97results about How to "Increase tuning range" patented technology

The invention concerns a wireless microphone system. The object of the present invention is to further develop such wireless microphone systems. A further aim of the invention is to provide an improvement in the intermodulation spacing of HF transmitters so that more transmitters can be used in the same frequency band. A wireless microphone system comprising antennae connected thereto, wherein a circulator and/or an HF isolator is connected to the antennae or the antenna.

A MEMS tunable capacitor with angular vertical comb-drive (AVC) actuators is described where high capacitances and a wide continuous tuning range is achieved in a compact space. The comb fingers rotate through a small vertical angle which allows a wider tuning range than in conventional lateral comb drive devices. Fabrication of the device is straightforward, and involves a single deep reactive ion etching step followed by release and out-of-plane assembly of the angular combs.

A voltage controlled oscillator generates an output signal whose frequency varies as a first function of a control voltage applied to a control terminal. The voltage controlled oscillator has a wide range of frequency of operation. A gain adjust circuit adjusts the gain of the voltage controlled oscillator such that the first function varies as a second function of the gain. In a preferred embodiment the gain adjust circuit includes a variable impedance that may be external or integrated onto a common chip with the oscillator core.

A tuning apparatus is provided, wherein the on and off resistances of semiconductor switches within an tuning IC are optimized, so as to provide high sensitivity and superior stability, a wide range of tuned frequency variation, compactness and high performance. The tuning apparatus has a tuning circuit, which has N-channel MOS transistors (N transistors) 5a through 5f, serving as a plurality of semiconductor switches, and a counter circuit 6, which controls the opening and closing of the N transistors, a plurality of capacitors 4a through 4f, which are each connected in series with the plurality of N transistors, and a receiving antenna 2 wherein the total electrostatic capacitance of the plurality of capacitors is varied by the opening and closing of the plurality of N transistors, thereby varying the frequency tuned by the plurality of capacitors and the receiving antenna.

This invention features an absorptive tunable bandstop filter with wide tuning range including first and second branches of all-pass filter networks, an input power divider for splitting the input signal and passing approximately half of the input signal power through each said branch of said all-pass filter networks, and an output power divider for recombining the signal power from each said branch of said all-pass filter networks, at least one of said branches of said all-pass filter networks being electrically tunable to provide an approximately 180° phase difference with similar amplitudes of the split said signal power to be recombined at said output power divider for rejecting but substantially absorbing selected frequencies.

The invention relates to a voltage controlled oscillator, which comprises four transistors, an integrated on-chip inductor and two symmetric variable capacitors, wherein, two transistors realize negative resistance through cross coupling, thereby providing energy to oscillate an LC circuit comprising the inductor and the variable capacitors; by changing the capacitance of the variable capacitors, different output frequencies of the oscillator are obtained. The invention also comprises two resistors with the same value and two capacitors with the same value; a grid terminal of one of the rest transistors is connected with a terminal of a resistor and a terminal of a capacitor at the same time, which jointly form an active inductor; a grid terminal of the last transistor is connected with a terminal of a resistor and a terminal of a capacitor at the same time, thus jointly forming another active inductor; the two active inductors provide bias current for the voltage controlled oscillator. The invention enlarges the tuning range of the voltage controlled oscillator and reduces the phase noise.

The invention discloses a mid-series type hybrid permanent-magnet adjustable flux motor having passive adjustable flux magnetic barriers, and belongs to the field of permanent-magnet motors, and solves the problem that advantages of serial and parallel hybrid permanent-magnet adjustable flux motors cannot be combined. The mid-series type hybrid permanent-magnet adjustable flux motor comprises a stator iron core, an armature winding, a rotor iron core and a rotating shaft; the rotor iron core is fixed on the rotating shaft, and is positioned inside the stator iron core; the armature winding isarranged on the stator iron core; the mid-series type hybrid permanent-magnet adjustable flux motor further comprises low-coercivity permanent-magnet slots, low-coercivity permanent magnets, radial slots, high-coercivity permanent magnets and the passive adjustable flux magnetic barriers; the low-coercivity permanent-magnet slots and the radial slots are distributed on the rotor iron core alternately and uniformly along a circumferential direction; the low-coercivity permanent-magnet slots and the radial slots are penetrated through the whole motor along an axial direction; the low-coercivitypermanent magnets are installed in the low-coercivity permanent-magnet slots; and the high-coercivity permanent magnets and the passive adjustable flux magnetic barriers are jointly installed in the radial slots.

A resonator of a VCO includes a fine tuning main varactor circuit, an auxiliary varactor circuit, and a coarse tuning capacitor bank circuit coupled in parallel with an inductance. The main varactor circuit includes a plurality of circuit portions that can be separately disabled. Within each circuit portion is a multiplexing circuit that supplies a selectable one of either a fine tuning control signal (FTAVCS) or a temperature compensation control signal (TCAVCS) onto a varactor control node within the circuit portion. If the circuit portion is enabled then the FTAVCS is supplied onto the control node so that the circuit portion is used for fine tuning. If the circuit portion is disabled then the TCAVCS is supplied onto the control node so that the circuit portion is used to combat VCO frequency drift as a function of temperature. How the voltage of the TCAVCS varies with temperature is digitally programmable.

The present invention relates to a semiconductor based parabolic waveguide-type collimating lens and a monolithically integrated type tunable external cavity laser diode light source. The monolithically integrated type tunable external cavity laser diode light source includes a gain medium for generating a gain of an optical signal, a collimating lens for correcting an divergent light beam to a parallel light beam, a passive waveguide through which the parallel light beam travels, an optical deflector to change a traveling direction of the parallel light beam changing a refractive index of medium on a traveling path of the parallel light beam traveling through the slab waveguide in response to an external electric signal and a diffraction grating to diffract the parallel light beam passing through the optical deflector, wherein these are integrate into one substrate made of an InP-based semiconductor as well as a material such as a GaAs-based semiconductor, a Si-based semiconductor, LiNbO₃-based semiconductor or the like.

A PN-junction varactor includes a first ion well of first conductivity type formed on a semiconductor substrate of second conductivity type. A first dummy gate is formed over the first ion well. A first gate dielectric layer is formed between the first dummy gate and the first ion well. A second dummy gate is formed over the first ion well at one side of the first dummy gate. A second gate dielectric layer is formed between the second dummy gate and the first ion well. A first heavily doped region of the second conductivity type is located in the first ion well between the first dummy gate and the second dummy gate. The first heavily doped region of the second conductivity type serving as an anode of the PN-junction varactor. Second heavily doped regions of the first conductivity type located in the first ion well at one side of the first dummy gate that is opposite to the first heavily doped region and at one side of the second dummy gate that is opposite to the first heavily doped region, the second heavily doped regions being electrically connected to each other and serving as a cathode of the PN junction varactor.

A method and a device for realizing a low-cost tunable semiconductor laser based on a reconstruction-equivalent chirp technology belong to the technical field of optoelectronics, and relate to the design and manufacture of a complex distributed feedback tunable semiconductor laser. The invention aims to provide a low-cost tunable distributed feedback semiconductor laser for the future WDM-PON market by adopting the reconstruction-equivalent chirp technology for low-cost manufacture. The basic technology is that a plurality of distributed feedback semiconductor lasers of different wavelengths are integrated on the same chip through a series/parallel hybrid mode, and a mode of crosstalk isolation between adjacent laser chips is provided. According to the invention, DFB lasers of different working wavelengths based on the reconstruction-equivalent chirp technology are integrated by a series/parallel combination mode, one of the lasers is selected by current to work, and the working wavelength of the laser can be controlled by adjusting the temperature or current, thus realizing continuous tuning of the working wavelength of the laser.

A variable capacitor. The variable capacitor has a movable capacitor electrode including a major surface and a fixed capacitor electrode including a major surface. The major surface of the fixed capacitor electrode is opposite the major surface of the movable capacitor electrode and is separated therefrom by a gap. The major surface of the movable capacitor electrode includes a rigidity-increasing feature. The rigidity-increasing feature further provides a capacitance-increasing topography and reduces snap-together of the capacitor electrodes.

A differential and quadrature harmonic voltage controlled oscillator (VCO), and a method for generating a differential and quadrature harmonic signal. The VCO may include a first oscillation unit for generating a first and a third signal, a first combining unit for combining the first and the third signal, a second oscillation unit for generating a second and a fourth signal, and a second combining unit for combining the second and the fourth signal. The phase of the second signal is determined through a phase-invert and delay using the first signal, the phase of the third signal is determined through a phase-invert and delay using the second signal, the phase of the fourth signal is determined through a phase-invert and delay using the third signal, and the phase of the first signal is determined through a phase-invert and delay using the fourth signal.

A frequency fine tuning circuit for use in a voltage-controlled oscillator is provided. The frequency tuning circuit includes a first varactor, a second varactor and a center bias unit. The second varactor is coupled to the first varactor at a first node. The center bias unit maintains a node voltage of the first node at a constant bias voltage level.