15results about How to "Low spurious" patented technology

The invention provides a satellite communication system based on Beidou RDSS. The satellite communication system specifically comprises a receiving channel and a transmitting channel. A receiving channel adopts a low-intermediate frequency structure, an antenna receives a radio frequency signal, the radio frequency signal is directly down-converted into a low-intermediate frequency signal through a mixer, and then the low-intermediate frequency signal is converted into a baseband signal through an analog-to-digital conversion chip. The system adopts a low-intermediate frequency structure and uses primary frequency mixing, so that compared with secondary frequency mixing of a superheterodyne structure, the system has the advantages of simple link, low cost, low power consumption, high integration and the like. Meanwhile, the system is down-converted to low-intermediate frequency, and low-intermediate frequency signals are far away from direct current, so that the problems of direct current offset, flicker noise and the like of the system are solved. A transmitting channel adopts a direct frequency conversion structure, and a baseband signal skips an intermediate frequency stage through a frequency mixer and is directly up-converted to a radio frequency signal transmitted by an antenna. The system not only ensures the advantages of simple link, low cost, low power consumption, high integration and the like of the system, but also improves the stray problem of signals transmitted by the system.

The invention discloses a multichannel comprehensive radio frequency microsystem supporting fast frequency hopping, a multichannel receiving module, a transmitting module, a fast frequency hopping source, a processor SOC and an external interface IO are integrated in the multichannel comprehensive radio frequency microsystem, and the multichannel receiving module comprises an amplitude limiter, a power divider, a first balun 1, a second balun 2, a third balun 3, a fourth balun 4, a first transceiver chip 1 and a second transceiver chip 2. The transmitting module comprises a third transceiver chip 3, a fifth balun 5, a low noise amplifier and a first filter 1. The invention has the advantages of miniaturization, generalization, reconfiguration and the like, and can be widely applied to the field of wireless communication.

The invention provides an ultra-low phase noise frequency source circuit based on YTO and a frequency planning method, and belongs to the technical field of microwave radio frequency and frequency sources, the frequency source circuit comprises a main ring circuit, a first offset ring circuit, a second offset ring circuit, a clock circuit, a YTO driving circuit, a control circuit and the like; the main loop circuit comprises a first phase discriminator module U1, a first loop module U2, a YTO module U3, a first coupler module U4, a first mixer module U5, a first filter module U6, an amplifier module U7, a second mixer module U8 and the like. The method is realized based on the frequency source circuit. According to the scheme of the invention, the multi-stage conversion loop is adopted to generate the frequency signal with the low phase noise, the frequency is gradually expanded, finally, the YTO module can output the frequency signal with the low phase noise, frequency spectrum planning is carried out according to the frequency range output by the YTO module, and the finally output frequency spectrum of the YTO module is pure and low in stray.

The utility model relates to the technical field of active microwaves, in particular to a small millimeter wave frequency source. Comprising a comb spectrum generation unit, a frequency synthesis unit and a frequency multiplication processing unit. A frequency synthesis unit is arranged by adopting a technology of combining direct digital frequency synthesis and a phase-locked loop, miniaturization of a frequency source module is realized through frequency-band synthesis, and millimeter wave signals with sparse stepping, relatively low stray and high stability can be output; and the first switch and the second switch are arranged to be matched for use, so that the switching between the frequency doubling channel and the frequency quadruplicating channel is realized, the output of radio-frequency signals of different working frequency bands is realized, and the frequency conversion device has the advantages of higher frequency resolution, wider output frequency band and higher frequency conversion speed.

The invention belongs to the field of electronic technology and discloses a hybrid frequency synthesizer based on orthogonal modulation, comprising: an integrated phase-locked loop, a loop filter, a voltage-controlled oscillator, a power divider, an orthogonal modulator, a standard frequency generator, two direct digital frequency synthesizers, a radio frequency amplifier, a filter, and a controller. The hybrid frequency synthesizer is applied to a local oscillator or radio frequency excitation signal of an ultrashort wave superheterodyne communication device, has a wide frequency coverage range, low noise and spurious, short frequency switching time, and excellent noise and spurious performance.

The invention belongs to the technical field of precision measurement, and particularly relates to a power supply system for reducing low-frequency spurious signals of a measuring instrument and a phase compensation method, which comprise three stages of power supply loops, the first stage is used for completing conversion of AC-DC (Alternating Current-Direct Current) DC bus voltage, and the second stage is used for completing conversion from the DC bus voltage to each path of required voltage and low-pass filtering. And in the third stage, active rate filtering of various power supplies is realized through the LDO, and the power supplies are output to each whole device for use. An innovative multi-channel coherent clock output phase compensation algorithm is used, each channel of clock output phase of an external reference clock synchronization circuit is optimized, clock phases of power supply conversion circuits are different, multi-channel same-frequency clock spurious signals and harmonic waves thereof are enabled to generate incoherent offset, and space radiation interference of low-frequency spurious signals is reduced.

The invention provides a frequency synthesizer based on a phase discriminator and a frequency synthesis method thereof. The frequency synthesizer based on the phase discriminator comprises a first-stage phase-locked loop circuit, a second-stage phase-locked loop circuit, a third-stage phase-locked loop circuit and a frequency multiplication amplification circuit, wherein the first-stage phase-locked loop circuit is used for generating a first-stage frequency signal based on a reference clock signal; the frequency multiplication amplification circuit is used for generating a frequency multiplication amplification signal based on the reference clock signal; the second-stage phase-locked loop circuit is used for generating a second-stage frequency signal based on the first-stage frequency signal and the frequency multiplication amplification signal; and the third-stage phase-locked loop circuit is used for generating a frequency output signal based on the second-stage frequency signal. According to the frequency synthesizer based on the phase discriminator and the frequency synthesis method of the frequency synthesizer, the problems that integer boundary stray is difficult to avoid by using a single-loop phase-locked source and frequency stepping cannot meet the requirement sometimes in an existing frequency synthesizer can be solved.

The present invention proposes a high-performance phase-locked digital frequency synthesis device, comprising: the output end of a crystal oscillator circuit is connected to the input end of a DDS device, the output end of a DSP device is connected to the input end of the DDS device, the output end of the crystal oscillator circuit is connected to the input end of a mixer, the output end of the mixer is connected to the input end of a bandpass filter, the output end of the bandpass filter is connected to the input end of a phase detector, the output end of the phase detector is connected to the input end of a low-pass filter device, the output end of the low-pass filter device is connected to the input end of an amplifier, the output end of the amplifier is connected to the input end of a voltage-controlled oscillator, the output end of the voltage-controlled oscillator is connected to the input end of a dual-mode pre-frequency divider, the output end of the dual-mode pre-frequency divider is connected to the input end of an N-frequency divider, and the output end of the N-frequency divider is connected to the input end of the phase detector.

The present invention relates to the technical field of chip packaging, and specifically to an EMI shielding wafer-level chip packaging structure, comprising: a wafer base plate, a wafer chip is arranged in the wafer base plate, a solder ball is arranged on the front side of the wafer chip, an insulating film is arranged on the back side of the wafer chip, a silicon oxide layer is bonded to the back side of the insulating film, and a shielding layer is arranged on the back side of the silicon oxide layer; a reinforcing layer comprises a rib mesh layer and a reinforcement layer, a thickening layer is bonded to the back side of the reinforcement layer, and the thickening layer is bonded to the front side of the shielding layer; the beneficial effect is: by arranging an insulating film on the back side of the wafer base plate, a silicon oxide layer is arranged on the back side of the insulating film, and a shielding layer is arranged on the back side of the silicon oxide layer, the shielding layer forms a covering shield for the entire wafer, reduces stray and radiation in the packaging, and the shielding layer is made of metal electroplating, and by controlling the electroplating thickness, a recessed portion can be formed on the back side of the shielding layer to improve the packaging strength and stability during subsequent plastic sealing.

The invention provides a 0.8 GHz-40GHz multi-channel multi-mode frequency conversion method and a transmitting-receiving system. A multifunctional multi-mode fusion design is used, eight receiving channels and one transmitting channel are reasonably matched for frequency source switching, and three functions of simultaneous working of the transmitting-receiving channels, simultaneous working of multiple receiving channels and independent working of the transmitting channels can be realized; through reasonable scheme design and frequency range planning, the up-down frequency conversion function from 0.8 GHz to 40GHz to 2.1 GHz + / -500MHz is realized by the transmitting and receiving channel, and the antenna has the characteristics of wide application range, ultra wide band and low stray; the transmitting channel and the receiving channel both adopt a two-time frequency mixing scheme, a complete transmitting and receiving function can be completed only by using two frequency sources, the transmitting channel and the receiving channel adopt the same type of filters, switches and mixers, the types of components are reduced, links are simplified, and the system has the characteristics of low cost and high integration level; the transceiver system is designed by adopting a high-integration multifunctional chip, is assembled by adopting a micro-assembly process, and has the characteristics of small size, high reliability and high consistency between channels.

The utility model provides an optical system for improving optical display performance and wearable equipment, which belong to the technical field of optical imaging and comprise a display unit, a transmitting mirror, a prism and a reflecting mirror. The transmitting mirror is arranged on an emergent light path of the display unit, the prism is arranged on a transmitted light path of the transmitting mirror, the front surface of the prism is an inclined plane which is inclined downwards from back to front and faces the transmitting mirror, and the rear surface of the prism faces human eyes. An absorption film, a polarization reflection film and a phase delay film are sequentially arranged on the front surface of the prism, and the reflector is arranged on the side, away from human eyes, of the prism. The optical system is compact in structure, small in size, light in weight, thin in thickness, low in stray, good in imaging quality and large in field angle, and the user experience is greatly improved.

The utility model provides a thinned large FOV optical display system and wearable equipment, belongs to the optical imaging technology field, and comprises a display unit, a transmitting mirror, a first prism, a second prism and a compensating mirror, the transmitting mirror is arranged on a light-emitting light path of the display unit, the first prism is arranged on a transmitting light path of the transmitting mirror, and the second prism is arranged on a light-emitting light path of the compensating mirror. A partial transmission and partial reflection film is arranged on the front surface of the first prism, the second prism is arranged on the rear side of the first prism, a phase delay film, a polarization reflection film and an absorption film are sequentially arranged between the first prism and the second prism, and the compensating mirror is arranged on the front side of the first prism; and one part of the light transmitted from the transmitting mirror enters the first prism from the upper surface of the first prism, and the other part of the light enters the compensating mirror from the upper surface of the compensating mirror and then enters the first prism. The optical system is compact in structure, small in size, light in weight, thin in thickness, low in stray, high in light utilization rate, good in imaging quality and large in field angle, and greatly improves user experience.

The invention provides a broadband high-integration integrated Ku wave band microwave transmit-receive assembly, which comprises a shell, a frequency source module, a transmitter module and a receiver module, and is characterized in that the frequency source module is installed in the shell, and the frequency source module comprises a transmission intermediate frequency circuit, a first transmission local oscillator circuit and a second transmission local oscillator circuit; the transmitter module is mounted in the shell, and the transmitter module is configured to perform up-conversion on the output frequency of the transmitting intermediate frequency circuit and the output of the transmitting local oscillator circuit I and perform up-conversion on the obtained mixed frequency output and the output of the transmitting local oscillator circuit II to obtain a Ku-band transmitting signal; the receiver module is installed in the shell, and the receiver module is configured to mix a received Ku wave band receiving signal with a receiving local oscillator signal of the transmitter module to obtain an intermediate frequency signal, so that the technical problem that the size, the performance, the reliability and the like of an existing radio frequency front-end transceiving assembly cannot be considered at the same time is solved.

The invention relates to the technical field of radio frequency electronics, and discloses a multi-channel radio frequency signal source device and an implementation method, and the device comprises a satellite receiver, a frequency reference source, a clock signal source, a multi-channel radio frequency signal source, a frequency monitoring module and a phase monitoring module. The frequency reference source locks a satellite signal generation benchmark; the clock signal source generates a driving clock based on a reference; the multi-path radio frequency signal source generates multi-path radio frequency signals by using a driving clock based on a direct digital frequency synthesis principle; the phase monitoring module measures signal phase difference through IQ phase discrimination and feeds back the signal phase difference, and realizes closed-loop phase locking in cooperation with multiple paths of radio frequency signal sources. A two-stage driving framework is adopted, synchronous frequency modulation of multiple paths of signals can be achieved by adjusting a clock, the phase relation is not changed, and automatic phase recovery after independent frequency modulation can be achieved through phase compensation. The invention has the advantages of continuous frequency modulation phase, stable amplitude, no need of automatic level control, low phase noise, high phase resolution and the like.

The utility model provides a kind of multiple folding optical display system and wearable equipment of thinning and lightening belong to optical imaging technical field, including display unit, first optical element, second optical element, third optical element, fourth optical element and fifth optical element;First optical element is set on the light path of display unit;Second optical element is set on the transmission light path of first optical element, third optical element is set on the front side of second optical element;Fourth optical element is set on the front side of third optical element, and the front surface of fourth optical element is Fresnel surface;Fifth optical element is set on the back side of second optical element, and there is polarized light splitting element between the front surface of fifth optical element and the back surface of second optical element.It is compact in structure, small in size, thin in thickness, light in weight, low in stray, good in imaging quality, large in field of view angle, greatly improves the experience of user.