46results about "Discontinuous tuning by electric means" patented technology

A dual-band antenna matching system and a method for dual-band impedance matching are provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; and, simultaneously tuning a second tuning circuit to a second frequency. In response, a conjugate match is supplied to the antenna in the first communication band in response to the first frequency. Simultaneously, the antenna is matched in the second communication band in response to the second frequency. When the first tuning circuit is tuned to a third frequency, and the second tuning circuit is tuned to a fourth frequency, then conjugate matches are supplied for the third and fourth communication bands, responsive to the third and fourth frequencies, respectively.

A system and method is provided for full-duplex antenna impedance matching. The method comprises: effectively resonating a first antenna at a frequency selectable first channel in a first frequency band; generating a first antenna impedance at the first channel frequency; effectively resonating a second antenna at a frequency selectable second channel in the first frequency band; generating a second antenna impedance at the second channel frequency; supplying a first conjugate impedance match at the first channel frequency; and, supplying a second conjugate impedance match at the second channel frequency. For example, the first antenna may be used for transmission, while the second antenna is used for received communications. The antennas effectively resonant in response to: supplying frequency selectable conjugate impedance matches to the antennas; generating frequency selectable antenna impedances; and/or selecting the frequency of antenna resonance.

A method and apparatus for fully integrating a Voltage Controlled Oscillator (VCO) on an integrated circuit. The VCO is implemented using a differential-mode circuit design. The differential-mode implementation of the VCO preferably comprises a differential mode LC-resonator circuit, a digital capacitor, a differential pair amplifier, and a current source. The LC-resonator circuit includes at least one tuning varactor and two high Q inductors. The tuning varactor preferably has a wide tuning capacitance range. The tuning varactor is only used to "fine-tune" the center output frequency f0 of the VCO. The center output frequency f0 is coarsely tuned by the digital capacitor. The VCO high Q inductors comprise high gain, high self-resonance, and low loss IC inductors. The IC VCO is fabricated on a high resistivity substrate material using a trench isolated guard ring. The guard ring isolates the fully integrated VCO, and each of its component parts, from RF signals that may be introduced into the IC substrate by other devices. By virtue of the improved performance characteristics provided by the digital capacitor, the analog tuning varactor, the high Q inductor, and the trench isolated guard ring techniques, the inventive VCO is fully integrated despite process variations in IC fabrication.

An implantable medical device (IMD) as described herein includes an input filter circuit having variable capacitor elements that can be electronically adjusted based upon current operating conditions (such as electromagnetic conditions, noise conditions, and/or environmental conditions). The variable capacitor elements can be adjusted to accommodate pre-designated operating modes of the IMD and/or dynamically in response to changing operating conditions. In one embodiment, the variable capacitor elements are realized using digitally programmable switched capacitor arrangements.

A method is provided for controlling a resonant circuit (1) of an ICPT system. The resonant circuit has a controlled variable reactance (2), and a predetermined perturbation is introduced in the magnitude of variable reactance. The change in a property of the resonant circuit in response to the perturbation is sensed, and the variable reactance is varied to alter the resonant frequency of the circuit in response to the sensed change.

A circuit block which comprises a non-linear capacitor with two different values of capacitance dependent on a value of a voltage of a resonant signal on the capacitor; a plurality of second capacitors each coupled to a respective switch to enable a said second capacitor to be switched in or out of parallel connection with the nonlinear capacitor; and a tuning control, coupled to the second capacitor switches, and sensing an amplitude of the resonant signal. The tuning control circuit is configured to control the second capacitor switches to successively switch the second capacitors in/out of parallel connection with the non-linear capacitor dependent on the amplitude of the resonant signal until the non-linear capacitor has substantially a single one of two different values, such that in a resonant circuit the circuit block then behaves as a fixed value capacitor.

A wireless communications device reconfigurable radiation desensitivity bracket, and associated reconfigurable radiation desensitivity method are provided. The method includes: generating a radiated wave at a first frequency; in response to generating the radiated wave at the first frequency, creating a maximum current per units square (I/units²) through a minimal area of an electrical circuit groundplane; generating a radiated wave at a second frequency; in response to generating the radiated wave at the second frequency, maintaining the maximum I/units² through the minimal area of the groundplane. Alternately stated, the method controls the distribution of current flow through a groundplane, responsive to radiated emissions, as the wireless device changes operating frequency or communication band. More specifically, the method maintains the maximum I/units² through the minimal area of the groundplane by coupling the groundplane to a bracket having a selectable effective electrical length.

There is disclosed a tuning circuit having a coil and a capacitor comprises a resistance-adjustment circuit connected in parallel with the coil and the capacitor. The resistance-adjustment circuit changes a resistance of the tuning circuit when resonant. The resistance-adjustment circuit comprises a series circuit of a resistor and a switching element having an ON-resistance smaller than the resistance of the resistor, and turning on/off the switching element causes the resistance of the tuning circuit when resonant to change.

A method and device bracket are presented for reconfigurable radiation desensitivity. The method includes: accepting a radiated wave from a source such as a transmitter, antenna, microprocessor, electrical component, integrated circuit, camera, connector, or signal cable; in response to the radiated wave, creating a first current per units square (I/units²) through a groundplane of an electrical circuit such as a printed circuit board (PCB), display, connector, or keypad; accepting a control signal; and, in response to the control signal, creating a second I/units² through the groundplane. This step couples the groundplane to a bracket having a selectable effective electrical length. Typically, the groundplane is coupled to a bracket with a fixed physical length section to provide a combined effective electrical length responsive to the fixed physical length and the selectable effective electrical length. The coupling mechanism can result from transistor coupling, p/n junction coupling, selectable capacitive coupling, or mechanically bridging.

An induction sealing device for the production of pourable food packaging, for which purpose transversely seals a tube (13) of sheet-like packaging material comprising at least one layer (12) of induction heatable material, said induction heating The heated material is covered by a plastic material (16). Said sealing device has: a generator (3), is used for producing alternating power signal S (ω); Inductor (4), is used for receiving alternating power signal S (ω) so that in said layer (12 ) to induce parasitic currents and locally melt said plastic material (16) to form a transverse seal; and a matching circuit (7) for optimum power between generator (3) and inductor (4) transmission. The matching circuit (7) includes an inductance-capacitance circuit, wherein the capacitance of the capacitive elements (20, 24, 25, 26, 27) with variable capacitance can be adjusted so that the current-voltage phase angle can be close to zero.

An electrical resonance network comprising a first capacitor and a first inductor whose resonance frequency can be tuned by means of a second capacitor and/or a second inductor. The resulting effective capacitor- or inductor value of a network period is controlled by a variable coupling respectively decoupling interval by means of at least one coupling switch. The coupling respectively decoupling interval is synchronized by a sign change of a current and/or voltage in the network.

In accordance with an embodiment, an adjustable capacitance circuit comprising a first branch comprising plurality of transistors having load paths coupled in series with a first capacitor. A method of operating the adjustable capacitance circuit includes programming a capacitance by selectively turning-on and turning-off ones of the plurality of transistors, wherein the load path of each transistor of the plurality of transistors is resistive when the transistor is on and is capacitive when the transistor is off.

A fully integrated single-loop frequency synthesizer, which can serve as a local oscillator for a broadband tuner, is disclosed, thus allowing the creation of a single-chip solution for broadband applications. The tank circuits are integrated into the tuner chip through the combination of a phase-locked loop and multiple on-chip VCOs comprising narrow-tuning range varactors. Drift in the VCOs caused by heat is overcome by designing the VCOs to overlap each other. Initial tolerance problems associated with the VCOs are overcome by the use of a calibration method. The calibration of the VCOs is accomplished by utilizing the lock detect output of the phase-locked loop and a binary search algorithm. The edges of each VCO are determined with this calibration method, thereby enabling VCO selection based on the desired channel. A sufficient number of VCOs are provided such that whatever the initial tolerance shift, the full broadband spectrum can still be covered after calibration. Additionally, the problem of coupling between the local oscillator signal and the incoming radio frequency signal is mediated by the use of a programmable 2/4 divider. This 2/4 divider also provides additional flexibility in choosing the number of VCOs to put on the chip and which VCO to use in a particular implementation.

A tunable inductor arrangement arrangable on a chip or substrate is disclosed. The tunable inductor comprises a first winding part connected at one end to a first input of the tunable inductor arrangement, a second winding part connected at one end to the other end of the first winding part, a third winding part connected at one end to a second input of the tunable inductor arrangement, a fourth winding part connected at one end to the other end of the third winding part, and a switch arrangement arranged to tune the tunable inductor arrangement by selectively provide a circuit either comprising the first and fourth winding parts in parallel and the second and third winding parts in parallel, with the parallel couplings in series between the first and second inputs, or a circuit comprising the first, second, fourth and third winding parts in series between the first and second inputs. A transceiver, communication device, method and computer program are also disclosed.

A television tuner contains a mixer unit for converting a television signal into an intermediate frequency signal and an intermediate frequency tuning circuit provided at the next stage of the mixer unit for passing the intermediate frequency signal. The intermediate frequency tuning circuit is switched such that a tuning frequency has different values according to whether the television signal is at least a weak electric field or a strong electric field. The tuning frequency is tuned to a frequency close to a picture intermediate frequency when the television signal is at least the weak electric field, and the tuning frequency is tuned to a frequency close to a sound intermediate frequency when the television signal is at least the strong electric field.