47 results about "Noise-equivalent power" patented technology

Described is a Schottky diode using semi-conducting single-walled nanotubes (s-SWNTs) with titanium Schottky and platinum Ohmic contacts for high-frequency applications. The diodes are fabricated using angled evaporation of dissimilar metal contacts over an s-SWNT. The devices demonstrate rectifying behavior with large reverse-bias breakdown voltages of greater than −15 V. In order to decrease the series resistance, multiple SWNTs are grown in parallel in a single device, and the metallic tubes are burnt-out selectively. At low biases, these diodes showed ideality factors in the range of 1.5 to 1.9. Modeling of these diodes as direct detectors at room temperature at 2.5 terahertz (THz) frequency indicates noise equivalent powers (NEP) comparable to that of the state-of-the-art gallium arsenide sold-state Schottky diodes, in the range of 10-13 W/square-root (√) Hz.

The invention discloses a spontaneous Brillouin scattering optical time domain reflectometer (BOTDR) based on a superconductive nanowire single-proton detector, which is characterized in that an optical pulse emitted by an optical pulse generating unit is coupled to a sensing optical fiber through a circulator, backward scattered light scattered from the sensing optical fiber is subjected to filtration of rayleigh scattering light through an optical filter unit to obtain Brillouin scattering light, a back scattering light signal is detected by the superconductive nanowire single-proton detector, an electric signal output from the superconductive nanowire single-proton detector is acquired and processed by a data acquiring and processing unit, and finally, a result is obtained through a certain demodulation relation. Compared with the traditional BOTDR, the BOTDR provided by the invention is used for carrying out data acquisition and processing by adopting the noise equivalent power (NEP) low/no-bandwidth-limit superconductive nanowire single-proton detector as a detection unit and adopting a single-proton counting technology.

An apparatus and method are disclosed for detecting terahertz radiation at room temperature. A detecting pixel includes a sub-wavelength split-ring resonator, and is mechanically coupled to (but thermally decoupled from) a substrate via a cantilever formed from two materials that have a significant mismatch in their thermal expansion coefficients. Incident radiation causes the split-ring resonator to resonate, thereby generating heat that is transferred to the cantilever, causing the cantilever to flex. An optical readout system includes a secondary light source, such as a laser, that shines on a reflective surface on the pixel, whereby a photodiode detects the reflected light and permits calculation of a relative deflection of the pixel in the nanometer range. An exemplary detector has a noise equivalent power rating of approximately 60 pW/√Hz.

An over sampled image sensor in which the pixel size is small enough to provide spatial oversampling of the minimum blur size of the sensor optics is disclosed. Image processing to detect targets below the typical limit of 6× the temporal noise floor is also disclosed. The apparatus is useful in detecting dimmer targets and targets at a longer range from the sensors. The inventions exploits signal processing, which allows spatial temporal filtering of the superpixel image in such manner that the Noise Equivalent Power is reduced by a means of Superpixel Filtering and Pooling, which increases the sensitivity far beyond a non-oversampled imager. Overall visual acuity is improved due to the ability to detect dimmer targets, provide better resolution of low intensity targets, and improvements in false alarm rejection.

A system for processing signals includes a receiver assembly for receiving a signal. The signal has a sample component with a sample electric field and a sample polarization, and has a reference component with a reference electric field and a reference polarization. The receiver assembly includes an analyzer for polarimetrically processing the signal, including differencing the signal to generate a difference electric field proportional to the difference of the sample and reference electric fields. By polarimetrically differencing the signal, the analyzer reduces the magnitude of the common-mode signal at the difference signal receiver. The receiver assembly includes an electric-field detector for measuring the difference electric field such that the reduction in common-mode amplitude decreases the noise equivalent power of the electric-field detector. One advantage of the present invention, then, is the reduction of noise equivalent power of the electric-field detector when measuring small variations in large electric fields.

A method, system and apparatus for reliable multicarrier communication in the presence of timing phase error is disclosed. Phase noise due to a sampling-time phase mismatch between a transmitter device and a receiver device is measured in a signal. A Gaussian noise power level in the signal is determined, and a gain factor associated with the phase noise is calculated. The gain factor is applied to the Gaussian noise power level to calculate an equivalent noise power. In one aspect, the equivalent noise power is used to determine a signal-to-noise ratio. In another aspect, the signal is a multicarrier signal including a plurality of sub-carriers.

The invention relates to the terahertz signal detection field, and especially to a room temperature terahertz detector based on a gallium nitride high electron mobility transistor and a preparation method thereof. The detector includes a gallium nitride high electron mobility transistor provided with a source electrode, a gate electrode, and a drain electrode, and also includes a nanometer antenna. The nanometer antenna is located between the source electrode and the drain electrode of the gallium nitride high electron mobility transistor and at one side of the gate electrode. The nanometer antenna is arranged at a distance from the gate electrode. One side of the gate electrode, adjacent to the nanometer antenna, is provided with a protrusion array having the corresponding shape and interval as the nanometer antenna. The protrusion array and the nanometer antenna form a tip-to-tip structure for increasing a terahertz electric field. The room temperature terahertz detector based on the gallium nitride high electron mobility transistor employs a unique nanometer antenna structure and combines a special gate electrode structure, effectively improves the coupling efficiency of the detector to a terahertz electromagnetic wave, and realizes the detection of the room temperature of the terahertz electromagnetic wave, and the high sensitive and low equivalent noise power.

The invention discloses an optical time-domain reflectometer comprising a trigger, a laser, an attenuator, a circulator, an up-conversion single-photon detector and a time-to-digital converter. The optical time-domain reflectometer (OTDR) of the invention employs the up-conversion single-photon detector. The up-conversion single-photon detector employs a pump light wavelength of 1900 nm to 2000 nm to carry out narrowband filtering on sum frequency light, a noise equivalent power (NEP) lower than the NEP of a classic detector is obtained under the same quantum efficiency, and the NEP value can reach -140dbm. The lower the NEP value is, the larger the detected dynamic range is. Therefore, the up-conversion single-photon detector effectively increases the detectable dynamic range of the OTDR, the detection resolution is improved, the measuring time is reduced, and dead zones after a Fresnel reflection peak are effectively prevented.

The invention provides an interference coordination method based on Home eNodeB (HeNB) active cognition in a Femtocell. The HeNB perceives the interference energy from self to a macro-cell user (Muser) and sends the information of the interference energy to a macro-cell eNodeB (MeNB), the equivalent noise power of the Muser is calculated by the MeNB based on the interference energy perceived by each HeNB, the interference threshold of each HeNB is respectively calculated according to the equivalent noise power, and the HeNB calculates self frequency domain emission predictive codes according to an interference channel from self to the Muser, the interference threshold, the frequency deviation of the HeNB and the Muser and the channel between the HeNB and the Muser. The invention also discloses a device and a system for realizing the method. The invention has the technical scheme that the number of subcarriers occupied at the Muser is smaller than that of subcarriers occupied at the Femtocell, when the Muser and the HeNB have frequency deviation, the performance decline ratio of the Muser can be effectively ensured to be smaller than the preset permitted maximum value eta, and simultaneously effective power distribution can be carried out on the subcarriers unoccupied by a main user so as to promote the transmission performance of the Femtocell, so the throughput of a cellular network is effectively increased.

The invention provides a photoelectric detector detection device. The photoelectric detector detection device comprises a photoelectric detector to be detected, a data acquisition module, a computer,a driving circuit control module, a light source driving module, a light source module, and a coupler which are connected successively; and also comprises a temperature control module, and an opticalpowder measuring module which are connected with the computer; an output terminal of the coupler is connected with the photoelectric detector to be detected, and another output terminal of the coupleris connected with the optical powder measuring module; the photoelectric detector to be detected is arranged in the temperature control module. The invention also provides a photoelectric detector detection method. The photoelectric detector detection method can be used for measuring parameters such as the noise voltage, the zero level, the zero drift, the responsibility, the noise equivalent power, and the dynamic range. The photoelectric detector detection device and the detection method is capable of realizing photoelectric detector automatic detection, reducing artificial operation, saving manpower, shortening time, and especially increasing production efficiency and reducing error caused by artificial measuring in large batch detection.

The invention discloses a terahertz wave detector, which is used for detecting terahertz waves coming from a terahertz wave radiation source. The terahertz wave detector comprises a substrate and a superconducting-material thin film which is attached onto the substrate, wherein the superconducting-material thin film is of a single long-range line structure which extends on the substrate in a zigzag and compact way; and in the working process, the superconducting-material thin film is in a superconducting transformation temperature zone and is directly irradiated by the terahertz waves to be detected, and the thermal radiation of the terahertz waves is received through the superconducting-material thin film to enable resistance to be obviously changed to detect the terahertz waves. The terahertz wave detector has the advantages that the sensitivity and the signal-to-noise ratio are high, the noise equivalent power is low, the structure is simple and the stability is good; and the terahertz wave detector is particularly suitable for detecting low-power and large-beam-spot terahertz wave radiation sources.

The invention provides a continuous-terahertz-wave imaging system, which comprises a continuous terahertz radiation source, a sample table, a terahertz focal plane array, an optical system, a camera and a computer. The continuous-terahertz-wave imaging system also comprises a modulator between the continuous terahertz radiation source and the sample table, and is used for modulating the light intensity of a terahertz continuous wave. The invention also provides a continuous-terahertz-wave imaging method. According to the continuous-terahertz-wave imaging system and the continuous-terahertz-wave imaging method provided by the invention, the effects on reducing the system noise equivalent power and improving the system detection sensitivity can be achieved.

The invention provides a terahertz sensor based on a tunneling transistor structure. When a substrate of the tunneling transistor structure is P type/N type, a source region formed by ion implantation is P+ type/N+ type, and a drain region formed by ion implantation is accordingly N+ type/P+ type. A silicon dioxide insulation layer is grown and a polycrystalline silicon gate oxide layer is deposited on the source region. The area of the source region is greater than the area of the drain region. According to the novel terahertz sensor, the barrier width at a tunneling junction is controlled by the gate voltage to enable electrons in the source region to reach a conduction band of a channel region through tunneling, thus starting the terahertz sensor. Based on the nonlinear relationship between the startup current and the gate voltage, high-frequency frequency signals can be rectified. The novel terahertz sensor based on a tunneling transistor structure is quick in response and low in equivalent noise power, and can better meet the demand of high-frequency applications.

A semiconducting microbolometer sensor for detecting electromagnetic waves in the medium wavelength infrared (MWIR) and long-wavelength infrared (LWIR) is provided. A preferred embodiment provides a substrate layer, a bottom and top support structure with a strut-based mesh design, a meandered electrode layer that follows the top support structure design, a bolometer sensing material with a high TCR, and a disk-shaped absorber on top of the sensing material to maximize the heat flux absorption on the sensor. The bottom support of the sensor suspends the top support mesh, creating an air cavity. This air cavity along with the strut based mesh design and optimized thickness, dimension and shape of the layers contributed towards minimizing the thermal conductance of microbolometer and hence improved the figures of merits—responsivity, detectivity, noise equivalent power and noise equivalent temperature difference of microbolometer.

The invention relates to a complementary metal oxide semiconductor (CMOS)-based high-response working method for a terahertz sensor. When a metal-oxide-semiconductor filed effect transistor (MOSFET) is working, an external circuit is used for providing a stable driving current for a source end and a drain end of a device so as to change direct-current conductance of a channel; and a direct-current bias voltage V<gs> is applied to a grid (201) of an MOSEFT device, a terahertz signal is input from the source end (202), and the drain end (203) is connected with a stable current source (204) to output a voltage. In such working mode, the channel direct-current conductance (GDS) of the channel current is changed, thus, the voltage response (RV) of a CMOS terahertz signal sensor can be larger, and the noise equivalent power (NEP) is lower.

Optical detection apparatus (300) comprising an optical detector (302, 304, 306), a detector amplifier (336, 338, 340), and switching means, e.g., a multiplexer (344, 348), for dynamically selecting at least one of the optical detector or the detector amplifier by switching from among at least two alternative optical detectors and/or at least two detector amplifiers such as to minimize noise equivalent power (NEP) of a selected detector or combination of detector and amplifier under given operating conditions.

The invention discloses a hollow coil structure parameter simulation design method and device and electronic equipment, and the method comprises the steps: building an impedance function of a hollow coil according to a structure parameter variable, wherein the hollow coil is of a differential structure, and the hollow coil is wound in a completely parallel winding mode; calculating an equivalent bandwidth, sensitivity and an equivalent noise power spectrum by utilizing the impedance function, and establishing an index function of the hollow coil; utilizing the mass and/or volume limit, and combining the index function and the structure parameter variable limit to construct a limit function; and calculating the optimal solution of the limiting function to obtain the structural parameters ofthe hollow coil. The method is intuitive, the optimized process structure parameters are more simply and conveniently calculated, the calculation amount is reduced, and the calculation time is saved.

The invention relates to the field of electronic materials, and in particular to a semimetal/semiconductor Schottky junction, a method for fabricating the same, and a Schottky diode. The semimetal/semiconductor Schottky junction comprises a semiconductor layer and a semimetal layer, wherein a Schottky contact is formed between the semiconductor layer and the semimetal layer; and a compound formingthe semimetal layer is a compound composed of a rare earth element and a group VA element. The semimetal/semiconductor Schottky junction has good thermal stability at an interface between the semiconductor layer and the semimetal layer. The Schottky diode based on the semimetal/semiconductor Schottky junction has an ideal factor of about 1.05, noise equivalent power that can be reduced to the order of pW/Hz1/2 or even sub-pW/Hz1/2, and sensitive detection performance.