Showing papers on "Equivalent series resistance published in 1969"

Electrochemical double layer capacitor

Abstract: An electrolytic double layer capacitor having low series resistance, high capacitance, and low inductance characterized by activated carbon plates of very high true surface to geometric volume ratio separated by a highly porous inert spacer as thin as 0.0005 inch, impregnated with highly concentrated electrolytes such as KOH or H2SO4.

Contact resistance on diffused resistors

Abstract: The electrical behavior of contacts on diffused resistors can be explained by an equivalent transmission line. What contributes to the contact resistance and how the contacts can be optimized will be discussed in this paper.

Geometrically dependent distributed-section transmission line attenuator

Abstract: The attenuators include distributed series and distributed shunt resistance sections which attenuate signals propagating in one direction with minimal distortion and reflection, and attenuate signals propagating in a second direction with equivalent minimal distortion but with significant reflection. In the distributed series and shunt resistance sections, the characteristic impedance, which is determined by the geometry of the transmission structure, varies continuously. Disclosed transmission line attenuators include two distributed series resistance sections separated by a distributed shunt resistance section or two distributed shunt resistance sections separated by a distributed series resistance section. The distributed series resistance is a resistive section in the signal line and the distributed shunt resistance is a section of lossy dielectric between and interconnecting the signal line and the ground conductor.

Nonlinear analysis of the avalanche transit-time oscillator

Abstract: The nonlinear operating characteristics of the avalanche transit-time oscillator are studied by means of Fourier-series representation. For optimum operation, the oscillator must be designed such that start-oscillation conditions are satisfied simultaneously at the first and the second harmonic of the desired oscillation frequency. Under those conditions the oscillation frequency does not depend on the dc bias current; the signal level increases smoothly with bias current. For large signals, the diode exhibits negative resistance for frequencies substantially below the avalanche frequency; the oscillation frequency therefore may be below the avalanche frequency corresponding to the dc bias current required for large-signal operation. A condition for attaining large-signal operation is that the product of drift-zone capacitance and total load resistance must be small compared to the oscillation period; this condition also yields small starting currents. The output power at the oscillation frequency is obtained explicitly in terms of diode and external circuit parameters. The maximum attainable output power is limited by parasitic series resistance and by permissible RF voltage swing as compared to dc bias voltage. The best power-impedance product is obtained by choosing the transit angle equal to 0.74 π. In practice, it may be advantageous to choose a smaller value for the transit angle, in order that the tuning condition for the second harmonic may be more easily satisfied. The dc-to-RF conversion efficiency in principle is linearly proportional to the dc current density; the maximum efficiency again is limited by parasitic series resistance and by permissible RF voltage swing.

Low voltage dc control of voltage-variable capacitors

Abstract: This disclosure covers voltage-variable capacitors, and circuits for applying a control voltage to voltage-variable capacitors. More particularly, this disclosure is of circuits for connecting a plurality of voltage-variable capacitors to be actuated by a common control voltage.

Test circuit including bridge type oscillator means for monitoring equivalent series resistance of quartz crystals

Abstract: A CIRCUIT FOR TESTING THE SERIES EQUIVALENT RESISTANCE OF QUARTZ CRYSTALS HAVING A QUARTZ CRYSTAL FOR TEST IN A BRIDGE CIRCUIT COUPLED TO A DIFFERENTIAL AMPLIFIER WITH THE OUTPUT THEREOF FED BACK TO THE BRIDGE CIRCUIT PRODUCING AN OSCILLATOR THAT WILL OSCILLATE WHEN THE EQUIVALENT RESISTANCE OF THE CRYSTAL IS LESS THAN A PREDETERMINED RESISTANCE IN THE BRIDGE CIRCUIT AND STOP OSCILLATION WHEN THE CRYSTAL EQUIVALENT RESISTANCE EQUALS OR EXCEEDS THE PREDETERMINED RESISTANCE, THE OUTPUT OF THE DIFFERENTIAL AMPLIFIER BEING OPERATIVE TO DRIVE AN INDICATOR OF THE OSCILLATOR CONDITION AND THUS INDICATE THE RESISTANCE VALUE ABOVE OR BELOW THE PREDETERMINED RESISTANCE VALUE.

Device for determining the center of gravity and/or the weight of airplanes

Abstract: Device for determining the center of gravity and the weight of airplanes with potentiometric pressure indicators by means of which latter the bearing loads being transmitted to the landing gear may be represented as electrical resistance values, comprising an analog computing circuit being charged with a constant input voltage and in the form of a counter coupled operational amplifier equipped with a series resistance and a feedback resistance, wherein the ratio of the feedback resistance to the series resistance is determined by the pressure-indicating potentiometers and whose output voltage serves as indication for the location of the center of gravity and the weight.

Stabilisation of transferred-electron amplifiers with large n0L products

Abstract: The small-signal stability of a transferred-electron device (t.e.d.) driven with a voltage generator of finite impedance is discussed. It is shown that the series impedance significantly alters the stability condition. Computations for a resistor in series with the t.e.d. show that the maximum n0L product for stable operation increases with increasing series resistance. The practical implications of this result are discussed.

On the relation between microwave series resistance, capacitance, and output power of IMPATT diodes

Abstract: Measurements at X-band of capacitance C, microwave series resistance R, and CW output power P, on Si IMPATT diodes with epitaxial layers of varying thickness are used to show that P = (constant)/(RC2). This relation is known from the large-signal theory of the ideal Read structure, but is found to be valid far beyond its theoretical limits.

Wave filter with lossy inductors and capacitors

Abstract: 1,183,484. Filter networks. B. LILJEBERG. 6 March, 1967, No. 10507/67. Heading H3U. A low-pass filter network is built-up from lossy inductors and capacitors which contribute resistance features. For example, as shown, inductor L 2 has a resistance R 2 and capacitor C 1 has a resistance G 1 . The circuit values are: L 2 = 0A511 mH, L 4 = 0A191 mH, R 2 = 264 ohm, R 4 = 419 ohm, C 1 = 330 AAF, C 3 = 2425 AAF, G 1 = 5700 ohm, G 3 = 790 ohm. The bulk of the specification is devoted to the analysis and synthesis of the network.

Stability Criteria for Nonlinear RLC Networks

Abstract: This paper presents a stability criterion for a class of nonlinear RLC networks for which the nonlinear characteristic curves lie in Popov sectors. The nonlinear elements considered are resistors, charge-controlled capacitors, and flux-controlled inductors. It is shown that if the only nonlinear elements are resistors, then for arbitrarily large sector boundaries the circuit is both asymptotically stable in the large and, for properly placed sources, bounded-input bounded-output stable. Furthermore, if the only nonlinear elements are inductors and capacitors, any set of linear inductors and capacitors which can make the circuit oscillate define the nonlinear sector boundaries. Conditions for asymptotic stability and bounded-input bounded-output stability for networks of nonlinear resistors, inductors, and capacitors are developed.

Cutoff frequency of punch-through diodes

Abstract: The cutoff frequency of punch-through diodes has been derived in a form which includes the dependence of bias voltage and extrinsic series resistance. The conditions for high cutoff frequency are described. Lower cutoff frequencies are predicted for thin epitaxial diodes.

Improvements in or relating to filter circuit components

Abstract: 1,149,764. Filter networks. MINISTER OF TECHNOLOGY. 15 July, 1966 [25 June, 1965], No. 27070/65. Heading H3U. A filter comprises a length of transmission line having series resistance in milliohms/mm. and shunt capacitance in nanofarads/mm. whose product exceeds unity. As shown, the line consists of a copper inner conductor 1 upon which are formed a dielectric coating 2 of glass and a resistive coating 3 of tin oxide forming an outer conductor. A resistor 8 is connected between the inner conductor and earth and connections made as indicated. It is stated that the value of resistor 8 for best selectivity is given by dividing the resistance of layer 3 by a factory of 17A8 whereby an attenuation notch occurs at a frequency f 0 given by 2#f 0 RC = 11A8 where R and C are respectively the total series resistance of the length of line used and the total shunt capacitance in ohms and farads. The frequency f 0 may be varied by changing the length of the line. A variable embodiment is described (Fig. 5, not shown) in which the resistive elements 3, 8 are in the form of concentric circular resistive tracks (18, 19) cooperating with wipers (21, 22) carried by the same rotatable radial arm (20). The outer track (18) which provides series resistance 3, is formed upon a dielectric layer (17) which in turn is formed upon a conductive layer (12) providing conductor 1. The various tracks and layers are all carried by an insulative substrate, e.g. of glass or alumina. The conductive, dielectric and resistive materials may be aluminium, tantalum pentoxide and tantalum respectively.

Measurement of High Q at High Frequencies

Abstract: A high Q tuned circuit is shock excited by the pulsed interruption of current flow through a pair of charge-storage diodes. The resulting damped oscillation is recorded via an FET source follower on a CRO or X-Y recorder. The Q is calculated from the observed logarithmic decay period. A Q of over 900 is readily measured at 60 MHz. The method is useful in the measurement of varactor series resistance and in the checking of the loading imposed by other components. The accuracy of the method is also discussed.