Multi-band tuner
    1.
    发明授权
    Multi-band tuner 失效
    多频调谐器

    公开(公告)号:US4115737A

    公开(公告)日:1978-09-19

    申请号:US851283

    申请日:1977-11-14

    摘要: A tuner for receiving signals broadcast on two spaced bands, each divided into several channels, has two fixed bandpass filters, one to pass all of the channels in the lower band between the lowest frequency f.sub.P of the lowest channel and the highest frequency f.sub.S of the highest channel of the lower band, and the other to pass all of the channels in the upper frequency band between the lowest frequency f.sub.T of the lowest channel and the highest frequency f.sub.W in the highest channel of the upper band. The bandwidth of each channel is f.sub.B. The tuner includes an amplifier and a third filter to which signals of either band are supplied by selective operation of a switch. The third filter has a cut-off frequency below the second harmonic of the lowest frequency of the upper band to simplify the avoidance of image interference from second harmonic signals of the band. A tunable local oscillator supplies a heterodyning signal to the mixer to convert any selected channel of the received signal to an intermediate frequency (i.f.) band, and image interference is avoided by setting the local oscillator frequency f.sub.n required to convert channel n to the i.f. at a frequency above that channel such that the lowest frequency f.sub.L of the i.f. band satisfies the following conditions: ##EQU1##

    摘要翻译: 用于接收在两个间隔的频带上广播的信号的调谐器,每个分成几个信道,具有两个固定带通滤波器,一个通过最低信道的最低频率fP和最低频率的最高频率fS之间的较低频带中的所有信道 较低频带的最高频道,另一方通过最高频带的最低频率fT和上频段最高频道中最高频率fW之间的上频段中的所有频道。 每个通道的带宽为fB。 调谐器包括放大器和第三滤波器,通过开关的选择性操作来提供任一频带的信号。 第三滤波器具有低于上频带最低频率的二次谐波的截止频率,以简化避免来自频带二次谐波信号的图像干扰。 可调本地振荡器向混频器提供外差信号以将接收信号的任何所选信道转换为中频(i.f.)频带,并且通过将通道n转换为i.f来设置所需的本地振荡器频率fn来避免图像干扰。 在该频道之上的频率处,使得i.f.的最低频率fL。 带满足以下条件:(1)(2)和或(3)

    Multi-band tuner with fixed broadband input filters
    2.
    发明授权
    Multi-band tuner with fixed broadband input filters 失效
    带固定宽带输入滤波器的多频调谐器

    公开(公告)号:US4132952A

    公开(公告)日:1979-01-02

    申请号:US873963

    申请日:1978-01-31

    摘要: A tuner for receiving signals broadcast on two spaced bands, each divided into several channels, has two fixed bandpass filters, one to pass all of the channels in the lower frequency band and the other to pass all of the channels in the higher frequency band. The tuner includes a mixer to which signals of either band are supplied by selective operation of a double-throw switch. A tunable local oscillator supplies a heterodyning signal to the mixer to convert any selected channel of the received signal to an intermediate frequency (i.f.) band chosen to avoid image interference from undesired channels, whether the local oscillator frequency is above or below the selected channel. To ease the constraints on the choice of the i.f. band, different i.f. filters tuned to first and second i.f. bands may be used for the higher and lower received bands. A second double-throw switch ganged with the first switch can then be used to direct the heterodyned signals to the proper i.f. filter.

    High frequency modulator, such as an amplitude modulator, including a
frequency multiplier
    3.
    发明授权
    High frequency modulator, such as an amplitude modulator, including a frequency multiplier 失效
    高频调制器,例如幅度调制器,包括倍频器

    公开(公告)号:US3974460A

    公开(公告)日:1976-08-10

    申请号:US576737

    申请日:1975-05-12

    摘要: A high-frequency modulator circuit including a frequency multiplier comprised of a first differential amplifier for receiving a base oscillating signal and for multiplying the frequency of the base oscillating signal to thereby produce a higher frequency carrier signal; and a modulating circuit connected to the first differential amplifier for modulating the carrier signal with input information. The first differential amplifier includes a pair of output terminals; and the modulating circuit is comprised of a second and third differential amplifier, each having a pair of input terminals connected to the respective output terminals of the first differential amplifier such that the higher frequency carrier signal is applied differentially to each of the second and third differential amplifiers. The second and third differential amplifiers each includes a pair of output terminals, the second differential amplifier output terminals being connected to oppositely phased ones of the third differential amplifier output terminal. The input information is supplied to at least one of the second and third differential amplifiers to thereby vary the higher frequency carrier currents which flow therethrough.

    摘要翻译: 一种高频调制器电路,包括:频率乘法器,包括用于接收基本振荡信号的第一差分放大器,并且用于乘以基本振荡信号的频率,从而产生较高频率的载波信号; 以及连接到第一差分放大器的调制电路,用于利用输入信息调制载波信号。 第一差分放大器包括一对输出端子; 并且调制电路包括第二和第三差分放大器,每个差分放大器具有连接到第一差分放大器的相应输出端的一对输入端,使得较高频率载波信号被差分地施加到第二和第三差分 放大器 第二和第三差分放大器各自包括一对输出端子,第二差分放大器输出端子连接到第三差分放大器输出端子的相对相位的输出端子。 输入信息被提供给第二和第三差分放大器中的至少一个,从而改变流过其中的较高频率载波电流。

    Gain control circuit
    4.
    发明授权
    Gain control circuit 失效
    增益控制电路

    公开(公告)号:US3968453A

    公开(公告)日:1976-07-06

    申请号:US528935

    申请日:1974-12-02

    CPC分类号: H03G1/0052 H03G3/00 H03G3/02

    摘要: A signal to be controlled is applied to the base of an emitter-follower input transistor, the emitter of which is connected to an input terminal of a differential amplifier. This input terminal of the amplifier is connected by a diode to a controllable current source so that the base current of the differential amplifier input transistor is controlled. A constant current source is connected to the common emitter circuit of the differential amplifier, and the gain of the circuit is determined by the ratio of current in the latter source to current in the controllable source. A current conducting circuit, such as, an emitter load resistor, is connected to the emitter of the input transistor to hold the output impedance thereof at a substantially constant low value inspite of changes in the current of the controllable current source, Maximum gain of the circuit may be determined by separating the controllable current source into a controllable portion and a fixed portion in parallel so that the minimum current is at least as great as the current of the fixed portion. This limits the maximum circuit gain by limiting the maximum ratio of fixed current to controllable current. A fixed voltage source connected to the common circuit point between the controllable current source and the diode assures that the gain of the circuit will not fall below a selected minimum value.

    摘要翻译: 要控制的信号被施加到射极跟随器输入晶体管的基极,其发射极连接到差分放大器的输入端。 放大器的该输入端子通过二极管连接到可控电流源,以便控制差分放大器输入晶体管的基极电流。 恒流源连接到差分放大器的公共发射极电路,电路的增益取决于后者的电流与可控电源电流的比值。 诸如发射极负载电阻器的电流传导电路连接到输入晶体管的发射极,以将其输出阻抗保持在基本上恒定的低值,从可控电流源的电流变化来看,最大增益为 可以通过将可控电流源分成可控部分和平行的固定部分来确定电路,使得最小电流至少与固定部分的电流一样大。 这通过限制固定电流与可控电流的最大比例来限制最大电路增益。 连接到可控电流源和二极管之间的公共电路点的固定电压源确保电路的增益不会低于所选择的最小值。

    Television sound receiver
    5.
    发明授权
    Television sound receiver 失效
    电视声音接收器

    公开(公告)号:US4419695A

    公开(公告)日:1983-12-06

    申请号:US341465

    申请日:1982-01-21

    IPC分类号: H04N5/60

    CPC分类号: H04N5/607

    摘要: A television sound receiver having an input terminal for receiving a television sound signal, a tuner including a local oscillator connected to the input terminal, an intercarrier sound demodulating circuit connected to the tuner, a split-carrier sound demodulating circuit, including a limiter amplifier connected to the tuner, a sound signal output terminal, and a switching device for selectively and operatively connecting either the intercarrier or split-carrier sound demodulating circuits between the tuner and the sound signal output terminal. Additionally, the receiver includes an error detecting device connected to the split-carrier sound demodulating circuit for detecting the frequency error of the local oscillator and a first operational device which is responsive to an output signal from the error detecting device and which produces a first operational device output signal which activates the switching device such that the split-carrier sound demodulating circuit is operatively connected between the tuner and the sound output terminal when the output signal from the error detecting device is less than a predetermined level. Level detectors are connected to the limiter amplifier and detect a level of the split-carrier sound signal. A second operational device, which is responsive to the output signal from the level detectors, produces an output signal which activates the switching device such that the intercarrier sound demodulating circuit is operatively connected between the tuner and the sound output terminal when the output signals from the level detectors are less than a predetermined value.

    摘要翻译: 一种具有用于接收电视声音信号的输入端子的电视声音接收器,包括连接到输入端子的本地振荡器的调谐器,连接到调谐器的载波间声音解调电路,分离载波声音解调电路,包括限幅放大器 调谐器,声音信号输出端子和用于选择性地和可操作地连接调谐器和声音信号输出端子之间的载波间或分离载波声音解调电路的开关装置。 此外,接收机包括连接到分离载波声音解调电路以检测本地振荡器的频率误差的误差检测装置和响应于来自错误检测装置的输出信号并且产生第一操作的第一操作装置 装置输出信号,其激活开关装置,使得当来自误差检测装置的输出信号小于预定电平时,分离载波声音解调电路可操作地连接在调谐器和声音输出端子之间。 电平检测器连接到限幅放大器并检测分离载波声音信号的电平。 响应于来自电平检测器的输出信号的第二操作装置产生激活开关装置的输出信号,使得当来自所述开关装置的输出信号时,载波间声音解调电路可操作地连接在调谐器和声音输出端子之间 电平检测器小于预定值。

    Muting circuit
    6.
    发明授权
    Muting circuit 失效
    静音电路

    公开(公告)号:US4238771A

    公开(公告)日:1980-12-09

    申请号:US886427

    申请日:1978-03-14

    CPC分类号: H04N5/455 H03G3/34 H03G3/348

    摘要: A muting circuit for a television or AM signal receiver which uses a synchronous detector.The muting circuit includes an input terminal for receiving an amplitude modulated signal, a synchronous detector for detecting such AM signal, a circuit for supplying a reference signal having a predetermined frequency and phase to the synchronous detector, an amplifier, a circuit path for delivering to the amplifier the detected signal produced by the synchronous detector, a level detecting device connected to the output of the synchronous detector for producing an excess signal when the detected signal exceeds a predetermined level, an integrator for producing a muting signal in response to the production over an extended period of time of the excess signal, and a switching device connected to the amplifier for muting the signal produced by the amplifier in response to the production of the muting signal.

    摘要翻译: 一种使用同步检波器的电视或AM信号接收机的静音电路。 静音电路包括用于接收幅度调制信号的输入端子,用于检测这种AM信号的同步检波器,用于向同步检测器提供具有预定频率和相位的参考信号的电路,放大器,用于传送到 放大器由同步检测器产生的检测信号,电平检测装置连接到同步检测器的输出端,用于当检测信号超过预定电平时产生过量信号;积分器,用于响应于生产过程产生静噪信号 多余信号的延长的时间段以及连接到放大器的开关装置,用于根据产生的静噪信号使由放大器产生的信号静音。

    Demodulating apparatus with phase shift compensation
    8.
    发明授权
    Demodulating apparatus with phase shift compensation 失效
    具有相移补偿的解调装置

    公开(公告)号:US4163196A

    公开(公告)日:1979-07-31

    申请号:US891279

    申请日:1978-03-29

    CPC分类号: H03D1/22 H03D1/00 H03D1/04

    摘要: Demodulating apparatus for a modulated signal comprised of a carrier deriving circuit which is supplied with the modulated signal and which derives an unmodulated carrier therefrom, the carrier deriving circuit including a tuned circuit having a center frequency substantially coincident with the carrier frequency of the modulated signal and a limiter circuit in which the limiter circuit imparts a phase shift to the signal supplied thereto in connection with its elimination of the amplitude fluctuations in the signal produced by the tuned circuit. A synchronous detector receives the modulated signal and the derived carrier so as to detect the modulated signal with the derived carrier. A phase shift circuit supplies the synchronous detector with a phase shifted modulated signal, the phase shift substantially compensating for the phase shift imparted by the limited circuit in the carrier deriving circuit, whereby the modulated signal and the carrier which are applied to the synchronous detector are substantially in phase with each other.

    摘要翻译: 一种调制信号的解调装置,包括一个载波导出电路,该载波导出电路被提供有调制信号,并从其中导出未调制的载波,该载波导出电路包括调谐电路,该调谐电路的中心频率与调制信号的载波频率基本一致, 限制器电路,其中限制器电路相对于消除由调谐电路产生的信号中的振幅波动而向所提供的信号施加相移。 同步检测器接收调制信号和导出载波,以便用导出的载波检测调制信号。 相移电路为同步检波器提供相移调制信号,相移基本上补偿由载波导出电路中的受限电路产生的相移,由此调制信号和施加到同步检波器的载波是 基本上彼此同相。

    Transistor biasing circuit
    9.
    发明授权
    Transistor biasing circuit 失效
    晶体管偏置电路

    公开(公告)号:US3987317A

    公开(公告)日:1976-10-19

    申请号:US635365

    申请日:1975-11-26

    IPC分类号: H03F1/30 H03K17/00

    CPC分类号: H03F1/302

    摘要: A transistor biasing circuit having a single biasing transistor for biasing first and second operational transistors. The biasing transistor has means connecting its base to its collector and means are provided to connect the base of each of the first and second operational transistors to the collector circuit of the biasing transistor. Each of the three transistors are arranged in a circuit between a pair of voltage terminals which are connected to a power supply. The arrangement of the resistors in the circuit paths of the biasing transistor and the operational transistors are in such a way as to provide circuit means for stabilizing the collector currents of the first and second transistors regardless of variations in the factor of h.sub.FE. This circuit arrangement provides an improved stabilization of the collector currents over prior art devices.

    摘要翻译: 一种晶体管偏置电路,具有用于偏置第一和第二操作晶体管的单个偏置晶体管。 偏压晶体管具有将其基极连接到其集电极的装置,并且提供装置以将第一和第二操作晶体管中的每一个的基极连接到偏置晶体管的集电极电路。 三个晶体管中的每一个被布置在连接到电源的一对电压端子之间的电路中。 偏置晶体管和操作晶体管的电路中的电阻器的排列方式是提供用于稳定第一和第二晶体管的集电极电流的电路装置,而与hFE因子的变化无关。 该电路布置提供了集电极电流相对于现有技术装置的改进的稳定性。

    Synchronous detector particularly adapted for a video IF signal
    10.
    发明授权
    Synchronous detector particularly adapted for a video IF signal 失效
    同步检测器特别适用于视频IF信号

    公开(公告)号:US4234963A

    公开(公告)日:1980-11-18

    申请号:US906406

    申请日:1978-05-16

    CPC分类号: H03D1/24 H03D1/04 H04N5/455

    摘要: A synchronous detector adapted to detect a modulated information signal, such as a video IF signal. The modulated information signal is provided in the form of a vestigial sideband signal. A band-pass filter including a tuned circuit tuned to the frequency of the carrier on which the information signal is modulated has a pass band which is less than the frequency spectrum of the vestigial sideband signal so as to limit the frequency spectrum of the signal passed by the filter to a double sideband signal. A limiter is coupled to the band-pass filter to receive the double sideband signal and for deriving a switching carrier therefrom, the frequency of the switching carrier being equal to the frequency of the carrier on which the information signal is modulated. An emitter-follower circuit is connected between the band-pass filter and the limiter so as to couple the double sideband signal from the filter to the limiter. A multiplier circuit has first input terminals coupled to the limiter for receiving the derived switching carrier and second input terminals for receiving the modulated information signal, whereby the modulated information signal is multiplied with the switching carrier to obtain the information signal.

    摘要翻译: 一种适用于检测诸如视频IF信号的调制信息信号的同步检测器。 调制信息信号以残留边带信号的形式提供。 包括被调谐到信号信号被调制的载波的频率的调谐电路的带通滤波器具有小于残留边带信号的频谱的通带,以限制通过的信号的频谱 通过滤波器到双边带信号。 限幅器耦合到带通滤波器以接收双边带信号并从其导出交换载波,切换载波的频率等于信息信号被调制的载波的频率。 射频跟随器电路连接在带通滤波器和限幅器之间,以将来自滤波器的双边带信号耦合到限幅器。 乘法器电路具有耦合到限幅器的第一输入端子,用于接收导出的切换载波和用于接收调制信息信号的第二输入端,由此将调制信息信号与切换载波相乘以获得信息信号。