中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

46 records (took 0.021 seconds)

    Tone-controlled speech scrambler
    3.
    发明授权
    Tone-controlled speech scrambler 失效
    音调控制的语音扫描器

    公开(公告)号：US3624297A

    公开(公告)日：1971-11-30

    申请号：US3624297D

    申请日：1969-04-21

    Applicant: MOTOROLA INC

    Inventor： CHAPMAN RONALD H

    IPC: H04K1/04 ,  H04M1/70 ,  H04M3/16

    CPC classification number: H04K1/04

    Abstract: A speech-coding or scrambling system which operates by changing a speech signal by means of an inverter signal, also incorporates a tone signal outside of the speech frequency band to inform the receiver that the speech is being coded. Upon the receipt of the tone signal the receiver automatically operates to decode the received signal.

    Multifrequency receiver with automatic channel selection and priority channel monitoring
    4.
    发明授权
    Multifrequency receiver with automatic channel selection and priority channel monitoring 失效
    具有自动通道选择和优先通道监控的多功能接收机

    公开(公告)号：US3614621A

    公开(公告)日：1971-10-19

    申请号：US3614621D

    申请日：1969-08-08

    Applicant: MOTOROLA INC

    Inventor： CHAPMAN RONALD H ,  MOORE GEORGE G

    IPC: H04B1/40 ,  H03J5/24 ,  H03J7/18 ,  H03J7/20 ,  H04B1/16 ,  H04B1/36

    CPC classification number: H03J5/246 ,  H03J7/18

    Abstract: A channel scanning and priority channel monitoring circuit for a multifrequency receiver utilizes a bistable multivibrator to control the local oscillator frequencies corresponding to the channels, with one output of the multivibrator corresponding to the priority channel. A low-frequency free-running oscillator and a pair of monostable delay circuits, having a relatively short time interval, produce pulses to change the state of the multivibrator. With no signals being detected on any of the channels, the multivibrator is controlled by the monostable delay circuits to provide a relatively rapid sequential scanning of the channels. Detection of a carrier on a nonpriority channel, however, shifts control of the bistable multivibrator to the free-running oscillator to reset the bistable multivibrator to scan the priority channel, whereupon control is returned to the monostable circuits. Provision is made for attenuating the audio output whenever a nonpriority channel is being received and for increasing the sensitivity of the squelch circuit whenever a nonpriority channel is being scanned.

    Active filter for selecting and controlling signals
    6.
    发明授权
    Active filter for selecting and controlling signals 失效
    主动过滤器用于选择和控制信号

    公开(公告)号：US3696252A

    公开(公告)日：1972-10-03

    申请号：US3696252D

    申请日：1970-11-20

    Applicant: MOTOROLA INC

    Inventor： CHAPMAN RONALD H

    IPC: H04W88/02 ,  H03K1/16

    CPC classification number: H04W88/027

    Abstract: The signal control circuit utilizes an active, bandpass filter having a first resonant frequency virtually equal to the frequency of a first input signal selected thereby. An amplitude responsive circuit changes the resonant frequency of the filter to a second predetermined value during the times that the instantaneous magnitude of the output signal, provided in response to the first input signal, exceeds a threshold level. This action maintains the amplitude of the output signal at a substantially constant level even though the amplitude of the first input signal is varying. Moreover, the threshold level and second resonant frequency are chosen so that the phase difference between the first input signal and the output signal remains relatively constant even though the frequency of the first input signal is varying so that the output signal can be damped out by a second input signal having a selected phase relationship to the first input signal.

    Abstract translation: 信号控制电路利用有源带通滤波器，该有源带通滤波器的第一谐振频率基本上等于由此选择的第一输入信号的频率。 在响应于第一输入信号提供的输出信号的瞬时幅度超过阈值水平的时间内，幅度响应电路将滤波器的谐振频率改变为第二预定值。 即使第一输入信号的幅度变化，该动作将输出信号的幅度保持在基本恒定的水平。 此外，选择阈值电平和第二谐振频率，使得即使第一输入信号的频率变化，第一输入信号和输出信号之间的相位差保持相对恒定，使得输出信号可被 第二输入信号与第一输入信号具有选定的相位关系。

    Oscillator having feedback amplitude control and switchable output phase shifter
    7.
    发明授权
    Oscillator having feedback amplitude control and switchable output phase shifter 失效
    具有反馈幅度控制和可切换输出相位振荡器的振荡器

    公开(公告)号：US3609578A

    公开(公告)日：1971-09-28

    申请号：US3609578D

    申请日：1970-03-18

    Applicant: MOTOROLA INC

    Inventor： CHAPMAN RONALD H ,  MICHALIK JAMES J

    IPC: H03B5/30 ,  H03B3/02 ,  H03B27/00

    CPC classification number: H03B5/30

    Abstract: An oscillator circuit for providing a constant amplitude output tone includes a differential amplifier and a frequency-selective, feedback network. A regulating circuit is connected from an oscillator output to the feedback network, and as the output of the oscillator exceeds a predetermined threshold, the regulating circuit develops a regulating signal which is proportional to the amplitude of the output and opposite phase to the feedback signal. This regulating signal and the feedback signal interreact to provide a composite feedback signal whose amplitude is inversely proportional to the oscillator output to thereby hold the output at a preselected level. The oscillator is operable to provide a predetermined phase shift in the output tone.

    Squelch tail eliminator for dual squelch
    9.
    发明授权
    Squelch tail eliminator for dual squelch 失效
    SQUELCH TAIL ELIMINATOR FOR DUAL SQUELCH

    公开(公告)号：US3584304A

    公开(公告)日：1971-06-08

    申请号：US3584304D

    申请日：1969-06-11

    Applicant: MOTOROLA INC

    Inventor： CASTERLINE BURNHAM ,  CHAPMAN RONALD H

    IPC: H03G3/00 ,  H03G3/34 ,  H04B1/10

    CPC classification number: H03G3/005 ,  H03G3/34 ,  H03G3/344

    Abstract: A radio receiver which incorporates dual squelch systems, one system operated by the carrier and the other operated by a coded tone signal, is responsive to the tone signal of the proper frequency to operate the tone coded squelch system and temporarily disable the carrier squelch system when the receiver is in the carrier squelch mode. By permitting the tone coded squelch system to disable the carrier squelch when the proper tone signal is received, noise bursts or squelch tails at the end of a transmission are eliminated.

Patent Agency Ranking