CN206743204U - Sub- cycle microwave pulse sequence generating device for the manipulation of cold atom quantum state - Google Patents

Abstract

A subperiod microwave pulse sequence generating device manipulated by cold atomic quantum states, including sequentially connected DDS excitation source units, power amplifiers, SRD signal generating and shaping circuits, and broadband antennas; the SRD signal generating and shaping circuits include pulse generating circuits and pulse shaping circuit. The utility model solves the problem that the time interval between the pulses is longer when the sub-period pulse is generated in the past, and the pulse sequence with different time intervals can be obtained by adjusting the DDS, and the pulse generating device is simplified, the operation is simple, and the implementation is easier. It can generate pulses with narrower pulse width (within 100 picoseconds); and by adding a pulse shaping part, it solves the phenomenon of severe tailing of pulses in the past.

Description

Subperiod Microwave Pulse Sequence Generator for Cold Atom Quantum State Manipulation

technical field

The utility model relates to a subperiod microwave pulse sequence generating device.

Background technique

Ultra-wideband technology (UWB) is a new type of microwave communication technology developed in recent years. The ultra-wideband pulse has a bandwidth of several GHz, and its pulse has fast rising and falling edges. Subperiod microwave pulses are ultra-broadband microwave pulses with an oscillation period less than one period. They have the characteristics of strong penetrating power, strong anti-interference ability, wide frequency band, and strong anti-stealth ability. They are very suitable for short-distance communication and have been widely used in Applications such as covert communication, wall-penetrating radar, detection radar, etc. UWB can also be applied to the manipulation of atoms. For example, microwave pulse sequences can be used to act on atoms, and then their quantum states can be manipulated to realize energy level transitions and population transfers of atoms. Interaction studies play an important role.

There are two main methods for generating single-period or sub-period pulses, namely, generating single-period or sub-period pulses based on the avalanche effect of avalanche diodes and generating single-period or sub-period pulses using the tunneling effect of tunnel diodes. . Both of these methods are based on circuit methods, and pulses at the nanosecond and sub-nanosecond levels can be generated using these two methods. However, since these two methods require more components when designing the circuit, the waveform of the pulse will be greatly distorted during transmission, such as pulse tail jitter or ringing is more serious. Therefore, it will bring a lot of inconvenience in the actual research and the practical application of the pulse.

Contents of the invention

The utility model overcomes the above-mentioned shortcomings of the prior art, and provides a subperiod microwave pulse sequence generating device for cold atomic quantum state control.

The sub-period microwave pulse sequence generating device controlled by the quantum state of cold atoms is characterized in that it includes a sequentially connected DDS excitation source unit 1, a power amplifier 2, an SRD signal generation and shaping circuit 3, and a broadband antenna 4; the SRD signal generation And shaping circuit 3 comprises pulse generating circuit 31 and pulse shaping circuit 32;

The pulse generation circuit 31 includes: the positive pole of the DDS excitation source V1 is connected to the first end of the tuning capacitor C1 and the first end of the excitation inductor L1 and connected to the ground, the negative pole of the DDS excitation source V1 is connected to the second end of the tuning capacitor C1, and the step recovery Both the anodes of the diode SRD are grounded; the second end of the excitation inductor L1 is connected to the first end of the first resistor R1, the negative electrode of the SRD and the first end of the first DC blocking capacitor C2, and the second end of the first load resistor R1 is connected to the first DC The positive pole of the bias voltage V2 is connected, and the negative pole of the first DC bias voltage V2 is grounded; the second terminal of the first DC blocking capacitor C2 is connected to the first Schottky diode SCR1 of the pulse shaping circuit 32 as the output terminal of the pulse generating circuit 31 positive electrode;

The pulse shaping circuit 32 includes: the cathode of the first Schottky diode SCR1 is connected to the first end of the second resistor R2 and the first end of the second DC blocking capacitor C3; the second end of the second DC blocking capacitor C3 is connected to the second Schottky The base diode SCR2 negative pole, the first end of the third DC blocking capacitor C4, the first end of the fourth resistor R4; the second end of the third DC blocking capacitor C4 is connected to the first end of the third resistor R3, the fourth resistor R4 The second terminal is connected to the negative pole of the second DC bias voltage V3, the positive pole of the second DC bias voltage V3, the second terminal of the third resistor R3, the second terminal of the second resistor, and the positive pole of the second Schottky diode SCR2 All grounded.

In order to obtain a pulse sequence with a shorter time interval between two adjacent pulses and simplify the sub-period microwave pulse sequence generator and generate a single-period or sub-period microwave pulse with a narrower pulse width, the utility model uses DDS to generate an excitation signal with an adjustable frequency , excite the step recovery diode (SRD) in the pulse generating device to generate a sub-period pulse sequence with a single pulse width at the level of hundreds of picoseconds, and use shaping components and adjustment components to shape the generated pulses, reducing the Due to the loose impedance matching in the circuit and the pulse tail oscillation phenomenon caused by the components, a pulse with a better shape is obtained, thereby obtaining a different pulse sequence.

The technical scheme adopted by the utility model to solve the technical problem is: use the adjustable frequency feature of DDS to generate an excitation signal of a specific frequency, then amplify its power through a power amplifier, and transmit the amplified excitation signal to the step The recovery diode (SRD), using the step current turn-off characteristics of the step recovery diode (SRD), generates a single sub-period microwave pulse sequence with a width of about 100 picoseconds, and adds a pulse generation circuit based on the step recovery diode. A small capacitor of 0.1-0.5pF is used as the tuning capacitor of the circuit to adjust the resonant frequency of the circuit, and then a resistor is added after the pulse generation part, and the Schottky diode is used as the main device of the shaping part to shape the pulse.

The beneficial effects of the utility model are as follows: the utility model solves the problem that the time interval between the pulses is longer when the sub-period pulse is generated in the past, and the pulse sequence with different time intervals can be obtained by adjusting the DDS, and the pulse generating device is simplified. It is easy to operate, easier to implement, and can generate pulses with narrower pulse widths (within 100 picoseconds); and by adding a pulse shaping part, it solves the phenomenon of severe tailing of pulses in the past.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the utility model.

Fig. 2 is the current turn-off characteristic diagram of SRD under sine wave excitation.

Fig. 3 is a circuit diagram of SRD signal generation and shaping circuit.

detailed description:

Below in conjunction with accompanying drawing, the utility model is further described.

The sub-period microwave pulse sequence generating device controlled by the quantum state of cold atoms is characterized in that it includes a sequentially connected DDS excitation source unit 1, a power amplifier 2, an SRD signal generation and shaping circuit 3, and a broadband antenna 4; the SRD signal generation And shaping circuit 3 comprises pulse generating circuit 31 and pulse shaping circuit 32;

The pulse generation circuit 31 includes: the positive pole of the DDS excitation source V1 is connected to the first end of the tuning capacitor C1 and the first end of the excitation inductor L1 and connected to the ground, the negative pole of the DDS excitation source V1 is connected to the second end of the tuning capacitor C1, and the step recovery Both the anodes of the diode SRD are grounded; the second end of the excitation inductor L1 is connected to the first end of the first resistor R1, the negative electrode of the SRD and the first end of the first DC blocking capacitor C2, and the second end of the first resistor R1 is connected to the first DC bias The positive pole of the set voltage V2 is connected, and the negative pole of the first DC bias voltage V2 is grounded; the second terminal of the first DC blocking capacitor C2 is connected to the positive pole of the first Schottky diode SCR1 of the pulse shaping circuit 32 as the output terminal of the pulse generating circuit 31 ;

The pulse shaping circuit 32 includes: the cathode of the first Schottky diode SCR1 is connected to the first end of the second resistor R2 and the first end of the second DC blocking capacitor C3; the second end of the second DC blocking capacitor C3 is connected to the second Schottky The base diode SCR2 negative pole, the first end of the third DC blocking capacitor C4, the first end of the fourth resistor R4; the second end of the third DC blocking capacitor C4 is connected to the first end of the third resistor R3, the fourth resistor R4 The second terminal is connected to the negative pole of the second DC bias voltage V3, the positive pole of the second DC bias voltage V3, the second terminal of the third resistor R3, the second terminal of the second resistor, and the positive pole of the second Schottky diode SCR2 All grounded.

See Figure 1

The utility model subperiod microwave pulse sequence generating device for cold atomic quantum state control includes DDS excitation source unit 1, power amplifier 2, SRD signal generation and shaping circuit 3, broadband antenna 4; the entire pulse sequence generation process includes: The excitation signal of a specific frequency is generated by the DDS excitation source unit 1. The frequency of the signal can be adjusted by the DDS device, and the excitation signal of any frequency can be set, and then the excitation signal is amplified by the power amplifier 2, and then enters the SRD signal generation and The shaping circuit 3 excites and generates a pulse sequence of a specific frequency and shapes the pulse, and finally receives it by the broadband antenna 4 .

See Figure 3

The SRD signal generating and shaping circuit 3 for subperiod microwave pulse generation includes two parts, namely a pulse generating circuit 31 and a pulse shaping circuit 32 .

The working process of the pulse generation circuit 31:

An excitation signal of a specific frequency is generated by the DDS excitation source V1. When the voltage difference between the signal and the first DC bias voltage V2 is negative, the step recovery diode SRD is in the conduction state. At this time, the current flows through the step jump recovery diode SRD and charge it, when the voltage difference between the excitation signal and the first DC bias voltage V2 changes from negative to positive, the current shutdown characteristic of the step recovery diode SRD is used, that is, the step recovery diode The SRD will not cut off immediately, but the current quickly reaches the reverse saturation state and maintains it for a period of time. The time is at the ns level, and then the reverse discharge is performed quickly. The discharge time is at the ps level, so that the reverse current is instantly zero. After that The excitation inductance L1 excites a sub-period microwave pulse at the negative pole of the step recovery diode SRD, the tuning capacitor C1 plays the role of adjusting the resonant frequency of the circuit, and the first resistor R1 plays the role of protecting the circuit. The sub-period pulse generated by this process enters the pulse shaping circuit 32 through the first DC blocking capacitor C2 for shaping.

The working process of the pulse shaping 32 circuit:

The sub-period microwave pulse transmitted by the first DC blocking capacitor C2 passes through the first Schottky diode SCR1, and the first Schottky diode SCR1 only allows the part of the pulse whose voltage amplitude is positive to pass through the first Schottky diode After SCR1, the sub-period microwave pulse removes the negative part of the voltage amplitude, and then passes through the second resistor R2 to attenuate the trailing part of the sub-period microwave pulse, and then passes through the second Schottky diode SCR2, the second Xiao The threshold voltage of the Tertky diode SCR2 is determined by the second DC bias voltage V3, when the voltage value of the second DC bias voltage V3 is adjusted so that the threshold voltage of the second Schottky diode SCR2 is just equal to the sub-period microwave transmitted from the previous stage When the voltage amplitude of the pulse tail part is at the maximum value, the second Schottky diode SCR2 at this time only allows the part of the sub-period microwave pulse whose voltage amplitude is greater than the maximum value to pass through, so after passing through the second Schottky diode SCR2, The tailing phenomenon in the sub-period microwave pulse is basically eliminated, and finally the sub-period microwave pulse whose tailing phenomenon is basically eliminated is received by the broadband antenna through the third DC blocking capacitor C4, the second DC blocking capacitor C3 and the third DC blocking capacitor C4 functions to isolate the DC signal generated by the second DC bias voltage V3, the third resistor R3 acts as a load resistor, and the fourth resistor R4 functions to protect the circuit.

Claims (1)

1. A subperiod microwave pulse sequence generating device manipulated by cold atomic quantum states, characterized in that it includes sequentially connected DDS excitation source units (1), power amplifiers (2), SRD signal generation and shaping circuits (3), and broadband antennas (4); Described SRD signal generation and shaping circuit (3) comprise pulse generating circuit (31) and pulse shaping circuit (32); The pulse generation circuit (31) includes: the positive pole of the DDS excitation source V1 is connected to the first end of the tuning capacitor C1 and the first end of the excitation inductor L1 and connected to the ground, the negative pole of the DDS excitation source V1 is connected to the second end of the tuning capacitor C1, the step The anodes of the jump recovery diode SRD are all grounded; the second end of the excitation inductor L1 is connected to the first end of the first resistor R1, the negative electrode of the SRD and the first end of the first DC blocking capacitor C2, and the second end of the first load resistor R1 is connected to the first end of the first load resistor R1. The positive pole of the DC bias voltage V2 is connected, and the negative pole of the first DC bias voltage V2 is grounded; the second terminal of the first DC blocking capacitor C2 is connected to the first output terminal of the pulse shaping circuit (32) as the output terminal of the pulse generating circuit (31). Anode of Schottky diode SCR1; The pulse shaping circuit (32) includes: the cathode of the first Schottky diode SCR1 is connected to the first end of the second resistor R2 and the first end of the second DC blocking capacitor C3; the second end of the second DC blocking capacitor C3 is connected to the second DC blocking capacitor C3. Schottky diode SCR2 cathode, the first end of the third DC blocking capacitor C4, the first end of the fourth resistor R4; the second end of the third DC blocking capacitor C4 is connected to the first end of the third resistor R3, the fourth resistor The second terminal of R4 is connected to the negative pole of the second DC bias voltage V3, the positive pole of the second DC bias voltage V3, the second terminal of the third resistor R3, the second terminal of the second resistor, and the second Schottky diode SCR2 positive poles are grounded.