51results about "Multiple resonant circuits tuned to different frequencies" patented technology

A tunable filter circuit includes a first differential pair biased by a first current, a second differential pair biased by a second current, a first capacitor and a second capacitor. The tunable filter circuit of the present invention can be configured as a bandpass filter or a bandstop filter by connecting the input voltage signal to different input nodes of the tunable filter circuit. The tunable filter circuit can be tuned by adjusting the values of the first current and the second current. In an alternate embodiment, frequency tuning is achieved either by switching capacitive loads or changing resistive impedances introduced at the emitter of the differential pairs, which also extends the input voltage range of the filter. This emitter resistance is implemented using MOS switches whose on-resistance can be controlled for a precise tuning within a large frequency range.

An analogue single conversion tuner comprises a plurality of channels (1, 2, 3) for covering the whole of a desired reception bandwidth. Each tuner comprises an image reject mixer (18) connected to the tuner input (4) by a single tracking filter (16), for example of the single-tuned type.

A resonator system and method are provided which includes/uses a tunable reference resonator, parts for tuning the reference resonator to a reference value via a controlled variable for the reference resonator, a tunable circuit resonator, and parts for tuning the circuit resonator which are designed such that the controlled variable for the reference resonator is used as a measure of the tuning of the circuit resonator, and wherein the reference resonator and/or the circuit resonator is/are designed as a surface acoustic wave component, a bulk acoustic wave component and/or a diaphragm oscillator.

The present invention relates to an oscillating circuit arrangement having a resonating arrangement with a first resonance frequency (coo) comprising a voltage controlled oscillator arrangement. It further comprises a tunable filter arrangement connected to the source node of said voltage controlled oscillator (VCO) arrangement. Said filter arrangement particularly comprises an equivalent current source resonating at a second resonance frequency cθf, the second resonance frequency being a multiple n, n=1 or 2 of said first resonance frequency (α>o), n being equal to the minimum number of switch transistors required for oscillation of said VCO arrangement. The filter arrangement particularly comprises an inductor connected in parallel with a capacitor, said capacitor being adapted to be tunable such that the phase noise of the resonating arrangement can be minimized through tuning of the filter arrangement.

An oscillation frequency changing means is inserted between a tuner and an oscillator of local oscillator (56) of a high frequency receiving device, and the oscillation frequency changing means, in each frequency band received, changes the oscillation frequency characteristic of local oscillator (56) in relation to the tuning voltage supplied from PLL circuit (78), and operates in accordance with the frequency characteristic of tuning filter (52, 54, 62, 64) to obtain an oscillation signal varied just by a predetermined frequency, thereby making it possible to receive broadband channels of continuous VHF broadcast band and UHF broadcast band.

A component having an acoustically active material, whose acoustic constants can be at least partially altered. The acoustically active material is located at least partially at a phase transition point and/or in the vicinity of a phase transition point.

According to an example embodiment, an apparatus is provided that produces a small-step switchable capacitor, which can have steps that are smaller in value than the smallest capacitor used in the system. In one embodiment, an input signal is connected to a switchable capacitor system that includes at least one and/or a plurality of small-step, switchable capacitors. In an example embodiment, a capacitor system may be provided that includes a first capacitance block coupled in series with a second capacitance block. In an example embodiment, the second capacitance block may include one or more switchable capacitors to provide a step in capacitance for the capacitor system between a first setting and a second setting using the one or more switchable capacitors. Also, in an example embodiment, the step in capacitance of the capacitor system may be determined based, at least in part, on a ratio of the capacitance of the second capacitance block to the capacitance of the first capacitance block.

In a method for calibrating or aligning a multistage selective amplifier including an oscillator circuit and at least one tuning circuit, the tuning voltages respectively necessary for aligning the respective tuning circuits to the required receiving frequency are calculated directly from a mathematical relationship between the respective tuning voltage and the oscillator voltage. In order to achieve this, a characteristic multiplicative coefficient and a characteristic additive factor for each tuning circuit are stored in a memory upon manufacturing or switching on the device. In order to select a desired receiving frequency, the respective stored values as well as an oscillator voltage are provided to an amplification circuit, which correspondingly amplifies the oscillator voltage by the multiplicative coefficient and the additive factor and then provides the resulting output value as a tuning voltage to the respective tuning circuit. Thus, all necessary tuning voltages can be determined from the two respective stored values per tuning circuit, as necessary for selecting any desired receiving frequency.

In a T network tuner, a variable shunt capacitor is provided between the signal input and ground that is ganged to the variable input matching capacitor. The operation is mechanically arranged such that, as one decreases the capacitance of the variable input matching capacitor, one increases the capacitance of the shunt capacitor to assist in high frequency matching, both to increase the maximum matchable load resistance and to decrease the minimum matchable load resistance. The variable shunt capacitor therefore assists at the high frequency ranges to bring the antenna impedances down to the transmitter output impedance, thus to establish an extended matching range tuner capable working between 160 and 10 meters.

A tuning circuit comprises, at least, a first circuit K1 which serially connects a first variable capacitor element 21a and a second variable capacitor element 31a, an inductance element 23a which is parallely connected to the first circuit K1 and constitutes a resonance circuit with the first circuit K1; a second circuit K2 which includes a switch element 26a and a third resistor 27a serially connected to each other and is parallely connected to the first circuit K1; and a first resistor 24a and a second resistor and 25a which are connected to both ends of the first variable capacitor element 21a, respectively and apply a predetermined tuning voltage.

The invention discloses a tuner and a pre-circuit thereof. The tuner comprises a plurality of channels, wherein at least one channel comprises a pre-filtering circuit, an amplifier and a tracking filter; the tracking filter comprises a variable capacitor and an inductor; and the variable capacitor and the inductor are coupled to an output end of the amplifier. In addition, in the tuner, at least the amplifier and the variable capacitor are arranged in a complementary metal oxide semiconductor chip. The tuner and the pre-circuit thereof have low manufacturing cost and higher filtering quality.

A multiple conversion tuner comprises a plurality of cascade-connected frequency changers, each of which comprises a mixer and a local oscillator. The tuner also comprises a local oscillator frequency selecting circuit which controls the frequencies of the local oscillators. The frequencies are controlled so that the final mixer (10) converts a desired signal to the final intermediate frequency and so that the frequency band occupied by the desired signal at the output of each mixer is within the passband of the following intermediate frequency part of the tuner. The local oscillator frequencies are also chosen so that there is no signal of unacceptably large level in the frequency band of the desired signal at the final intermediate frequency resulting from mixing of an undesired signal with harmonics higher than the first harmonic of the local oscillator signals.

According to one or more aspects of the present invention, a receiver arrangement is disclosed that is configured to receive digital television signals. The receiver arrangement has at least one first frequency conversion device with the signal input, a local oscillator input and an output. The at least one first frequency conversion device is designed to convert a signal which is applied to the input side to an intermediate frequency. A first amplifier is also provided and is designed with amplification in order to compensate for the signal level loss in a filter which is connected downstream from the first amplifier. The first amplifier is coupled to the output of the frequency conversion device. An intermediate-frequency amplifier with a variable gain factor is also provided, and is coupled to the first amplifier. At least the at least one first frequency conversion device the first amplifier are formed in a common semiconductor body.

The invention discloses a power distribution network electric energy distributed transaction model based on distributed database support, which is characterized in that electricity purchasing and selling parties send electricity purchasing and selling information through a distributed database network, and an electric energy transaction negotiation market chain code model completes negotiation oftransaction electric quantity and transaction price to form a temporary contract; the network security constraint chain code model performs security check on the temporary contract line power flow andthe node voltage; and the on-chain and off-chain model determines the temporary contract passing the security check as a final contract, and executes a transaction. According to the invention, the market main body is allowed to participate in the power market in a decentralized manner and negotiate the transaction electric quantity and the transaction price, the electricity purchasing cost of themarket main body can be effectively reduced, and the electricity selling income of the market main body is increased. Line power flow blocking and node voltage deviation conditions can be effectivelyjudged, and safe operation of a power distribution network is facilitated. The constructed distributed database capacity expansion architecture can ensure the safety and traceability of all historical data storage while ensuring the computing power of the distributed database.

First varactor diodes for changing tuning frequency are provided at tuning circuits, a second varactor diode for changing an oscillating frequency is provided at an oscillator, tuning voltages between both ends of the first varactor diodes become equal to the tuning voltage between both ends of the second varactor diode when a television tuner receives a television signal, and the tuning voltages between both ends of the first varactor diodes become lower than the tuning voltage between both ends of the second varactor diode when the television tuner receives a FM broadcasting signal.

A band switchable type tuning circuit has first switch mean interposed between a power supply Vcc and an anode of a switch diode, a first resistor whose one end is connected to a cathode of the switch diode, second switch means interposed between the other end of the first resistor and a ground, a second resistor connected between the power supply Vcc and a connection point of the first resistor and the second switch means, and the third resistor connected between the ground and a connection point of the first switch means and the anode of the switch diode. The first switch means and the second switch means are turned on or off together by means of a band switching voltage.

A control system for an energy storage device is coupled to sensors on an electrical grid. The control system is configured to receive a measurement from each of the sensors. The control system determines, based on the received measurements, whether a grid event is a local event or a distributed event. The control system selects a response mode for controlling the energy storage device based on whether the grid event is determined to be a local event or a distributed event.

A receiver of double conversion system wherein unwanted components included in received signals can be removed without fail and wherein the number of constituent parts has been reduced. The receiver comprises an antenna tuning circuit 10 including a tuning coil 11 and a variable-capacitance diode 13; a high frequency amplification circuit 20 for performing a high frequency amplification of a signal outputted by the antenna tuning circuit 10; two-stage mixing circuits 22, 28 for performing two frequency conversions of an output from the high frequency amplification circuit 20; and a detecting circuit 36 for detecting an output from the latter-stage mixing circuit 28.