frequency signal after power amplification; and the high-frequency signal In a transmission circuit of a portable terminal comprising a control unit that controls the power amplification unit so that the signal power reaches a predetermined transmission power level,
A first output terminal, a second output terminal, and a third output terminal, wherein the high-frequency signal after the power amplification is output to the antenna through the first output terminal; A coupler that branches a part of a high-frequency signal and outputs the branched signal through the second output terminal and the third output terminal, respectively .
The generation unit detects a first signal output from the coupler through the second output terminal , converts the first signal into a power value,
Transmitter circuit before Symbol coupler and further comprising and a detection circuit for converting the power value by detecting a second signal output through the third output terminal. Generate high-frequency signals,
Amplifying the power of the generated high-frequency signal to a predetermined transmission power level;
Radiating the high frequency signal after power amplification,
The high-frequency signal after the power amplification is output in the direction of the antenna, and a part of the high-frequency signal is branched to output a first signal and a second signal in a first direction and a second direction, respectively. And
Detecting and converting the first signal into a power value;
Converted into power values by detecting the pre-Symbol second signal,
A voltage value based on the converted first signal, based on the voltage value which can be based on are converted second signal, calculates the output voltage after power amplification, after the calculated power amplifier output A transmission power control method comprising: controlling the power of the high-frequency signal to reach the predetermined transmission power level based on a voltage.

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