JP4386999B2 - Apparatus and method for enhancing ACPR by gain modulation - Google Patents

Description

【００３３】
のプロダクション中、キャリブレートされる。例えば、ここで、
【００３４】
【外２】

【００３５】
はPA１７５の出力における平均送信電力である。実施例において、このキャリブレーションは、セルラーバンドにおいて、０．９MHｚオフセットで行われる。そのキャリブレートされた結果が、移動電話機のメモリに保存される。操作中、例えば、係数w_iは、
【００３６】
【外３】

【００３７】
のセット値のために、そのメモリから読み出される。
【００３８】
図８に示す送受信機６００において行われる開ループ線形化は、全ての係数の最適値を決定するために、キャリブレーションが必要となる。これに対して、図１に示す送受信機１００のPAフィードバックにエンベロープ検波器１７７を用いることは、PA１７５がそのPA１７５の入力と共に変化する信号によって変調されるので、簡単なキャリブレーションのみが必要となる。この簡単なキャリブレーションは、一つの特定の送信周波数f _TXにおいて単一点のみ、例えば、最大送信電力P _TXで、行われてもよい。
【００３９】
先に図１に基づいて記述した定値E を用いる線形化技術と異なり、PAの先行歪ませは、図８に示すように、多くの場合のようにベースバンド信号I(t)及びQ(t)が電力制御に用いられていなければ、エンベロープ利得E は送信電力と共に線形に変化する必要がある。その全エンベロープ利得は、式（３）によって与えられる。
【００４０】
【数１】

【００４１】
ここで、
【００４２】
【外４】

【００４３】
は、線形にされている非線形装置、即ち、PA１７５の平均送信電力である。
本発明の他の実施例において、ACPRを増加する方法が提供される。特に、これらの方法は、PA１７５の利得を変調するために、エンベロープ信号e(t)を用いることによってACPRを増加することを含む。図８の送受信機６００を用いる一つの方法において、エンベロープ信号e(t)は、送信ベースバンドユニット１６５に提供された送信ベースバンド信号から引き出される（図１）。もう一つの方法において、そのエンベロープ信号e(t)は、図１〜図５に示すように、エンベロープ検波器１７７を用いるPA１７５の出力から直接引き出される。そのエンベロープ検波器１７７はPA１７５に提供されたRF出力信号a₁s(t)のエンベロープを検出する。
【００４４】
上述した本発明の好ましい実施例は、本発明を限定するものではない。当業界の如何なる熟練者は、本発明の要旨及び範囲内において、各種の変更及び修飾を行うことができる。従って、本発明の保護範囲は、特許請求範囲に準ずる。
【図面の簡単な説明】
【図１】本発明に係る電力増幅器（PA）を有する送受信機回路を示し、エンベロープ検波器を用いて直接そのPA出力から引き出されたエンベロープ信号によってそのPAが変調されることを示す図である。
【図２】本発明に係る図１に示す送受信機回路の一部分としての変調器ユニットをより詳細に示す図である。
【図３】本発明に係る図１に示す送受信機回路に用いられた電圧又は電流制御増幅器、例えば、電力増幅器又はLNA を示す図である。
【図４】本発明に係る図１に示す送受信機回路に用いられたエンベロープ検波器の異なる例を示す図である。
【図５】本発明に係る図１に示す送受信機回路に用いられたエンベロープ検波器の異なる例を示す図である。
【図６】本発明に係るCDMAの送信された信号のスペクトルを示す図である。
【図７】本発明に係る二倍にされたエンベロープ利得対ACPRのプロットを示す図である。
【図８】本発明の他の実施例に係るACPR増のための開ループ電力増幅器利得変調を有する送受信機回路を示すである。
【符号の説明】
１００ 送受信機回路
１０５ 送信セクション
１１０ 受信セクション
１１５ アンテナ
１２０ 送受切換え器
１３０ イメージフィルタ
１３５ ミキサ
１４０ 局部発振信号
１４５ 局部発振器
１５０ チャンネルフィルタ
１５５ 復調器ユニット
１６０ 受信ベースバンドユニット
１６５ 送信ベースバンドユニット
１７０ 変調器ユニット
１７５ 電力増幅器（PA）
１７７ エンベロープ検波器
１９０ 位相変換器
M1、M2 ミキサ
３１０ 逓倍器
３２０ フィルタ
３３０ エンベロープ増幅器
３４０ 電力検波器
４００ スペクトル
５００ シミュレーション
６１０、６１５、６５５ D/A 変換器
６２０、６２５、６７０ フィルタ
６３０、６３５ ２乗ユニット
６５０ 仕事関数発生器f _(x) [0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for enhancing the adjacent channel power ratio (ACPR) of a transmitter in a transceiver. Here, as a transceiver, for example, a code division multiple access (CDMA) telephone or a time division multiple access (TDMA) telephone operating in 900 MHz and 1.9 GHz cellular and / or personal communication system (PCS) bands, respectively. Yes, or any transmission device that transmits a non-constant envelope signal.
[0002]
[Prior art]
Mobile transceivers, such as CDMA / TDMA mobile telephone handsets, face one important problem. The problem is transmission signal distortion due to non-linearity of the transmitter power amplifier (PA). The nonlinearity of the power amplifier degrades or reduces the transmitter ACPR. The ACPR is, for example, as a ratio of transmission power (for example, at a total bandwidth of 1.23 MHz) to power of 30 kHz bandwidth at a location where the 0.9 MHz frequency is shifted from a transmitter center frequency of 900 MHz, for example. Defined.
[0003]
For example, highly linear transmitter blocks such as power amplifiers, drivers, and mixers are expensive and require large currents, which quickly drain the mobile handset battery. Attempts have been made to linearize nonlinear power amplifiers instead of these highly linear power amplifiers, drivers and mixers.
Conventional methods for linearizing transmitter power amplifiers use feed-forward or feedback closed-loop compensation techniques between the transmitted signal and the reference signal.
[0004]
[Problems to be solved by the invention]
However, if these technologies are applied to a mobile phone, it becomes expensive.
To alleviate that need for a highly linear transmitter block, European Patent Application No. 0 435 578 uses a distortion compensation circuit provided between the input signal and the power amplifier to reduce the transmitter power amplifier. It has been proposed to compensate. The envelope detection circuit detects the envelope of the power amplifier output and provides the detection output to a control circuit that controls the distortion compensation circuit.
[0005]
This circuit reduces distortion due to non-linearization of the power amplifier, but requires additional circuit elements, such as its control circuit and distortion compensation circuit. These additional circuits lead to an increase in mobile phone size and power consumption.
Therefore, to minimize transmitter current or power consumption, distortion must be reduced without using a high linear LNA with a large third order intercept point (TO1) and with minimal additional circuitry .
[0006]
One object of the present invention is to provide a controlled transceiver or transmitter and a control method capable of solving the problems existing in the above-described conventional transmitter or transceiver.
Another object of the present invention is to provide a transmitter or transceiver having enhanced ACPR without resorting to high linear power amplifiers.
[0007]
[Means for Solving the Problems]
In order to achieve the above and other objects, the present invention provides a transceiver or transmitter having a berth band unit for outputting a baseband signal, and a modulation for modulating the baseband signal and outputting a modulated signal. Provide a bowl. A transmission amplifier amplifies the modulated signal and outputs a transmission signal to a duplexer, for example. The transmit amplifier has a gain modulated by the envelope signal. The envelope signal is proportional to the transmission signal, for example, proportional to the power of the transmission signal.
[0008]
The envelope signal is provided by the baseband unit. In a preferred embodiment of the invention, the envelope signal is provided by an envelope detector that receives the output of the transmit amplifier.
The present invention, in another embodiment, provides a method for increasing the adjacent channel power ratio of a transmitter. The method is
Generate a baseband signal using the baseband unit,
Modulate the baseband signal to generate a modulated signal,
Amplifying the modulated signal with a transmit amplifier to provide a transmit signal;
Each step of modulating the gain of the transmission amplifier using an envelope signal proportional to the transmission signal, for example, proportional to the power of the transmission signal.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
The present invention generally relates to enhancing ACPR in a power amplifier of a transceiver or transmitter. The ACPR is generally due to the nonlinearity of the power amplifier. In an embodiment, the transceiver includes CDMA telephones or associated RF baseband integrated circuits (ICs).
[0010]
Instead of closed loop compensation, transmitter power amplifier (PA) open loop compensation is used. Also, the use of additional circuitry is minimized, and the power amplifier does not provide any external compensation for linearization in the transmitter integrated circuit chip itself, eg, from a digital control processor (DSP). Linearized without any control. Open loop compensation via DSP may be used to determine higher order linearization. The linearization of the transmitter power amplifier is performed using the open loop gain modulation of the power amplifier.
[0011]
FIG. 1 shows a transceiver circuit 100 that is used to reduce its ACPR by first-order linearization of a power amplifier using open-loop gain modulation of the power amplifier.
The transceiver circuit 100 has a transmission section 105 and a reception section 110 that are selectively connected to an antenna 115 via a duplexer 120. The duplexer 120 selectively determines a signal route based on the frequency. For example, a signal having a receive frequency is substantially sent to the receive section 110 and is substantially isolated from the transmit section 105. Similarly, a signal having a transmission frequency is substantially transmitted from the transmission section 105 to the antenna 115 and is substantially isolated from the reception section 110. The receiving section 110 has an amplifier, for example an LNA 125. The LNA 125 is connected to receive a radio frequency (RF) signal from the antenna 115 via the duplexer 120.
[0012]
The LNA 125 amplifies the received RF signal x ′ (t) and outputs an amplified signal y ′ (t). A first filter called image filter 130 filters the amplified RF signal y ′ (t) and provides the filtered signal to mixer 135. In the embodiment, the image filter 130 is a wideband filter that passes signals within the reception band and blocks signals outside the reception band. Mixer 135 downconverts the filtered RF signal to an intermediate frequency (IF) signal by mixing the filtered RF signal with local oscillation signal 140 from local oscillator 145.
[0013]
The IF signal is filtered by a channel filter 150 having a narrow band, for example. The IF signal filtered from the channel filter 150 is provided to a demodulator unit 155 having an in-phase and quadrature (IQ) demodulator, an automatic gain control (AGC) circuit, and a filter. The demodulator 155 demodulates the received baseband signals I _R (t) and Q _R (t) and outputs them to the reception baseband unit 160. The receiving baseband unit 160 passes the demodulated baseband signal to a processor, eg, a digital signal processor (DSP), via an analog / digital converter for further processing, eg, extracting received information. provide.
[0014]
A transmission baseband unit 165 receives digital information signals I (n) and Q (n) from its DSP and converts these signals into analog transmission baseband signals I (t) and Q (t) for transmission. Convert. In particular, the transmission baseband unit 165 provides the transmission baseband signals I (t) and Q (t) to the modulator unit 170 of the transmission unit 100. The modulator 170 includes an IQ modulator as well as an AGC circuit and filter. The modulator 170 performs filtering, modulation, and further up-conversion to RF using a well-known local oscillator, thereby modulating the baseband signals I (t) and Q (t) into a modulated RF signal s (t ).
[0015]
The modulated RF signal s (t) is amplified by a power amplifier (PA) 175. The power amplifier (PA) 175 outputs the amplified signal a ₁ s (t). The envelope detector 177 receives the RF amplified signal a ₁ s (t) output from the PA 175, detects and extracts the envelope signal e (t) from the received signal, and controls the control port of the PA 175. Provide directly to. The envelope signal e (t) modulates the gain of the PA 175 for linearization.
[0016]
FIG. 2 shows the modulator unit 170 in more detail, along with the PA 175 and envelope detector 177. In particular, the modulator unit 170 includes first and second mixers M1 and M2 that receive baseband signals I (t) and Q (t), respectively. A local oscillator LO provides a reference signal to the mixers M1, M2. The reference signal is phase-shifted 90 degrees by the phase converter 190. The second mixer M2 receives the converted reference signal. The modulated RF output signals of the mixers M1, M2 are provided to the adder 195. The adder 195 combines these output signals and provides an RF signal s (t) to the PA 175 having a gain a1. The PA 175 then amplifies the input RF signal s (t) and sends it to the duplexer 120 to transmit the amplified RF signal a ₁ s (t) to the antenna 115 as shown in FIG. Output.
[0017]
As shown in FIGS. 1 and 2, the RF output a ₁ s (t) of the PA 175 is provided to the envelope detector 177 to reduce distortion and enhance the transmitter ACPR. The envelope detector 177 detects the envelope of the amplified RF signal a ₁ s (t) and outputs an envelope signal e (t) in order to control the gain of the PA 175. Preferably, the envelope signal e (t) changes or modulates the gain of the PA 175 in accordance with the square of the envelope change of the amplified RF signal a ₁ s (t).
[0018]
In particular, if the instantaneous level of the amplified RF signal a ₁ s (t) is reduced by the gain loss of the PA 175 due to, for example, distortion or non-linearization, the gain of the PA 175 is enhanced by the gain modulation. . Such gain compensation has been active indefinitely and enhances its PA gain as the PA output compresses. In contrast, conventional PA gain control detects when the PA signal reaches a certain threshold. In the state where the threshold is reached, the PA gain is reduced to keep the PA signal below the threshold, to prevent saturation or to reduce PA non-linearization.
[0019]
In another embodiment shown in FIG. 8, higher order linearization is performed and the envelope signal e (t) is not directly derived from the envelope of the amplified RF signal a ₁ s (t). Rather, its gain modulated signal, ie its envelope signal e (t), is generated from the transmitted baseband digital signals I (n), Q (n) received by the transmitted baseband unit 165 as shown in FIG. Is done.
[0020]
In order to ease the demand for highly linear PA 175 that consumes high currents, its ACPR is enhanced. In particular, the ACPR is enhanced by performing modulation at PA 175 for linearization. Thus, the gain of PA175 is changed or modulated. As shown in FIGS. 1 and 2, the PA gain is modulated using an envelope signal e (t) obtained from the envelope of the amplified signal a ₁ s (t).
[0021]
Its first linearization is done in accordance with the apparatus shown in FIG. 2, where the mixers M1, M2, adder 195 and local oscillator LO are quadrature amplification of the carrier signal ω _c provided from the local oscillator LO. Perform modulation. The non-linear PA 175 has a voltage or coulometer control gain, and is configured to have equation (1) as shown in FIG. In Equation (1), the PA input signal is x (t), the envelope or gain modulation signal is e (t), and the PA output signal is y (t) given by Equation (1).
[0022]
y (t) = a ₁ [1 + e (t)] x (t) + a ₃ x ³ (t) (1)
4 and 5 show modifications 177 'and 177 "of the envelope detector 177 shown in FIGS. 1 and 2. As shown in FIG. 4, the multiplier 310 receives the amplified output signal y (t). by squaring the output signal y (t), the square output signal, i.e., outputs a y ² (t). Part squared signal y ² (t) is filtered by the filter 320. Part The filter 320 includes, for example, an RC circuit having a resistance R and a capacitor C. Therefore, 1 / τ = 1 / (RC) << ω _c ω _c is a carrier frequency of the RF signal y (t). The filtered signal is provided to an envelope amplifier 330 having a gain E. Thus, for example, E is the envelope gain and is preset during initial calibration.
[0023]
In the embodiment shown in FIG. 5, the power detector 340 replaces the multiplier 310 that receives the PA output signal y (t) and outputs the square signal y ² (t) of the signal. In this embodiment, power detector 340 is a Schottky diode. Since the power signal is related to the square of the voltage signal, the output of the power meter 340 is proportional to the squared voltage signal y ² (t), that is, the same as the output of the multiplier 310 ( FIG. 5).
[0024]
Linearizing the PA175 is a transmitter at the receiver as described in the related application filed simultaneously: “Reduction of Transmitter Induced Cross Modulation in Receiver”. Similar to linearizing LNA 125 to reduce induced intermodulation noise. However, gain compression in PA175 is half of the LNA sensitivity loss. In particular, the envelope gain E is set to approximately 0.5 for LNA intermodulation linearization, whereas it is set to approximately 0.5 for PA linearization.
[0025]
FIG. 6 shows a spectrum 400 of a CDMA transmission signal for an envelope gain E (FIGS. 4 and 5) of approximately 0.65, TO1 = 15 dBm, and transmission power P _TX = 0 dBm. TO1 is the third-order intercept point of PA175 and is a measure of the nonlinearity of PA175. In particular, TO1 increases as PA linearity increases. Its spectrum 400 is for a 30 kHz resolution bandwidth. The ACPR is defined as the ratio of the transmit power (1.23 MHz full bandwidth) to the 30 kHz power at 0.9 MHz frequency offset 405 from the 900 MHz center frequency fc of the center lobe 410. Uncompensated ACPR at a frequency offset from the center frequency fc by the offset frequency f _0ffset is indicated by reference numeral 415 in FIG.
[0026]
The uncompensated transmit signal is indicated by a dashed line, while the compensated transmit signal is indicated by a dotted line, where the envelope gain E is 0.65, as can be seen from point 510 in FIG. It is. As can be seen from the spectrum 400 of FIG. 6, ACPR improves from point AA at about 55 dB to point BB at about 88 dB for a modulator input or source ACPR 420 of about 90 dB. ACPR the compensated at point BB is about, a frequency that is offset from the center frequency f _c by the offset frequency _f 0ffset 405.
[0027]
FIG. 7 shows a simulation 500 of the ratio of double, ie 2E envelope gain, to ACPR for TO1 = 15 dBm and transmitter power P _TX = 0 dBm. From this simulation 500, the optimum value 510 of the envelope gain E is chosen, which is about 0.65 (as used in the spectrum 400 of FIG. 6), where the ACPR of P175 is maximal. From this simulation 500, the optimum value for the envelope gain E is determined and used in the envelope detector as shown in FIGS. Similar to a single third-order nonlinear power amplifier (PA) 175, a two-stage cascaded power amplifier can be used. The ACPR of the two-stage cascade is improved or increased, where each stage contributes equally to a decrease in the third order intercept (TO1). It can be seen that the optimum gain envelope E for the two-stage PA is similar to that of the single-stage PA.
[0028]
Instead of performing gain modulation with an envelope power detector, the same linearization is obtained by performing a simplified open-loop predistortion using a device 600 having a transmitter section 105 ′, as shown in FIG. It is possible. For clarity, the portion of the transceiver shown in FIG. 1 is not shown in FIG. However, the apparatus 600 is part of a transceiver similar to the transceiver 100 shown in FIG. Thus, envelope detector 177 has been eliminated and is not used to generate the envelope or modulated signal e (t). Instead, the envelope signal e (t) is generated from the time varying baseband signals I (t), Q (t) provided from the transmit baseband unit 165, or provided from a processor, eg, DSP. Generated from digital signals I (n), Q (n).
[0029]
As shown in FIG. 8, the DSP outputs transmission digital baseband signals I (n) and Q (n). These signals I (n) and Q (n) are amplified by the PA 175 for transmission via the antenna 115. In particular, the digital baseband signals I (n) and Q (n) are converted to analog form by digital / analog converters 610 and 615 and further filtered by filters 620 and 625, respectively. Signals I (n) and Q (n). These signals are provided to the PA 175 in the same manner as described with reference to FIG.
[0030]
Instead of an envelope detector that detects the RF envelope input to the PA 175, the envelope signal e (t) used to modulate the PA 175 as described with reference to FIG. It is obtained directly from the digital baseband signals I (n) and Q (n) in the loop device 600. In particular, squaring units 630 and 635 square the digital baseband signals I (n) and Q (n), respectively, and provide the squared digital IQ signal to adder 640. The adder 640 adds the square digital signals I 2 (n) and Q 2 (n) and provides the addition result to the work function generator f _(x) 650. The output of the work function generator f _(x) 650 is converted into an analog voltage by a digital / analog converter (D / A) 655 to become an envelope signal e (t). The envelope signal e (t) is provided via a filter 670 to the control port of the voltage controlled PA 175 for modulating its gain. The anti-aliasing filter 670 removes unnecessary high frequency signals from the output of the D / A 655.
[0031]
The work function f _(x) is given by equation (2).
f _(x) = w ₁ x + w ₂ x ² + w ₃ x ³ + ... w _i x ⁱ + ... (2)
The mobile phone has all the coefficients w _i for the maximum ACPR.
[Outside 1]

[0033]
It is calibrated during production. For example, where
[0034]
[Outside 2]

[0035]
Is the average transmission power at the output of PA175. In an embodiment, this calibration is performed with a 0.9 MHz offset in the cellular band. The calibrated result is stored in the memory of the mobile phone. During operation, for example, the coefficient w _i is
[0036]
[Outside 3]

[0037]
For that set value.
[0038]
The open loop linearization performed in the transceiver 600 shown in FIG. 8 requires calibration in order to determine the optimum values of all coefficients. On the other hand, using envelope detector 177 for the PA feedback of transceiver 100 shown in FIG. 1 requires only simple calibration because PA 175 is modulated by a signal that changes with the input of PA 175. . This simple calibration may be performed only at a single point, eg, maximum transmission power P _TX at one specific transmission frequency f _TX .
[0039]
Unlike the linearization technique using the constant value E described above with reference to FIG. 1, the predistortion of the PA, as shown in FIG. 8, is often the baseband signals I (t) and Q (t ) Is not used for power control, the envelope gain E needs to change linearly with transmit power. Its total envelope gain is given by equation (3).
[0040]
[Expression 1]

[0041]
here,
[0042]
[Outside 4]

[0043]
Is the average transmission power of the linearized nonlinear device, i.e. PA175.
In another embodiment of the present invention, a method for increasing ACPR is provided. In particular, these methods include increasing ACPR by using envelope signal e (t) to modulate the gain of PA175. In one method using the transceiver 600 of FIG. 8, the envelope signal e (t) is derived from the transmission baseband signal provided to the transmission baseband unit 165 (FIG. 1). In another method, the envelope signal e (t) is derived directly from the output of the PA 175 using an envelope detector 177, as shown in FIGS. The envelope detector 177 detects the envelope of the RF output signal a ₁ s (t) provided to the PA 175.
[0044]
The preferred embodiments of the invention described above are not intended to limit the invention. Any person skilled in the art can make various changes and modifications within the spirit and scope of the present invention. Therefore, the protection scope of the present invention conforms to the claims.
[Brief description of the drawings]
FIG. 1 shows a transceiver circuit having a power amplifier (PA) according to the present invention, showing that the PA is modulated by an envelope signal derived directly from the PA output using an envelope detector. .
2 shows in more detail a modulator unit as part of the transceiver circuit shown in FIG. 1 according to the invention.
3 is a diagram showing a voltage or current control amplifier, such as a power amplifier or LNA, used in the transceiver circuit shown in FIG. 1 according to the present invention.
4 is a diagram showing a different example of an envelope detector used in the transceiver circuit shown in FIG. 1 according to the present invention.
FIG. 5 is a diagram showing a different example of the envelope detector used in the transceiver circuit shown in FIG. 1 according to the present invention.
FIG. 6 is a diagram illustrating a spectrum of a CDMA transmitted signal according to the present invention.
FIG. 7 is a plot of doubled envelope gain versus ACPR according to the present invention.
FIG. 8 shows a transceiver circuit with open loop power amplifier gain modulation for ACPR enhancement according to another embodiment of the present invention.
[Explanation of symbols]
100 transceiver circuit 105 transmission section 110 reception section 115 antenna 120 duplexer 130 image filter 135 mixer 140 local oscillation signal 145 local oscillator 150 channel filter 155 demodulator unit 160 reception baseband unit 165 transmission baseband unit 170 modulator unit 175 Power amplifier (PA)
177 Envelope detector 190 Phase converter
M1, M2 Mixer 310 Multiplier 320 Filter 330 Envelope amplifier 340 Power detector 400 Spectrum 500 Simulation 610, 615, 655 D / A converter 620, 625, 670 Filter 630, 635 Square unit 650 Work function generator f _{(x )}

Claims (7)

A receiver for receiving a signal from the duplexer;
A baseband unit that outputs a baseband signal;
A modulator that modulates the baseband signal and outputs a modulated signal;
A transmission amplifier that amplifies the modulated signal and outputs a transmission signal to the duplexer ;
An envelope detector for obtaining an envelope signal from the transmission signal and supplying the envelope signal directly to the transmission amplifier in order to adjust a gain of the transmission amplifier;
Transceiver characterized in that it comprises a.   The transceiver according to claim 1, wherein the envelope signal is proportional to the power of the transmission signal. A baseband unit that outputs a baseband signal;
A modulator that modulates the baseband signal and outputs a modulated signal;
A transmission amplifier that amplifies the modulated signal and outputs a transmission signal ;
A work function generator for generating a work function from the baseband signal, wherein the work function includes a plurality of frequency coefficients;
A digital / analog converter for converting the work function into an analog voltageized envelope signal;
An envelope signal supplier for supplying the envelope signal to the transmission amplifier to control the gain of the transmission amplifier;
Transmitter comprising: a. A method for increasing the adjacent channel power ratio of a transmitter, comprising:
A baseband signal is formed by the baseband unit,
Modulating the baseband signal to form a modulated signal;
Amplifying the modulated signal using a transmit amplifier to provide a transmit signal to the duplexer;
Generating a work function including a plurality of frequency coefficients from the baseband signal;
Converting the work function into an analog voltageized envelope signal;
Supplying the envelope signal to the transmit amplifier;
Using the envelope signal proportional to the transmission signal, the method comprising the step of adjusting the gain of said transmission amplifier. The method of claim 4 , wherein the envelope signal is proportional to the power of the transmitted signal. A method for increasing the adjacent channel power ratio of a transmitter, comprising:
It amplifies the transmission signal by the amplifier of the transmitter,
Transmitting the amplified transmission signal via a duplexer;
Obtaining an envelope signal proportional to the power of the amplified transmission signal from the amplified transmission signal;
A method comprising the steps of supplying the envelope signal directly to the amplifier to adjust the gain of the amplifier . 4. The transmitter of claim 3, wherein the transmitter is calibrated with each power coefficient associated with each frequency coefficient.

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