75 results about "Superheterodyne receiver" patented technology

An optical communications system includes a receiver subsystem with at least two heterodyne receivers. The receiver subsystem receives a composite optical signal having two or more subbands of information and corresponding tones. An optical splitter splits the composite optical signal into optical signals. Each optical signal includes a subband(s) and corresponding tone. Each heterodyne receiver receives an optical signal. The receiver includes a heterodyne detector coupled to a signal extractor. The heterodyne detector mixes the optical signal with an optical local oscillator to produce an electrical signal which includes a frequency down-shifted version of the subband and the tone of the optical signal. The signal extractor mixes the frequency down-shifted subband with the frequency down-shifted tone to produce a frequency component containing the information.

A modulated laser light detector that converts laser light energy into electrical signals which exhibit a frequency that is substantially the same as the laser light modulation frequency, in which these signals allow the detector unit to determine a position where the laser light is impacting upon a photodiode array. A superheterodyne receiver circuit is used to provide high gain at an improved signal-to-noise ratio to improve the range at which the modulated laser light signal can be reliably detected. Various types of signal detection circuits are available. Various processing algorithms are disclosed, including one which rejects laser light strikes that are due to reflections, rather than due to a direct strike from the laser transmitter.

This invention relates to a global digital broadcast technology characterizing in applying two step double orthogonal zero IF including the following steps: transforming a RF signal to a high IF then to be switched to a base band directly via a double orthogonal mixed frequency structure. In practice, two different modes can be applied according to the different places set for the A/D converter by digitalizing after the first time of mixing the frequency then carrying out a second time orthogonal mixing and digitalization after that, which overcomes the shortcoming of converting frequencies for many times of the traditional superheterodyne receivers used at present in the global digital broadcast system

An optoelectronic RF signal receiver utilizes a first RF to photonic modulator for receiving an optical carrier signal and an electrical signal from a local oscillator and producing an optical carrier signal with first optical sidebands offset from the carrier signal by the local oscillator frequency. A second RF to photonic modulator receives an electrical RF signal and the signals from the first modulator and produces second sidebands to each of the first optical sidebands from the first modulator with each of the second sidebands being offset from the first sidebands by the RF signal frequency. A detector then receives signals produced by the second modulator and produces an electrical IF signal for further processing. The receiver does not utilize a frequency translation device in the RF signal path and thereby eliminates RF loss, noise, and limited dynamic range characteristic of prior art electro-optical receivers. The two modulators can be biased for optimum linearity and for optimum rejection of in-band spurious signal products.

The invention relates to a system for achieving transient signal capture and spectral analysis. The system comprises a superheterodyne receiver and a digital intermediate frequency capture and analysis module. The digital intermediate frequency capture and analysis module comprises an analog-digital conversion unit, an IQ modulation unit, a rapid Fourier transform unit and a mapping and recording unit. The mapping and recording unit is used for calculating the signal amplitude of each frequency component output by the rapid Fourier transform unit, conducting probability mapping on the signal amplitudes and recording the appearing frequency of frequency points. According to the system for achieving transient signal capture and spectral analysis, by the adoption of the structure, the information of the frequency, amplitude and occurrence probability and time of signals can be analyzed and recorded at the same time, the method for comprehensively analyzing suddenly-burst signals is provided, the occurrence probability and the specific time of the signals are analyzed from the perspective of the frequency domain, four-dimensional analysis can be carried out on the signals, and the system is widely applied in the actual signal analysis, has good flexibility and expandability and is applicable to large-scale popularization and application.

Wireless communication is ubiquitous today with increasing deployments leading to increased interference, increasing conflicts, etc. Monitoring the wireless environment is therefore important for regulators, service providers, Government agencies, enterprises etc. Such monitoring should be flexible both in networks monitored within the wireless environment as well as detecting unauthorized transmitters, allowing dynamic network management, etc. However, such real time spectral/signal analysis in the prior art requires both a wideband direct conversion receiver (DCR), for high performance, wideband, fast, programmable spectral analysis, and a super heterodyne receiver for fast, narrowband, programmable demodulation for signal analysis. According to embodiments of the invention a single receiver design methodology exploiting a single RF circuit to provide superheterodyne and direct conversion receiver functionalities.

The invention discloses a passive radar system for the switching among multiple antenna arrays. The system comprises a plurality of array antennas, and the combined airspace coverage orientation of the array antennas is 360 degrees. A multi-channel radio frequency switching device selects one array antenna in a fixed time period according to the time sequence, and sends signals received by the array antenna to a multi-channel superheterodyne receiver. In this way, multiple channels of radio-frequency signals are converted to fixed intermediate-frequency signals. After that, the intermediate-frequency signals are sent to a multi-channel AD acquisition and preprocessing sub-machine, so that the AD acquisition and the digital down-conversion of the intermediate-frequency analog signals are completed. After that, the clutter suppression, the target detection, the positioning and the tracking are conducted by a high-speed parallel digital signal processing machine. By adopting the system, aplurality of antenna arrays are switched to take turn and run according to a certain time sequence, so that the orientation360-degree airspace coverage of the passive radar system is realized. Compared with a traditional circular array antenna, the antenna side lobe is low, and the clutter suppression capability is high. Meanwhile, the low-altitude target detection capability is high, and the cost of the system can be effectively controlled.

A multi-channel superheterodyne receiver employs a low intermediate frequency (IF) and both high-side injection and low-side injection of a selected local oscillator (LO) signal into the mixer in order to position image frequencies outside the passband of a single image reject filter. Any channel that falls within a used portion of the image reject filter passband can be downconverted with image rejection if the utilized bandwidth portion is no greater than about 4 times the IF minus the bandwidth of a channel in the filter passband. Low side injection is used for channels falling within the lower half of the passband of the image reject filter, while high-side injection is used for channels falling within the upper half thereof. The image always remains outside the passband and the receiver can accommodate a greatly increased number of channels.

A MIMO signal receiving apparatus includes a first antenna (402 in chart 4) for receiving a first RF signal; a second antenna (404) for receiving a second RF signal; a superheterodyne receiver for receiving one or all of the first and second RF signals into at least one first analog signal; a direct conversion receiver (410) for converting one or all of the first and second RF signals into at least one second signal; and an antenna switching module coupling the first and second antennas to the superheterodyne receiver (408) and the direct conversion receiver for electively directing the first and second RF signals to the superheterodyne receiver and/ or the direct conversion receiver, depending on an antenna switch control signal indicating a signal quality derived from the first and second analog signals.

The invention relates to a wideband integrated reconnaissance receiver, which comprises an analog channelized module and a digital channelized module, wherein the analog channelized module further comprises a four-way power divider, bandpass filters from a first to a fourth, two-way power dividers from a first to a fourth, detectors from a first to a fourth, delay modules from a first to a fourth, an acquisition analysis module, a four-point source module, a 4-1 microwave switch module and a mixing module; and the digital channelized module further comprises an AD conversion module, a multi-phase filter module, an FFT calculation module, a threshold detection module, a frequency calculation module and a data storage module. The reconnaissance receiver thoroughly merges features of a direct detection-type receiver, a superheterodyne receiver and a digital channelized receiver, the quick response ability of the receiver and the adaptability to a complex electromagnetic environment are increased, and the adaptability to the complex electromagnetic environment and the reconnaissance real-time performance are met.

The invention discloses a height measurement method for a continuous wave search radar. In the method, a multi-port network is adopted to receive a pair of wave beams in mirror image distribution generated by a pitching surface of an antenna array; a slot waveguide and two output ports are distributed on the multi-port network; the two output ports of the multi-port network are connected to input ends of two paths of symmetric microwave receivers respectively; the used microwave receivers are superheterodyne receivers; the two paths of microwave receivers change the received echo to be intermediate frequency through amplification, frequency mixing and filtration and generate I and Q-baseband signals through amplification of an amplification filter and orthogonal demodulation; the I and Q-baseband signals are converted into digital quantity through A/D (Analog to Digital) conversion; modulo operation is performed through a signal processing module; a directional value is solved by using a sum-difference device; and a numerical value of an elevation angle is obtained from a pulse-out meter or through polynomial fitting by taking the directional value as an address. The method is easy to implement, has high data rate and is suitable for a small-sized three-coordinate search radar.

The invention provides a design method of a radar communication integrated shared construction module architecture superheterodyne receiver, and aims to provide a rapid and efficient multi-purpose receiving complete machine design method. The method is realized through the following technical scheme of according to a superheterodyne system, firstly planning six common construction modules, namelya radio frequency front end module, a radar intermediate frequency module, a communication intermediate frequency module, a power supply module, a control module and a frequency source module; secondly, for the circuit principle of the six common construction modules, serializing a series of product libraries of the common construction modules; then designing a superheterodyne radar-communicationintegrated receiving complete machine, and respectively selecting the corresponding shared construction modules for combination according to an existing shared construction module product series in the design of the radar-communication integrated receiving superheterodyne receiver in combination with the technical index requirements to realize the radar-communication integrated receiving superheterodyne complete machine.

The invention discloses a multi-slot transceiver. The multi-slot transceiver comprises a frequency generation unit. The frequency generation unit a control unit, a first frequency synthesis unit, a second frequency synthesis unit, a third frequency synthesis and a frequency processing unit, wherein the first frequency synthesis unit is used for outputting a first high frequency local oscillator; the second frequency synthesis unit is used for outputting a second high frequency local oscillator; the third frequency synthesis unit is used for outputting an intermediate frequency local oscillator; and the frequency processing unit is used for using the first high frequency local oscillator and the intermediate frequency local oscillator as two local oscillators of a superheterodyne receiver in a receiving timeslot respectively, processing the first high frequency local oscillator and the intermediate frequency local oscillator in a transmission timeslot, using a processed signal as a transmission local oscillator, and using the second high frequency local oscillator as a preparatory local oscillator of frequency hopping in the next receiving or transmission timeslot. According to the technical scheme, the multi-slot transceiver occupies a small space, and is low in cost and power consumption, a few serial peripheral interface (SPI) resources are occupied, the interference of transmission of a same-frequency signal with reception in a same-frequency reception-to-transmission working mode of adjacent timeslots can be avoided, and noise signals generated by the modulation of a modulator in a different-frequency transmission-to-transmission working mode of adjacent timeslots are easy to filter.

The invention discloses a self-adaptive fault detection and diagnosis method and device for a superheterodyne receiver. The method comprises the steps of inputting an input signal in the superheterodyne receiver and processing the input signal by the superheterodyne receiver; processing the input signal and an output signal of the superheterodyne receiver in previous time by a trained first-level GRNN observer, thereby obtaining an estimated output signal; obtaining a residual error according to the estimated output signal and the output signal of the superheterodyne receiver in current time; processing the input signal and the residual error by employing a trained second-level GRNN observer, thereby obtaining a self-adaptive threshold value; and determining whether a fault occurs in the superheterodyne receiver or not according to the residual error and the self-adaptive threshold value. According to the method and the device, whether the fault occurs in the superheterodyne receiver or not can be detected, and a fault type can be diagnosed.

A receiver with a local oscillator, a quadrature modulator, a first mixer and a second mixer, wherein a first input of the quadrature modulator is connected to a second signal input of the receiver circuit and a second input of the quadrature modulator is connected to the local oscillator. Further, a first input of the first mixer is connected to a first signal input of the receiver circuit, a second input of the first mixer is connected to an output of the quadrature modulator, and an output of the first mixer is connected to a first signal output of the receiver circuit. A first input of the second mixer is connected to the second signal input, a second input of the second mixer is connected to the output of the quadrature modulator, and an output of the second mixer is connected to a second signal output of the receiver circuit.

A non-radiating dielectric waveguide circuit between two multilayer parallel metal plates. Due to the multiple layers, the circuit has spacers of different heights between the boards, so non-radiating dielectric waveguides of different sizes designed according to their frequency of use are all inserted into a single circuit. By utilizing the present invention, we are able to construct a superheterodyne receiver which has the property of being able to mix received waves by a local oscillator to produce an intermediate frequency. The amplitude can easily be increased by means of the intermediate frequency, thus improving the reception sensitivity.