公开(公告)号：US3835399A

公开(公告)日：1974-09-10

申请号：US36663873

申请日：1973-06-04

申请人： HOLMES R

发明人： HOLMES R

IPC分类号： H03H11/12 ,  H03H11/48 ,  H03J7/02 ,  H03J7/04 ,  H03L7/081 ,  H03B1/04

CPC分类号： H03H11/1252 ,  H03H11/485 ,  H03J7/02 ,  H03J7/04 ,  H03L7/0812

摘要： A stable tunable Q bandpass filter adapted to have its parameters dynamically varied over a wide range of bandwidths and center frequencies. The filter includes a capacitor and a network coupled in parallel across the capacitor. The network includes a plurality of operational amplifiers coupled to simulate an inductor without utilizing coils. A feature of the filter is that it can be readily made adaptive to track an input signal which may randomly vary in frequency. A further feature of the invention is to have one input of each operational amplifier coupled directly to ground to minimize stray capacitance. The performance characteristics of this filter are in part attained by the method of component layout and shielding techniques used, in addition to the method of circuit excitation.

摘要翻译： 一个稳定的可调Q带通滤波器，适用于其参数在宽带宽和中心频率范围内动态变化。 滤波器包括电容器和并联在电容器上的网络。 该网络包括多个运算放大器，其耦合以在不利用线圈的情况下模拟电感器。 滤波器的特征在于可以容易地自适应地跟踪频率可能随机变化的输入信号。 本发明的另一个特征是使每个运算放大器的一个输入直接耦合到地，以使杂散电容最小化。 除了电路激励的方法之外，该滤波器的性能特征部分地通过使用的部件布局和屏蔽技术的方法来实现。

公开(公告)号：US3787774A

公开(公告)日：1974-01-22

申请号：US3787774D

申请日：1972-08-28

申请人： HEWLETT PACKARD GMBH

发明人： TIETZE U ,  COURTIN E ,  TRAUB S

IPC分类号： H03H11/12 ,  H03B1/04

CPC分类号： H03H11/1217

摘要： Circuitry for filtering a distinct variable spectral component includes a band-rejection filter formed by a summing amplifier with a feedback loop and a bandpass-filter connected to one of its inputs. The summing amplifier is connected to form the difference between the unfiltered spectrum at one of its inputs and the spectrum component to be suppressed at another of its inputs. The summing amplifier delivers the filtered signal spectrum at its output. A control circuit locks the common center frequency of the bandpass and band-rejection filters to the frequency of the spectral component to be suppressed.

摘要翻译： 用于对不同可变频谱分量进行滤波的电路包括由具有反馈回路的求和放大器和连接到其输入之一的带通滤波器形成的带阻滤波器。 该相加放大器连接以形成其输入端之一的未滤波频谱与待抑制在另一输入端的频谱分量之间的差值。 求和放大器在其输出端提供滤波后的信号频谱。 控制电路将带通和带阻滤波器的公共中心频率锁定到待抑制的频谱分量的频率。

公开(公告)号：US3755749A

公开(公告)日：1973-08-28

申请号：US3755749D

申请日：1971-11-22

申请人： WHITE INSTR INC

发明人： VAN RYSWYK C ,  BONER C

IPC分类号： H03H11/12 ,  H03B1/04 ,  H04B1/10

CPC分类号： H03H11/1217

摘要： An active filter in combination with a sound reenforcement equalization system is provided. The filter permits variation of the notch frequency over a wide range of frequencies and adjustment of the notch depth from zero to any desired value independent of frequency control. Active filters may be cascaded without additional loss in the pass band.

摘要翻译： 提供了一种与声音增强均衡系统相结合的有源滤波器。 滤波器允许在宽范围的频率上改变陷波频率，并且将陷波深度从零调整到与频率控制无关的任何期望值。 有源滤波器可以级联，而在通带中没有额外的损耗。

公开(公告)号：US3714588A

公开(公告)日：1973-01-30

申请号：US3714588D

申请日：1970-10-13

申请人： NASA

发明人： DEBOO G ,  HEDLUND R

IPC分类号： H03H11/12 ,  H03J7/08 ,  H03B1/04

CPC分类号： H03J7/08 ,  H03H11/1291

摘要： An electronic filter which simultaneously maintains a constant bandwidth and a constant center frequency gain as the input signal frequency varies, and remains self-tuning to that center frequency over a decade range. The filter utilizes a field effect transistor (FET) as a voltage variable resistance in the bandpass frequency determining circuit. The FET is responsive to a phase detector to achieve self-tuning.

公开(公告)号：US3631353A

公开(公告)日：1971-12-28

申请号：US3631353D

申请日：1969-10-24

申请人： SINGER CO

发明人： JARECKI HERBERT S ,  RUTHERFORD E ,  NAYDAN BOB N

IPC分类号： G01R19/22 ,  H03B1/04

CPC分类号： G01R19/22

摘要： A method of converting an AC voltage to a DC voltage corresponding substantially to the fundamental sinusoidal AC components by dropping said AC voltage through an input line across a series resistor and parallel capacitor, to an output line, comprising the step of opening up the input line at a predetermined time of the changing input sinusoidal voltage depending on its frequency and the values of the capacitor and resistor so as to obtain a DC voltage having a large percentage of the AC sinusoidal fundamental component while minimizing the effects of the harmonic and quadrature content.

公开(公告)号：US3628154A

公开(公告)日：1971-12-14

申请号：US3628154D

申请日：1968-05-31

申请人： LAWRENCE R WEILL

发明人： WEILL LAWRENCE R

IPC分类号： H03D7/00 ,  H04B1/26 ,  H03B1/04

CPC分类号： H03D7/00 ,  H03D2200/0021 ,  H03D2200/0027 ,  H03D2200/006

摘要： Simple switches are used for shifting a signal band, fo, to a new location, fo+f1, without distortion. The band is split into two opposed phases, chopped with square waves of frequencies f1 and odd harmonies 3f1, 5f1, etc., which are weighted in amplitude by the factors 1, one-third, one-fifth, etc., and are finally added. Unwanted components 3f1, 5f1, etc., are found to be easily canceled, obviating a difficult filtering problem.

公开(公告)号：US3621407A

公开(公告)日：1971-11-16

申请号：US3621407D

申请日：1970-02-27

申请人： NASA

发明人： KERWIN WILLIAM J ,  SHAFFER CHARLES V

IPC分类号： H03B5/20 ,  H03H11/12 ,  H03B1/04

CPC分类号： H03B5/20 ,  H03H11/1204

摘要： A multiloop RC active filter network having low parameter sensitivity with low amplifier gain comprising at least two passive components and two voltage amplifiers one of which has a positive gain K1 which is less than unity and the other providing a negative gain of magnitude of K2 in the outer feedback loop. These circuits can provide any Q and can be made to oscillate with K1 and K2 within certain given ranges. Monolithic integrated circuit thick or thin film techniques are used in the preferred embodiment to provide the passive RC components.

公开(公告)号：US3611165A

公开(公告)日：1971-10-05

申请号：US3611165D

申请日：1970-06-30

申请人： NAT RES DEV

发明人： HILLS MICHAEL

IPC分类号： H03H11/34 ,  H03B1/04

CPC分类号： H03H11/34

摘要： An electrical frequency filter of the kind having several filter units covering adjacent passbands has negative feedback between adjacent units to tend to cancel unwanted frequencies.

公开(公告)号：US3596203A

公开(公告)日：1971-07-27

申请号：US3596203D

申请日：1969-01-02

申请人： NIPPON ELECTRIC CO

发明人： SAKAMOTO KAZUO ,  TAMURA RYOJI

IPC分类号： H03B1/04 ,  H03B5/18

CPC分类号： H03B5/1805 ,  H03B2202/05

摘要： Oscillator apparatus is provided in accordance with the teachings of this invention wherein the total output power as well as the power consumed thereby is equally divided among a plurality of transistor means. The resulting transistorized oscillator apparatus is particularly well adapted for high frequency, high power applications because high frequency transistor means may be appropriately utilized therein without exceeding the rated collector dissipation of such transistor means. According to one embodiment of the present invention, oscillator apparatus is described wherein a plurality of transistors are individually coupled to high Q tuned circuit means through a plurality of impedance matching means interposed between the inputs to said high Q tuned circuit means and each of said plurality of transistor means. The output of the oscillator apparatus may then be made available to a load through load matching circuit means connected to said high Q tuned circuit means. The loaded Q of the high Q tuned circuit means is selected to be sufficiently above that exhibited by said impedance matching means and said load matching circuit means so that the frequency of said oscillator means determines the oscillation frequency of said oscillator apparatus and maintains the reactive portion of the overall impedance thereof at a constant value whereby said impedance matching means may be independently adjusted to match the impedance of its respective transistor means to the impedance of high Q tuned circuit means without adversely effecting any of the other transistor means present therein.

公开(公告)号：US3555439A

公开(公告)日：1971-01-12

申请号：US3555439D

申请日：1968-04-16

申请人： RANK ORGANISATION LTD

发明人： STARR ARTHUR TISSO ,  REEVE THOMAS CHARLES

IPC分类号： G01R23/165 ,  G01B21/30 ,  H03H11/04 ,  H03H11/12 ,  H03H15/00 ,  H03H17/06 ,  H03B1/04

CPC分类号： H03H15/00 ,  H03H11/04

摘要： AN ELECTRIC SIGNAL INCLUDING HIGH AND LOW FREQUENCY COMPONENTS IS (A) FILTERED TO REMOVE THE HIGH FREQUENCIES WITHOUT DISTORTING THE LOW FREQUENCIES, AND (B) DELAYED TO SYNCHRONISE IT, WITHOUT DISTORTION, WITH THE FILTERED SIGNALS. THE FILTERED SIGNAL IS SUBTRACTED FROM THE DELAYED SIGNAL TO PROVIDE A SIGNAL COMPRISING THE UNDISTORED HIGH FREQUENCY COMPONENT.