Plural feedback loop digital frequency synthesizer
    2.
    发明授权
    Plural feedback loop digital frequency synthesizer 失效
    多路反馈回路数字频率合成器

    公开(公告)号:US4912432A

    公开(公告)日:1990-03-27

    申请号:US339534

    申请日:1989-04-17

    IPC分类号: H03L7/16 H03L7/22 H03L7/23

    CPC分类号: H03L7/23

    摘要: A multiple feedback loop frequency synthesizer, having a first and a second feedback loop, each fed by one of a pair of reference frequency signals having a frequency separation equal to the desired frequency separation of the output signals provided by the synthesizer. The frequency of each of such reference frequency signals is greater than the desired frequency separation of the output signals provided by the synthesizer. With such arrangement, because the bandwidth of each of the feedback loops must be less than the frequency of the reference frequency signal fed to such loop, achievement of frequency separation less than the frequency of either one of the reference frequencies enables each of the feedback loops to have increased bandwidth and hence reduced frequency switching times and increased noise suppression.

    Signal tracking electronically tunable filter
    3.
    发明授权
    Signal tracking electronically tunable filter 失效
    信号跟踪电子可调谐滤波器

    公开(公告)号:US5019792A

    公开(公告)日:1991-05-28

    申请号:US425144

    申请日:1989-10-23

    IPC分类号: H01P1/218 H03J7/02

    CPC分类号: H01P1/218 H03J7/02

    摘要: A tunable bandpass filter for radio frequency energy with a phase-locked loop for tracking an input signal and to control the filter to keep the center frequency of the passband coincident with the frequency of the input signal is shown. Using a Yttrium Iron Garnet (YIG) filter as a frequency determining element and as a passive dispersive reference element for a frequency discriminator, the bandpass filter uses the output signal of the discriminator to form a fine tuning signal to control the center frequency of the passband of the YIG filter.

    摘要翻译: 示出了用于射频能量的可调谐带通滤波器,其具有用于跟踪输入信号的锁相环并且控制滤波器以保持通带的中心频率与输入信号的频率一致。 使用钇铁石榴石(YIG)滤波器作为频率确定元件,并作为用于鉴频器的无源色散参考元件,带通滤波器使用鉴频器的输出信号形成微调信号,以控制通带的中心频率 的YIG滤波器。

    Automatic gain controlled frequency discriminator for use in a phase
locked loop
    4.
    发明授权
    Automatic gain controlled frequency discriminator for use in a phase locked loop 失效
    用于锁相环的自动增益控制鉴频器

    公开(公告)号:US4510463A

    公开(公告)日:1985-04-09

    申请号:US487778

    申请日:1983-04-22

    IPC分类号: H03D3/22 H03L7/02

    摘要: A frequency discriminator having a wide capture band is shown to comprise, in addition to a conventional phase detector having two channels fed by a signal whose frequency is to be determined (the first one of the channels containing a tuned circuit operative to shift the phase of the signal in accordance with the difference between the frequency of the signal and the center frequency of the tuned circuit and the second one of the channels containing a phase shifter operative to shift the phase of the signal by 90.degree. regardless of the frequency of the signal), a compensating circuit operative substantially to equalize the amplitudes of the signals applied to the phase detector, the compensating circuit including an amplifier in the first one of the channels to amplify the signal out of the tuned circuit, the gain of the amplifier being controlled by a signal indicative of the difference between the amplitudes of the signals fed to the phase detector.

    摘要翻译: 具有宽捕获带的鉴频器除了具有由要被确定频率的信号馈送的两个信道的常规相位检测器之外还包括(第一个信道包含调谐电路,该调谐电路可操作以使 根据信号的频率和调谐电路的中心频率之间的差异以及包含移相器的通道的第二个信号的信号可操作以将信号的相位偏移90°,而不管信号的频率如何 ),补偿电路基本上用于均衡施加到相位检测器的信号的幅度,补偿电路包括在第一通道中的放大器以放大调谐电路中的信号,放大器的增益被控制 通过表示馈送到相位检测器的信号的幅度之间的差异的信号。

    Ferrite phase shifter having conductive material plated around ferrite
assembly
    5.
    发明授权
    Ferrite phase shifter having conductive material plated around ferrite assembly 失效
    具有导电材料的铁素体相变材料在铁素体组件周围

    公开(公告)号:US4001733A

    公开(公告)日:1977-01-04

    申请号:US605789

    申请日:1975-08-18

    IPC分类号: H01P1/195 H01P1/40

    CPC分类号: H01P1/195

    摘要: A radio frequency phase shifter suitable for X-band operation is disclosed. Such phase shifter incudes a waveguide structure and a ferrite assembly disposed within such waveguide structure. The ferrite assembly has a conductive material plated on the sides thereof. A pair of such plated sides is in contact with the wide walls of the waveguide structure thereby preventing the generation of longitudinal section modes (i.e. LSE.sub.1,1, LSM.sub.1,1, and LSE.sub.1,2) and another pair of such plated walls is displaced from the narrow walls of such waveguide structure to form a pair of waveguide sections cut off to the dominant mode of the radio frequency energy passing through the ferrite phase shifter thereby inhibiting such energy from coupling to wires passing through such waveguide sections for supplying drive current to the enclosed ferrite assembly. Because the waveguide structure may be flexed and has a width greater than the width of the ferrite assembly, the ferrite assembly may be inserted within the waveguide structure, when flexed, to provide the desired contact between the plated sides of the ferrite assembly and the wide walls of the waveguide structure when the latter returns to its original dimensions.

    Low noise magnetically tuned resonant circuit
    7.
    发明授权
    Low noise magnetically tuned resonant circuit 失效
    低噪声磁调谐谐振电路

    公开(公告)号:US4758800A

    公开(公告)日:1988-07-19

    申请号:US33306

    申请日:1987-04-02

    CPC分类号: H01P1/218

    摘要: A magnetically tuned resonant circuit having improved noise performance includes a ferrimagnetic or gyromagnetic body such as a YIG sphere which is disposed within r.f. structure, The r.f. structure is disposed between a pair of pole pieces of a biasing magnet and flux return path. Several techniques are described for reducing fluctuations in magnetic fields through the gyromagnetic body. The gyromagnetic body is isolated from conductive surfaces, or the bulk of conductive surfaces in the region adjacent to the magnetic body are reduced. Further, a technique is also described which provides a break in the electrical continuity around the r.f. structure. Each of these technique reduce the magnitude of thermally induced eddy current flow in conductive regions adjacent to the resonant body. It is believed that such eddy current flow produce random magnetic field variations which produce random variations in the frequency characteristics of conventional magnetically tuned resonant circuits.