21 results about "Spurious emission" patented technology

Aspects of this disclosure relate to squelching a symbol at a symbol boundary. A transmit squelch block can squelch a portion of a symbol at a symbol boundary. The transmit squelch block can be included in a symbol based envelope tracking system. Transmit squelching can reduce spurious emissions associated a symbol based envelope tracking voltage toggling on a symbol boundary.

This invention discloses a 10-20GHz fast local oscillator module, including a reference source module. The reference source module generates a 100MHz reference frequency. The 100MHz reference frequency is divided by a first comb spectrum to obtain 1GHz, 4GHz, and 2.6 / 2.8 / 3 / 3.2 / 3.4GHz branches. The 1GHz branch is passed through a second comb spectrum to obtain 3 / 4 / 5 / 6 / 7GHz branches and a 20GHz branch. The 4GHz frequency is input to a DDS module, and the DDS module outputs an adjustable frequency of 0.4-0.6GHz, which is then mixed with the 2.6 / 2.8 / 3 / 3.2 / 3.4GHz branches to generate a 2-3GHz frequency. The 2-3GHz frequency is mixed with the 20GHz high local oscillator frequency, and then mixed with the 3 / 4 / 5 / 6 / 7GHz branches after passing through a filter switch group before being output. This invention provides seamless multi-band output with high precision adjustment, meeting multiple performance indicators such as fast agility, low spurious emissions, and low phase noise.

The invention provides a surface clutter real-time generation method and device, and the method comprises the steps: determining a target time domain range and a target frequency domain range of a to-be-generated surface clutter signal according to the real-time motion state parameter of a carrier carrying a radar seeker and the beam pointing parameter of the radar seeker; generating a random clutter sequence covering the target time domain range and the target frequency domain range according to a preset amplitude statistical distribution model and a preset power spectrum model; a surface clutter signal is generated by modulating a reference radar signal, the modulation including convolving the reference radar signal using a random clutter sequence, and parameter adjusting the convolved signal to match dynamic characteristics of a carrier. According to the invention, the problem of insufficient fidelity of clutter simulation signals in the prior art is solved.

This invention belongs to the field of mixed-signal circuits and relates to a modulator structure applied in a multi-charge pump phase-locked loop (PLL), specifically providing a method for implementing a modulator with fractional spurious emission suppression due to mismatch. In multi-charge pump PLLs, mismatches between different shunt charge pumps, such as current source mismatch and layout mismatch, can lead to integer boundary spurious emission. To alleviate the problem of integer boundary spurious emission degradation caused by mismatch in multi-charge pump PLLs, this invention proposes a method for implementing a modulator with fractional spurious emission suppression due to mismatch. This is achieved by making the net injected charge of long-range mismatch zero and filtering out the low-frequency components of the mismatch injected charge, thereby suppressing fractional spurious emission. Simulation results show that this invention can significantly suppress fractional spurious emission caused by mismatch.

An antenna includes a first conductive plate, a first conductive loop, a second conductive plate, a second conductive loop, a first conductive path, and a second conductive path. The first conductive loop can be disposed below the first conductive plate. The second conductive loop can be disposed below the second conductive plate. The first conductive path can include a first terminal electrically connected to the first conductive plate, and a second terminal electrically connected to a ground layer. The second conductive path can include a first terminal electrically connected to the second conductive plate, and a second terminal electrically connected to the ground layer. The first conductive plate and the second conductive plate can be used to access wireless signals, and the first conductive loop and the second conductive loop can be used to suppress a signal portion of a frequency band.

The invention discloses electronic equipment and a radiation spurious suppression assembly, and relates to the technical field of terminals and the technical field of antennas. Wherein the radiation spurious suppression circuit comprises one or more first devices; the radiation spurious suppression circuit comprises a first branch circuit and a second branch circuit which are connected in parallel, the first branch circuit comprises an inductor, and the second branch circuit comprises a capacitor; the first ends of the first branch and the second branch are connected with the same first device; the second ends of the first branch and the second branch are grounded; wherein the radiation spurious suppression circuit is used for reducing RSE generated by the first device. When the antenna works, the fundamental wave of the antenna enters the cavity in the electronic equipment, the current generated by the PIM effect on the electric connection contact surface of the first device in the cavity is transmitted to the radiation spurious suppression circuit, and the radiation spurious suppression circuit realizes energy loss, so that the radiation power of the harmonic wave is reduced; and therefore, radiation spurious suppression can be realized.

This invention discloses an amplitude-phase adjustable carrier generation device and method, belonging to the field of precision measurement and signal synthesis. The phase accumulator of this invention incorporates a phase adjuster. The phase adjuster counts the system clock, and when a set count value C is reached, it outputs a phase adjustment value S. At this time, the value of the phase register is simultaneously added to the frequency control word FCW and the phase adjustment value S. Subsequently, the phase register overflows, is cleared to zero, and accumulation restarts. The phase adjuster supplements the decimal part discarded during the rounding of the frequency control word FCW, which helps improve the frequency stability of the carrier. The CORDIC calculator of this invention employs a parallel interpolation structure, which can use n CORDIC cores to calculate the sine values ​​of n consecutive phases in parallel. The interval between two adjacent phases is the frequency control word FCW. The interpolation unit arranges the n data streams and outputs them serially. The parallel interpolation structure improves the speed and accuracy of CORDIC calculation through parallel computation, which can greatly reduce phase truncation errors and help reduce carrier spurious emissions.

This invention provides a baseband chip, transmitter, and terminal device, relating to the field of communications. The baseband chip includes: a low-order filter for filtering a target signal to obtain a transmitted signal, and transmitting the transmitted signal to a radio frequency unit. The low-order filter is determined based on the out-of-band spurious emission suppression level requirements of the target channel, which is a communication channel used to transmit the transmitted signal. A pre-compensator is used to pre-compensate the baseband signal based on pre-compensation parameters to obtain the target signal, compensating for in-band distortion caused by the low-order filter's filtering of the target signal. The pre-compensation parameters are determined based on the parameters of the low-order filter. This invention solves the problem in related technologies of meeting the miniaturization requirements of baseband chips, achieving both improved communication quality and meeting the design requirements of baseband chip miniaturization.

There is a need to reduce spurious emissions from elastic wave equipment. [Solution] The elastic wave device includes a substrate having a piezoelectric material and an end face, and a plurality of strip electrodes located above the substrate and each extending in parallel, wherein at least some of the plurality of strip electrodes are excitation sections capable of exciting elastic waves, the end face is parallel to the direction in which the strip electrodes extend when viewed from above in plan view, and is located in the elastic wave propagation direction relative to the excitation section, the plurality of strip electrodes include a first strip electrode located closest to the end face in the elastic wave propagation direction, and a second strip electrode which is further from the end face than the first strip electrode in the elastic wave propagation direction and is the excitation section, in a cross section cut in the elastic wave propagation direction, the average thickness of the first strip electrode is smaller than the average thickness of the second strip electrode, the substrate has a groove on its upper surface, and the end face is part of the side surface of the groove.

An amplifier system for radio frequency hot switching of a power amplifier can include a field-effect transistor, a forward biasing network, and a reverse biasing network. The forward biasing network is configured to provide a positive bias voltage to a gate terminal of the field-effect transistor, and the reverse biasing network is configured to provide a negative bias voltage to the gate terminal, with resistance of both biasing networks selected to independently control an on and off-switching time of the field-effect transistor. The independent on and off-switching time can allow for rapid “hot switching” in a connected power amplifier while the power amplifier is energized, while reducing spurious emissions of radio frequency signals by the power amplifier.

This invention belongs to the field of wireless communication technology and provides a low-jitter, low-reference-spurious orthogonal subsampling phase-locked loop (PLL). It includes a subsampling PLL and a frequency-locked loop. The subsampling PLL includes a functionally multiplexed QVCO, which is a Class F noise-cycled VCO. It comprises two identically structured Class F VCOs with I-core and Q-core noise cycles. The I-core and Q-core Class F VCOs achieve orthogonal outputs through cross-coupling of transistor gates. The sources of the oscillating transistors of both the I-core and Q-core Class F VCOs are connected in series with transistors and form a sixth-order resonant cavity, creating a noise-cycled path. The source output signal of the oscillating transistor is sent to a gate-isolated subsampling phase detector. The sampling switch of the gate-isolated subsampling phase detector is isolated from the outputs of the I-core and Q-core Class F VCOs by transistors to suppress binary frequency shift keying (BFS) effects. This invention features lower jitter, lower reference spurious emissions, lower power consumption, and a higher FoMJ value.

The present invention provides an elastic wave device that can suppress spurious emissions and prevent a decrease in the bonding strength of the insulating layer. [Solution] The elastic wave device 100 comprises a substrate 10, a piezoelectric layer 14 provided on the substrate 10, a pair of comb-shaped electrodes 20 provided on the piezoelectric layer 14 and each having a plurality of electrode fingers 27, and an insulating layer 13 provided between the substrate 10 and the piezoelectric layer 14, having a plurality of modified regions 30 that overlap with an intersection region 25 where the plurality of electrode fingers 27 of the pair of comb-shaped electrodes 20 intersect in a plan view, and the plurality of modified regions 30 having a different crystalline state from the region 31 surrounding the plurality of modified regions 30.

This invention discloses a fractional phase-locked loop (PLL) based on multi-path quantization noise compensation. It introduces a data synchronization circuit based on the falling edge of the reference clock, ensuring that the divider signals of all paths have reached steady state before the phase detector is triggered by the next rising edge of the PFD, thus completely eliminating dynamic timing interference in the mixed-signal path. By introducing a multi-path retimer with a sign bit, the compensable quantization noise range is expanded. The current-DAC type charge pump proposed in this invention adopts a charge pump architecture based on a source switch array and a static discharge current. The source switch array utilizes the low impedance characteristics of the source nodes of the current source transistors, significantly improving the switching speed and reducing the settling time. The static discharge current forces the loop to maintain a fixed non-zero phase offset in the locked state, permanently shifting the charge pump operating point out of the nonlinear region and deeply suppressing fractional spurious emissions.

The invention relates to transmit signal squelch at symbol boundaries. Aspects of the present disclosure relate to silencing symbols at symbol boundaries. The transmit squelch block may squelch a portion of the symbol at the symbol boundary. The transmit squelch block may be included in a symbol-based envelope tracking system. Transmit squelch may reduce spurious emissions associated with symbol-based envelope tracking voltages that switch over symbol boundaries.

This invention belongs to the field of integrated circuit design technology, specifically relating to a design method, system, and device for a Sigma-Delta modulator based on a 180nm process. First, the noise transfer function of the modulator is parameterized to minimize in-band quantization noise power, while simultaneously applying composite constraints on stability and realizability. A covariance matrix strategy is used to optimize under these constraints, obtaining the optimal transfer function and feedforward coefficients. Based on these coefficients, a switched-capacitor circuit is designed. Random mismatch noise is shaped to out-of-band by modulating cyclic selection logic with a high-pass dithering signal. Based on the quantizer output, the inherent bias of each capacitor is estimated and compensated, breaking periodic locking to suppress coherent spurious emissions. This invention achieves a close connection between theoretical design and physical implementation and possesses excellent voltage and temperature robustness.

In various embodiments of the present disclosure, provided is a system to perform reduced complexity frequency selective linearization. In an embodiment, multistage digital predistortion (DPD) can linearize different parts of the spectrum differently. The first stage captures the signal across the entire linearization bandwidth where the least stringent linearization requirement and general unwanted emission requirements are targeted. Second stage pre-distorts a down-sampled signal where second least stringent requirements across the linearization bandwidth are aimed for. This “peel-off” process continues until the final stage which pre-distorts the portion of the spectrum with the most stringent linearization requirements. Consequently, earlier stages run at higher rates to linearize wider spectrum while later stages run at lower rates to selectively further linearize portions of spectrum that have already passed through earlier stages.

This invention discloses a method for detecting and suppressing spurious signals in a radio frequency (RF) ADC, comprising: performing a fixed-point FFT spectral analysis on the signal acquired by the RF ADC to obtain the original spectral analysis result; obtaining the input signal and spurious signal based on the original spectral analysis result; determining a fixed-frequency spurious signal based on the obtained spurious signal; performing fixed-frequency spurious compensation on the acquired signal; extracting nonlinear spurious features; using the extracted nonlinear spurious features to generate training data to train a one-dimensional convolutional neural network model; inputting the signal to be suppressed into the model; and the model outputting a spurious suppression signal. This method for detecting and suppressing RF ADC spurious signals can automatically suppress signals using a trained model, greatly improving efficiency.

The application discloses a circuit board assembly, a radiation spurious emission anomaly detection method and electronic equipment. The circuit board assembly comprises a main board, a signal detection circuit is arranged on the main board; a shielding cover is arranged above the main board and connected with the main board, a cavity is formed between the shielding cover and the main board; a support is arranged above the shielding cover and connected with the main board, a signal processing circuit is arranged on the support, the signal processing circuit is used for receiving a spurious signal leaked from the shielding cover, filtering and processing the spurious signal to obtain a harmonic signal, and transmitting the harmonic signal to the signal detection circuit; the signal detection circuit is used for receiving the harmonic signal, detecting the energy of the harmonic signal, and determining that the electronic equipment has a radiation spurious emission anomaly when the energy of the harmonic signal exceeds a threshold value. Through the arrangement of the signal processing circuit on the support and the signal detection circuit on the main board, whether the electronic equipment has a radiation spurious emission anomaly can be detected in real time.

There is a need to reduce spurious emissions from elastic wave equipment. [Solution] The method for manufacturing an elastic wave apparatus involves forming a plurality of strip electrodes on a substrate, forming a mask on the strip electrodes, forming an end face on the substrate by etching, and removing a portion of the first strip electrode, which is located closest to the end face in the elastic wave propagation direction, by etching.

The present application relates to the technical field of radio frequencies. Provided are a radio-frequency front-end module, a radio-frequency transceiving apparatus, and an electronic device. The present application aims to mitigate the degradation of radio-frequency performance of an electronic device that is caused by insufficient antenna isolation and to address radiated spurious emissions from a radio-frequency transceiving apparatus. The radio-frequency module comprises a first radio-frequency channel and a second radio-frequency channel, the first radio-frequency channel comprising a radio-frequency processing device, a filter circuit, and a first antenna, wherein the radio-frequency processing device is coupled to the first antenna by means of the filter circuit; and the second radio-frequency channel comprising a second antenna. The filter circuit is used for suppressing, when the first antenna receives a signal transmitted by the second antenna, the signal transmitted by the second antenna from being transmitted to the radio-frequency processing device, or for suppressing, when the signal transmitted by the second antenna is transmitted to the radio-frequency processing device and the signal transmitted by the second antenna is distorted and generates harmonics, the harmonics from being transmitted from the radio-frequency processing device to the first antenna.

There is a need to reduce spurious emissions from elastic wave equipment. [Solution] An elastic wave apparatus comprising a substrate having a piezoelectric material and including an end face, and a plurality of strip electrodes located above the substrate and each extending in parallel, wherein at least a portion of the plurality of strip electrodes is an excitation section capable of exciting elastic waves, the end face is in a plan view parallel to the direction in which the strip electrodes extend and is located in the elastic wave propagation direction relative to the excitation section, the plurality of strip electrodes includes a first strip electrode located closest to the end face in the elastic wave propagation direction and a second strip electrode further from the end face than the first strip electrode in the elastic wave propagation direction, the second strip electrode is the excitation section, and in a cross section cut in the elastic wave propagation direction, the average thickness of the first strip electrode is smaller than the average thickness of the second strip electrode.