Transmitter with compensation of power amplifier distortion
    4.
    发明公开
    Transmitter with compensation of power amplifier distortion 失效
    发信人Verzerrungskompensation vonLeistungsverstärker

    公开(公告)号:EP0705010A1

    公开(公告)日:1996-04-03

    申请号:EP95115349.3

    申请日:1995-09-28

    申请人: NEC CORPORATION

    IPC分类号: H04L27/20 H03F1/32

    摘要: It is an object of the present invention to provide a transmitter which is inexpensive and small in size and is reduced in power dissipation and besides wherein the output power of a power amplifier can be varied to an arbitrary value.
    A phase modulator, a variable attenuator, a high power amplifier, a directional coupler, a detector, an error amplifier, a switch and an analog multiplier form an envelope feedback loop. The envelope feedback loop controls an envelope of a modulated wave detected by the detector so that a base band signal and the envelope of the modulated wave may coincide with each other. The circuits mentioned above, a smoothing circuit, another error amplifier, another switch and an adder form an operation point feedback loop. The operation point feedback loop smoothes an error of an output envelope detection signal of the detector and controls so that the smoothed error may be in the minimum.
    Accordingly, with the transmitter of the present invention, even if a variation of the gain of the high power amplifier or the like occurs, a reference amplitude signal for the envelope feedback loop to be inputted from a rectifier to the error amplifier is controlled by an ALC loop which feeds back the reference amplitude signal so that a smoothed level of a root mean square value of the envelope detection signal and a first reference voltage may coincide with each other, and a fixed output power corresponding to the first reference voltage is obtained at an output terminal.

    摘要翻译: 本发明的目的是提供一种廉价且体积小并且功率消耗降低的发射机,此外,功率放大器的输出功率可以变化到任意值。 相位调制器,可变衰减器,高功率放大器,定向耦合器,检测器,误差放大器,开关和模拟乘法器形成包络反馈回路。 包络反馈环控制由检测器检测到的调制波的包络,使得基带信号和调制波的包络彼此一致。 上述电路,平滑电路,另一误差放大器,另一开关和加法器构成操作点反馈回路。 操作点反馈环路平滑检测器的输出包络检测信号的误差,并进行控制,使得平滑的误差可能最小。 因此,利用本发明的发射机,即使发生高功率放大器等的增益的变化,也可以将由整流器输入到误差放大器的包络反馈回路的基准振幅信号由 ALC回路,其反馈参考振幅信号,使得包络检测信号的均方根值的平滑化水平和第一参考电压可以彼此一致,并且获得与第一参考电压相对应的固定输出功率 输出端子

    Balanced phase modulator used in microwave band
    5.
    发明公开
    Balanced phase modulator used in microwave band 失效
    平衡相位调制器用于微波频段

    公开(公告)号:EP0645916A3

    公开(公告)日:1995-09-13

    申请号:EP94115048.4

    申请日:1994-09-23

    申请人: NEC CORPORATION

    IPC分类号: H04L27/20 H03C7/02

    CPC分类号: H03C7/027

    摘要: A phase modulator for microwave band having a desirable modulation characteristic by maintaining the impedance thereof constant, comprising two PIN diodes (2) and (3) connected to a merchant balun (1) and a bias circuit (18) which supplies bias voltages to the PIN diodes (2) and (3) such that the sum of the bias voltages applied to the diodes (2)and (3) to be constant. The bias voltages are selected so as to have the input and output impedances to be in the most stable state when a modulation signal is equal to zero.

    摘要翻译: 一种通过保持其阻抗恒定而具有所需调制特性的微波频带相位调制器,包括连接到商用平衡 - 不平衡变换器(1)的两个PIN二极管(2)和(3),以及偏置电路(18) PIN二极管(2)和(3)使得施加到二极管(2)和(3)的偏置电压的总和恒定。 选择偏置电压以使得当调制信号等于零时输入和输出阻抗处于最稳定状态。