阅读说明：本技术 一种基于数字相位推算的宽带快速调制域测频方法 (Broadband rapid modulation domain frequency measurement method based on digital phase calculation ) 是由 毛黎明 朱伟 刘强 丁建岽 孙宝征 于 2019-11-14 设计创作，主要内容包括：本发明涉公开了一种基于数字相位推算的宽带快速调制域测频方法,具体涉及频率测量技术领域。该装置包括功率调理单元、功率监测单元、宽带可变分频器、低通滤波器、高速AD采样模块和FPGA,FPGA包括相位推算单元和频率计算单元；信号输入后分为两路,一路进入功率监测单元,另一路进入功率调理单元；功率调理调理单元包括信号放大和衰减,功率调理单元依据功率监测单元的测量数据对信号进行功率调理后,将信号送入宽带可变分频器,宽带可变分频器将信号频率分频至250MHz以下的较低频率,再通过低通滤波器,滤除分频输出的谐波,之后进入高速AD采样模块,将模拟信号变为数字信号送入FPGA进行运算。(The invention discloses a frequency measurement method of a broadband fast modulation domain based on digital phase estimation, and particularly relates to the technical field of frequency measurement. The device comprises a power conditioning unit, a power monitoring unit, a broadband variable frequency divider, a low-pass filter, a high-speed AD sampling module and an FPGA, wherein the FPGA comprises a phase calculation unit and a frequency calculation unit; after the signal is input, the signal is divided into two paths, wherein one path enters a power monitoring unit, and the other path enters a power conditioning unit; the power conditioning unit comprises signal amplification and attenuation, the power conditioning unit is used for conditioning the power of the signal according to the measurement data of the power monitoring unit, then the signal is sent to the broadband variable frequency divider, the broadband variable frequency divider divides the frequency of the signal to a lower frequency below 250MHz, the harmonic wave output by frequency division is filtered by the low-pass filter, and then the signal enters the high-speed AD sampling module, and the analog signal is converted into a digital signal and sent to the FPGA for operation.)

1. A frequency measurement device of a broadband fast modulation domain based on digital phase calculation is characterized by comprising a power conditioning unit, a power monitoring unit, a broadband variable frequency divider, a low-pass filter, a high-speed AD sampling module and an FPGA.

2. The digital phase estimation based broadband fast modulation domain frequency measurement device as claimed in claim 1, wherein the FPGA comprises a phase estimation unit and a frequency calculation unit.

3. A digital phase estimation based wideband fast modulation domain frequency measurement method, which adopts the digital phase estimation based wideband fast modulation domain frequency measurement device of claim 1 or 2, and is characterized by comprising the following steps:

after the signal is input, the signal is divided into two paths, wherein one path enters a power monitoring unit, and the other path enters a power conditioning unit;

the power conditioning unit comprises signal amplification and attenuation, the power conditioning unit is used for conditioning the power of the signal according to the measurement data of the power monitoring unit, then the signal is sent to the broadband variable frequency divider, the broadband variable frequency divider divides the frequency of the signal to a lower frequency below 250MHz, the harmonic wave output by frequency division is filtered by the low-pass filter, and then the signal enters the high-speed AD sampling module, and the analog signal is converted into a digital signal and sent to the FPGA for operation.

4. The digital phase estimation-based frequency measurement method for the broadband fast modulation domain according to claim 3, wherein the specific process of the FPGA for operation is as follows:

assuming that the signal input is a sinusoidal signal, note:

wherein s (t) is the signal to be measured, t is time, A is the signal amplitude, ω is the signal angular frequency,

after broadband frequency division, assuming the frequency division ratio to be N,

wherein, B is the signal amplitude after frequency division;

assume a sampling rate f in high-speed AD acquisition_cThe sampling period is T, and after high-speed AD acquisition, T is_iAnd T_i+1Two time sampling point signals are s_i，s_i+1Is provided with

Suppose the phase of the middle point of two sampling points is

After trigonometric operation, we obtain:

the signal phase is deduced from the signal phase;

then, the frequency is calculated by

Calculating a signal frequency f:

s can be obtained continuously through uninterrupted AD sampling_i，s_i+1Therefore, the signal frequency can be continuously calculated, and the broadband frequency measurement can be realized through broadband variable frequency division.

Technical Field

The invention relates to the technical field of frequency measurement, in particular to a frequency measurement method of a broadband fast modulation domain based on digital phase calculation.

Background

With the development of electronic technology, the frequency domain covered by electronic signals is larger and larger, that is, the signal frequency band is widened, the electronic signals can reach the millimeter wave frequency band, the number of pulses per second is increased, that is, the signal density is increased, the signal modulation types are more and more diversified, complex pulse compression, frequency agile signals, complex time-varying waves and the like exist, and a broadband, high-speed and continuous no-dead-zone frequency measurement technology is needed for accurately analyzing the change relation of the frequency of the signals along with time.

The modulation domain analysis is a visual and effective test means for analyzing the relation of the signal frequency changing along with the time by combining the time parameter in the time domain analysis and the frequency parameter in the frequency domain analysis. The current modulation domain frequency measurement method is a frequency counting method, the principle is shown in fig. 1, after frequency division and shaping, a signal is synchronized with a gate, the frequency of the signal is measured by measuring the signal times of a time counter and an event counter in one gate, and the calculation formula is as follows:

wherein, the event count is M, and the time count is N. Gate time Tg, period of time base signal T₀Frequency of f₀。

In order to improve the frequency measurement precision, an interpolation technology is also needed, an analog interpolation method and a digital interpolation method are usually adopted, the interpolation speed is limited, the frequency measurement time of the analog interpolation method is generally more than 1us, the frequency measurement time of the digital interpolation method is generally more than 100ns, and the fastest frequency measurement time of the existing modulation domain analyzer is 100 ns.

Disclosure of Invention

The invention aims to provide a digital phase estimation-based broadband rapid modulation domain frequency measurement method which can realize broadband high-speed frequency measurement by combining a broadband frequency division technology and digital phase estimation.

The invention specifically adopts the following technical scheme:

a frequency measurement device of a broadband fast modulation domain based on digital phase calculation comprises a power conditioning unit, a power monitoring unit, a broadband variable frequency divider, a low-pass filter, a high-speed AD sampling module and an FPGA.

Preferably, the FPGA includes a phase estimation unit and a frequency calculation unit.

A frequency measurement method of a broadband fast modulation domain based on digital phase estimation adopts the frequency measurement device of the broadband fast modulation domain based on digital phase estimation, and comprises the following steps:

after the signal is input, the signal is divided into two paths, wherein one path enters a power monitoring unit, and the other path enters a power conditioning unit;

the power conditioning unit comprises signal amplification and attenuation, the power conditioning unit is used for conditioning the power of the signal according to the measurement data of the power monitoring unit, then the signal is sent to the broadband variable frequency divider, the broadband variable frequency divider divides the frequency of the signal to a lower frequency below 250MHz, the harmonic wave output by frequency division is filtered by the low-pass filter, and then the signal enters the high-speed AD sampling module, and the analog signal is converted into a digital signal and sent to the FPGA for operation.

Preferably, the specific process of the FPGA for operation is as follows:

assuming that the signal input is a sinusoidal signal, note:

wherein s (t) is the signal to be measured, t is time, A is the signal amplitude, ω is the signal angular frequency,

is the initial phase;

after broadband frequency division, assuming the frequency division ratio to be N,

wherein, B is the signal amplitude after frequency division;

assume a sampling rate f in high-speed AD acquisition_cThe sampling period is T, and after high-speed AD acquisition, T is_iAnd T_i+1Two time sampling point signals are s_i，s_i+1Is provided with

Suppose the phase of the middle point of two sampling points isIs provided with

After trigonometric operation, we obtain:

the signal phase is deduced from the signal phase;

then, the frequency is calculated by

Calculating a signal frequency f:

s can be obtained continuously through uninterrupted AD sampling_i，s_i+1Therefore, the signal frequency can be continuously calculated, and the broadband frequency measurement can be realized through broadband variable frequency division.

The invention has the following beneficial effects:

the scheme combines the broadband frequency division technology and the digital phase calculation, can realize the broadband high-speed frequency measurement, has the frequency measurement bandwidth of more than 1 octave and the frequency measurement time of less than 10ns, can realize the continuous frequency measurement without dead zones,

drawings

FIG. 1 is a schematic diagram of a conventional modulation domain frequency measurement method;

fig. 2 is a schematic diagram of a wideband fast modulation domain frequency measurement method based on digital phase estimation.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings:

FPGA (Field-Programmable Gate Array), i.e. a Field Programmable Gate Array.

As shown in fig. 2, a wideband fast modulation domain frequency measurement device based on digital phase estimation includes a power conditioning unit, a power monitoring unit, a wideband variable frequency divider, a low-pass filter, a high-speed AD sampling module, and an FPGA, where the FPGA includes a phase estimation unit and a frequency calculation unit;

a frequency measurement method of a broadband fast modulation domain based on digital phase estimation adopts the frequency measurement device of the broadband fast modulation domain based on digital phase estimation, and comprises the following steps:

after the signal is input, the signal is divided into two paths, wherein one path enters a power monitoring unit, and the other path enters a power conditioning unit;

the power conditioning unit comprises signal amplification and attenuation, the power conditioning unit is used for conditioning the power of the signal according to the measurement data of the power monitoring unit, then the signal is sent to the broadband variable frequency divider, the broadband variable frequency divider divides the frequency of the signal to a lower frequency below 250MHz, the harmonic wave output by frequency division is filtered by the low-pass filter, and then the signal enters the high-speed AD sampling module, and the analog signal is converted into a digital signal and sent to the FPGA for operation.

The specific process of the FPGA for operation is as follows:

assuming that the signal input is a sinusoidal signal, note:

where s (t) is the signal to be measured and t isTime, A is the signal amplitude, ω is the signal angular frequency,

is the initial phase.

After broadband frequency division, assuming the frequency division ratio to be N,

wherein, B is the signal amplitude after frequency division.

Assume a sampling rate f in high-speed AD acquisition_cThe sampling period is T, and after high-speed AD acquisition, T is_iAnd T_i+1Two time sampling point signals are s_i，s_i+1Is provided with

Suppose the phase of the middle point of two sampling points is

Is provided with

After trigonometric operation, we obtain:

the signal phase is deduced from the signal phase;

then, the frequency is calculated by

Calculating a signal frequency f:

s can be obtained continuously through uninterrupted AD sampling_i，s_i+1Therefore, the signal frequency can be continuously calculated, and the broadband frequency measurement can be realized through broadband variable frequency division.

If the AD sampling frequency is 500MHz and the sampling period is 2ns, the signal frequency can be calculated by sampling two points, namely 4ns can be measured. Wideband frequency measurement may be achieved by wideband variable frequency division, the division ratio may be divided as in table 1:

TABLE 1

Frequency range	Divide ratio selection	Frequency after frequency division
			1GHz～3GHz	20	50MHz～150MHz
3GHz～9GHz	60	50MHz～150MHz
			9GHz～27GHz	180	50MHz～150MHz

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.