58results about "Limiting amplitude using diodes" patented technology

The invention provides a high-power amplitude limiting circuit based on a gallium nitride Schottky diode, and relates to the technical field of radio frequency microwave integrated circuits. Comprising an input port of a high-power amplitude limiting circuit, a capacitor C1, a post-start detection network and a pre-stage amplitude limiting network, and the pre-start detection network, a capacitor C2, a post-stage amplitude limiting network, a capacitor C3 and an output port of the high-power amplitude limiting circuit are sequentially connected in series. The front-stage amplitude limiting network comprises a plurality of first PIN diodes which are connected in parallel, the number of the rear-stage amplitude limiting networks is one or more, and the plurality of rear-stage amplitude limiting networks are connected in series; the anodes of the plurality of first PIN diodes are connected with the output end of the post-start detection network and the input end of the pre-start detection network, and the cathodes of the plurality of first PIN diodes are grounded. Therefore, the high-power amplitude limiting circuit based on the gallium nitride Schottky diode can reach a myriawatt-level amplitude limiting level, the occupied area is smaller, the power endurance capability is more stable, and the insertion loss is smaller.

The utility model provides an adjustable amplitude limiter structure and radio frequency equipment, and relates to the technical field of radio frequency. According to the invention, multiple stages of diode discharge links formed by forward series connection of multiple diodes are arranged, so that respective middle connection points of two adjacent stages of diode discharge links are connected through a microstrip line, and respective anode connection ends of the multiple stages of diode discharge links are externally connected with forward bias voltage signals through the same choke inductor; and meanwhile, the respective cathode connecting ends of the multistage diode discharge links are grounded, and at the moment, the actual voltage values of the forward bias voltage signals can be adjusted, so that the multistage diode discharge links can be grounded under the action of different forward bias voltage signals. And the amplitude limiting circuit is used for carrying out amplitude limiting processing of different degrees on the radio frequency input signal acquired by the input matching circuit so as to dynamically adjust the amplitude limiting level of the corresponding amplitude limiter structure, so that the corresponding radio frequency output signal meets the input power requirements of the rear-end amplifier of different degrees.

The invention discloses a ferrite and solid state combined amplitude limiting circuit and a high-power microwave front door protection device, and belongs to the field of microwave devices.The combined amplitude limiting circuit comprises a ferrite substrate, and a ferrite amplitude limiting circuit and a solid state amplitude limiting circuit which are connected with each other are arranged on the front face of the ferrite substrate. The solid-state amplitude limiting circuit comprises two amplitude limiting diodes and two transmission lines, an inductor is arranged between the two transmission lines, one amplitude limiting diode is connected with an output transmission line, and the other amplitude limiting diode is connected with the output of the microstrip amplitude limiting circuit through the transmission line; the high-power microwave front door protection device has high power capacity (hundred kW magnitude), fast response and recovery time (several ns) and high amplitude limiting isolation (higher than 32 dB) in the HPM electromagnetic environment, the ideal high-power microwave front door comprehensive protection effect is achieved, the size of the device is small, and the device can be applied to microwave receiver strong electromagnetic pulse engineering protection.

The application provides an amplifier current-limiting control method for fusing power regulation and load characteristic monitoring, comprising: realizing controllable front-stage signal through differential input and band-pass clamping, establishing voltage, current and multi-point temperature monitoring and combining overvoltage detection to generate out-of-limit indication, setting voltage and current upper limit in silicon-controlled voltage regulating module and executing voltage reduction and current limiting, realizing orderly switching through front-stage shutdown and relay stable control when impedance gear is switched, keeping front-stage closed and shutting down power drive when out-of-limit continues to exist, and until monitoring quantity recovers to safe range. Through the collaborative design of "source power limiting, state monitoring, orderly switching and linkage protection", the application effectively suppresses transient impact, shortens protection response time, reduces distortion accumulation, and realizes the unity of high-power output and high reliability of wide-band multi-gear amplifier.

A near-field transmitter includes a power amplifier, a resonant network, an envelope detector, and an antenna tuning circuit. The power amplifier has an input for receiving a communication signal, and an output for providing a differential output signal. The resonant network is coupled to the output of the power amplifier and has a tunable reactive element tuned by a tuning signal. The envelope detector is coupled to the output of the power amplifier for providing an envelope signal in response to the differential output signal. The antenna tuning circuit is for adjusting the tuning signal in response to the envelope signal.

To provide a semiconductor device capable of measuring a minute current.SOLUTION: In a semiconductor device including an operational amplifier and a diode element. an inverting input terminal of the operational amplifier and an input terminal of the diode element are electrically connected to a first terminal to which a current is input, and an output terminal of the operational amplifier and an output terminal of the diode element are electrically connected to a second terminal from which a voltage is output. As the diode element, a diode-connected transistor including a metal oxide in a channel formation region is used. Since an off-state current of the transistor is extremely low, a minute current can be caused to flow between the first terminal and the second terminal. Thus, by outputting a voltage from the second terminal, a minute current flowing from this voltage through the first terminal can be estimated.SELECTED DRAWING: Figure 3

The disclosure provides a self-detection multi-stage limiter based on micro-assembly and a preparation method thereof. The limiter comprises a ceramic tube shell, a substrate, and a front-stage power detection processing circuit and a rear-stage leakage power processing circuit fixed on one side surface of the substrate based on a micro-assembly process. The rear-stage leakage power processing circuit is a monolithic microwave integrated circuit, and the monolithic microwave integrated circuit is integrated with M series limiting units in series. Each limiting unit comprises two element strings in reverse parallel connection, and each element string comprises a plurality of gallium nitride Schottky diodes in series connection. The self-detection limiter based on the micro-assembly process can realize a fast response time, clamp the leakage peak power leaked after the front-stage processing by using the rear-stage leakage power processing circuit, and realize flexible adjustment of the amplitude threshold and the leakage level by adjusting the number of limiting unit stages or the number of GaN SBDs in series connection in the limiting unit, so as to facilitate matching of the signal power range and the protection requirements of different use scenarios.

The application provides a limiter circuit, which comprises a plurality of transmission lines connected in series, one end of the transmission lines is used as an input end of a radio frequency signal, the other end of the transmission lines is connected with an input end of an amplifier, and an output end of the amplifier is used as an output end of the radio frequency signal; a limiter branch is connected between adjacent transmission lines and the amplifier in sequence, and the parasitic capacitance of each limiter branch is equal; a limiter bias circuit is electrically connected with each limiter branch, and is used for making the opening power voltage of each limiter branch equal. According to the application, the size of each limiter branch is adjusted according to the uneven distribution of current, so that the current density of each limiter branch is balanced, and the insertion loss and impedance matching can be effectively improved, and the bandwidth is improved under the premise of realizing the current density balance and improving the power protection ability.

The invention relates to the technical field of audio signal processing, in particular to an audio voltage limiter based on a Schottky diode and application of the audio voltage limiter, the audio voltage limiter comprises a diode threshold value unit and a voltage division attenuation unit, the diode threshold value unit sets a voltage limit threshold value through diode type combination; the voltage division attenuation unit forms an N: 1 voltage division network by two resistors so as to realize compression ratio control; the diode threshold unit is formed by at least two diodes which are reversely connected in parallel or are subjected to bridge rectification; the voltage limiter breaks through the cost and volume limitation of the traditional voltage limiter, realizes efficient dynamic control through the extremely simple combination of the diodes and the resistors, and is particularly suitable for the scenes sensitive to the cost, such as automobile audio and the like. The modular design supports flexible adjustment of a threshold value, and a signal protection scheme with high cost performance is provided for the fields of vehicle-mounted sound equipment, consumer electronics and the like.

The invention relates to the technical field of radio frequency devices, in particular to an amplitude limiter circuit structure integrated with a filtering function by a gallium arsenide process, and the circuit sequentially comprises a 50-ohm microstrip input matching section, a first-stage amplitude limiting filtering unit, a second-stage amplitude limiting filtering unit and an output matching section along a main transmission line, in the first stage, three forward PIN diodes and three reverse PIN diodes are stacked and connected to a main circuit in parallel, high power tolerance and symmetrical amplitude limiting capacity are achieved, and two low-frequency transmission zero points are formed by fusing a micro-strip grounding branch knot and an MIM capacitor resonator; in the second stage, two anti-parallel PIN diodes are matched with a grounding inductor to form a third transmission zero point, three groups of resonant structures are integrated, six transmission zero points are introduced, the filtering performance in a 12-18GHz frequency band is remarkably enhanced, a PIN diode parasitic capacitor and a microstrip inductive structure are skillfully utilized by the circuit to cooperatively realize filtering, extra passive elements are not needed, and the cost is low. The method is suitable for integrated protection of sensitive devices in a high-frequency radar and communication system.

A broadband low insertion loss limiter chip based on a hybrid π-type topology, belonging to the technical field of microwave passive devices, solves the problems of high small-signal insertion loss, narrow operating bandwidth and large size of existing microwave limiters; by replacing the quarter-wavelength transmission line between the limiter circuits with a capacitive-loaded hybrid π-type structure, the electrical lengths of the first and second tapered U-shaped transmission lines in the two hybrid π-type structures are much less than 90° and are bent, reducing the area of the limiter chip; the first-stage limiter circuit reduces the total equivalent capacitance, thereby reducing the insertion loss; the electrical length of the transmission line is shortened, and its physical length is correspondingly shortened, reducing the insertion loss; in the two hybrid π-type structures, the total turn-off capacitance of each stage of the limiter circuit is absorbed into the hybrid π-type structure, making the limiter equivalent to a quasi-50-ohm transmission line model at small signals, thereby eliminating the influence of the turn-off capacitance reactance loaded on the transmission channel on impedance matching and expanding the operating bandwidth of the limiter.

The invention relates to a high-power dual-coupling detection amplitude limiting circuit, which belongs to the field of microwave amplitude limiters and comprises a pre-stage amplitude limiting circuit, an auxiliary detection network and a post-stage amplitude limiting circuit which are sequentially connected along a main signal path, and the auxiliary detection network is used for reducing the power input to the post-stage amplitude limiting circuit by coupling input power before the detector tube D1 of the pre-stage amplitude limiting circuit is not fully conducted, and assisting the conduction of the PIN tube in the pre-stage amplitude limiting circuit. According to the high-power dual-coupling detection amplitude limiting circuit, the auxiliary detection network is added on the basis of a traditional semi-active circuit structure, and excessive radio-frequency power leaked into the rear-stage amplitude limiting circuit is coupled out from a main signal path through the auxiliary detection network before a detector tube of the front-stage amplitude limiting circuit is not fully conducted; therefore, the input power of the PIN tube in the post-stage amplitude limiting circuit is reduced, and the PIN tube is not burnt down; and meanwhile, the part of power can be used for assisting the conduction of a PIN tube in preceding stage amplitude limiting.

A semiconductor device capable of measuring a minute current is provided. The semiconductor device includes an operational amplifier and a diode element. An inverting input terminal of the operational amplifier and an input terminal of the diode element are electrically connected to a first terminal to which current is input, and an output terminal of the operational amplifier and an output terminal of the diode element are electrically connected to a second terminal from which voltage is output. A diode-connected transistor that includes a metal oxide in a channel formation region is used as the diode element. Since the off-state current of the transistor is extremely low, a minute current can flow between the first terminal and the second terminal. Thus, when voltage is output from the second terminal, a minute current that flows through the first terminal can be estimated from the voltage.

The invention discloses a DC-DC converter control circuit suitable for a high pulse load, and belongs to the field of DC-DC converter control circuits, and the DC-DC converter control circuit comprises a voltage outer loop compensation circuit, a current amplitude limiting circuit, a current inner loop compensation circuit and a pulse width modulation circuit. The output end of the voltage outer loop compensation circuit is connected with one end of the current amplitude limiting circuit, the other end of the current amplitude limiting circuit is connected with the input end of the current inner loop compensation circuit, and the output end of the current inner loop compensation circuit is connected with the pulse width modulation circuit. According to the invention, the current amplitude limiting circuit and the loop compensation circuit are utilized to realize closed-loop regulation of the output inductive current, so that the capacity of outputting the capacitor of the converter is improved, the current response speed is accelerated, the stable output capacity and reliability of the converter are ensured, and the adaptability of a high-pulse load working condition is improved.

The invention belongs to the technical field of radio and microwaves, and discloses a microwave amplitude limiting device capable of removing peak leakage. According to the invention, through skillfully combining the coupling and resonance principles, quick response can be realized at the moment when a strong signal arrives, and the time window of energy leakage is obviously reduced. Compared with a traditional microwave amplitude limiter, the microwave amplitude limiter has the advantages that the response speed is higher, the response to strong signals can be made in an extremely short time, and therefore the risk of sharp point leakage is greatly reduced; the device provided by the invention is high in design flexibility, and can be optimized and adjusted according to different working frequency bands and signal characteristics so as to adapt to diversified application scenes; the device is compact in structure and can be easily integrated into an existing receiving link, large-scale transformation of the system is not needed, and the overall reliability and stability of the receiving link are further guaranteed.

The invention discloses an active amplitude limiting and filtering integrated module for a T / R assembly of phased array equipment. The module comprises first to fourth level LC resonance circuits, a PIN tube, a control circuit, an input port, an output port and a control port. The input port is connected with one end of the first-stage LC resonance circuit, and the other end of the first-stage LC resonance circuit is sequentially connected with one end of the second-stage LC resonance circuit, the anode of the PIN tube, one end of the third-stage LC resonance circuit and one end of the fourth-stage LC resonance circuit; the other end of the second-stage LC resonance circuit is grounded, the cathode of the PIN tube is grounded, the other end of the third-stage LC resonance circuit is grounded, and the other end of the fourth-stage LC resonance circuit is connected with an output port; one end of the control circuit is connected with the anode of the PIN tube, and the other end is connected with the control port. According to the invention, the integrated design is adopted, the size is small, the insertion loss is small, the anti-emission leakage signal burning performance of the receiving channel of the T / R assembly is improved, and the safety and stability of the T / R assembly are enhanced.

A clamping circuit that may be used to provide efficient and effective voltage clamping in an RF front end. The clamping circuit comprises two series coupled signal path switches and a bypass switch coupled in parallel with the series coupled signal path switches. A diode is coupled from a point between the series coupled signal path switches to a reference potential. In addition, an output selection switch within an RF front end has integrated voltage clamping to more effectively clamp the output voltage from the RF front end. Additional output clamping circuits can be used at various places along a direct gain signal path, along an attenuated gain path and along a bypass path.

The invention relates to the technical field of microwave passive devices, and provides a collaborative fusion-based adjustable amplitude limiting filter chip, which comprises a main transmission line, and a first-stage amplitude limiting circuit, a quarter-wavelength microstrip line TL1, a second-stage adjustable amplitude limiting circuit, an open-circuit quarter-wavelength microstrip line TL3 and a lumped parallel resonator which are loaded on the main transmission line and are sequentially connected, and the second-stage adjustable amplitude limiting circuit is loaded with an adjustable bias voltage source VDC. According to the chip designed by the invention, a filtering function is fused in an amplitude limiting circuit, and an amplitude limiting level adjustable function is realized while stopband suppression and circuit area are optimized.

A voltage limiting circuit for a power amplifier that includes a diode circuit, a bias circuit to generate a bias voltage, and a sink circuit. The diode circuit is coupled to an output of an amplification stage of the power amplifier and configured to provide a conductive path from the output when an output voltage of the amplification stage exceeds a predetermined threshold. The sink circuit includes an attenuator, coupled to the diode circuit and the bias circuit, and is configured to reduce the bias voltage when the output voltage exceeds the predetermined threshold to thereby limit the output voltage, and the attenuator is configured to reduce a feedback of the output voltage routing through the sink circuit.

The invention discloses an ultra-wideband high-power-resistance amplitude limiting switch multifunctional chip, and relates to the technical field of amplitude limiting switches and integrated circuits. The chip comprises a PIN amplitude limiter and a single-pole four-throw PIN switch, the PIN amplitude limiter equally divides the power of a radio frequency input signal into two paths to improve the power capacity of the amplitude limiter, adjusts the amplitude limiting level through an anti-parallel diode, and transmits an amplitude limiting radio frequency input signal to the single-pole four-throw PIN switch; according to the single-pole four-throw PIN switch, a spiral inductor is adopted, resistors are introduced between coils of the spiral inductor to eliminate resonance points caused by parasitic capacitance and expand bandwidth, four corresponding branches are turned on or turned off according to four control voltages, and then an amplitude limiting radio frequency input signal is transmitted to the low-noise amplifier according to the turned-on branches. The power capacity of the amplitude limiter can be improved, the amplitude limiting level can be adjusted, and the bandwidth can be expanded while the amplitude limiting of the radio frequency input signal is realized.

The present invention discloses a K-band limiting low-noise amplifier, which belongs to the field of radio frequency microelectronics technology. The amplifier comprises an input matching module, a diode limiting module, an inter-stage matching module, a low-noise amplifier module, and an output matching module, which are sequentially connected in cascade. The input matching module is used to achieve impedance matching between the radio frequency signal input end and the diode limiting module, and transmit the radio frequency signal. The diode limiting module is used to limit the radio frequency signal and transmit it. The inter-stage matching module is used to achieve impedance matching between the diode limiting module and the low-noise amplifier module. The low-noise amplifier module is used to amplify and transmit the limited radio frequency signal. The output matching module is used to achieve impedance matching between the low-noise amplifier module and the radio frequency signal output end, and output the amplified radio frequency signal. The present invention can limit the amplitude of the input signal so that it remains within the range that the low-noise amplifier circuit can withstand, thereby ensuring the stability and reliability of the entire system.

The invention discloses a multistage microwave amplitude limiting circuit and a passive amplitude limiter. The multi-stage microwave amplitude limiting circuit is a multi-stage microwave amplitude limiting circuit of a gallium nitride Schottky diode adopting Schottky contact metal with different work functions and comprises a multi-stage amplitude limiting structure formed by cascading a plurality of amplitude limiting structures, and each stage of amplitude limiting structure comprises the gallium nitride Schottky diode adopting Schottky contact metal with different work functions. In the multi-stage amplitude limiting structure, Schottky metals with different work functions are used for modulating the turn-on voltage, so that the turn-on voltage of a diode in each stage of amplitude limiting structure is decreased progressively, and the lower amplitude limiting power of a high-power input signal is decreased progressively step by step. According to the invention, gallium nitride Schottky diodes of Schottky metal with different work functions are used in different stages of the amplitude limiting circuit, so that the power capacity is improved, the insertion loss is reduced, the response time and the recovery time are reduced, and the amplitude limiter can effectively protect a post-stage circuit under high-power input.

The invention discloses a millimeter wave amplitude limiter with a harmonic suppression characteristic. The millimeter wave amplitude limiter comprises an input radio frequency transmission line, a first amplitude limiting PIN diode pair, a grounding metal via hole, a radio frequency matching circuit, a harmonic suppression unit, a second amplitude limiting PIN diode pair and an output radio frequency transmission line, the input radio frequency transmission line is connected with the output radio frequency transmission line through the radio frequency matching circuit; the first amplitude limiting PIN diode and the second amplitude limiting PIN diode pair are both connected with the radio frequency matching circuit; the radio frequency matching circuit is located at one side of the radio frequency matching circuit. The millimeter wave amplitude limiter with the harmonic suppression characteristic has the functions of an amplitude limiter and harmonic suppression at the same time, can save a harmonic suppression filter when being applied to a millimeter wave receiving circuit, optimizes the overall receiving performance, and has the advantages of simple structure and low cost.

The invention discloses a heterogeneous integrated diode amplitude limiter with local heat dissipation channels and a preparation method thereof, and relates to the technical field of diode amplitude limiter manufacturing. The invention provides a heterogeneous integrated diode amplitude limiter with local heat dissipation channels, and aims to provide a diode amplitude limiter which is high in heat dissipation capability and high in power resistance level. The semiconductor material with high thermal conductivity is used as the substrate and is heterogeneously integrated with the diode amplitude limiter prepared from the semiconductor material with low thermal conductivity, so that the overall heat dissipation level of the amplitude limiter is improved. Meanwhile, a heat dissipation channel is etched on the substrate right below the diode and is filled with diamond, graphene, boron nitride and other heat dissipation materials with good thermal conductivity, so that the local heat dissipation of the diode is enhanced, and the power tolerance level of the amplitude limiter is further improved. The overall heat dissipation and local heat dissipation of the diode amplitude limiter are enhanced through heterogeneous integration and local heat dissipation channels, the power resistance level of the amplitude limiter is improved, and a rear-end communication system can be better protected.

The present invention discloses a PIN limiter based on GaAs process. The PIN limiter includes: a first-stage limiting circuit, a second-stage limiting circuit, a third-stage limiting circuit and a control circuit; a radio frequency input end is connected to the input end of the first-stage limiting circuit; the output end of the first-stage limiting circuit is respectively connected to the input end of the second-stage limiting circuit; the output end of the second-stage limiting circuit is connected to the input end of the third-stage limiting circuit; the output end of the third-stage limiting circuit is connected to a radio frequency output end; one end of the control circuit is connected to the output end of the first-stage limiting circuit; the other end of the control circuit is grounded. By configuring the periphery of the control circuit, the amplitude of the limited output level can be conveniently changed, so that the output level changes within a certain range, which is more flexible and can meet diverse application requirements.

The present invention discloses a high-power waveguide limiter, which comprises a waveguide box body, a rectangular waveguide integrated in the waveguide box body, a coupling detection device and a height-reducing waveguide connected to the rectangular waveguide; a PIN switch diode assembly, a first-stage PIN limiter diode assembly and a second-stage PIN limiter diode assembly are sequentially arranged in a stepped manner on the height-reducing waveguide, and the PIN limiter diodes in the first-stage PIN limiter diode assembly and the second-stage PIN limiter diode assembly are arranged in opposite directions. This high-power waveguide limiter not only improves the power capacity of the limiter, reduces the peak leakage, but also speeds up the recovery time of the limiter, and has a smaller limiting level and a faster recovery time.

Provided is a cascade connection type amplifier circuit in which overvoltage input is suppressed. An amplifier circuit (1) is provided with: an input terminal (101) and an output terminal (102); an FET (11) having a gate terminal (g1), a drain terminal (d1), and a source terminal (s1); an FET (12) having a gate terminal (g2), a drain terminal (d2), and a source terminal (s2); a diode (511) having a first anode terminal and a first cathode terminal; and a diode (512) having a second anode terminal and a second cathode terminal, the gate terminal (g1) being connected to the input terminal (101), the drain terminal (d1) being connected to the source terminal (s2), the drain terminal (d2) being connected to the output terminal (102), the first anode terminal and the second cathode terminal being connected to a first path connecting the input terminal (101) and the gate terminal (g1), and the second anode terminal and the first cathode terminal being connected to the drain terminal (d1).

This invention discloses an RF power amplifier module and its power protection method. The module includes a controller chip, an RF power amplifier chip, and a filter connected in sequence. The controller chip is connected to a power supply voltage VCC that powers the RF power amplifier chip. The controller chip detects the power supply voltage VCC and outputs a limiting bias voltage that increases with the increase of the power supply voltage VCC when VCC exceeds a set threshold. The RF power amplifier chip includes a limiting circuit and a power amplifier unit. The limiting circuit limits and attenuates the RF input signal according to the limiting bias voltage to obtain an attenuated RF signal. The power amplifier unit amplifies the attenuated RF signal before outputting it. The filter filters the amplified RF signal to output an RF signal in the target frequency band. This invention can adaptively change the limiting degree according to the power level and improve the speed of power detection.

The application provides a limiter circuit, which comprises a plurality of transmission lines connected in series, one end of the transmission lines serving as an input end of a radio frequency signal, the other end of the transmission lines being connected with an input end of an amplifier, and an output end of the amplifier serving as an output end of the radio frequency signal; a limiter branch connected between adjacent transmission lines and the amplifier in series, each limiter branch comprising a first symmetric branch and a second symmetric branch, the first symmetric branch and the second symmetric branch in each limiter branch being symmetrically distributed on both sides of the transmission line, so that the parasitic capacitance of each limiter branch is consistent and evenly distributed; and a bias control circuit connected with the first symmetric branch and the second symmetric branch in each limiter branch, so that the current and the density of each limiter branch are the same under the same size. The limiter circuit of the application improves the insertion loss and the effective power tolerance of the limiter circuit.

An envelope detection circuit and a method for detecting the envelope of a signal using such an envelope detection circuit. One exemplary envelope detection circuit generally includes a first diode, a capacitive element, and a clamp circuit. The first diode has an anode coupled to an input node of the envelope detection circuit and a cathode coupled to an output node of the envelope detection circuit. The capacitive element is coupled in shunt between the output node and a reference potential node, and the clamp circuit is coupled in shunt between the input node and the reference potential node. The clamp circuit generally includes a resistive element coupled in series with a second diode.