LU101014B1 - A double sideband doppler radar structure with phase shifter added at output of local oscillator - Google Patents

A double sideband doppler radar structure with phase shifter added at output of local oscillator Download PDF

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Publication number
LU101014B1
LU101014B1 LU101014A LU101014A LU101014B1 LU 101014 B1 LU101014 B1 LU 101014B1 LU 101014 A LU101014 A LU 101014A LU 101014 A LU101014 A LU 101014A LU 101014 B1 LU101014 B1 LU 101014B1
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input
mixer
power divider
signal
local oscillator
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LU101014A
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German (de)
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Jianguo Ma
Shaohua Zhou
Zikai Yang
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Univ Tianjin
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/03—Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/08—Systems for measuring distance only
    • G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
    • G01S13/347—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal using more than one modulation frequency
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/28—Details of pulse systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/28—Details of pulse systems
    • G01S7/285—Receivers
    • G01S7/292—Extracting wanted echo-signals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G01S7/354—Extracting wanted echo-signals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/36—Means for anti-jamming, e.g. ECCM, i.e. electronic counter-counter measures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
    • G01S7/415—Identification of targets based on measurements of movement associated with the target
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
    • A61B5/0507—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves using microwaves or terahertz waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/03—Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
    • G01S7/034—Duplexers

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

The present invention discloses a double sideband Doppler radar structure with a phase shifter added at output of a local oscillator, comprising a receiving antenna (8) and a transmitting antenna (7), wherein the receiving antenna (8) is connected in series with a low noise amplifier (9), a first receiver mixer (10) and a second receiver mixer (11) in turn; the transmitting antenna (7) is connected with a transmitter mixer (6), a first power divider (2) is connected between input of the transmitter mixer (6) and input of the first receiver mixer (10), and a second power divider (4) and a phase snifter (5) are connected between input of the transmitter mixer (6) and input of the second receiver mixer (11), wherein input of the first power divider (2) is connected with a first voltage-controlled oscillator (1), and input of the second power divider (4) is connected with a second voltage-controlled oscillator (3). According to the present invention, it is unnecessary to adjust the frequency of the local oscillator when the distance between the radar and the detected object changes, thereby reducing the complexity and implementation costs of the double sideband Doppler radar.

Description

A DOUBLE SIDEBAND DOPPLER RADAR STRUCTURE WITH
PHASE SHIFTER ADDED AT OUTPUT OF LOCAL OSCILLATOR
Field of the Disclosure
The present invention relates to the field of Doppler radars, and more specifically to a double sideband Doppler radar structure with a phase shifter added at output of a local oscillator.
Background of the Disclosure
Microwave Doppler radars are already applied many years as a wireless sensor. They are often applied to aspects such as volume change detection (see reference [1]), after-disaster rescue (see reference [2]) and cardiopulmonary monitoring of sleep apnea hypopnea syndrome (see reference [3]). As compared with a conventional contact-type sensor, the microwave Doppler radar needn’t directly contact a detected object, so it does not affect physiological activities of the detected object, nor does it cause uncomfortable feeling to the detected object, which substantially expands the application space of the microwave Doppler radars. Since Lin et al. attempts to use the microwave Doppler radar to detect a person’s physiological movement (including breathing and heat beat) for the first time, microwave Doppler radars already attract so much attention as non-contact type vital sign monitoring system (see reference [4]).
After decades of research, many scientific research achievements have been achieved in vital sign detection based on the continuous wave Doppler radar. It is found in initial research that there exists a zero point problem with the receiver structure using a single-channel mixer, which seriously reduces a measurement precision (see reference [5]) of the radar. Regarding the zero point problem, people sequentially propose a receiver structure (see reference [6]) of quadrature mixing and frequency adjustment technology (see reference [7]) based on transmitting double sidebands. As compared with the quadrature mixing demodulation structure, the frequency adjustment technology based on the double sidebands needn’t generate quadrature local oscillator signal, and does not need a mirror suppress filter and an intermediate frequency filter (see reference [8]), which reduces complexity and implementation costs of the Doppler radar structure. However, there is still a drawback in the double-sideband Doppler radar structure, i.e., when the distance between the radar and the detected object changes, the frequency in the intermediate-frequency local oscillator needs to be adjusted. However, adjusting the frequency of the local oscillator is complicated in hardware implementation and costly.
Based on drawbacks in the prior art, it is necessary to propose an improved double sideband Doppler radar structure, to solve the drawbacks of the conventional double-sideband radar structures.
[References] [1] Lin J C. Microwave sensing of physiological movement and volume change: a review. [J]. Bioelectromagnetics, 1992, 13(6):557-565.
[2] Chen K M, Huang Y, Zhang J, et al. Microwave life-detection systems for searching human subjects under earthquake rubble or behind barrier [J], Biomedical Engineering IEEE Transactions on, 2000, 47(1):105-114.
[3] Droitcour A, Lubecke V, Lin J, et al. A microwave radio for Doppler radar sensing of vital signs[C]. Microwave Symposium Digest, 2001 IEEE MTT-S International. IEEE, 2001:175-178 vol.l.
[4] Xiao Y, Lin J, Boric-Lubecke O, et al. A Ka-Band Low Power Doppler Radar System for Remote Detection of Cardiopulmonary Motion[J], 2005, 7:7151-7154.
[5] Droitcour A D, Boric-Lubecke O, Lubecke V M, et al. Range correlation effect on ISM band EQ CMOS radar for non-contact vital signs sensing[C], Microwave Sym-posium Digest, 2003 IEEE MTT-S International. IEEE, 2003:1945-1948 vol.3.
[6] Droitcour A D, Boric-Lubecke O, Lubecke V M, et al. Range correlation and I/Q per-formance benefits in single-chip silicon Doppler radars for noncontact cardiopulmo-nary monitoring[J]. Microwave Theory & Techniques IEEE Transactions on, 2004, 52(3):838-848.
[7] Li C, Lin J, Xiao Y. Robust Overnight Monitoring of Human Vital Sign by a Non-contact Respiration and Heartbeat Detector[J]. 2006, 1:2235-2238.
[8] Xiao Y, Lin J, Boric-Lubecke O, et al. Frequency-tuning technique for remote detection of heartbeat and respiration using low-power double-sideband transmission in the ka-band[J]. IEEE Transactions on Microwave Theory & Techniques, 2006, 54(5):2023-2032.
Summary of the Disclosure
An object of the present invention is to overcome drawbacks in the prior art and provide a double sideband Doppler radar structure with a phase shifter added at output of a local oscillator, by which it is unnecessary to adjust the frequency of the local oscillator when the distance between the radar and the detected object changes, thereby reducing the complexity and implementation costs of the double sideband Doppler radar.
An object of the present invention is achieved with the following technical solutions.
The double sideband Doppler radar structure with a phase shifter added at output of a local oscillator according to the present invention comprises a receiving antenna and a transmitting antenna, the receiving antenna is connected in series with a low noise amplifier, a first receiver mixer and a second receiver mixer in turn; the transmitting antenna is connected with a transmitter mixer, a first power divider is connected between input of the transmitter mixer and input of the first receiver mixer, a second power divider and a phase shifter are connected between input of the transmitter mixer and input of the second receiver mixer, input of the first power divider is connected with a first voltage-controlled oscillator, and input of the second power divider is connected with a second voltage-controlled oscillator.
Output of the second power divider is divided into two paths: one path is connected with input of the second receiver mixer via a phase shifter, and the other path is connected with input of the transmitter mixer; output of the first power divider is divided into two paths: one path is connected with input of the first receiver mixer, and the other path is connected with input of the transmitter mixer.
The second voltage-controlled oscillator is used to generate a radio frequency signal L^t) having a frequency ƒ, the signal passes through the second power divider and is divided into two paths: one path is used as a transmitted signal, and the other path passes through the phase shift and then is used as a local oscillator signal; then, the first voltage-controlled oscillator is used to generate a radio frequency signal L2(t) having a frequency ƒ>, the signal passes through the first power divider and is divided into two paths: one path is used as a local oscillator signal, and the other path is used as a transmitted signal, which is mixed with the transmitted signal generated by the second voltage-controlled oscillator in the transmitter mixer; the signal after the mixing is transmitted through the transmitting antenna. At a receiving end, the antenna receives a body-modulated signal, then the signal is amplified by a low noise amplifier, and then mixed with the local oscillator signal L2(t) generated by the first voltage-controlled oscillator in the first receiver mixer, then finally mixed with the local oscillator signal Z-i(t) generated by the second voltage-controlled oscillator in the second receiver mixer, to obtain a baseband signal.
As compared with the prior art, the technical solution of the present invention may bring about the following advantageous effects: (1) The present invention implifies the operation method of the double-sideband Doppler radar. It is only necessary to change the phase shift value of the phase shifter when the distance between the radar and the detected object changes. This operates simpler than the adjustment of the frequency of the local oscillator. (2) The present invention needn’t change the value of the frequency of the local oscillator any more, simplifies the design of the local oscillator, reduces the complexity of the whole radar structure, and also allows for lower implementation costs of the radar. 1
Brief Description of Drawings
Fig. 1 is a schematic diagram of a double sideband Doppler radar structure with a phase shifter added at output of a local oscillator according to the present invention.
Detailed Description of Preferred Embodiments
The present invention will be further described with reference to figures to more clearly illustrate the technical solution of the present invention. Those having ordinary skill in the art may further obtain other figures according to these figures without making any inventive efforts.
The double sideband Doppler radar structure with a phase shifter added at output of a local oscillator according to the present invention comprises a receiving antenna 8 and a transmitting antenna 7, the receiving antenna 8 is connected in series with a low noise amplifier 9, a first receiver mixer 10 and a second receiver mixer 11 in turn. The transmitting antenna 7 is connected with a transmitter mixer 6, a first power divider 2 is connected between input of the transmitter mixer 6 and input of the first receiver mixer 10, a second power divider 4 and a phase shifter 5 are connected between input of the transmitter mixer 6 and input of the second receiver mixer 11, input of the first power divider 2 is connected with a first voltage-controlled oscillator 1, and input of the second power divider 4 is connected with a second voltage-controlled oscillator 3.
Specifically, output of the first power divider 2 is divided into two paths: one path is connected with input of the first receiver mixer 10, and the other path is connected with input of the transmitter mixer 6. Output of the second power divider 4 is divided into two paths: one path is connected with input of the second receiver mixer 11 via a phase shifter 5, and the other path is connected with input of the transmitter mixer 6.
The second voltage-controlled oscillator 3 is used to generate a radio frequency
I signal L}(t) having a frequency ƒ, the signal passes through the second power divider 4 and is divided into two paths: one path is used as a transmitted signal, and the other path passes through the phase shift 5 and then is used as a local oscillator signal; then, the first voltage-controlled oscillator 1 is used to generate a radio frequency signal Lyit) having a frequency fi, the signal passes through the first power divider 4 and is divided into two paths: one path is used as a local oscillator signal, and the other path is used as a transmitted signal, which is mixed with the transmitted signal generated by the second voltage-controlled oscillator 3 in the transmitter mixer 6; the signal after the mixing is transmitted through the transmitting antenna 7. At a receiving end, the antenna receives a body-modulated signal, then the signal is amplified by a low noise amplifier 9, and then mixed with the local oscillator signal Z2(z) generated by the first voltage-controlled oscillator 1 in the first receiver mixer 10, then finally mixed with the local oscillator signal Li(t) generated by the second voltage-controlled oscillator 3 in the second receiver mixer 11, to obtain a desired baseband signal. To minimize the residual phase noise of the baseband signal after the mixing, two local oscillator chips (the first voltage-controller oscillator 1 and second voltage-controlled oscillator 3) are driven with the same crystal oscillator.
It is assumed that the frequency of the local oscillator signal L](t) generated by the second voltage-controlled oscillator 3 is ƒ, as shown by Equation (1):
where t is time.
It is assumed that the frequency of the local oscillator signal Z2(r) generated by the first voltage-controlled oscillator 1 is /2, as shown by Equation (2):
At the transmitter portion, local oscillator signals generated by the two local oscillators perform mixing, and frequencies of the obtained mixed signal L(t) snà.f2+fi respectively, as shown by Equation (3):
I
It is assumed thatfy=fi+f J~l= kL=dfL, wherein c is a propagation speed of the signal. At the receiver portion, after down conversion for the first time, the received signal £,(/) is as shown by Equation (4):
(4)
In Equation (4), do is a distance between the radar and a detected object, and x(t) is a person’s thoracic cavity motion. Down conversion is performed for R](t) for a second time. Since the output of the first local oscillator is added a phase shifter 5, if a phase shift value is φ, a baseband signal B(t) output by the down conversion of the second time is as shown by Equation (5):
(5)
According to document [8],let0H = ^7^ + φ, 0L = ^-7^· — φ, an analysis result xh xl is as shown by the following Equation (6):
(6)
When ΘΗ - 0L is equal to the result of Equation (6), a measurement result is at the optimal position, namely, the measurement result is most accurate. When a value of ΘΗ - 0L is not equal to the result of Equation (6), the phase shift value φ of the phase shifter 5 is adjusted to make ΘΗ -θΕ=Κπ +—, k = 0, ±1, ±2,.... As compared with the previous adjustment of the frequency of the local oscillator, directly adjusting the phase shift value φ of the phase shifter 5 operates more simply and causes lower costs.
Embodiment
Models of elements specifically used in the present invention are described below: the first voltage-controlled oscillator 1 and second voltage-controlled oscillator
3 both employ LTC6948IUFD of Analog Devices, Inc., a frequency ƒ> generated by the first voltage-controlled oscillator 1 is 2.14GHz; a frequency fi generated by the second voltage-controlled oscillator 3 is 1,2GHz; the first power divider 2 and second power divider 4 both employ PD0409J7575S2HF of Anaren, Inc.; the low noise amplifier 9 employs HMC374ETR of Analog Devices, Inc.; the first receiver mixer 10, the second receiver mixer 11 and the transmitter mixer 6 all employ LT5522EUF#PBF of Analog Devices, Inc.; the phase shifter 5 employs HMC936A of Analog Devices, Inc.
Although functions and operation process of the present invention are described above with reference to figures, the present invention is not limited to the above specific functions and operation process. The above specific implementation modes are only exemplary and unrestrictive. Those having ordinary skill in the art, as suggested or taught by the present invention, may further envisage many forms without departing from the essence of the present invention and extent of protection of claims, and all these forms fall within the extent of protection of the present invention.

Claims (3)

1. Doppelseitenband-Doppler-Radarstruktur mit einem an dem Ausgang eines lokalen Oszillators addierten Phasenschieber, dadurch gekennzeichnet, dass die Radarstruktur eine Empfangsantenne (8) und eine Sendeantenne (7) umfaßt, wobei die Empfangsantenne (8) mit einem rauscharmen Verstârker (9), einem ersten Empfangermischer (10) und einem zweiten Empfangermischer (11) hintereinander in Reihe verbunden ist, wobei die Sendeantenne (7) mit einem Sendermischer (6) verbunden ist, und ein erster Leistungsteiler (2) zwischen den Eingang des Sendermischers (6) und den Eingang des ersten Empfangermischers (10) geschaltet ist, und ein zweiter Leistungsteiler (4) und ein Phasenschieber (5) zwischen den Eingang des Sendermischers (6) und den Eingang des zweiten Empfangermischers (11) geschaltet sind, und wobei der Eingang des ersten Leistungsteilers (2) mit einem ersten spannungsgesteuerten Oszillator (1) verbunden ist, und der Eingang des zweiten Leistungsteilers (4) mit einem zweiten spannungsgesteuerten Oszillator (3) verbunden ist.1. A double sideband Doppler radar structure comprising a phase shifter added at the output of a local oscillator, characterized in that the radar structure comprises a receiving antenna (8) and a transmitting antenna (7), the receiving antenna (8) being connected to a low-noise amplifier (9). a series-connected first receiver mixer (10) and a second receiver mixer (11), the transmitter antenna (7) being connected to a transmitter mixer (6) and a first power divider (2) connected between the transmitter mixer (6) input and the input of the first receiver mixer (10) is connected, and a second power divider (4) and a phase shifter (5) are connected between the input of the transmitter mixer (6) and the input of the second receiver mixer (11), and wherein the input of the first power divider (2) with a first voltage-controlled oscillator (1) is connected, and the input of the second power divider (4) with a second Spannungsgesges expensive oscillator (3) is connected. 2. Doppelseitenband-Doppler-Radarstruktur mit einem an dem Ausgang eines lokalen Oszillators addierten Phasenschiebemach Anspruch 1, dadurch gekennzeichnet, dass der Ausgang des zweiten Leistungsteilers (4) in zwei Pfade aufgeteilt ist: ein Pfad über einen Phasenschieber(5) mit dem Eingang des zweiten Empfangsmischers (11) verbunden ist, und der andere Pfad mit dem Eingang des Sendermischers (6) verbunden ist, und dass der Ausgang des ersten Leistungsteilers (2) in zwei Pfade unterteilt ist: ein Pfad mit dem Eingang des ersten Empfângermischers (10) verbunden ist, und der andere Pfad mit dem Eingang des Sendermischers (6) verbunden ist.A double sideband Doppler radar structure comprising a phase shifter added at the output of a local oscillator according to claim 1, characterized in that the output of the second power divider (4) is divided into two paths: a path through a phase shifter (5) to the input of the first second receiving mixer (11) is connected, and the other path is connected to the input of the transmitter mixer (6), and that the output of the first power divider (2) is divided into two paths: a path to the input of the first receiver mixer (10) is connected, and the other path is connected to the input of the transmitter mixer (6). 3. Doppelseitenband-Doppler-Radarstruktur mit einem an dem Ausgang eines lokalen Oszillators addierten Phasenschieber nach Anspruch 1, dadurch gekennzeichnet, dass der zweite spannungsgesteuerte Oszillator (3) verwendet wird, um ein Radiofrequenzsignal Ll(t) mit einer Frequenz fl zu erzeugen, das den zweiten Leistungsteiler (4) durchläuft und in zwei Pfade unterteilt ist: ein Pfad als Sendesignal verwendet ist und der andere Pfad die Phasenschieber(5) durchläuft und dann als ein lokales Oszillatorsignal verwendet wird, und dann der erste spannungsgesteuerte Oszillator (1) verwendet wird, um ein Radiofrequenzsignal L2(t) mit einer Frequenz f2 zu erzeugen, das den ersten Leistungsteiler (2) durchläuft und in zwei Pfade unterteilt ist: ein Pfad als ein lokales Oszillatorsignal verwendet wird und der andere Pfad als ein Sendesignal verwendet wird, das mit dem von dem zweiten spannungsgesteuerten Oszillator (3) im Sendemischer (6) erzeugten Sendesignal gemischt wird, wobei das Signal nach dem Mischen durch die Sendeantenne (7) gesendet wird, wobei an einem Empfangsende die Antenne ein kôrpermoduliertes Signal empfangt, das dann durch einen rauscharmen Verstârker (9) verstârkt und dann mit dem von dem ersten spannungsgesteuerten Oszillator (1) im ersten Empfangermischer (10) erzeugten lokalen Oszillatorsignal L2(t) gemischt wird, und dann schließlich mit dem von dem zweiten spannungsgesteuerten Oszillator (3) in dem zweiten Empfangermischer (11) erzeugten lokalen Oszillatorsignal Ll(t) gemischt wird, um ein Basisbandsignal zu erhalten.3. A double-sideband Doppler radar structure comprising a phase shifter added at the output of a local oscillator according to claim 1, characterized in that the second voltage-controlled oscillator (3) is used to generate a radio-frequency signal Ll (t) having a frequency fl passes through the second power divider (4) and is divided into two paths: one path is used as a transmission signal and the other path passes through the phase shifters (5) and then is used as a local oscillator signal and then the first voltage controlled oscillator (1) is used to generate a radio frequency signal L2 (t) having a frequency f2 that passes through the first power divider (2) and is divided into two paths: one path is used as a local oscillator signal and the other path is used as a transmission signal with the transmission signal generated by the second voltage-controlled oscillator (3) in the transmitter mixer (6) is mixed, the signal nac h is sent to the mixing by the transmitting antenna (7), wherein at a receiving end the antenna receives a body-modulated signal which is then amplified by a low noise amplifier (9) and then coupled to that of the first voltage controlled oscillator (1) in the first receiver mixer (10 ), and then finally mixed with the local oscillator signal Ll (t) generated by the second voltage controlled oscillator (3) in the second receiver mixer (11) to obtain a baseband signal.
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