42results about How to "Avoid self-excitement" patented technology

A multi-band antenna adapted for used in a portable electronic device, includes: a first antenna including a first radiating element, a common grounding element, and a first connecting element connecting the first radiating element and the common grounding element; a second antenna, including a first radiating portion, the common grounding element, and a second connecting element connecting the radiating portion and the grounding element. Free end portions of the first radiating element and the first radiating portion do not align with each other in any direction.

A method for imaging a printing form, in which a laser (140) generates a sequence of pulses (172, 220) of electromagnetic radiation corresponding to the image information of an image area (200, 202, 204, 206) to be generated on the printing form (118), and the image area (200, 202, 204, 206) to be generated on the printing form (118) is patterned according to the image information by interaction with the electromagnetic radiation, has the feature that the sequence of pulses (172, 220) of electromagnetic radiation is amplified by an amplifier (160); the amplifier (160) being discharged in a controlled manner by additional pulses (176, 222) corresponding to a non-image area (132, 208, 210, 212) of the printing form (118) in such a way that interference pulses of the amplifier (160) are prevented.

The invention belongs to the technical field of millimeter waves and particularly relates to a W-waveband pulse traveling-wave tube high-power combination system. The system comprises a waveguide power divider, a first adjustable attenuator, a first solid-state amplifier, a first isolator, a first traveling-wave tube amplifier, a second adjustable attenuator, a phase shifter, a second solid-state amplifier, a second isolator, a second traveling-wave tube amplifier and a waveguide power combiner. According to the W-waveband pulse traveling-wave tube high-power combination system, high-power combination of a W-waveband two-way pulse traveling-wave tube is achieved technically, the two ways are respectively provided with an isolator, and therefore the solid-state amplifiers can be prevented from being burnt; the same signal source power is divided into two through the power divider with the output phase difference of 90 degrees, a 90-degree phase difference exists between the two ways to prevent mutual interference and self excitation of the two traveling-wave tube amplifiers, and a 90-degree phase difference exists between two inputs of the power combiner to guarantee effective combination of two ways of power.

A phase shifter is provided. The phase shifter includes a first phase shifter that is continuously adjustable within a range of 0 degrees to 90 degrees, two 4-way switches each configured to selectively switch on one of a capacitance, an inductance, an open circuit, and a short circuit under control of a control voltage, and a bridge. A first input end and a first output end of said bridge are respectively connected to a first 4-way switch of the two 4-way switches. A second input end of said bridge is connected to an output end of said first phase shifter or a second output end of said bridge is connected to an input end of said first phase shifter.

The invention discloses a power control module, comprising: a power control unit, a VGA, a digital domain AGC and a transmitting chain AGC, the power control unit firstly transmits the corresponding preset initial gain to the VGA, the digital domain AGC and the transmitting chain AGC respectively; before the power control module is stabilized, the power control unit executes the following operations cyclically: transmitting an instruction for augmenting the gain by preset stepping to the transmitting chain AGC, and sending a gain adjustment instruction for normalizing the power of output signals to 1 to the VGA; and when the power control module is stable, the power control unit transmits a gain adjustment instruction for normalizing the power of output signals to 1 to the VGA according to the preset cycle. The invention also discloses a transmitter-receiver comprising the power control module as well as a power control method. The invention can maintain the stability of the transmitter-receiver while eliminating echo signals.

The invention provides a wireless digital repeater station with the carrier scheduling function and a method for realizing carrier scheduling. The method is characterized in that when the traffic statistics result reported by the wireless digital repeater station exceeds the set range of a base station, the wireless digital repeater station identifies an adjacent wireless digital repeater station satisfying the requirement of carrier scheduling through information interaction with a network control center and sends a command of starting carrier scheduling to the adjacent wireless digital repeater station; the two wireless digital repeater stations simultaneously start a relay and forward system and establish the relation between relay and forward; and the traffic exceeding the load of the wireless digital repeater station sending the command of carrier scheduling is scheduled to the relay channel of the adjacent wireless digital repeater station through the relay channel of the wireless digital repeater station sending the command of carrier scheduling and then is scheduled to a covering system of the base station corresponding to the wireless digital repeater station sending the command of carrier scheduling by frequency selecting and frequency shift, thereby establishing traffic relation and completing carrier scheduling. The invention can not only make full use of the resources of the repeater station and lower the cost, but also effectively improve the traffic quality.

The invention, which relates to the fields of the aerospace system, positioning navigation, and control, provides an air coaxial output structure for an active antenna. The air coaxial output structure comprises a semi-closed hole type sleeve, an elastic embedded locking structure, a pin type connector, a sealing rubber ring, an adjusting gasket, a radio-frequency circuit board, a shielding box body base plate, and a shielding box body cover plate. The radio-frequency circuit board is fixedly installed on the upper surface of the shielding box body base plate; the adjusting gasket is fixedly installed at the upper surface of the radio-frequency circuit board; the shielding box body cover plate is fixedly installed at the upper surface of the shielding box body base plate; and the edge of the shielding box body cover plate is in contact with the upper surface of the radio-frequency circuit board. The elastic embedded locking structure is installed in the semi-closed hole type sleeve fixedly, vertically and axially. The pin type connector is fixedly installed at the upper surface of the shielding box body cover plate. The air coaxial output structure provided by the invention has advantages of optimizing the structural dimension, being convenient to install, being connected reliably, and arranging an output port flexibly and can met various installation needs.

This invention provides a system and a method for suppressing self-excitation in an optical ring net multiplex section share protection, in which, the system forms an outer cycle and an inner cycle bya first and a second fibers of adjacent nodes, each cycle includes a working service path and a protection service path and the system includes a switching control unit for controlling signals of thering net to be switched between the working service path and the protection service path, a vibration-resistant unit having vibration-resistant and through states set on the protection service path of the cycle to control the on-off of the protection service path by the switch between the vibration -resistant and through states.

A control device for a direct-current output potential of a power amplifier. The control device is implemented on the basis of an active temperature control bias circuit. In the active temperature control bias circuit, a direct-current output potential deviation detection circuit detects a direct-current output potential deviation value of the power amplifier, and a temperature control circuit correspondingly heats or cools a voltage regulating circuit according to the detected direct-current output potential deviation value. The voltage regulating circuit correspondingly regulates, according to the heating or cooling of the temperature control circuit, a bias voltage of a device generating a temperature drift in the power amplifier. Accordingly, the bias voltage can be regulated by means of active temperature control, so as to achieve the purpose of controlling the direct-current output potential, self-excitation and transient intermodulation distortion caused by negative feedback in the prior art are avoided, and the performance of an amplifier circuit is improved.

The present invention discloses a down-conversion module with ultra-wide and large instantaneous bandwidth and a frequency conversion method thereof. The circuit structure of the down-conversion module with ultra-wide and large instantaneous bandwidth comprises a low-frequency stage double conversion branch, a high-frequency stage double conversion branch, a single-pole double-throw switch S1, and an intermediate-frequency amplification branch. The low-frequency stage double conversion branch and the high-frequency stage double conversion branch are symmetrical structures; one end of the low-frequency stage double conversion branch and one end of the high-frequency stage double conversion branch are configured to receive radio-frequency signals, and the other end of the low-frequency stage double conversion branch and the other end of the high-frequency stage double conversion branch are configured to connect with the single-pole double-throw switch S1; and the single-pole double-throw switch S1 is configured to select one of the low-frequency stage double conversion branch and the high-frequency stage double conversion branch to connect with the intermediate-frequency amplification branch. The down-conversion module with ultra-wide and large instantaneous bandwidth has the advantages of high integration density, light weight, small size, low cost, high reliability, good manufacturability and the like. The present invention further discloses a frequency conversion method of a down-conversion module with ultra-wide and large instantaneous bandwidth.