31results about How to "Wide tuning range" patented technology

The inventions presented herein provide a electronically controlled phase shifters that incorporate analog and digital phase shift architectures in a novel manner that realizes the best advantages of each architecture. This combination of complementary phase shift architectures provides the high-performance and low loss characteristics of switched digital phase shift architectures with the high resolution and precision of continuous analog phase shift architectures. The circuit embodiments are electronically controlled, which simplifies implementation of what is a complex circuit. The analog phase shift elements comprise electronically-tuned varactors, which provide fine resolution and enables the incorporation of active compensation for manufacturing variation before use or for environmental conditions during use.

The invention discloses a double-stator hybrid excitation motor with a T-type core inner stator. A center rotor is coaxially arranged in the middle of an outer stator and an inner stator. 12 T-type teeth are uniformly distributed along the circumferential direction of the inner stator yoke of the inner stator. The T-type teeth are sleeved with excitation windings. The top of each T-type tooth is near the center rotor. An inner stator slot is formed between every two adjacent T-type teeth. An arc permanent magnet is embedded fixedly between the tops of every two T-type teeth. The permanent magnets are magnetized along the tangential direction, and every two adjacent permanent magnets are magnetized in opposite directions. The inner and outer diameters of the permanent magnets are equal to the inner and outer diameters of the tops of the T-type teeth. The excitation windings are wound on the vertical parts of the T-type teeth of the inner stator, and thus, an electric excitation magnetic field connected in parallel with a permanent magnetic field is formed. The electric excitation magnetic field does not demagnetize the permanent magnets. When direct currents in different directions are fed to the excitation winding, the electric excitation magnetic field and the permanent magnetic field interact with each other to strengthen or weaken the magnetism.

A disclosed method tunes a signal from a channelized spectrum having a predetermined channel spacing. A signal of interest having a predetermined maximum bandwidth is mixed with a local oscillator signal, which has a frequency that is an integer multiple of the channel spacing or one-half of a channel spacing displaced from an integer multiple of the channel spacing. The local oscillator signal is selected to frequency translate the signal of interest to within a near-baseband passband whose lower edge is spaced from DC by at least about the maximum bandwidth of the signal of interest. Problems associated with 1/f noise, DC offsets, and self-mixing products are avoided or substantially diminished. Other methods and systems are also disclosed.

The present invention provides a current controlled oscillator comprising a first section providing a first differential output and a second section providing a second differential output. A loading structure comprised of resistive and reactive elements electrically connects the first differential output with the second differential output. The resistive and reactive elements have values chosen such that the resistive elements substantially extend the linear operating frequency range of the current controlled oscillator. Transistors of the loading structure have which are tied to a power supply rejection ratio compensation section for compensating for variations in power supply voltage.

An apparatus and source arrangement for filtering an electromagnetic radiation can be provided which may include at least one spectral separating arrangement configured to physically separate one or more components of the electromagnetic radiation based on a frequency of the electromagnetic radiation. The apparatus and source arrangement may also have at least one continuously rotating optical arrangement, e.g., polygonal scanning mirror and spinning reflector disk scanner, which is configured to receive at least one signal that is associated with the one or more components. Further, the apparatus and source arrangement can include at least one beam selecting arrangement configured to receive the signal.

To secure the benefits of a low phase noise, wide tune range SAW oscillator in noisy environments, the tunable two port SAW resonator circuit within the oscillator is employed in differential mode, connected to a differential amplifier circuit to create a differential oscillator. In the absence of any need for ground or power supply voltage level references, low phase noise/edge jitter is maintained even in hostile environments while providing sufficient tune range to track small frequency changes. The resulting differential mode SAW oscillator is thus well-suited for use, for instance, in clock recovery within SONET applications.

The present invention provides a new method for spectral filtering of optical radiation wherein the light to be filtered is directed onto two or more spaced apart layers of photosensitive material. A holographic grating is recorded in the layers so that each layer of the photosensitive material contains a portion of the recorded holographic grating. The output optical signal is formed as the result of interference of the light reflected due to the Bragg diffraction from the parts of the diffraction grating recorded in different layers. The reflected light propagates through the spaced apart electrooptical layers sandwiched between the photosensitive layers. The refractive index of the electrooptical layers is varied by the application of the appropriate electrical field to provide the phase difference between the reflected optical signals in order to obtain the desired value of the total output signal resulted from the interference of the reflected light.

The invention provides a continuously tunable narrow linewidth laser which comprises a silicon-based outer cavity (111). The silicon-based outer cavity (111) comprises a substrate layer (101); an optical waveguide layer (104) which is arranged above the substrate layer (101) and forms a self-injection micro-ring resonant cavity to obtain the frequency-adjustable continuous wave laser; and a distributed feedback laser (103) which is coupled with the end surface of the silicon-based outer cavity (111), couples the laser into the micro-ring resonator (110), and outputs the frequency-modulated continuous wave laser through the silicon-based outer cavity (111). According to the narrow linewidth laser, the continuous tunable frequency modulation can be achieved, the application of a frequency modulation light source is met, and the design size and the laser coupling optimization can be achieved.

A cascaded arrangement of resonant tanks capable of widening frequency selection and tuning within an RF circuit is presented. Moreover, usage of DTC allows for larger frequency tuning per tank as well as handling of higher voltage swings while maintaining high linearity across the tuning range.

A tunable extended cavity laser is disclosed having a single flexure pivot or hinge forming a pivot axis about which a grating tuning element is rotated. The pivot axis does not move appreciably as the grating is pivoted. The most preferred embodiment of the flexure hinge is a cartwheel hinge.

A wide tuning range and constant swing VCO is described that is based on a multipass Ring Oscillator enhanced with feed-backward connections. This VCO is designed to overcome tuning range limitations of prior-art “feed-forward” ring oscillators. The Feedback multipass Ring Oscillator of the invention provides decreasing frequency when tuned by increasing the feedback, thus covering a much wider tuning range irrespective of the speed limit of the technology while at the same time providing almost constant amplitude.

A tunable semiconductor laser device includes a semiconductor structure, a longitudinal structure provided on the top surface of the semiconductor structure, a first longitudinal interdigitated transducer, wherein the first IDT is arranged on one lateral side of the longitudinal structure and at a distance along the lateral axis from said structure and parallel to the longitudinal structure.

The invention discloses a stator partition type hybrid excitation motor with a built-in adjustable magnetic ring structure. The motor comprises an outer stator, a rotor and an inner stator, the outer stator (1) and the rotor (2) are separated by an air gap, and the inner stator (3) and the rotor (2) are separated by an air gap; 12 outer stator teeth are uniformly arranged on the outer stator (1) along the circumferential direction, and armature windings (4) are wound on the outer stator teeth; 12 inner stator teeth are uniformly arranged on the inner stator (3) along the circumferential direction, a centralized excitation winding (5) is wound on the inner stator teeth, 12 permanent magnets (6) are uniformly inserted into a yoke part of the inner stator along the circumferential direction, each permanent magnet is magnetized in the tangential direction, the difference between the magnetizing directions of the two adjacent permanent magnets is 90 degrees, and 6 alternating magnetic bridges (7) are uniformly arranged on the inner side of the inner stator (3) and connected with a magnetism adjusting ring (8); and the middle rotor is composed of seven magnetism adjusting blocks which are evenly arranged. According to the invention, the output torque can be adjusted up and down according to the requirements of application occasions, and the flexibility is high.

The invention discloses a photonic crystal high-power laser preparation method. The method comprises the following steps: adding an isolation layer between a quantum well light-emitting layer and a lower Bragg reflection layer; after the epitaxial wafer is grown, carrying out laser etching to form an air column to form a photonic crystal, wherein the photons generated by work of the quantum well light-emitting layer can only pass through the surface of the photonic crystal through a resonance tunnel effect, and a wider harmonizing range and a narrower line width can be effectively improved; integrating a lower Bragg emitting layer and an upper Bragg reflecting layer in one laser to form two independent gratings, so that a wider wavelength harmonizing range, narrower spectral line width andhigher power are realized, and stimulated radiation light and external light causing stimulated radiation have the same frequency, phase, polarization and propagation direction. Through stimulated radiation, homomorphic photon number amplification can be realized so as to obtain coherent light with extremely high photon degeneration degree. Due to the fact that the power of an existing laser is generally low, long-distance and multi-path laser application can be achieved through high power.

A variable frequency oscillator comprising a first transistor (10) and a second transistor (20); wherein the first transistor (10) has a first terminal—collector—which is connected to a reference voltage, and a second terminal—emitter—which is connected to a first terminal of a first current source (13), which second terminal is connected to ground, and a third terminal—base—connected to a first terminal of a first inductor (14) and to a top terminal of a first capacitor (11), wherein the first capacitor (11) has a bottom terminal which is connected to the second terminal—emitter—of the first transistor (10) but also to a top terminal of a second capacitor (12) having a bottom terminal being connected to ground;

• • wherein the second transistor (20) has a first terminal—collector—which is connected to a reference voltage, and a second terminal—emitter—which is connected to a first terminal of a second current source (23), which second terminal is connected to ground, and a third terminal—base—connected to a first terminal of a second inductor (14) and to a top terminal of a third capacitor (21), wherein the third capacitor (21) has a bottom terminal which is connected to the second terminal—emitter—of the second transistor (20) and also to a top terminal of a fourth capacitor (22) having a bottom terminal connected to ground;
  • wherein the first and second inductors (14, 24) have a second terminal which are connected via a circuit (100) achieving variable capacitance, so as to form a circuit connecting in series all passive components composing the LC tank, so as to achieve a variable capacitance which can be used for performing a tuning of the oscillator, and
  • wherein the second capacitor (12) and the fourth capacitor (22) are both connected to the physical ground thereby avoiding a 2nd harmonic common mode oscillation that might dominate over the differential fundamental one and might destroy the first and the second transistors (10, 20).

The invention relates to an asymmetric-structure high-power laser with a Bragg reflector and a preparation method thereof, and belongs to the field of lasers. The laser comprises a GaAs substrate, wherein a GaAs buffer layer, a Ga<1-x>In<x>P transition layer, an Al<1-x>InxP lower limiting layer, an (Al<1-x>Gax)yIn<1-y>P lower waveguide layer, a Ga<1-x>InxP quantum well light emitting region, a (Al<1-x>Gax) yIn<1-y>P upper waveguide layer, an Al<1-x>GaxAs Bragg reflection layer, an Al<1-x>GaxAs upper limiting layer and a GaAs cap layer are sequentially deposited on the GaAs substrate from bottom to top. According to the invention, a narrower spectral line width can be obtained, the internal loss is effectively reduced, the generation of heat is reduced, the electro-optical conversion efficiency is improved, the stability of the device is improved, the service life of the device is prolonged, and thus the 630-710nm series high-power semiconductor laser can be widely applied in long distance, multiple paths and the like.

The present invention provides a widely tunable, single mode emission semiconductor laser which comprises a semiconductor substrate, a first linear ridge waveguide which forms a first coupled cavity, and a second linear ridge waveguide which forms a second coupled cavity, with the first coupled cavity being separated from the second coupled cavity by a gap. The first and second coupled cavities comprise p-contacts and n-contacts for allowing laser currents I₁, I₂ to be injected into the first and second coupled cavities, respectively. The first and second coupled cavities comprise first and second heating resistors, respectively, for heating the first and second coupled cavities when heating currents H₁, H₂ are applied to the first and second heating resistors, respectively. A heating resistor is provided for heating the semiconductor substrate of the semiconductor laser so as to regulate the base temperature T of the chip (i.e., the semiconductor substrate).

A low profile, 4-element, slot-based, frequency reconfigurable MIMO antenna for cognitive radio (CR) platforms for cellular communication front ends. The antenna is on a board having a top layer substrate and a bottom layer ground plane. The bottom layer ground plane contains four antenna elements, each antenna element having a circular slot and an annular slot spaced outwardly from and extending circumferentially around the circular slot. The bottom layer contains a microstrip feed-line for each antenna element. Varactor diodes on the top layer span the width of each annular slot to tune the resonance frequency over a wide operation band. The antenna covers a wide frequency band from 1800 MHz to 2450 MHz and supports several well-known wireless standards bands, including GSM1800, LTE, UMTS and WLAN, as well as many others.

The invention discloses a terahertz voltage-controlled oscillator based on multiple oscillation cores, which is characterized in that a plurality of oscillation cores are connected in parallel, negative resistance is reduced, transmission connected with each VCO oscillation core is designed according to index requirements of the oscillator, and finally oscillation signals are input into a buffer amplifier circuit and a frequency multiplier circuit. According to the structure, under the condition that the process is limited, the value of a passive device can be effectively reduced, relatively good phase noise is realized, and a high-quality local oscillation signal is provided for a terahertz frequency band transceiving front end.