40results about "Limiting amplitude using diodes" patented technology

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 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.

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 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.

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 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.

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.

The invention relates to the technical field of radio frequency front ends, in particular to a broadband amplitude-limiting low-noise amplifier. On the basis of a traditional broadband amplitude-limiting low-noise amplifier, an input matching network unit and an amplitude limiter unit of a circuit are subjected to innovative topological transformation, and a source-level negative feedback unit is fused, so that noise coefficients in a broadband are remarkably optimized; a parasitic capacitor introduced by an amplitude limiter unit is integrated with an input matching unit, and the parasitic capacitor of the amplitude limiter is absorbed as a part of an input matching network through dynamic conversion of circuit topology according to impedance matching requirements of different working frequencies, so that impedance matching of a target frequency is completed by using parasitic parameters, and the impedance matching of the target frequency is completed by using the input matching unit. And the introduction of extra noise to a signal path when a stray capacitor of the amplitude limiter exists independently in the traditional design is avoided, and the noise deterioration phenomenon caused by the stray parameter of the amplitude limiting unit is reduced fundamentally.

A differential amplifier system is provided for receiving first and second input signals and generating first and second differential output signals. The system includes: a differential amplifier for receiving the first and second input signals, providing a first output current at a first current channel, and providing a second output current at a second current channel; a cascode stage for receiving the first and second output currents and generating the first and second differential output signals; and a detector for detecting when the first output current flowing through the first current channel satisfies the first condition, and / or detecting when the second output current flowing through the second current channel satisfies the second condition, wherein a current sink stage is configured to redirect at least a portion of the first and second output currents away from the cascode stage when the first output current satisfies the first condition, and / or redirect at least a portion of the first and second output currents away from the cascode stage when the second output current satisfies the second condition.

The invention discloses a center frequency reconfigurable amplitude limiting filter based on series-parallel topology. The center frequency reconfigurable amplitude limiting filter comprises a main transmission line, a first-stage amplitude limiting circuit, a transmission line TL1, a second-stage amplitude limiting circuit, a frequency reconfigurable unit and a lumped parallel resonator, the frequency reconfigurable unit realizes working center frequency adjustability by adjusting bias voltage VDC; and the second-stage amplitude limiting circuit widens the out-of-band rejection width by introducing a transmission zero point. Compared with an existing amplitude limiting filter, the band-pass filter has the advantages that the out-of-band rejection width is remarkably improved while the frequency reconfigurable function is achieved, and the band-pass filter can be applied to a multifunctional and high-performance radio frequency front-end system.

The present invention discloses a radio frequency protection circuit with integrated limiting threshold control and energy recovery functions, belonging to the technical field of reflective limiters. The circuit includes a radio frequency input terminal, a circulator, a branch line directional coupler, a bias and limiting network, an energy recovery unit, a load terminal, and a radio frequency output terminal. The energy recovery unit includes a high-power rectifier and a pass-through filter. The circulator and branch line directional coupler reflect overload signals, and the reflected power is introduced into the high-power rectifier via the circulator to achieve radio frequency energy recovery. The bias and limiting network includes a GaN-based Schottky diode and a symmetrical bias network, which are used to achieve limiting protection and adjustable limiter threshold functions. The present invention realizes the organic unification of high-power radio frequency signal limiting protection and reflected energy reuse, improves the functional integration and energy utilization efficiency of the radio frequency system, and is suitable for protection scenarios of high-power front-end circuits such as radar communication and satellite navigation.

The invention provides an ultra-wideband gallium nitride amplitude limiting circuit based on a pi-type matched microstrip, and the circuit comprises an input matched microstrip which is used for matching input impedance to standard impedance; the first-stage amplitude limiting circuit is used for carrying out preliminary amplitude limiting processing on the obtained radio frequency signal under standard impedance to obtain a first amplitude-limited radio frequency signal; the inter-stage matching circuit is used for matching the standard impedance to the target impedance; the second-stage amplitude limiting circuit is used for performing final amplitude limiting processing on the first amplitude limiting radio frequency signal under target impedance to obtain a second amplitude limiting radio frequency signal; the output matching microstrip is used for recovering the target impedance of the ultra-wideband gallium nitride amplitude limiting circuit to the standard impedance; the output port is used for outputting the second amplitude limiting radio frequency signal under standard impedance; wherein the first-stage amplitude limiting circuit takes a gallium nitride device auxiliary silicon PIN tube as a main amplitude limiting element; and the second-stage amplitude limiting circuit takes a silicon PIN tube as a main amplitude limiting element. And finally, high power resistance and low insertion loss performance are considered in a wide frequency band.

The application provides a clipper, a chip and a receiver. By designing the positions of the microstrip line and the diode unit in the clipper, the clipper can evenly distribute the power of the diode unit, and by synthesizing the output of the distributed power, the clipper can reduce the power loss and improve the power utilization rate of the input signal. By applying voltage to the diode unit, the clipper can widen the working frequency range by adjusting the junction capacitance of the diode unit. In addition, the application also provides a chip and a receiver comprising the clipper. Ultimately, the application can realize a clipper, a chip and a receiver with high power utilization rate, good power distribution performance and wide working frequency range.

The application is suitable for the field of radio frequency communication technology, and provides a one-way microwave limiter and a communication system.The limiter comprises a bidirectional coupler, a forward detection module, a reverse detection module, an integration module, a choke inductor and a PIN diode.The first main branch end of the bidirectional coupler is connected with an antenna end, the second main branch end is connected with the first end of the choke inductor, the anode of the PIN diode and a power transmitting end respectively, the first coupling end is connected with the input end of the forward detection module, and the second coupling end is connected with the input end of the reverse detection module.The output end of the forward detection module is connected with the output end of the reverse detection module and the first end of the integration module and the second end of the choke inductor respectively.According to the characteristics of the bidirectional coupler, when a high-power signal is injected into the antenna end, the output of the forward detection module and the output of the reverse detection module are jointly connected to the anode of the PIN diode through the integration module to make the PIN diode conductive, thereby realizing one-way protection of the high-power signal.

This invention discloses a limiter chip, which includes a dielectric substrate and a limiting unit disposed on the dielectric substrate. The limiting unit includes a limiter cell disposed on the upper surface of the dielectric substrate and a ground plane that fully covers the back side of the dielectric substrate. The limiter cell includes an input terminal, an output terminal, six limiting stage diodes, four buffer stage diodes, two detection stage diodes, two choke inductors, a tuning capacitor, four ground terminals distributed at the four corners, multiple vias, and multiple transmission lines for connection. Each stage of diodes is grounded using an anti-parallel structure, and different stages are connected using choke inductors. The tuning capacitor is located after the choke inductor between the limiting stage and the buffer stage, connecting it in parallel to ground. This structure is used to limit the input signal. By integrating it onto a chip using integrated circuit technology, it has advantages such as high integration, wide bandwidth performance, wide application range, and low cost.

The present invention discloses a heterogeneously integrated fast-recovery response high-power limiter and a preparation method thereof, belonging to the field of radio frequency / microwave circuit protection. The device sequentially comprises an input port, a first limiter unit, an impedance matching and rectification bias network, a second limiter unit, and an output port. The first limiter unit adopts a Si-based PIN diode for carrying a high-power input signal. The impedance matching and rectification bias network comprises a 1 / 4 wavelength impedance transformation line, a GaN-based Schottky diode, and an LRC series-parallel network for quickly triggering the front-stage PIN diode to conduct. The second limiter unit comprises a GaAs-based PIN diode for further absorbing the residual high-power energy leaked from the front stage, thereby improving the final isolation of the limiter. The present invention can significantly improve the limiting response speed and recovery time performance, reduce the limiting threshold, improve the protection sensitivity, improve the high-power processing capability, enhance the reliability, improve the device integration, and reduce the packaging complexity and volume.

The invention discloses a radio frequency power amplifier module and a power protection method thereof. The module comprises a controller chip, a radio frequency power amplifier chip and a filter which are connected in sequence, the controller chip is connected with a power supply voltage VCC for supplying power to the radio frequency power amplifier chip, and the controller chip is used for detecting the power supply voltage VCC and outputting an amplitude limiting bias voltage which is increased along with the increase of the power supply voltage VCC when the power supply voltage VCC exceeds a set threshold value; the radio frequency power amplifier chip comprises an amplitude limiting circuit and a power amplifier unit; the amplitude limiting circuit is used for carrying out amplitude limiting attenuation on the radio frequency input signal according to the amplitude limiting bias voltage to obtain an attenuated radio frequency signal; the power amplifier unit is used for performing power amplification on the attenuated radio frequency signal and then outputting the amplified radio frequency signal; and the filter is used for filtering the amplified radio frequency signal so as to output the radio frequency signal of the target frequency band. According to the invention, the amplitude limiting degree can be adaptively changed according to the power, and the power detection speed is improved.