17 results about "Intermediate frequency" patented technology

A wideband receiver for a wireless communication system and a method for controlling the same are provided. In the wideband receiver for a wireless communication system, a receive path includes a mixer for receiving a Radio Frequency (RF) signal having a frequency f_SG and for converting the RF signal into an Intermediate Frequency (IF) signal having a frequency f_IF by mixing the RF signal with a first local oscillation signal having a first local oscillation frequency f_LO1, and at least one Phase Locked Loop (PLL) for providing the local oscillation signal to the mixer. A control block determines whether a half-IF signal having a center frequency of f_SG-f_IF/2 exists in the IF signal, and when the half-IF signal exists, controls the at least one PLL to generate a second local oscillation signal having a second local oscillation frequency f_LO2 greater than the first local oscillation frequency f_LO1.

The embodiment of the invention relates to the technical field of wireless communication, in particular to a method, a system and equipment for scheduling, which are used for conducting span-carrier wave scheduling on overlapped subframes after using carrier wave aggregation with different TDD (time division duplex) uplink/downlink configuration. The method in the embodiment of the invention comprises the following steps: when network side equipment needs to carry out scheduling to user equipment using the carrier waves with different TDD uplink/downlink configuration to carry out aggregation, SIF (sound intermediate frequency) for scheduling the carrier waves with the configuration different from the TDD uplink/downlink configuration of the carrier waves is determined; the network side equipment transmits DCI (data communication interrogate) containing the SIF to a user terminal by bearing downlink subframes n in the carrier waves of downlink control information, wherein n is integral number not less than 0. In the invention, span-carrier wave scheduling can be carried out on the overlapped subframes aiming at the aggregated carrier waves with different TDD uplink/downlink configuration, and the system performance and the resource utilization rate can be improved.

A triple-band antenna for an electronic device with a communication capability comprises a first radiating body, a second radiating body, a metal base and a signal feed source. A dual-band antenna for low frequency and high frequency bands may be formed by the first radiating body. A middle-frequency band antenna and a balun may be formed by the combination of the first radiating body and the second radiating body, and the balun may be used to increase the bandwidth of operating frequencies of the intermediate frequency band antenna.

A pulse-echo ranging system and method wherein transmit burst pulses are transmitted to a target at a first repetition frequency, an intermediate frequency signal is generated by sampling the received echo pulses from the target at a second repetition frequency slightly lower than the first repetition frequency, and the intermediate frequency signal is evaluated to determine the target distance. In order to compensate for phase error and thermal drift which may occur when the transmit and sampling instants are generated, the transmit burst pulses are periodically and alternately transmitted at the first and second repetition frequencies while the received echo pulses are simultaneously sampled at the second and first repetition frequencies, and the target distance is determined as half of the distance between echoes appearing in the intermediate frequency signal and resulting from the different clocks.

The invention discloses a spray method for preparing oxidation-resisting phosphorous copper alloy powder. The spray method is characterized in that the oxidation-resisting phosphorous copper alloy powder is prepared by the following components: 500 parts of raw copper powder, 25-30 parts of tin power, 8-10 parts of phosphorus powder, 3-7 parts of benzotriazole, 3-7 parts of benzene sulfonic acid sodium salt and 6-8 parts of glycerol. By smelting the raw materials through intermediate frequency smelting equipment and adjusting the contents of copper, tin and phosphorus, the product lead-free effect is realized, and the oxidation-resisting phosphorous copper alloy powder is prepared by the spray method. The prepared oxidation-resisting phosphorous copper alloy powder has the characteristics of good sphericity, component uniformity, good moldability, excellent sinterability and low surface oxidation. The spray method is low in production cost, high in production efficiency and stable in product quality.

The invention relates to a digital tuner solving the problem that the power levels of television signals are lowered because of a great number of combined two-order and three-order beat interference signals generated by dense channel signals of the prior high-level cable digital televisions. The digital tuner comprises an antenna input device, a radio-frequency AGC low-noise wideband pre-amplifier, a power divider, a frequency selective network, a tracking filter, a frequency mixer, a local oscillator, an intermediate-frequency filter, a circular signal output device, a rheostatic diode, an alternating current gain controller and a delay controller, wherein the alternating current gain controller is connected in series with the frequency selective network and the tracking filter and also connected in parallel with the delay controller and a high-frequency AGC voltage. The invention adopts a step-by-step AGC control mode to control intermediate-frequency AGC, high-level AGC and radio-frequency AGC step by step so that the functions that a small signal receives a low noise factor and a large signal has a large receiving dynamic range is achieved, and the acceptable maximum cable television signal level can not be lowered.

The invention discloses a segmented heating and cooling quenching process for a wheel body of a thrust wheel. The process comprises the following steps of 1, placing and positioning the thrust wheel, wherein the thrust wheel is grabbed through a mechanical arm and placed on a support platform in a quenching device; 2, sequentially conducting intermediate frequency, high frequency and intermediate frequency induction heating on the thrust wheel through induction coil bodies; 3, cooling the thrust wheel obtained after induction heating, wherein spray cooling implemented through water, saline water and oil is sequentially conducted on the thrust wheel obtained after induction heating. According to the thrust wheel quenching process, the water-saline water-quenching oil cooling process is adopted, so that the problems that in the prior art, the quenching speed of a thrust wheel is low, the thrust wheel is deformed and cracked, and the thrust wheel is inconsistent in hardness after being quenched; the quenching process has the advantages of being uniform in thrust wheel hardness and high in quenching efficiency.

The invention discloses a QPSK-DS communication detecting method based on delay multiplication. A system is initialized and begins to scan a target frequency band to amplify signals entering the system from the radio frequency front end, radio frequency signals are converted into fixed middle frequency to be amplified through a difference frequency method, digital signals can be achieved through analog-digital conversion, delay multiplication operation is carried out, digital lowpass filtering is carried out to obtain lowpass signals, and a frequency spectrum of the lowpass signals can be achieved through an FFT algorithm. The QPSK-DS communication detecting method has the advantages of adopting a linear and non-linear processing method to achieve full detection on QPSK-DS communication through simple comprehensive analysis and processing on time frequency domains and being simple to achieve, strong in operability and strong in capacity adapting to low signal to noise ratio. Meanwhile, the method adopts the middle frequency analysis instead of radio frequency or baseband processing to avoid high requirements for performance of processing capacity of a receiver as possible. Furthermore, the method can achieve real-time processing easily and is strong in practicability.

The invention discloses an intermediate frequency direct current detuning calibration DCOC circuit applied to a radio frequency signal receiver, the intermediate frequency direct current detuning calibration DCOC circuit comprises an operational amplifier OPA1, an NMOS transistor M1, an NMOS transistor M2, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, one output end of the operational amplifier OPA1 is connected with the resistor R2, and two ends of the capacitor C1 are respectively connected with the output end and an in-phase input end of the operational amplifier OPA1. The other output end of the operational amplifier OPA1 is connected with the resistor R4, and the two ends of the capacitor C2 are connected with the output end of the operational amplifier OPA1 and the inverted input end of the operational amplifier OPA1 respectively. The source electrode of the NMOS transistor M1 is connected with the in-phase input end of the operational amplifier OPA1, and the drain electrode of the NMOS transistor M1 is connected with one end of the resistor R1. The source electrode of the NMOS transistor M2 is connected with the inverted input end of the operational amplifier OPA1, and the drain electrode of the NMOS transistor M2 is connected with one end of the resistor R3. According to the invention, low direct-current offset calibration high-pass turning frequency and small layout area can be realized, the overall area of a chip is reduced, and the manufacturing cost is reduced.

The invention discloses a correlation error correction method in a multichannel digital correlator, and belongs to the technical field of space microwave remote sensing. The method comprises the following steps: performing high-speed acquisition and quantization on multi-channel intermediate frequency data to obtain original sampling data d1-dn, n being the number of channels of a multi-channel digital correlator; calculating an in-phase component I and an orthogonal component Q of each channel; respectively calculating the offset accumulated values CmI and CmQ of the I and Q data of each channel in an integral period, the autocorrelation values SmII and SmQQ of the I and Q data of each channel, and the cross-correlation operation values CorII (i, j) and CorQI (i, j) between every two channels; calculating a cross-correlation value between every two channels according to the self-correlation value of the I and Q data of each channel and the cross-correlation operation value between every two channels; and correcting the cross-correlation value between every two channels according to the offset accumulated value of the I and Q data of each channel, the self-correlation value of the I and Q data of each channel and the cross-correlation operation value between every two channels.

The invention discloses a dust cleaning device for pipelines of an intermediate-frequency furnace. The dust cleaning device comprises a cleaner (1), the pipelines (2), an inlet (3) and outlets (4) andis characterized in that the cleaner (1) is mounted on the pipelines (2); the inlet (3) is formed in the upper end of the cleaner (1); and the outlets (4) are formed in the lower end of the cleaner (1). The cleaner is additionally arranged on the pipelines of the intermediate-frequency furnace, so that the problem that the pipelines of the intermediate-frequency furnace are likely to be full of accumulated dust when used for a long term, and therefore the working efficiency of the intermediate-frequency furnace is affected is solved; and the dust cleaning device has the advantages of being low in manufacturing cost, convenient and rapid to use and easy to popularize.