1342112 Π年2月M修正替換頁 玖、發明說明： - 【發明所屬之技術領域】 . 本發明係一種新的控制射頻功率放大器之輸出功率的電路設計方 法。尤指應用在無線通訊系統，搭配射頻功率放大器，調整控制其射 頻輸出功率大小的一種控制射頻功率之電路設計方法。運用此方法將 、 可設計出一個應用在無線通訊系統，具有產業競爭性之控制射頻功率 之積體電路控制器。搭配射頻功率放大器與運用本發明所設計出來之 控制器，將可製成一個含有射頻輸出功率控制之射頻功率放大模組》1342112 February 2004 M correction replacement page 玖, invention description: - [Technical field of the invention] The present invention is a new circuit design method for controlling the output power of a radio frequency power amplifier. Especially a circuit design method for controlling RF power, which is applied in a wireless communication system, with an RF power amplifier, and adjusts and controls the frequency of its RF output power. Using this method, an integrated circuit controller that is used in a wireless communication system and has an industrial competitive control of RF power can be designed. With the RF power amplifier and the controller designed by the invention, a RF power amplifier module with RF output power control can be made.
【先前技術】 目前習知運用在手機射頻功率放大器*控制射頻輸出功率大小的控 制方法有三種，如圖二、圖三及圖四所示，分別是功率感測（power sensing)之功率控制方法、電流感測（current sensing)之功率控制方 法、RFMD (RF Micro Devices Incorporation)專利之功率控制方法。 圖二是利用功率感測（power sensing)的控制方法。極少量比例 的射頻輸出功率（RF output power)藉由方向親合器18 (drectional coupler)傳送至功率感測控制電路20 (Power Sense Controller) ’這個極 少量比例的射頻輸出功率會被轉換成等效電壓，再藉由與基頻（Base Band)系統所提供之功率控制訊號；VAPC 19的電壓比較，從而調整射 頻功率放大器之基級（base) 17電壓的大小，因而達到對於射頻輸出功 率大小之精準度的控制。 圖三是利用電流感測（current sensing)的控制方法。當射頻功率 放大器操作時，其發射出的射頻功率大小與流過RSENSE 2丨的電流有一 個類似線性的比例關係。利用這個比例關係特性，電流感測控制電路 22 (Current Sense Controller)將流過RSENSE 21的電流轉換成等效電 壓，再藉由與基頻系統所提供之功率控制訊號；VAPC 23的電壓比較’ 從而調整射頻功率放大器之基級25電壓的大小，因而達到對於射頻輸[Prior Art] At present, there are three control methods for controlling the RF output power in the mobile phone RF power amplifier*, as shown in Fig. 2, Fig. 3 and Fig. 4, respectively, power sensing method of power sensing. , current sensing power control method, RFMD (RF Micro Devices Incorporation) patented power control method. Figure 2 is a control method using power sensing. A very small proportion of the RF output power is transmitted to the Power Sensing Controller 20 by the drageal coupler. 'This very small proportion of RF output power is converted to etc. The voltage is then adjusted by the voltage control signal provided by the baseband system and the voltage of the VAPC 19 to adjust the voltage of the base 17 of the RF power amplifier, thereby achieving the power output for the RF. The precision of the control. Figure 3 is a control method using current sensing. When the RF power amplifier is operated, the amount of RF power it emits has a linear proportional relationship with the current flowing through RSENSE 2丨. Using this proportional relationship characteristic, the current sense control circuit 22 (Current Sense Controller) converts the current flowing through the RSENSE 21 into an equivalent voltage, and then compares with the voltage control signal provided by the baseband system; the voltage of the VAPC 23' Thereby adjusting the voltage of the base level 25 of the RF power amplifier, thereby achieving the RF input
S 5 1342112 /畔夂月/(日修正替換頁 出功率大小之精準度的控制。 圖四是RFMD專利之功率控制方法，其VGS 34控制電路33是運用 TX_Enable (基頻系統所提供之是否開始輸出射頻功率之數値控制訊號) 31和VAPC 32兩個輸入訊號與回授的而且經過轉換的集級35電壓作比 較，從而來控制Vos 34電壓値的大小。Vos 34電壓値的大小會改變射 頻功率放大器之集級的電壓35。運用改變集級電壓的大小來控制射頻 輸出功率的大小，因而達到其控制射頻功率放大器的射頻輸出功率之 效果。 【發明内容】 以GSM手機系統爲例，如圖五所示，GSM手機系統對於射頻輸出 功率的精準度有著極爲嚴格的要求。因爲手機電池的電壓値會有相當 大的變化，其可能從3.2V到4.6V不等，因此會影響射頻功率放大器 之輸出功率的精準度，另外如溫度的變化，元件的差異…等因素，也 會影響精準度。功率控制（power control)的目的就是爲了克服此項困 難。本發明所述的電路設計方法，可以克服無線通訊系統對於射頻輸 出功率之精準度的要求》 如圖一所示，一個場效應電晶體5 (Field Effect Transistor)，使用P 型溝道式或是N型溝道式的皆可以。將此場效應電晶體5串聯接在介 於系統電源供應電池〗與射頻功率放大器的集級或漏極9 (Collector or Drain)之間（FET-放大器使用漏極，BJT-放大器使用集極）。 放大器偏壓控制電路7會偵測系統電源供應電池1的電壓値。當系 統電源供應電池1的電壓是保持在固定値時，無論系統對於射頻輸出 功率之要求大小如何(無論功率控制訊號6的電壓値大小如何），放大器 偏壓控制電路7都會控制場效應電晶體5的柵極2電壓保持在一個固 定電壓値。但是當系統電源供應電池1的電壓變動時，則放大器偏壓 控制電路7會控制場效應電晶體5的偏壓電路12，使柵極2電壓與電 6 HP月it曰修正替換頁 源供應電池1的電壓做比例線性式之變動。光是此點即與RFMD專利 之功率控制方法有著明顯與顯著之不同。 放大器偏壓控制電路7也同時會偵測Vc 3與Va 1之間的電壓差 値》放大器偏壓控制電路7使用此一電壓差値與基頻系統所提供之功 率控制訊號VAPC6 (—個類比訊號）的電壓値比較，從而調整射頻功率 放大器之基級或是柵極8 (FET-放大器使用柵極，BJT-放大器使用基極) 電壓的大小，因而達到對於射頻輸出功率大小之精準度的控制。 總而言之，本發明之技術原理是在利用Vc 3與Va 1之間的電壓差 値會隨著射頻功率放大器之輸出功率的大小而改變。圖六即顯示運用 本發明之技術結構，使用3.4V電池，所量測到之Vc 3對應Vd 8之曲 線圖42。其橫軸44是代表Vd 8，而其縱軸43則是代表Vc 3。改變 Vd 8之電壓値會改變射頻功率放大器之輸出功率的大小，同時也會改 變Vc 3之電壓値。當溫度的變化，元件的差異…等因素，造成射頻功 率放大器之輸出功率與功率控制訊號VAPC 6所代表之既定輸出功率設 定値有所差異時，在此同時也會造成(Vc-Va)與功率控制訊號VAPC 6所 代表之既定(Vc-Va)設定値會有所差異，差異比較器11則可利用此差異 來調整Vd 8之電壓，其即對應到調整射頻功率放大器之輸出功率，因 而達成對於射頻輸出功率的精準度之要求 【實施方式】 ίΐ年Μ2·丨日修正替換頁 根據本發明’可以製作具有控制射頻功率放大器的射頻輸出功率大 小之功能之功率控制積體電路，此功率控制積體電路： 1. 使用一個場效應電晶體5，將場效應電晶體5串聯接在介於系統 電源供應電池1與射頻功率放大器的集級9之間。則場效應電晶體 之Va 1與Vc 3之間的電壓差値會隨著射頻功率放大器之輸出功率 的大小而改變。 2. 結合場效應電晶體5，設計功率控制積體電路1〇。功率控制積體 電路含有放大器偏壓控制電路7，控制電路7會偵測系統電源供應 電池1的電壓値。當系統電源供應電池的電壓是保持在固定値時， 無論系統對於射頻輸出功率之要求大小如何(無論功率控制訊號6 的電壓値大小如何），控制電路7都會控制場效應電晶體的柵極電 壓2 ’使其保持在一個固定電壓値。但是當系統電源供應電池1的 電壓變動時，則放大器偏壓控制電路7會控制場效應電晶體5的柵 極電壓2，使其與電源供應電池的電壓1做比例線性式之變動。柵 極電壓之控制會控制場效應電晶體之Va 1與Vc 3之間的電壓差 値，使得這個代表射頻輸出功率大小之電壓差値不會隨著電源供應 電池的電壓1變動而變動太多。 3.放大器偏壓控制電路7將Va 1與Vc 3之間的電壓差値作增益放 大然後與功率控制訊號6的電壓値做比較(或是將功率控制訊號6 作衰減然後與Va 1與Vc 3之間的電壓差値做比較）。當轉換後之電 壓差値比功率控制訊號6的電壓値大時，則增加放大器之偏壓電壓 4，使得放大器增加射頻輸出功率。放大器偏壓控制電路7將增加 放大器之射頻輸出功率，直至轉換後之電壓差値與功率控制訊號6 的電壓値達到等値。當轉換後之電壓差値比功率控制訊號6的電壓 値小時，則降低放大器之偏壓電壓4，使得放大器降低射頻輸出功 率。放大器偏壓控制電路7將降低放大器之射頻輸出功率，直至轉 換後之電壓差値與功率控制訊號6的電壓値達到等値。 啤2月从曰修正替換頁 【圖式簡單說明】 圖一爲本發明使用的控制放大器射頻輸出功率之輸出功率控制器之 設計電路方法之示意圖。 圖二爲功率感測（power sensing)式之功率控制的設計電路示意圖。 圖三爲電流感測（current sensing)式之功率控制的設計電路示意 圖。 圖四爲RFMD專利功率控制的設計電路示意圖。 圖五 GSM手機射頻輸出功率之要求範圍》 圖六 Vc 3對應Vd 8之曲線圖 圖示之符號說明 1系統電源供應電池之電壓 2場效應電晶體之柵極 3射頻功率放大器的集級或漏極 4射頻功率放大器的基級或柵極 5場效應電晶體 6基頻系統提供之控制輸出射頻功 率大小之控制訊號 7放大器偏壓控制電路 8射頻功率放大器的基級或柵極 9射頻功率放大器的集級或漏極 10射頻輸出功率控制器 11 (Vc-Va)差異比較器 12場效應電晶體的偏壓電路 15系統電源供應電池之電壓 16射頻功率放大器的集級 17射頻功率放大器的基級 18方向耦合器 19 VAPC’·手機系統提供之控制輸 出射頻功率大小之控制訊號 20功率感測的控制電路 21 Rsense :電阻 22電流感測的控制電路 23 VAPC :手機系統提供之控制輸 出射頻功率大小之控制訊號 24射頻功率放大器的集級 25射頻功率放大器的基級 31 TX Enable :手機系統提供之” 可以傳送”控制訊號 32 VAPC :手機系統提供之控制輸 出射頻功率大小之控制訊號 33 VGS偏壓的控制電路 34 VGS :場效應電晶體的柵級到源 級的電壓 35射頻功率放大器的集級 36射頻功率放大器的基級 41 (Vc-Va)之差異値 42 Vc對應Vd之曲線 43曲線圖之縱軸 43曲線圖之橫軸S 5 1342112 / 夂月月 / (Day correction of the accuracy of the replacement page output power. Figure 4 is the RFMD patented power control method, its VGS 34 control circuit 33 is using TX_Enable (the basic frequency system provides whether to start Output RF power number 値 control signal) 31 and VAPC 32 two input signals are compared with the feedback and converted gradation 35 voltage to control the size of the Vos 34 voltage 。. The size of the Vos 34 voltage 会 will change. The voltage of the collector of the RF power amplifier is 35. The magnitude of the RF output power is controlled by changing the magnitude of the collector voltage, thereby achieving the effect of controlling the RF output power of the RF power amplifier. [Invention] Taking the GSM mobile phone system as an example, As shown in Figure 5, the GSM mobile phone system has extremely strict requirements on the accuracy of the RF output power. Because the voltage of the mobile phone battery will vary considerably, it may vary from 3.2V to 4.6V, thus affecting the RF. The accuracy of the output power of the power amplifier, as well as factors such as temperature changes, component differences, etc., also affect accuracy. The purpose of power control is to overcome this difficulty. The circuit design method of the present invention can overcome the requirement of the accuracy of the wireless communication system for the RF output power. As shown in Fig. 1, a field effect transistor 5 (Field Effect Transistor), either P-channel or N-channel can be used. Connect this field effect transistor 5 in series with the system power supply battery and the collector or drain of the RF power amplifier. 9 (Collector or Drain) (FET-amplifier uses drain, BJT-amplifier uses collector). Amplifier bias control circuit 7 detects system voltage supply battery 1 voltage 値. When system power supply battery 1 voltage When the fixed 値 is maintained, regardless of the system's requirements for the RF output power (regardless of the voltage 値 of the power control signal 6), the amplifier bias control circuit 7 controls the gate 2 voltage of the field effect transistor 5 to remain at A fixed voltage 値. However, when the voltage of the system power supply battery 1 fluctuates, the amplifier bias control circuit 7 controls the bias of the field effect transistor 5. The voltage circuit 12 makes the voltage of the gate 2 and the voltage of the battery of the replacement source of the page source a linear change. The light is obviously and significant with the RFMD patent power control method. The amplifier bias control circuit 7 also detects the voltage difference between Vc 3 and Va 1 . The amplifier bias control circuit 7 uses this voltage difference 値 and the power control signal VAPC6 provided by the baseband system ( Comparing the voltages of analog signals) to adjust the voltage of the base of the RF power amplifier or the gate 8 (the gate of the FET-amplifier, the base of the BJT-amplifier), thus achieving the accuracy of the RF output power. Degree of control. In summary, the technical principle of the present invention is that the voltage difference between Vc 3 and Va 1 varies with the output power of the RF power amplifier. Fig. 6 shows the use of the technical structure of the present invention, using a 3.4V battery, and the measured Vc 3 corresponds to the curve 42 of Vd 8. Its horizontal axis 44 represents Vd 8, while its vertical axis 43 represents Vc 3. Changing the voltage of Vd 8 will change the output power of the RF power amplifier and will also change the voltage of Vc 3. When the temperature changes, the difference of components, etc., the output power of the RF power amplifier differs from the established output power setting represented by the power control signal VAPC 6, it also causes (Vc-Va) The set (Vc-Va) setting represented by the power control signal VAPC 6 will vary, and the difference comparator 11 can use this difference to adjust the voltage of Vd 8, which corresponds to adjusting the output power of the RF power amplifier, thus Reaching the requirements for the accuracy of the RF output power [Embodiment] According to the present invention, a power control integrated circuit having a function of controlling the magnitude of the RF output power of the RF power amplifier can be fabricated. Controlling the integrated circuit: 1. Using a field effect transistor 5, the field effect transistor 5 is connected in series between the system power supply battery 1 and the collector stage 9 of the RF power amplifier. Then, the voltage difference V between Va 1 and Vc 3 of the field effect transistor changes with the output power of the RF power amplifier. 2. Design the power control integrated circuit 1〇 in combination with the field effect transistor 5. The power control integrated circuit includes an amplifier bias control circuit 7, which detects the voltage 値 of the system power supply battery 1. When the voltage of the system power supply battery is kept at a fixed level, regardless of the system's requirements for the RF output power (regardless of the voltage 値 of the power control signal 6), the control circuit 7 controls the gate voltage of the field effect transistor. 2 'Let it stay at a fixed voltage 値. However, when the voltage of the system power supply battery 1 fluctuates, the amplifier bias control circuit 7 controls the gate voltage 2 of the field effect transistor 5 to be linearly changed in proportion to the voltage 1 of the power supply battery. The control of the gate voltage controls the voltage difference V between Va 1 and Vc 3 of the field effect transistor, so that the voltage difference representing the magnitude of the RF output power does not fluctuate too much with the voltage 1 of the power supply battery. . 3. The amplifier bias control circuit 7 amplifies the voltage difference between Va 1 and Vc 3 and then compares it with the voltage 功率 of the power control signal 6 (or attenuates the power control signal 6 and then Va 1 and Vc The voltage difference between 3 is compared). When the converted voltage difference 値 is greater than the voltage of the power control signal 6, the bias voltage 4 of the amplifier is increased, so that the amplifier increases the RF output power. The amplifier bias control circuit 7 will increase the RF output power of the amplifier until the converted voltage difference 値 is equal to the voltage 功率 of the power control signal 6. When the converted voltage difference 値 is less than the voltage of the power control signal 6, the bias voltage 4 of the amplifier is lowered, so that the amplifier reduces the RF output power. The amplifier bias control circuit 7 will reduce the RF output power of the amplifier until the converted voltage difference 値 is equal to the voltage 功率 of the power control signal 6. Beer February revised from 曰 correction page [Simplified illustration] Figure 1 is a schematic diagram of the design circuit method of the output power controller of the control amplifier RF output power used in the present invention. FIG. 2 is a schematic diagram of a design circuit of power sensing power control. Figure 3 is a schematic diagram of the design of a current sensing power control circuit. Figure 4 is a schematic diagram of the design circuit of RFMD's patented power control. Figure 5: GSM mobile phone RF output power requirements range Figure 6 Vc 3 corresponds to Vd 8 curve diagram symbol Description 1 system power supply battery voltage 2 field effect transistor gate 3 RF power amplifier grading or leakage The base stage of the pole 4 RF power amplifier or the gate 5 field effect transistor 6 base frequency system provides control signal output control of the RF power level 7 amplifier bias control circuit 8 RF power amplifier base stage or gate 9 RF power amplifier Cascade or Drain 10 RF Output Power Controller 11 (Vc-Va) Difference Comparator 12 Field Effect Transistor Bias Circuit 15 System Power Supply Battery Voltage 16 RF Power Amplifier Set Level 17 RF Power Amplifier Base level 18 directional coupler 19 VAPC'·Mobile phone system control signal output control RF power control signal 20 power sensing control circuit 21 Rsense: resistance 22 current sensing control circuit 23 VAPC: mobile phone system control output RF Power Level Control Signal 24 RF Power Amplifier Level 25 RF Power Amplifier Base Level 31 TX Enable : Mobile The "can transmit" control signal 32 VAPC: control signal provided by the mobile phone system to control the output RF power level 33 VGS bias control circuit 34 VGS: field-effect transistor gate-to-source voltage 35 RF power amplifier The difference of the base level 41 (Vc-Va) of the set 36 RF power amplifier 値 42 Vc corresponds to the curve of Vd 43 The vertical axis of the graph of the graph 43 The horizontal axis of the graph