366 results about "Type frequency" patented technology

The invention discloses a cold and warm type frequency conversion air conditioner and a defrosting method thereof. The air conditioner comprises an indoor machine and an outdoor machine, wherein the outdoor machine is provided with a frequency conversion compressor, a four-way valve, a throttling element and an outdoor heat exchanger which are communicated through a connecting pipeline, and the connecting pipeline of the outdoor machine is also provided with a by-pass loop; and the indoor machine is internally provided with an electric heating device which is at least turned on to operate in the defrosting process of the air conditioner. The defrosting method for the air conditioner comprises that when a defrosting condition is reached, the electric heating device is turned on, and a by-pass defrosting process is carried out by the by-pass loop. The air conditioner and the defrosting method not only can guarantee the using comfort of users, but also can improve the defrosting efficiency of the air conditioner, and cannot influence the using reliability of the frequency conversion compressor of the air conditioner.

A spectrum analyzer is provided that includes components to achieve from below 9 kHz to above 20 GHz operation range while remaining hand-held. Components of the spectrum analyzer include an integrated precision stand-alone step attenuator that does not rely on printed circuit board (PCB) mounted circuit elements within the signal path. Further, a PIN diplexing switch separates signals into different base-band and highband paths. The baseband path includes a pre-amplifier for low frequency signals, while the higher frequency bands may not necessarily include a pre-amplifier. The baseband path further provides improved broadband termination of its 1^st mixer IF port by incorporating a new quadrature-coupled directional (QCD) filter that includes a ring resonator. An inexpensive air dielectric multi-cavity baseband filter is also used to suppress 2^nd mixer IF images. The highband path incorporates multi-throw MMIC PIN diode switches to selectively filter different bands of input signals. At least three total 1^st mixers are used to increase operation bandwidth. A phase locked loop providing a 1^st LO to the 1^st mixers is created that uses a divide-by-two frequency divider in cascade with a sampler-type frequency downconverter. The output of the 1^st LO is frequency doubled and filtered to increase the frequency range of the highband signal path.

A wide-band multimode frequency synthesizer using a Phase Locked Loop (PLL) is provided. The multiband frequency synthesizer includes a multimode prescaler, a phase detector/a charge pump, a swallow type frequency divider, and a switching bank LC tuning voltage-controlled oscillator having wide-band and low phase noise characteristics. The multimode prescaler operates in five modes and divides a signal up to 12 GHz. The wide-band frequency synthesizer can be used in various fields such as WLAN/HYPERLAN/DSRC/UWB systems that operate in the frequency range from 2 GHz to 9 GHz. The wide-band multimode frequency synthesizer includes a frequency/phase detector for comparing a frequency and phase of a reference high-frequency signal with a frequency and phase of a feedback high-frequency signal; a charge pump for producing an output current corresponding to the result of the comparison performed by the frequency/phase detector; a loop filter for producing an output voltage corresponding to an accumulated value of the output current of the charge pump; a voltage-controlled oscillator for generating an oscillation signal having a frequency corresponding to the output voltage of the loop filter; and a variable frequency divider for dividing an output signal of the voltage-controlled oscillator by a designated integer value, and outputting the result as a feedback signal, wherein at lease two of an amount of unit pumping charges of the charge pump, an RLC value of the loop filter, an RLC value of the voltage-controlled oscillator, and a divisor value of the variable frequency divider are controlled according to a band.

The invention discloses a rubidium atomic magnetometer and a magnetic field measuring method. Based on the principle of nonlinear magneto-optic rotation, and through combination of timing control and tracking type frequency locking control, the atomic magnetometer achieves a large dynamic measurement range, high magnetic field sampling rate and high sensitivity. A DSP timing control module controls on-off of an acousto-optic modulator and a radio-frequency signal source in the physical part of the rubidium atomic magnetometer according to timing combination to adjust the magnetic field sampling rate N. The DSP timing control module further controls acquisition triggering of a data acquisition card. A calculation unit gets the Larmor precession frequency (f) through fast Fourier transform with use of a received rubidium atom Larmor precession free relaxation signal, and further calculates the value of an external magnetic field. The calculation unit selects a high magnetic field sampling rate module or a low magnetic field sampling rate module before measurement according to the pre-judged dynamic range of a to-be-measured magnetic field, and sets whether a tracking type frequency locking work mode is used when the low magnetic field sampling rate module is selected. In the working process, data is acquired and processed, and the value of the magnetic field is output.

A heterodyne receiving circuit for a digital communication system including a first band pass filter receiving a signal from an antenna, an amplifying circuit and a second narrow band pass filter for selecting one particular channel within a band of frequencies. The two filters are carried out with integrated BAW-type tunable resonators which can be adjusted, respectively, by a first electrical signal and a second electrical signal generated by two PLL-type frequency control loops. The second frequency control loop has a variable division factor for the purpose of selecting one particular channel within said band of frequencies. In addition, the receiving circuit includes a mixer for mixing the signal generated at the output of said second filter with a local oscillation frequency in order to produce an intermediate frequency. The division factor is controlled by a digital processing of the intermediate frequency.

The invention relates to a double-layer cascaded dual-polarized broadband absorbing type frequency selective surface. A conventional wave absorbing frequency selective structure is designed to be a bandpass type frequency selective structure which has limited pass band width and has difficulty in covering low frequency. According to the invention, a double-ring reflective plane is adopted, a waveabsorbing ring is designed on the other surface of the reflective plane, and the double-layer cascaded dual-polarized broadband absorbing type frequency selective surface is constructed by the combination of a single-ring circuit analog absorber. Therefore, insertion loss in a low frequency passband is low, and an extremely wide absorbing band can be generated near a high frequency place.

The invention discloses a method for correcting the frequency of a heterodyne type frequency spectrum analyzer. The method comprises the following steps: when signals are sent into the heterodyne type frequency spectrum analyzer for processing, judging the resolution bandwidth RBW; if when the RBW is more than 10-time fmin, carrying out amplification or compression on the signals by adopting a filter scanning method, carrying out envelop detection, and carrying out filtering processing on videos to obtain frequency spectrums of the signals; and when the RBW is less than or equal to the 10-time fmin, transforming difference values between recorded tuning frequency-point values and actual sending tuning frequency point values into errors of data points by adopting an FFT (Fast Fourier Transform) scanning method after FFT transformation to eliminate frequency-spectrum errors so as to improve the recognition accuracy of the frequency spectrums.

The invention discloses a UWB (ultra wide band) array antenna, and mainly solves a problem that the bandwidth of a conventional array antenna is limited by the bandwidth of an antenna unit. The antenna comprises a dipole antenna array plate (1), a resistor-type frequency selection surface plate (2), a grounding plate (3) and a feed Balun (4). The antenna array plate consists of a plurality of dipole radiation periodic units, and each dipole radiation periodic unit comprises a dipole arm (111), a metal via hole (112) and a dielectric plate (113), wherein the dipole arms (111) are arranged on the upper and lower surfaces of the antenna array plate in a cross manner. The resistor-type frequency selection surface unit consists of a resistor paster and a dielectric plate, wherein the resistor paster consists of a square ring paster, a circular ring, and a rhombus paster. Through the close coupling between units, the reflection coefficient of the antenna at the band from 0.63GHz to 4.6GHz is less than or equal to -6dB, and the array bandwidth can be increased to 7.3 frequency multiplications. The antenna is used for FOPEN radars and through-the-wall imaging radars.

Disclosed is a quadrature signal generator for generating an in-phase signal and a quadrature-phase signal, which is capable of generating a quadrature signal having the same frequency as a differential oscillating frequency, using a feedback control system. The quadrature signal generator includes an oscillator for generating a differential oscillation frequency signal having predetermined differential oscillation frequencies; a feedback type frequency doubler for generating a differential frequency signal having differential frequency components corresponding to differential frequency components of a frequency sum signal obtained by summing the differential oscillation frequency signal received from the oscillator and a differential feedback signal received at the differential feedback terminal; and a frequency divider for dividing the differential frequency signal received at the differential input terminal thereof by 2, thereby generating a quadrature signal consisting of two differential output frequency signals to supply at least one differential output frequency signal of the quadrature signal to the feedback type frequency doubler as the differential feedback signal.

The invention discloses a method and device for controlling a direct heat type double-source heat pump water heater and relates to a fluid heater provided with a solar heat collector and a heat pump and a control method of the fluid heater. A control device detects the outlet water temperature of the solar water heater and changes the temperature control strategy according to the outlet water temperature. When the water temperature is in a first water temperature control zone, the heating amount of the heat pump is changed and the water temperature is controlled by adjusting the operation frequency of the direct heat type frequency conversion heat pump. When the water temperature is in a second water temperature control zone, the water temperature is controlled by changing the water supplementing speed of a water supplementing flow adjusting element, solar energy is fully used for accumulating heat, the heat pump heating time in sunlight intensity lowering periods before and after the sunset is shortened, adaptation to different sunlight intensities is achieved, the solar energy is preferably and fully utilized, the water inlet temperature of a unit is low, operation efficiency is high, safety and reliability are achieved, high-pressure protection of the unit due to the excessively high outlet water temperature can be avoided, the requirement for hot water supply can be met, meanwhile, the requirement for the power of a compressor can be lowered, the utilization rate of equipment is improved, and early-stage investment cost is lowered.

In a phase locked loop type frequency synthesizer including a phase/frequency comparator for receiving an input signal, a charge pump circuit, a loop filter for generating a control voltage, a voltage control oscillator block including a plurality of voltage controlled oscillators controlled by the control voltage, and a frequency divider formed by a fixed frequency divider and a programmable frequency divider, a selecting circuit selects and activates only one of the voltage controlled oscillators, and counts a number of output pulses of the first frequency divider within a predetermined number of output pulses of the input signal while applying a bias voltage to the loop filter. Thus, the one of the voltage controlled oscillators being selected so that the number of the output pulses of the first frequency divider is brought close to an optimum value.

The invention discloses an electromagnetic interference monitoring and identification method for a power LTE wireless private network. The method comprises two processes: spectrum monitoring and interference identification. The spectrum monitoring comprises the steps: employing a scanning heterodyne type frequency spectrum monitoring design at a high frequency band; through multi-stage frequency conversion processing, converting an input signal to a lower intermediate frequency, and then adopting a Fourier spectrum monitoring design at a middle frequency band to perform A/D sampling quantification on the signal which is converted to the intermediate frequency, converting the signal into a digital signal, and then employing a digital intermediate frequency technology and Fourier transform to complete spectrum monitoring. The interference source identification process comprises the following steps: firstly, performing preprocessing, feature extraction and feature selection on acquired data, learning a relationship between acquired signal features and an interference source by utilizing a machine learning algorithm to obtain a classification model based on interference source identification, extracting features from a test signal, and identifying a result by adopting the obtained classification model. According to the invention, frequency spectrum monitoring and interference identification functions of the electromagnetic frequency spectrum can be tightly combined according to the requirements of a power system, and the method is suitable for a 1.8 GLTE wireless private network.

The invention discloses a method for performing frequency planning in a wireless Mesh returning network, which comprises the following steps: according to the traffic load reference gross in the wireless Mesh returning network, determining the total number of first type frequency blocks for performing fixed allocation in frequency resources, wherein the first type frequency blocks are used when performing communications between each network node and other network nodes having master-slave relations; according to the total number of the first type frequency blocks and the traffic load of each network node, determining the number of the first type frequency blocks required to be allocated to each network node; and according to the number of the first type frequency blocks required to be allocated to each network node, allocating corresponding number of the first type frequency blocks to each network node. Thus, the complexity of a frequency planning scheme is reduced effectively on the basis of ensuring the spectrum effectiveness, and the increase of network load is avoided. The invention simultaneously discloses a communication device and the wireless Mesh returning network.

The invention provides a passband embedded-type frequency selection absorber based on parallel LC resonator loading, mainly to solve the problem that the structure in the prior art is complicated. Thepassband embedded-type frequency selection absorber based on parallel LC resonator loading comprises m*n periodically-arranged absorber units, wherein the absorber unit comprises a passband embedded-type wave absorption structure and a bandpass frequency selection structure which are vertically cascaded and with an air layer arranged in the middle; the passband embedded-type wave absorption structure comprises a first dielectric plate, the lower surface is printed with four strip patches, the upper surface is printed with a Jerusalem cross patch loaded with parallel LC resonators and resistors, and the two are connected through metalized through holes; the bandpass frequency selection structure comprises a second dielectric plate and a third dielectric plate which are stacked vertically,the upper surface of the second dielectric plate is printed with a first square ring patch and a first tail-winding cross patch located inside, and the upper surface of the third dielectric plate is printed with a standard cross patch and the lower surface is printed with a second square ring patch and a second tail-winding cross patch located inside.

The embodiment of the invention discloses an optical transparent antenna, and the antenna comprises a three-layer structure which is formed by the sequential connection of a first layer, a second layer and a third layer. The first layer is an antenna radiator layer, the second layer is a dielectric layer with transparency, and the third layer is an antenna ground layer. The antenna radiator layer takes an ITO (indium tin oxide) film as a radiation paster, and the antenna ground layer employs a slotting-type frequency selection surface structure. According to the scheme of the invention, the frequency selection surface is a slotting type, so the frequency selection surface belongs to a band-pass frequency selection surface from the aspect of frequency attributes, the interior of a pass-band can achieve the reflection of an incident electromagnetic wave and the exterior of the pass-band displays transmission characteristics. Moreover, the frequency selection characteristics of the frequency selection surface enable the antenna to show directional characteristics when the antenna works at a pass-band of the frequency selection surface. Meanwhile, the slotting-type frequency selection surface is higher in light transmissivity. Therefore, the antenna solves a problem that an optical transparent antenna cannot achieve directional radiation in the prior art.

The invention discloses a miniaturization band elimination type frequency selective surface. The miniaturization band elimination type frequency selective surface is formed by periodically arranging a plurality of same unit structures on a dielectric substrate in the horizontal two-dimensional direction, and each unit structure comprises a pair of opened metal rings located on the upper surface of the dielectric substrate, a pair of opened metal rings located on the lower surface of the dielectric substrate and metal through holes; the opening directions of the two metal rings in each pair are opposite, the two pairs of opened metal rings on the upper surface and the lower surface are perpendicularly staggered in the electromagnetic wave incidence direction, and the four metal through holes symmetrically formed in each unit center are used for correspondingly connecting the opening ends of the four metal rings in an up and down mode. The frequency selective surface has the band elimination characteristic due to inductance and capacitance resonance provided by the unit structures, and propagation of electromagnetic waves within specific frequency bands can be blocked; meanwhile, the frequency selective surface further has the advantages of being stable in response to different-polarization and different-incidence-angle frequencies of the space electromagnetic waves and being miniaturized.

Dedicated comb type frequency spectrum is assigned to followed route pilot frequency. User of transmitting data maps the pilot frequency to frequency band to be as user's followed route pilot frequency corresponding to the user data in the dedicated comb type frequency spectrum assigned to followed route pilot frequency. Thus, there is no interference and restriction relation between density of followed route pilot frequency and quantity of user of transmitting data. Moreover, when sending followed route pilot frequency, user of transmitting data does not use resource of frequency spectrum except the dedicated comb type frequency spectrum. In the invention, measuring pilot frequency is not influenced by density of followed route pilot frequency. Thus, when measuring assignment of pilot frequency in remaining frequency spectrum resources, system is not restricted by followed route pilot frequency. The invention also discloses a radio communication system.

The invention relates to a realization method of a programmable controller integrating yarn cleaning and yarn breaking detection. The controller comprises a CPU (central processing unit) control module, a communication module, a sensing module, an input module, a motor driving module, an output module and a power supply module, wherein the sensing module adopts a phase-locked amplifier for extracting yarn shaking signals and diameter signals, the CPU control module adopts ladder diagrams for development, yarn simulated signals are converted into digital signals through an AD (analog-to-digital) sampling circuit, an embedded intelligent detecting algorithm is used for carrying out time domain and type frequency domain analysis on the yarn digital signals, the output module and the motor driving module are controlled to execute corresponding commands, and the transmitting of spinning parameters is realized through a high-reliability communication bus. Compared with the traditional detecting head, the realization method has the advantages that the system structure of the spinning control is simplified, the cost is reduced, and the system stability is improved.

The invention discloses a photon type frequency down-conversion device. The photon type frequency down-conversion device comprises an electro optic conversion module, a down-conversion signal output unit, a polarization modulator, an optocoupler, an analyzer, a photoelectric detector, a microwave band-pass filter, an amplifier and a phase shifter, wherein the optical input end and the optical output end of the polarization modulator are respectively connected with the output end of the electro optic conversion module and the input end of the optocoupler; the second output end of the optocoupler is connected with the input end of the analyzer, the analyzer, the photoelectric detector, the microwave band-pass filter, the amplifier and the phase shifter are connected in sequence, the output end of the phase shifter is connected with the electric input end of the polarization modulator to form a photoelectric oscillation loop; and the input end of a down-conversion signal output unit is connected with the first output end of the optocoupler, which can operate in a state of 2n frequency doubling of the oscillator signal in the photoelectric oscillation loop, and the n is a natural number. The invention also discloses a frequency down-conversion method. The photon type frequency down-conversion device is simple in structure, low in cost and favorable in frequency down-conversion performance.