CN105763175A - Ultra wide band pulse generation circuit - Google Patents

Abstract

The invention relates to an ultra-wideband pulse generation circuit, comprising: a differential circuit, a high-speed switch circuit, a pulse generation circuit and a voltage bias circuit; the differential circuit, the high-speed switch circuit and the pulse generation circuit are connected in sequence, and the voltage bias circuit respectively connected with the high-speed switching circuit and the pulse generating circuit; the differential circuit receives the digital square wave signal input from the outside, and converts the digital square wave signal into a sharp pulse signal with a width of nanosecond level; the high-speed switching circuit is in the Driven by the sharp pulse signal, the critical avalanche state is turned into an avalanche conduction state; the pulse generation circuit generates negative pulses when the high-speed switch circuit is turned on, and generates positive pulses when the pulse generation circuit discharges. According to the The negative-going pulse and the positive-going pulse generate an ultra-wideband pulse signal. The pulse signal generated by the above solution does not contain a DC component, and is suitable for antenna transmission; no additional pulse shaping circuit is needed, which reduces the complexity and cost of the circuit.

Description

UWB Pulse Generation Circuit

technical field

The invention relates to the technical field of wireless communication, in particular to a Gaussian ultra-wideband pulse generation circuit.

Background technique

Ultra-wideband technology is a new type of wireless communication technology. It uses pulse signals with extremely wide frequency bands (up to a few gigahertz) and extremely narrow widths (sub-nanosecond or nanosecond) as the carrier of information transmission, and has a high transmission rate. , anti-multipath interference ability, low interception and low cost and many other advantages, it is widely used in many fields such as short-distance high-speed wireless communication, radar detection and precise positioning. In an ultra-wideband communication system, the pulse generator is not only the core component of the transmitter, but also an important component of the receiver. The parameters of the generated pulse signal directly affect the performance index of the system. Therefore, the ultra-wideband pulse generator has been one of the important research directions of ultra-wideband technology.

According to the definition of the US Federal Communications Commission (FCC), an ultra-wideband signal refers to a signal with an absolute bandwidth greater than 500MHz or a relative bandwidth greater than 20% at -10dB and a center frequency greater than 500MHz. UWB signals appear as pulses of extremely short duration in the time domain, usually only a few hundred picoseconds or a few hundred nanoseconds. UWB pulses are often generated by semiconductor devices and transmission lines with high-speed switching characteristics. Devices commonly used to generate ultra-broadband pulses include tunnel diodes, step recovery diodes, avalanche transistors, and photoconductive switches. Among them, the rise time of pulses generated by tunnel diodes and step recovery diodes can reach tens to hundreds of picoseconds, but Its amplitude is very small, only tens to hundreds of millivolts. Photoconductive switches based on spark gaps can generate pulses above kilovolts, but the generated pulse repetition frequency is too low, and a power supply voltage of hundreds to thousands of volts is required for operation, which is bulky and unfavorable for miniaturization design requirements. The use of nonlinear transmission lines can also generate extremely narrow pulse signals on the order of picoseconds, but it requires high technology and is expensive, which limits its application range. The avalanche triode can generate nanosecond-level pulses, which can be triggered at a high frequency and have an amplitude of tens of volts. The circuit is simple to implement and can meet the technical requirements of general transceiver systems. It is more practical, so it is often used in the design of ultra-wideband pulse generators . However, the existing pulse generation circuit based on avalanche triode requires high power supply voltage, which is not conducive to the miniaturization and mobile portability of the equipment, and the general pulse generation circuit based on avalanche triode can only directly generate Gaussian pulse, and Gaussian pulse contains DC components and more low-frequency components are not suitable for antenna transmission, so it is necessary to add an additional pulse shaping circuit to differentiate and filter the generated Gaussian pulses to obtain high-order Gaussian pulses or other waveforms suitable for antenna transmission, and the traditional pulse The power of the generating circuit is small, the generated pulse amplitude is low, and an additional broadband amplifier is often required, which increases the complexity and cost of the circuit.

To sum up, the existing ultra-wideband pulse generation circuit has defects such as high requirements on power supply voltage, unsuitable pulse waveform for antenna transmission, low pulse amplitude, and high complexity and cost.

Contents of the invention

Based on this, it is necessary to provide an ultra-wideband pulse generating circuit for the technical problems that the pulse signal generated by the existing pulse generating circuit is not suitable for the transmission of electric wires and the circuit has high complexity and cost.

An ultra-wideband pulse generating circuit, including: a differential circuit, a high-speed switching circuit, a pulse generating circuit and a voltage bias circuit;

The differential circuit, the high-speed switching circuit and the pulse generating circuit are connected in sequence, and the voltage bias circuit is respectively connected to the high-speed switching circuit and the pulse generating circuit;

The differential circuit receives an externally input digital square wave signal, and converts the digital square wave signal into a sharp pulse signal with a width of nanosecond level;

The high-speed switch circuit receives the voltage provided by the high-voltage bias circuit and is in a critical avalanche state; and is driven by the spike signal from the critical avalanche state to an avalanche conduction state;

The pulse generating circuit generates a negative pulse when the high-speed switch circuit is turned on, and generates a positive pulse when the pulse generating circuit discharges, and generates an ultra-wideband pulse signal according to the negative pulse and the positive pulse.

The above-mentioned ultra-wideband pulse generating circuit converts the externally input digital square wave signal into a sharp pulse signal with a width of nanometers through a differential circuit, and the high-speed switching circuit is driven by the sharp pulse signal from a critical avalanche state to an avalanche conduction state, the pulse generation circuit directly generates an ultra-wideband pulse signal according to the negative pulse and positive pulse generated when the high-speed switch circuit is turned on. The pulse signal generated by the above technical solution does not contain a DC component, and is more suitable for the transmission of the antenna; moreover, unlike the traditional pulse generating circuit that requires an external pulse shaping circuit, the ultra-wideband pulse generating circuit of the present application can directly generate ultra-wideband pulses signal, reducing circuit complexity and cost.

Description of drawings

Fig. 1 is the structural representation of the ultra-wideband pulse generation circuit of an embodiment of the present invention;

Fig. 2 is the circuit principle diagram of the ultra-wideband pulse generation circuit of another embodiment of the present invention;

Fig. 3 is the wave form diagram that the pulse signal that the generation of the ultra-wideband pulse generation circuit of another embodiment of the present invention is simulated;

FIG. 4 is a waveform diagram of an actual measurement of a pulse signal generated by an ultra-wideband pulse generating circuit according to another embodiment of the present invention.

detailed description

In order to further illustrate the technical means adopted by the present invention and the achieved effects, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and preferred embodiments.

As shown in Figure 1, Figure 1 is a schematic structural diagram of an ultra-wideband pulse generation circuit according to an embodiment of the present invention, including: a differential circuit 101, a high-speed switch circuit 102, a pulse generation circuit 103 and a voltage bias circuit 104;

The differential circuit 101, the high-speed switch circuit 102 and the pulse generation circuit 103 are connected in sequence, and the voltage bias circuit 104 is connected to the high-speed switch circuit 102 and the pulse generation circuit 103 respectively;

The differential circuit 101 is configured to receive an externally input digital square wave signal, and convert the digital square wave signal into a spike signal with a width of nanosecond level;

The high-speed switch circuit 102 is configured to receive the voltage provided by the high-voltage bias circuit 104 and be in a critical avalanche state; and be driven by the spike signal from the critical avalanche state to an avalanche conduction state;

The pulse generation circuit 103 is used to generate negative pulses when the high-speed switch circuit 103 is turned on, and generate positive pulses when the pulse generation circuit is discharged, and generate ultra-wideband pulses according to the negative pulses and positive pulses. Pulse signal.

The above-mentioned ultra-wideband pulse generating circuit converts the externally input digital square wave signal into a sharp pulse signal with a width of nanometers through a differential circuit, and the high-speed switching circuit is driven by the sharp pulse signal from a critical avalanche state to an avalanche conduction state, the pulse generation circuit directly generates an ultra-wideband pulse signal according to the negative pulse and positive pulse generated when the high-speed switch circuit is turned on. The pulse signal generated by the above technical solution does not contain a DC component, and is more suitable for the transmission of the antenna; moreover, unlike the traditional pulse generating circuit that requires an external pulse shaping circuit, the ultra-wideband pulse generating circuit of the present application can directly generate ultra-wideband pulses signal, reducing circuit complexity and cost.

In one of the embodiments, the ultra-wideband pulse generation circuit of the present invention, the differential circuit 101 includes: a first RC differential circuit and a second RC differential circuit;

Output terminals of the first RC differential circuit and the second RC differential circuit are respectively connected to the high-speed switch circuit 102 .

In one of the embodiments, in the ultra-wideband pulse generation circuit of the present invention, the first RC differential circuit converts the input first digital square wave signal into a first spike signal, and transmits it to the high-speed switch circuit 102;

The second RC differential circuit converts the input second digital square wave signal into a second spike signal and transmits it to the high-speed switch circuit 102 .

In the above embodiments, the differential circuit of the UWB pulse generating circuit of the present invention converts the externally input digital square wave signal into a sharp pulse signal with a width of nanometer level, and provides a trigger signal for the high-speed switching circuit 102 of the next stage. In practical applications, the width of the spike signal is determined by the time constant τ=R×C, and the width of the spike signal determines the conduction time of the high-speed switch circuit 102, which is generally 1 ns.

In one of the embodiments, in the ultra-wideband pulse generation circuit of the present invention, the high-speed switch circuit 102 includes: a first avalanche triode and a second avalanche triode;

The first avalanche triode and the second avalanche triode are respectively connected to the pulse generating circuit.

In one of the embodiments, in the UWB pulse generation circuit of the present invention, the first avalanche triode receives the first spike signal, and is driven by the first spike signal from a critical avalanche state to an avalanche state. conduction state;

The second avalanche transistor receives the second spike signal, and is driven by the first spike signal from a critical avalanche state to an avalanche conduction state.

In the above-mentioned embodiment, the high-speed switch circuit 102 of the ultra-wideband pulse generating circuit of the present invention is composed of a first avalanche triode and a second avalanche triode connected in parallel. Driven by the sharp pulse signal generated by the differentiating circuit, the avalanche is turned on, thereby prompting the next-stage pulse generating circuit 103 to generate an ultra-wideband pulse signal.

In the above embodiment, by using two avalanche transistors connected in parallel, when the avalanche is turned on, the current flowing through the load resistance is doubled compared with the circuit of a single transistor, so that the generated pulse amplitude is doubled and the output is improved. The power of the pulse does not require an external broadband amplifier, which reduces the complexity and cost of the circuit.

In one of the embodiments, the ultra-wideband pulse generating circuit of the present invention, the pulse generating circuit 103 includes: a first energy storage capacitor, a second energy storage capacitor, an energy storage inductor and a load resistor;

The first energy storage capacitor is connected to the collector of the first avalanche transistor, and the second energy storage capacitor is connected to the collector of the second avalanche transistor; the energy storage inductance is connected in parallel to the load resistor both ends;

When the first avalanche triode and the second avalanche triode are in the conduction state at the same time, the first energy storage capacitor, the first avalanche triode and the load resistor form a first discharge loop, generating a first discharge current, the second energy storage capacitor, the second avalanche triode and the load resistor form a second discharge loop to generate a second discharge current;

The first discharge current and the second discharge current are simultaneously applied to the load resistor to form a negative pulse.

In one of the embodiments, the ultra-wideband pulse generating circuit of the present invention is also used for;

When the charges of the first energy storage capacitor and the second energy storage capacitor decrease, the first discharge current and the second discharge current start to decrease, and the energy storage inductance starts to discharge the load resistor, so that the The current in the load resistor is reversed and a positive going pulse is formed across the load resistor.

Under the action of the above-mentioned negative pulse and positive pulse, the output terminal of the pulse generating circuit forms an ultra-wideband pulse signal. Since the generated ultra-wideband pulse signal is similar to a first-order differential Gaussian signal, the generated ultra-wideband pulse signal can be called a first-order differential Gaussian ultra-wideband pulse signal.

In the above-mentioned embodiment, the load resistance of the pulse generating circuit in the ultra-wideband pulse generating circuit of the present invention is connected in parallel with the energy storage inductance, and the first-order differential Gaussian ultra-wideband pulse signal is directly generated at one time by utilizing the energy storage function of the energy storage inductance , no additional differential circuit and filter circuit are required, which reduces the complexity and cost of the circuit; in addition, the pulse generating circuit in the ultra-wideband pulse generating circuit of the present invention adopts a double-tube structure design, so that the amplitude of the output pulse signal is higher than that of a single-tube The structure is larger, up to 4.3V, which improves the signal power, meets the transmission power requirements without an external broadband amplifier, and reduces the complexity and cost of the circuit.

In one of the embodiments, the ultra-wideband pulse generating circuit of the present invention, the voltage bias circuit 104 includes: a first bias circuit and a second bias circuit;

The first bias circuit includes a first DC power supply, a first inductor and a first resistor, and is connected to the collector of the first avalanche transistor;

The second bias circuit includes a second DC power supply, a second inductor and a second resistor, and is connected to the collector of the second avalanche transistor.

In one of the embodiments, in the ultra-wideband pulse generation circuit of the present invention, when there is no digital signal input, the first DC power supply charges the first energy storage capacitor through the first voltage bias circuit; the The second DC power supply charges the second energy storage capacitor through the second bias circuit.

In the above embodiment, when the circuit is static, the first avalanche triode and the second avalanche triode are cut off, and the high-voltage bias circuit makes the avalanche triode be in a critical avalanche state, and the first storage of the pulse generating circuit is respectively The energy storage capacitor and the second energy storage capacitor are charged. Due to the energy storage effect of the first inductance and the second inductance, the voltage across the first energy storage capacitor and the second energy storage capacitor will exceed the power supply voltage, thereby storing more charges , so that the discharge current is larger and a larger pulse is generated, so the requirement for the power supply voltage can be reduced.

In the above embodiment, when there is no digital signal input and the circuit is static, the first voltage bias circuit charges the first energy storage capacitor through the first DC power supply, and the second voltage bias circuit charges the first energy storage capacitor through the second DC power supply. The second energy storage capacitor is charged. Due to the energy storage effect of the first inductance and the second inductance, the voltage at both ends of the first energy storage capacitor and the first energy storage capacitor exceeds the power supply voltage. When the first avalanche triode switch circuit and the second When the avalanche triodes are turned on at the same time, the first energy storage capacitor and the second energy storage capacitor are rapidly discharged through the first avalanche triode and the second avalanche triode respectively, and the discharge current of both will flow through the energy storage inductance and the load resistance, thus A negative narrow pulse is generated on the load resistance. Since the first energy storage capacitor and the second energy storage capacitor are very small, the amount of stored charge is very small, and the discharge current begins to decrease soon. At this time, due to the storage of the energy storage inductance function, the energy storage inductance starts to discharge the load resistance, so that the current of the load resistance is reversed, thereby generating a positive narrow pulse, and the two pulses are combined to form an approximate first-order differential Gaussian ultra-wideband pulse signal.

The ultra-wideband pulse signal obtained by the above method is more suitable for the transmission of the antenna because it does not contain a DC component; secondly, the energy storage inductor is connected in parallel at both ends of the load resistance of the pulse generation circuit, and the energy storage function of the energy storage inductor is used to directly generate an energy storage inductor at one time. The second-order differential Gaussian ultra-wideband pulse signal does not require additional differential circuits and filter circuits, which reduces the complexity and cost of the circuit; moreover, the pulse generation circuit adopts a double-tube structure design, which makes the amplitude of the output pulse signal higher than that of the single-tube structure. Large, up to 4.3V, which improves the signal power, meets the transmission power requirements without an external broadband amplifier, and reduces the complexity and cost of the circuit; finally, due to the energy storage function of the inductor in the voltage bias circuit, the storage When the energy storage capacitor is charged, the voltage at both ends of the energy storage capacitor will exceed the power supply voltage. Under the condition of ensuring the same output signal amplitude, more charges can be stored, the discharge current will be larger, and a larger pulse will be generated. Therefore, Can reduce the requirement on the power supply voltage.

As shown in Figure 2, Figure 2 is a circuit schematic diagram of an ultra-wideband pulse generating circuit according to another embodiment of the present invention, including a differential circuit, a high-speed switching circuit, a pulse generating circuit and a voltage bias circuit;

The differential circuit includes a first RC differential circuit 1011 and a second RC differential circuit; wherein, the first RC differential circuit 1011 is composed of R1 and C1 in series, and the second RC differential circuit 1012 is composed of R2 and C2 in series, Two sets of RC differential circuits convert the input digital square wave signal into two sets of sharp pulse signals with a width of nanosecond level, which provide trigger signals for the high-speed switching circuit of the next stage. In practical applications, the width of the spike signal is determined by the time constant τ=R×C, and the width of the spike signal determines the conduction time of the high-speed switch circuit 102, which is generally less than 1 ns.

The high-speed switching circuit is composed of a first avalanche transistor Q1 and a second avalanche transistor Q2 connected in parallel. When there is no digital signal input, both Q1 and Q2 are in the cut-off state; when a digital signal is input, the first avalanche transistor Q1 receives the first sharp pulse signal generated by the first RC differential circuit, and in the first sharp pulse Driven by the signal, it turns from the critical avalanche state to the avalanche conduction state; the second avalanche transistor Q2 receives the second spike signal generated by the second RC differential circuit, and is driven by the second spike signal by The critical avalanche state turns into an avalanche conduction state, thereby prompting the pulse generation circuit of the next stage to generate an approximate first-order differential Gaussian ultra-wideband pulse signal.

In this embodiment, two avalanche triodes are connected in parallel, so that when the avalanche is turned on, the current flowing through the load resistance is doubled compared with that of a single triode circuit, thereby doubling the pulse amplitude generated and improving the output The power of the pulse does not require an external broadband amplifier, which reduces the complexity and cost of the circuit.

In one of the embodiments, the ultra-wideband pulse generation circuit of the present invention, the pulse generation circuit includes: a first energy storage capacitor C1, a first energy storage capacitor C2, an energy storage inductance L and a load resistor R, the first energy storage The capacitor C1 is connected to the collector of the first avalanche transistor Q1, the second energy storage capacitor C2 is connected to the collector of the second avalanche transistor Q2, and the energy storage inductance L is connected to both ends of the load resistor R in parallel.

In one of the embodiments, the ultra-wideband pulse generating circuit of the present invention is also used for;

When the first avalanche transistor Q1 and the second avalanche transistor Q2 are in the conduction state at the same time, the first energy storage capacitor C1, the first avalanche transistor Q1 and the load resistor R form a first discharge loop to generate the first discharge current, and the second energy storage capacitor C1 Capacitor C2 forms a second discharge circuit with the second avalanche transistor Q2 and load resistor R to generate a second discharge current. The first discharge current and the second discharge current are loaded on the load resistor R at the same time and form a negative pulse.

When the charges of the first energy storage capacitor C1 and the second energy storage capacitor C2 decrease, the first discharge current and the second discharge current start to decrease, and the energy storage inductance L starts to load the load resistance R Discharge, reverse the current passing through the load resistor R, and form a positive pulse on the load resistor R, under the action of the negative pulse and positive pulse, the output terminal of the pulse generating circuit forms a super Broadband pulse signal.

In one of the embodiments, the ultra-wideband pulse generation circuit of the present invention, the voltage bias circuit includes: a first bias circuit 1041 and a second bias circuit 1042; wherein, the first bias circuit 1041 includes a second bias circuit A DC power supply V1, a first inductor L1 and a first resistor R3 are connected to the collector of the first avalanche transistor Q1; the second bias circuit 1042 includes a second DC power supply V2, a second inductor L2 and The second resistor R4 is connected to the collector of the second avalanche transistor Q2.

In practical applications, when there is no digital signal input, the first avalanche transistor Q1 and the second avalanche transistor Q2 are turned off, and the first DC power supply V1 charges the first energy storage capacitor C1 through the first voltage bias circuit 1041 The second DC power supply V2 charges the second energy storage capacitor C2 through the second bias circuit 1042, the first high-voltage bias circuit 1041 makes the first avalanche transistor Q1 in a critical avalanche state, and the second high-voltage bias The setting circuit 1042 puts the second avalanche transistor Q2 in a critical avalanche state, and due to the energy storage effect of the first inductance L1 and the second inductance L2, the voltage across the first energy storage capacitor C1 and the second energy storage capacitor C2 will exceed the power supply Voltage, so as to store more charge, make the discharge current larger, and generate a larger pulse, so the requirement for the power supply voltage can be reduced.

When the first avalanche transistor Q1 and the second avalanche transistor Q2 are avalanche-conducted at the same time, the first energy storage capacitor C1 and the second energy storage capacitor C2 are respectively rapidly discharged through the first avalanche transistor Q1 and the second avalanche transistor Q2. The discharge current will flow through the energy storage inductance L and the load resistance R, thereby generating a negative narrow pulse on the load resistance R. Since the first energy storage capacitor C1 and the second energy storage capacitor C2 are small, the stored charge Rarely, the discharge current begins to decrease soon. At this time, due to the energy storage function of the energy storage inductor L, the energy storage inductor L starts to discharge the load resistor R, so that the current of the load resistor R is reversed, thereby generating a positive narrow Two pulses are combined to form an approximate first-order differential Gaussian ultra-wideband pulse signal.

The ultra-wideband pulse signal obtained by the above method is more suitable for the transmission of the antenna because it does not contain a DC component; secondly, the energy storage inductor is connected in parallel at both ends of the load resistance of the pulse generation circuit, and the energy storage function of the energy storage inductor is used to directly generate an energy storage inductor at one time. The second-order differential Gaussian ultra-wideband pulse signal does not require additional differential circuits and filter circuits, which reduces the complexity and cost of the circuit; moreover, the pulse generation circuit adopts a double-tube structure design, which makes the amplitude of the output pulse signal higher than that of the single-tube structure. Large, up to 4.3V, which improves the signal power, meets the transmission power requirements without an external broadband amplifier, and reduces the complexity and cost of the circuit; finally, due to the energy storage function of the inductor in the voltage bias circuit, the storage When the energy storage capacitor is charged, the voltage at both ends of the energy storage capacitor will exceed the power supply voltage. Under the condition of ensuring the same output signal amplitude, more charges can be stored, the discharge current will be larger, and a larger pulse will be generated. Therefore, Can reduce the requirement on the power supply voltage.

As shown in Fig. 3, Fig. 3 is the pulse signal that the generation of the ultra-wideband pulse generating circuit of another embodiment of the present invention is simulated waveform diagram, wherein, the abscissa in the figure represents the width of the pulse signal, and the unit is ns, The vertical axis represents the voltage amplitude of the pulse signal, and the unit is V.

Use PspiceA/D to simulate the generated pulse signal, among them, the input signal is a 50MHz square wave signal, the peak value of the pulse shown in the figure is about 23.7V, and the pulse width is about 1.1ns. According to the above simulation waveform diagram, it can be known that the pulse signal generated by the ultra-wideband pulse generating circuit of the present invention has a relatively high amplitude and a pulse width of nanosecond level, and can be used as an ultra-wideband pulse.

As shown in Figure 4, Figure 4 is a waveform diagram of the actual measured pulse signal of the ultra-wideband pulse generation circuit of another embodiment of the present invention, using an Agilent oscilloscope DSO90804A to observe the waveform, wherein the input signal is a 25MHz square wave signal , the peak-to-peak value of the pulse in the figure is about 4.3V, and the pulse width is about 1.5ns. As can be seen from the test results, the pulse signal amplitude generated by the ultra-wideband pulse generating circuit of the present invention is relatively large, the pulse repetition frequency is high, and the pulse width is relatively narrow, which can meet the performance requirements of the ultra-wideband transceiver system, such as: short-distance wireless communication and Indoor positioning, etc., the circuit is simple and practical.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A kind of ultra-broadband pulse generation circuit, it is characterized in that, comprises: differential circuit, high-speed switch circuit, pulse generation circuit and voltage bias circuit; The differential circuit, the high-speed switching circuit and the pulse generating circuit are connected in sequence, and the voltage bias circuit is respectively connected to the high-speed switching circuit and the pulse generating circuit; The differential circuit is used to receive an externally input digital square wave signal, and convert the digital square wave signal into a sharp pulse signal with a width of nanosecond level; The high-speed switch circuit is used to receive the voltage provided by the high-voltage bias circuit, and is in a critical avalanche state; and is driven by the spike signal from the critical avalanche state to an avalanche conduction state; The pulse generating circuit is used to generate a negative pulse when the high-speed switch circuit is turned on, and generate a positive pulse when the pulse generating circuit is discharged, and generate an ultra-wideband pulse signal according to the negative pulse and the positive pulse . 2. The ultra-wideband pulse generation circuit according to claim 1, wherein the differential circuit comprises: a first RC differential circuit and a second RC differential circuit; Output terminals of the first RC differential circuit and the second RC differential circuit are respectively connected to the high-speed switch circuit. 3. The ultra-wideband pulse generation circuit according to claim 2, characterized in that: The first RC differential circuit converts the input first digital square wave signal into a first spike signal, and transmits it to the high-speed switch circuit; The second RC differential circuit converts the input second digital square wave signal into a second spike signal and transmits it to the high-speed switch circuit. 4. The ultra-wideband pulse generating circuit according to claim 3, wherein the high-speed switching circuit comprises: a first avalanche triode and a second avalanche triode; The first avalanche triode and the second avalanche triode are respectively connected to the pulse generating circuit. 5. The ultra-wideband pulse generation circuit according to claim 4, characterized in that: The first avalanche triode receives the first spike signal, and is driven by the first spike signal from a critical avalanche state to an avalanche conduction state; The second avalanche transistor receives the second spike signal, and is driven by the first spike signal from a critical avalanche state to an avalanche conduction state. 6. The ultra-wideband pulse generating circuit according to claim 5, wherein the pulse generating circuit comprises: a first energy storage capacitor, a second energy storage capacitor, an energy storage inductance and a load resistor; The first energy storage capacitor is connected to the collector of the first avalanche transistor, and the second energy storage capacitor is connected to the collector of the second avalanche transistor; the energy storage inductance is connected in parallel to the load resistor both ends; When the first avalanche triode and the second avalanche triode are in the conduction state at the same time, the first energy storage capacitor, the first avalanche triode and the load resistance form a first discharge loop to generate a first discharge current, The second energy storage capacitor, the second avalanche triode and the load resistor form a second discharge loop to generate a second discharge current; The first discharge current and the second discharge current are simultaneously applied to the load resistor to form a negative pulse. 7. The ultra-wideband pulse generation circuit according to claim 6, characterized in that, the pulse generation circuit is also used for; When the charges of the first energy storage capacitor and the second energy storage capacitor decrease, the first discharge current and the second discharge current start to decrease, and the energy storage inductance starts to discharge the load resistor, so that the The current in the load resistor is reversed and a positive going pulse is formed across the load resistor. 8. The UWB pulse generation circuit according to claim 7, characterized in that: Under the action of the negative-going pulse and the positive-going pulse, an ultra-wideband pulse signal is generated at the output end of the pulse generating circuit. 9. The UWB pulse generating circuit according to claim 8, wherein the voltage bias circuit comprises: a first bias circuit and a second bias circuit; The first bias circuit includes a first DC power supply, a first inductor and a first resistor, and is connected to the collector of the first avalanche transistor; The second bias circuit includes a second DC power supply, a second inductor and a second resistor, and is connected to the collector of the second avalanche transistor. 10. The UWB pulse generation circuit according to claim 9, characterized in that: When there is no digital signal input, the first DC power supply charges the first energy storage capacitor through a first voltage bias circuit; The second DC power supply charges the second energy storage capacitor through the second bias circuit.