Abstract: An apparatus, method, and system for measuring current within a converter. The converter including a resonant tank circuit with a capacitor, the resonant tank circuit is coupled to a DC input bridge and a first terminal of the capacitor is coupled to a ground of the DC input bridge. In addition, a voltage monitor coupled across the capacitor for measuring a voltage across the capacitor. The converter also includes a resonant current calculation module for computing a tank current value based on the voltage.
Abstract: In one embodiment, the present invention includes a transformer formed on a semiconductor die. Such transformer may have multiple coils, including first and second coils. Each coil may have segments that in turn are formed on a corresponding metal layer of the semiconductor die. The segments of a given coil are coupled to each other, and the first and second coils can be interdigitated with each other.
Abstract: In a parallel multistage band-pass filter, a transmission line having an electrical length substantially equal to half (&lgr;/2) of the wavelength of the transmission signal is incorporated between the port on the input terminal side of the odd number (2n−1)th resonator numbered from the input terminal side and the port on the input terminal side of the even number (2n)th resonator numbered from the input terminal side; and a transmission line having an electrical length substantially equal to &lgr;/2 is incorporated between the port on the output terminal side of the even number (2n)th resonator numbered from the input terminal side and the port on the output terminal side of the odd number (2n+1)th resonator numbered from the input terminal side. Moreover, a transmission line for adjustment of a transmission phase between the input terminal and the output terminal is incorporated between the first resonator numbered from the output terminal side and the output terminal.
August 26, 2003
March 4, 2004
Yasushi Sano, Eiichi Kobayashi, Shingo Okajima, Jun Hattori
Abstract: A microwave amplifier for amplifying microwave signals, such as the microwave signals received by a microwave repeater station. The amplifier is formed of solid state amplifier-transistors to which the microwave signals are applied by way of transmission lines. The amplification circuitry and transmission lines are formed upon a circuit board which is housed within a heat-dissipative housing. The amplifier can be used in substitution for a conventional travelling wave tube, conventionally utilized to amplifier microwave signals received at a microwave repeater station.
Abstract: A signal coupler includes a transformer having a primary and a secondary winding. Each transformer winding has a pair of associated winding terminals and is also split at an intermediate winding position to form a pair of supplemental winding terminals. Circuitry is provided between each pair of supplemental winding terminals so as to provide different impedances in different frequency bands. In particular, a first circuit, which provides a first impedance in a first frequency range, is connected across the supplemental winding terminals of one winding. A second circuit, is connected across the supplemental winding terminals of the other transformer winding. This second circuit, in combination with the first, provides a second impedance in a second frequency range. In the disclosed embodiment, the first circuit provides an impedance of 600 ohms in the voiceband frequency range. The second circuit in combination with the first provides an impedance of 100 ohms in a frequency range extending above 40 kHz.
Abstract: A gain control system for a receiver that combines some of the features of oth limiting and AGC. The AGC loop of the present invention has a relatively long time constant which reduces the gain so that the desired signal is only 10 to 15 db into limiting. This degree of limiting provides instantaneous control of small changes in signal level, but prevents the receiver from instantaneously opening to full gain in the case of loss of signal. This prevents erroneous data from being received during a time interval in which it is expected that the original signal will return.
September 17, 1973
Date of Patent:
October 30, 1990
The United States of America as represented by the Secretary of the Navy
Abstract: A local computer network transceiver is provided for a distributed control local computer network which applies a signal to a medium which has a DC component wherein isolation is implemented at the medium interface without need for direct current coupling of any active circuit to the communication medium. The medium is typically a coaxial cable. Transmit isolation transformers are coupled across a coaxial coupler, the medium side thereof being coupled in series with a diode. A plurality of transmit isolation transformers may be coupled in parallel to the medium to permit operation at substantially higher frequencies than would otherwise be permitted due to self-resonant frequencies of the isolation transformers. A receive interface through a receive isolation transformer is provided with capacitive balancing to prevent common mode voltages from being converted into recognizable signals.
Abstract: The present invention relates to a driver circuit for use in connecting a source of RF drive voltage to a power amplifier stage. The driver is comprised of a transformer having a center tap, a first terminal connected to a first branch of the transformer and a second terminal connected to a second branch of the transformer. A first capacitor is connected between the source and the center tap. A second capacitor is connected across the first and second terminals. The first terminal is connected to the input of the amplifier and the dummy load is connected to the second terminal. The dummy load can be replaced by a second power amplifier stage having an input impedance similar to the input impedance of the first mentioned power amplifier.
Abstract: Disclosed is an electric oscillation generator comprising an exciter and an output amplifier stage utilizing a vacuum tube connected in a common-grid circuit. A section of the input circuit of the vacuum tube is connected to the output of the exciter. The exciter is made as a power supply through a compensating-voltage producing device connected in series with said section of the input circuit and having an output voltage opposite in phase to the voltage across said section of the input circuit of the vacuum tube.
February 10, 1981
Date of Patent:
September 11, 1984
Matvei I. Pass, Nina S. Ogarkova, Jury K. Lesish, Lev I. Shapiro, Jury M. Lebedev, Oleg V. Filatov
Abstract: A transformer-coupled isolation amplifier which has a minimally sized transformer, high common mode rejection, and a highly linear response over a wide dynamic range. A first chopper periodically alternates by 180.degree. the connection of the input through a high resistance to the primary of a small square loop pulse transformer. The secondary, with the end of the winding closest to the primary grounded, has the inputs of an operational amplifier placed across it. Negative feedback is provided around the amplifier to provide an apparent very low impedance across the secondary of the transformer. The negative feedback induces a current in the transformer secondary which cancels the flux produced by current flowing in the primary, thereby allowing usage of the transformer normally suitable only for high speed pulses. The output of the amplifier connects to a second chopper synchronous with the first to generate the amplified analog signal.
Abstract: A vital narrow band-pass filter which operates in a fail-safe manner and includes a single stage input resonant circuit, an intermediate multistage parallel resonant circuit, and an output amplifying circuit for passing a given center carrier frequency signal and for attenuating adjacent carrier frequency signals.