31results about How to "Reduce spurious signals" patented technology

Disclosed is an electrical interconnect system using multiple grounding methods to reduce or prevent spurious signals from interfering with high density contacts carrying high speed transmissions. A first connector includes an insulative pillar partially surrounded by a plurality of signal contacts. A ground contact is at least partially located within the insulative pillar. A second connector includes a corresponding plurality of flexible signal contacts for mating with the signal contacts adjacent the insulative pillar. The second connector also includes a ground contact for receiving the ground contact of the first connector. The ground contacts provide a first method of providing a ground path to reduce spurious signals from entering the signal path. An electrically conducting shield is located outside the signal contacts when the first and the second connectors are mated. The first connector includes a member which provides a ground path between the first connector and the electrically conducting shield. Advantageously, the electrical interconnect system has two grounding methods which are particularly important in a high density electrical interconnect system where the contacts are closely spaced and susceptible to noise and other spurious signals.

In the mobile communication, a distortion compensation amplifying apparatus is provided. In a predistortion-type distortion compensation amplifying apparatus (9), a signal amplitude change processing unit (10) comprises an odd-power component calculating unit (14) extracting a power component of odd order of an amplitude quantity contained in a signal to be transmitted and outputting it, a coefficient information outputting unit (15) being operable to select one of plural pieces of coefficient information based on a signal from the outside and output it, a multiplying unit (16) multiplying a signal outputted from the odd-power component calculating unit (14) by coefficient information from the coefficient information outputting unit (15) and outputting an attenuation signal, and an adding unit (17) subtracting the attenuation signal from the signal to be transmitted and outputting a result, thereby making an amplifier operate within a range not exceeding a saturation region thereof, decreasing a spurious signal, decreasing an adjacent channel power, and enabling distortion compensating operation even if a frequency of reference to the memory is decreased.

A method for generating linear digital frequency-modulated (FM) signal includes generating basic digital specimen by second order IIR filter and using formula T[N]=2*A[n]*Y[n-1]-Y[n-2] to list it out as Y[n]-specimen series, A[n]-series frequency, multiplexing complementary variation amount with basic specimen series to obtain compensation amplitude and using formula G[n]=KG[n-1] to give out the amount as G[N]-compensation value and K-variation rate of the value; using formula Y[N]=G[n] as total output.

The invention relates to a 1.7micron fiber laser amplifier which structurally mainly comprises a signal source, an optical isolator, a pumped source, two wavelength division multiplexers, three thulium doped quartz fiber segments, two band pass filters separating the three thulium doped quartz fiber segments, a fiber bragg grating (FBG) and a fiber jumper wire head. The problems of signal gain saturation caused by ASE in the central wavelength position and severe signal light re-absorption in the 1.7micron short-wavelength operation process of the thulium doped fiber amplifier can be solved effectively, and output of 1.7micron-waveband amplification signals is stable and efficient.

The invention provides a low-stray rapid-frequency-hopping frequency synthesizer, comprising a single phase-locked ring, a frequency mixer and a gating device, wherein the single phase-locked ring is used for generating a signal with a fixed frequency; multiple frequency dividers for generating signals with different frequencies after being cascade connected to the phase-locked ring, wherein the signals with different frequencies have orthorhombic I and Q components; the signals generated by one part of multiple frequency dividers are input into the frequency mixer, so that a local oscillator signal is generated; and the rest parts of the frequency dividers are mutually connnected to the frequency mixer, and are used for selecting the required frequency. Moreover, the invention also provides a fast frequency hopping method which can be applied to the low-stray rapid-frequency-hopping frequency synthesizer.

A modulator being made small in size, low in costs, low in power consumption, small in heat generation and spurious signals. The modulator includes multipliers (101, 102) for code-modulating received transmission data (D(n), C(n)), and outputting the modulated data, a control channel gain factor signal generator (106) for generating a gain control signal, a control channel gain factor signal generator (107), and weighting coefficient setting signal generators (108, 109) for receiving the output of the complex-number computing section (120) and controlling the gains of the raised cosine filters (110 to 113).

The invention discloses a high-temperature superconducting duplex subsystem which is packaged in a refrigerator in vacuum; and the operating temperature is kept to be lower than the transition temperature of a superconducting material. The high-temperature superconducting duplex subsystem comprises two radio frequency (RF) ports, a large-power superconducting filter, a first circulator, a second circulator, a receiving channel and a microwave element. The system is applied in a wireless system and can realize the situation of simultaneously receiving and sending wireless signals.

The invention discloses a broadband receiving antenna with an active antenna and passive antenna switching function. The broadband receiving antenna comprises an antenna radiating unit, an integrated circuit, a relay and a transformer. The output of the antenna radiating unit is connected with the input of the integrated circuit and one input of the relay. The antenna radiating unit receives radio-frequency signals in the sky and transmits the radio-frequency signals to the integrated circuit and the relay. The integrated circuit amplifies the radio-frequency signals. The output of the integrated circuit is connected with the other input of the relay. The relay conducts switching between an active antenna and a passive antenna. The output of the relay is connected with the input of the transformer. The transformer outputs the radio-frequency signals. According to the broadband receiving antenna, the relay is additionally arranged, so that switching between the active antenna and the passive antenna is achieved through one antenna, and the antenna has common characteristics of the active antenna and the passive antenna simultaneously. The broadband receiving antenna can expand the signal receiving dynamic range, and the size of the antenna is effectively reduced.

The invention discloses an ultrasonic lens electrode manufacturing method for effectively reducing an acoustic parasitic signal. The method comprises the following steps: processing an acoustic emission surface of a waveguide rod or block of an ultrasonic lens and related acoustic probes; manufacturing and preparing an electrode mold of a special shape according to the size of the acoustic emission surface; cleaning the acoustic emission surface of the waveguide rod or the probe block of the ultrasonic lens and related acoustic probes; preparing an electrode material with a specific shape; cleaning an evaporated ultrasonic lens or probe; mounting and fixing an ultrasonic transducer; preparing and fixing an electrode material of a corresponding polarity on the other side of the ultrasonic transducer; connecting and fixing the electrode material with a related lead; and mounting a metal sleeve for fixation and protection. By adopting the ultrasonic lens electrode manufacturing method, the parasitic signal can be effectively reduced, and the microscopy quality of an ultrasonic microscope system can be improved.

The invention provides a low-spurious radio frequency signal source which comprises a DDS (digital direct synthesis) signal source unit, a phase locked frequency conversion unit, a through path, a control unit, a first switch and a second switch, wherein the control unit is used for generating a third control signal; the through path comprises a ground resistor and a third switch; the third switch is used for electrically connecting a signal input end of the through path to a non-grounding end of the ground resistor according to a third control signal when the first switch selects to input a DDS signal to the phase locked frequency conversion unit; when the first switch selects to input the DDS signal to the through path, a circuit between the signal input end of the through path and a signal output end of the through path is connected according to the third control signal. The DDS signal can be input to the ground through the ground resistor, the amplitude of the DDS signal output to an output port through the through path is reduced, spurious signals brought by the through path are reduced, nonharmonic stray of the output signals is reduced, and the spectrum purity of the output signals is improved.

A semiconductor package has a semiconductor chip electrically connected to a conductive lead of a lead frame through a bonding wire and it is encapsulated by an insulating molding body. In such a semiconductor package, an electromagnetic wave absorbing film is formed by coating an electromagnetic wave absorbent on predetermined portions or either of the bonding wire and the conductive lead to a predetermined constant thickness, and the electromagnetic wave absorbing film forms a closed loop. In this manner, the electromagnetic interference between the conductive lead and the bonding wire can be surely attenuated. The lead frame and the conductive lead can be shield from the electromagnetic wave applied from the outside of the semiconductor package. In addition, the spurious signal flowing through the conductive lead and the bonding wire can also be reduced.

A fractional-N frequency synthesizer having reduced fractional switching noise and spurious signals is provided. The synthesizer includes a voltage controlled oscillator for providing an output signal. A fractional-N divider is responsive to the voltage controlled oscillator for providing a divided output signal having fractional switching noise. A band pass filter is responsive to the fractional-N divider for reducing the fractional switching noise and non-linearities that result in spurious signals. A phase detector is responsive to a reference signal and the band pass filter for providing a control signal representative of the phase difference between the reference signal and the signal from the band pass filter. A loop filter is responsive to the phase detector for filtering the control signal to control the voltage controlled oscillator, the output of the loop filter having reduced fractional switching noise and spurious signals.

An acoustic wave filter includes a divided resonator group and series arm resonators in a path connecting an input-output terminal and an input-output terminal to each other and parallel arm resonators each between a node in the path described above and the ground. The divided resonator group, the series arm resonators, and the parallel arm resonators each include an acoustic wave resonator including an interdigital transducer electrode on a piezoelectric substrate. The divided resonator group includes divided resonators coupled in series with each other. The IDT electrode included in the divided resonator includes a first withdrawal electrode. The IDT electrode included in the divided resonator includes a second withdrawal electrode different from the first withdrawal electrode with respect to the electrode finger structure.

The invention discloses a radio frequency device and an amplifier working mode control method and device, and belongs to the technical field of communication. In the radio frequency device, a first input end of a power amplifier is connected with an output end of a radio frequency transmitter, a second input end and a third input end of the power amplifier are respectively connected with a first output end of a first control module and a first output end of a processor, and an output end of the power amplifier is connected with an input end of a coupler; the first input end and the second input end of the second control module are respectively connected with the first output end of the coupler and the second output end of the processor, and the first output end and the second output end of the second control module are respectively connected with the input end of the processor and the input end of the first control module; the second output end of the coupler is connected with an antenna of the electronic equipment, and the third output end of the processor is connected with the input end of the radio frequency transmitter.