6results about How to "Avoid self-excitement" patented technology

The invention provides a low-frequency signal receiving device, belongs to the technical field of low-frequency communication, and designs a large-gain isolation direct amplification and variable center frequency band-pass filter to replace a traditional frequency conversion receiver, so that the scale of a circuit is effectively reduced to 1 / 3 of that of the original frequency conversion receiver; front isolation amplification is designed, the two-stage automatic gain circuit has high-sensitivity 16 dB to 126 dB large dynamic range receiving capacity, isolation segmentation amplification is designed, a frequency-adjustable narrow-band filter is inserted in the middle of cascade connection of the two-stage automatic gain circuit in a penetrating mode to prevent circuit self-excitation, and direct large gain amplification stability is improved. The bandwidth of the two-stage frequency-adjustable narrow-band filter ranges from 400 Hz to 1200 Hz, the gradient coefficient is smaller than 4, and out-of-band interference can be effectively restrained. A 10dB-80dB amplifier is designed in front of a frequency-adjustable narrow-band filter, so that the noise of an LTC1068-25 switched capacitor filter is overcome, and the received noise of the whole machine is smaller than 5nV / Hz1 / 2. According to the invention, light, stable and miniaturized underwater receiving capability is realized, and the antenna is suitable for application scenarios with high requirements on power consumption and space, such as UUV and the like.

The present invention discloses an ultra-low frequency integrated receiving device, which belongs to the field of wireless communication technology. The device of the present invention comprises a preamplifier module, a small signal amplification module, a large signal amplification module, an AD sampling module and a main control module which are electrically connected in sequence; the preamplifier module performs low-noise amplification and low-pass filtering on the input signal; the small signal amplification module performs ultra-low frequency bandpass filtering, a first program-controlled amplification and a power frequency trap on the input signal; the large signal amplification module performs a second program-controlled amplification, program-controlled attenuation, a second power frequency trap and an ultra-low frequency low-pass filtering on the input signal; then the signal is divided into two paths, one path is amplified and then sent to the AD sampling module, and the other path is sent to the main control module after effective value detection; the AD sampling module performs analog-to-digital conversion and down-conversion processing on the input signal; the main control module controls and manages the receiving device; the receiving device of the present invention can realize stable and reliable gain amplification of ultra-low frequency signals.

The utility model discloses a low standing-wave ratio chip type temperature compensation attenuator. Comprising a ceramic substrate, two first electrodes arranged on one side of the ceramic substrate in a spaced mode, a second electrode arranged on the other side of the ceramic substrate and opposite to the two first electrodes, two film-shaped resistors arranged between the two first electrodes in a spaced mode, and two conductive electrodes connected between the film-shaped resistors and the second electrode respectively. The connecting electrode is arranged between the two film-shaped resistors, the back electrode is arranged on the bottom surface of the ceramic substrate and is respectively connected with the first electrode and the second electrode, and the ink encapsulation layer is arranged on the top surfaces of the two film-shaped resistors and the two conductive electrodes; according to the temperature compensation attenuator, by optimizing the number and configuration of the resistors, impedance matching of the temperature compensation attenuator is improved, return loss is reduced, self-excitation is avoided, a better temperature compensation effect is achieved, and the manufacturing cost is reduced on the premise that the reliability of the temperature compensation attenuator is improved.

This invention relates to the field of phased array radar antenna technology, and more particularly to a highly integrated, miniaturized, high-power, high-efficiency delay microwave T / R assembly. The assembly includes a housing and a PCB (Printed Circuit Board) for functional integration. The PCB is located on the lower left side of the housing, housing a multi-functional MMIC (Multi-Microelectronics Microcontroller) chip manufactured using MCM (Multi-Chip Module) technology. The multi-functional MMIC chip is located on one side of the PCB, and a wave control chip is located on the other side. The technical solution involves using an SMP (Surface Mount Multi-Fold) button RF connector, where the button and circuit board are softly interconnected inside the assembly. Microwave signals within the circuit board are transmitted via vias, resulting in high input / output isolation and preventing loop self-oscillation. This soft-contact interconnection between the button and the circuit board significantly improves the manufacturability of the assembly.

The invention discloses a radio frequency chip flip interconnection structure and a preparation method, the structure comprises a first substrate and a second substrate with the same size, a plurality of first nail head bumps are bonded on a bonding pad of the first substrate, and a plurality of second nail head bumps corresponding to the first nail head bumps in position are bonded on a bonding pad of the second substrate; wherein the diameter of the first nail head protruding point is smaller than the diameter of the bonding pad of the first substrate, the diameter of the first nail head protruding point is larger than the diameter of the second nail head protruding point, and the Vickers hardness of the first nail head protruding point is larger than the Vickers hardness of the second nail head protruding point. The low-Vickers-hardness nail head protruding points provide compensation for the height of the high-Vickers-hardness nail head protruding points on the other side through large deformation in the inversion process, and the high-Vickers-hardness nail head protruding points guarantee controllable collapse of the height of the air cavity through small deformation in the inversion process. And crosstalk and self-excitation of the radio frequency signal in the transmission process of the inverted structure are avoided.

The application provides a semiconductor device and a preparation method thereof, and relates to the technical field of semiconductors. A first gate field plate electrically connected with a gate metal is added between a source field plate and a drain metal, and the first gate field plate is electrically connected with the gate metal through a resistor. In this way, the first gate field plate has a lower potential. On one hand, the first gate field plate can shield the electric field between the drain and the gate, and can further deplete the two-dimensional electron gas at the channel, so as to reduce the Cgd of the device, improve the gain and stability of the device, and avoid self-excitation of the device. On the other hand, the first gate field plate can shield the electric field between the drain and the source, reduce the Cds of the device, and thus improve the drain efficiency of the device.