LU101012B1 - A novel doppler radar circuit structure for suppressing DC bias - Google Patents
A novel doppler radar circuit structure for suppressing DC bias Download PDFInfo
- Publication number
- LU101012B1 LU101012B1 LU101012A LU101012A LU101012B1 LU 101012 B1 LU101012 B1 LU 101012B1 LU 101012 A LU101012 A LU 101012A LU 101012 A LU101012 A LU 101012A LU 101012 B1 LU101012 B1 LU 101012B1
- Authority
- LU
- Luxembourg
- Prior art keywords
- power divider
- signal
- input
- path
- output
- Prior art date
Links
Classifications
-
- 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
- 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
- G01S7/35—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
- G01S7/41—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
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7225—Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation
-
- 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 Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias, wherein a first receiving antenna (1) and a second receiving antenna (2) are connected with input of a first power divider (3), output of the first power divider (3) is connected with input of a second power divider (4), output of the second power divider (4) is connected with a mixer (11); a transmitting antenna (5) is connected in series with a third power divider (6), a fourth power divider (7) and a local oscillator (8) in series; output of the third power divider (6) is divided into two paths: one path is connected with the transmitting antenna (5), and the other path is connected to the input of the second power divider (4) via a variable gain amplifier (9) and a phase shifter (10) which are connected in series; the input of the fourth power divider (7) is connected with a local oscillator (8), and its output is divided into two paths: one path is connected to input of the mixer (11), and the other path is connected with input of the third power divider (6). The present invention reduces implementation complexity and costs of radars on the basis of solving the problem of DC bias.
Description
A NOVEL DOPPLER RADAR CIRCUIT STRUCTURE FOR SUPPRESSING DC BIAS
Field of the Disclosure
The present invention relates to the field of Doppler radar circuits, and more specifically to a Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias.
Background of the Disclosure
Non-contact type vital sign detection based on microwave radar phase modulation action has been already researched many years. To achieve high precision and high robustness, in recent years researchers have been striving to solve some technical challenges. One of main challenges is the problem of DC bias. The DC bias mainly exists in a zero-intermediate frequency receiver structure. Although the structure does not have an issue of mirror frequency interference, local oscillator frequency and radio frequency signal frequency of the structure are equal, so a large DC output will be generated after mixing is performed in the receiver. This is apt to block a baseband amplifier, keeps input of an analog-digital converter at a higher amplitude all the time, and thereby limits a resolution of the analog-digital converter.
With respect to the DC bias problem in the zero-intermediate frequency receiver structure, some people propose a digital low-intermediate frequency receiver structure (see reference [1]), namely, input a local oscillator signal whose frequency is less different from a frequency of the transmitted signal into a mixer for mixing with the received signal, the low-intermediate frequency signal generated after the mixing is sampled by the analog-digital converter, and finally mixing is performed for a second time in a digital field to generate a baseband signal. In this structure, it is necessary to generate two signal sources with different frequencies, and perform mixing twice in the receiver, which makes the structure of the microwave radar more complicated and makes implementation costs of the microwave radar higher.
Based on drawbacks in the conventional radar structures, it is necessary to propose a novel microwave radar structure to further reduce complexity and costs of microwave radars on the basis of solving the problem of DC bias.
[References] [1] Wu Y, Li J. The design of digital radar receivers [J], IEEE Aerospace &Electronic Systems Magazine, 1998, 13(1):35-41.
Summary of the Disclosure
An object of the present invention is to overcome drawbacks in the prior art and provide a Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias, which reduces implementation complexity and costs of radars on the basis of solving the problem of DC bias. It is possible to first reduce the impact of the unmodulated signal via dual receiving antennas at different distances from a transmitting antenna, and then further reduce the impact of the DC bias via the phase shifter.
An object of the present invention is achieved with the following technical solutions.
The Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias according to the present invention comprises a first receiving antenna, a second receiving antenna and a transmitting antenna, the first receiving antenna and second receiving antenna are both connected with input of a first power divider, output of the first power divider is connected with input of a second power divider, and output of the second power divider is connected with a mixer; the transmitting antenna is connected in series with a third power divider, a fourth power divider and a local oscillator in turn; output of the third power divider is divided into two paths: one path is connected with the transmitting antenna, and the other path is connected to the input of the second power divider via a variable gain amplifier and a phase shifter which are connected in series; the input of the fourth power divider is connected with a local oscillator, and its output is divided into two paths: one path is connected to input of the mixer, and the other path is connected with input of the third power divider.
Both the first power divider and second power divider employ a structure with two paths of input and one path of output; both the third powder divider and fourth power divider employ a structure with one path of input and two paths of output.
At a receiving end, distances of the first receiving antenna and second receiving antenna away from the transmitting antenna are <7+z/2and d respectively, signals received by the two receiving antennas are first synthesized by the first power divider, and then synthesized with an output signal of the phase shifter via the second power divider, a finally synthesized signal is mixed with the local oscillator signal, and a baseband signal obtained after the mixing is sampled by a data acquisition card and converted into a digital signal, and processed in a computer; at a transmitting end, a frequency of a signal generated by the signal source of the local oscillator is 2.4GHz, and the signal is divided by the third power divider and fourth power divider into three paths: one path serves as the local oscillator signal, the second path passes through the variable gain amplifier and phase shifter and serves as a DC bias adjusting signal, and the third path serves as a transmitted 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 may solve the DC bias problem, may effectively solve the DC bias problem caused by the transmitted signal by using the dual receiving antennas, and may use the variable gain amplifier and phase shifter to effectively solve the DC bias problem caused by factors such as clutter scattering. (2) The present invention reduces complexity and implementation costs of the radar structure. Since it is unnecessary to generate two signal sources and unnecessary to perform mixing twice in the receiver portion, this reduces design complexity of radars, avoids interference between dual-frequency signals, and meanwhile reduces implementation costs of radars.
Brief Description of Drawings
Fig. 1 is a schematic diagram of a Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias.
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 Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias according to the present invention, as shown in Fig. 1, comprises a first receiving antenna 1, a second receiving antenna 2 and a transmitting antenna 5. The first receiving antenna 1 and second receiving antenna 2 are both connected with input of a first power divider 3, output of the first power divider 3 is connected with input of a second power divider 4, output of the second power divider 4 is connected with a mixer 11, and output of the mixer 11 is connected with a computer 13 via a data acquisition card 12.
The transmitting antenna 5 is connected in series with a third power divider 6, a fourth power divider 7 and a local oscillator 8 in turn. Output of the third power divider 6 is divided into two paths: one path is connected with the transmitting antenna 5, and the other path is connected with a variable gain amplifier 9, the variable gain amplifier 9 is connected with a phase shifter 10, and the phase shifter 10 is connected with input of the second power divider 4. The input of the fourth power divider 7 is connected with a local oscillator 8, and its output is divided into two paths: one path is connected to the input of the mixer 11, and the other path is connected with the input of the third power divider 6.
Wherein both the first power divider 3 and second power divider 4 employ a structure with two paths of input and one path of output. The mixer 11 employs a quadrature mixer; both the third powder divider 6 and fourth power divider 7 employ a structure with one path of input and two paths of output.
At a receiving end, distances of the first receiving antenna 1 and second receiving antenna 2 away from the transmitting antenna 5 are rt+z/2and d respectively. Signals received by the two receiving antennas are first synthesized by the first power divider 3, and then synthesized with an output signal of the phase shifter 10 via the second power divider 4. The finally synthesized signal is mixed with the local oscillator 8 signal, a baseband signal obtained after the mixing is sampled by the data acquisition card 12 and converted into a digital signal, and processed in the computer 13. At a transmitting end, a frequency of a signal generated by the signal source of the local oscillator 8 is 2.4GHz, and the signal is divided by the third power divider 6 and fourth power divider 7 into three paths: one path serves as the signal of the local oscillator 8, the second path passes through the variable gain amplifier 9 and phase shifter 10 and serves as a DC bias adjusting signal, and the third path serves as a transmitted signal.
When the vital sign detection is implemented, a mode of implementing reduction of DC bias specifically goes as follows. Since distances of the first receiving antenna 1 and second receiving antenna 2 away from the transmitting antenna 5 are d and d+λϋ respectively, the unmodulated transmitted signals can cancel each other after being received by the two receiving antennas, and then synthesized by the first power divider 3, which reduces the impact of the DC bias to a certain degree. However, this method cannot thoroughly solve the impact of DC bias, so the phase shift 10 is used to further solve the problem, as analyzed below. With changes of the amplitude of the transmitted signals are neglected, the received signal R1 (Z)is as shown by Equation (1):
In Equation (1), a is an amplitude of the received signal, ω is an angular speed of the received signal, t is time, do is a distance between a detected object and the radar, c is a signal propagation speed, and ψ is a phase change caused by vital sign movements; the second item is a factor leading to DC bias and is caused by factors such as clutter scattering, crosstalk and local oscillator leakage, wherein bi is an amplitude of a clutter signal, and I, is a propagation distance of the clutter signal. A result R2(t) obtained by summating the received signal and the output signal of the phase shifter 10 is as shown by Equation (2):
(2)
In Equation (2), φ is a phase shift value generated by the phase shifter 10, and A is an amplification value of the variable gain amplifier 9. A baseband signal B(t) generated by mixing the signal of Equation (2) with the signal of the local oscillator 8 is as shown by Equation (3):
(3)
It can be seen from Equation (3) that DC components in the baseband signal are the second item and third item, and an AC component is the first item. To remove the DC components, the second item and third item can cancel each other out by adjusting the phase shift value φ of the phase shifter 10, to further solve the DC bias problem.
Embodiment
Models of elements specifically used in the present invention are described below: the local oscillator 8 employs LTC6948IUFD of Analog Devices, Inc. and is
used to generate a signal with a 2.4GHz frequency; the first power divider 3, second power divider 4, third power divider 6 and fourth power divider 7 all employ PD2328J5050S2HF of Anaren, Inc.; the phase shifter 10 employs MAPS-010144-TR0500 of M/A-Com Technology Solution, Inc.; the variable gain amplifier 9 employs ADA4961 of Analog Devices, Inc.; the mixer 11 employs LT5575EUF of Analog Devices, Inc.; the data acquisition card 12 employs a NI USB-6211 data acquisition card of NI Corporation.
Although the present invention is described above with reference to figures, the present invention is not limited to the above. As suggested by the present invention, it is also possible to envisage many forms which all fall within the extent of protection of the present invention.
Claims (3)
1. A Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias, characterized in that the Doppler radar circuit structure comprises a first receiving antenna (1), a second receiving antenna (2) and a transmitting antenna(5), the first receiving antenna (l)and second receiving antenna (2) are both connected with input of a first power divider (3), output of the first power divider (3) is connected with input of a second power divider (4), and output of the second power divider (4)is connected with a mixer(l 1); the transmitting antenna (5)is connected in series with a third power divider (6), a fourth power divider (7) and a local oscillator (8) in turn; output of the third power divider (6) is divided into two paths: one path is connected with the transmitting antenna(5), and the other path is connected to the input of the second power divider(4) via a variable gain amplifier (9)and a phase shifter(lO) which are connected in series; the input of the fourth power divider (7) is connected with a local oscillator (8), and its output is divided into two paths: one path is connected to input of the mixer (11), and the other path is connected with input of the third power divider (6).
2. The Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias according to claim 1, characterized in that both the first power divider (3) and second power divider (4) employ a structure with two paths of input and one path of output; both the third powder divider (6) and fourth power divider (7) employ a structure with one path of input and two paths of output.
3. The Doppler radar circuit structure which has dual receiving antennas and is added a variable gain amplifier and a phase shifter, and suppresses DC bias according to claim 1, characterized in that at a receiving end, distances of the first receiving antenna (l)and second receiving antenna (2) away from the transmitting antenna (5)are d+X/2 and d respectively, signals received by the two receiving antennas are first synthesized by the first power divider (3), and then synthesized with an output signal of the phase shifter (10)via the second power divider (4), a finally synthesized signal is mixed with the signal of the local oscillator (8), and a baseband signal obtained after the mixing is sampled by a data acquisition card (12) and converted into a digital signal, and processed in a computer (13); at a transmitting end, a frequency of a signal generated by the signal source of the local oscillator (8) is 2.4GHz, and the signal is divided by the third power divider (6)and fourth power divider (7) into three paths: one path serves as the signal of the local oscillator (8), the second path passes through the variable gain amplifier (9) and phase shifter (10) and serves as a DC bias adjusting signal, and the third path serves as a transmitted signal.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811094573.XA CN109001691A (en) | 2018-09-19 | 2018-09-19 | A kind of Doppler radar circuit structure of novel inhibition direct current biasing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| LU101012B1 true LU101012B1 (en) | 2019-06-28 |
Family
ID=64592435
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| LU101012A LU101012B1 (en) | 2018-09-19 | 2018-11-23 | A novel doppler radar circuit structure for suppressing DC bias |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN109001691A (en) |
| LU (1) | LU101012B1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110501678B (en) * | 2019-09-29 | 2022-03-04 | 北京无线电测量研究所 | Frequency modulation continuous wave radar transceiver |
| CN110824464A (en) * | 2019-10-25 | 2020-02-21 | 深圳市海纳微传感器技术有限公司 | Microwave sensor and intelligent detection device |
| CN111157961B (en) * | 2020-01-18 | 2024-07-16 | 广东圣大电子有限公司 | Ku wave band multipath radar receiver |
| CN116087892B (en) * | 2023-04-10 | 2023-06-16 | 中山大学 | FMCW-SAR interference method, electronic equipment and storage medium |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003092180A1 (en) * | 2002-04-23 | 2003-11-06 | Fujitsu Limited | Direct conversion receiver |
| WO2013060026A1 (en) * | 2011-10-28 | 2013-05-02 | 华为技术有限公司 | Full-duplex communication device and method |
-
2018
- 2018-09-19 CN CN201811094573.XA patent/CN109001691A/en active Pending
- 2018-11-23 LU LU101012A patent/LU101012B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| CN109001691A (en) | 2018-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| LU101012B1 (en) | A novel doppler radar circuit structure for suppressing DC bias | |
| JP3968370B2 (en) | Radar system using quadrature signal | |
| US10101461B2 (en) | Radio frequency circuit structure for implementing function of converting GNSS satellite signal into baseband signal | |
| EP2454642B1 (en) | Integrated circuit, communication unit and method for phase adjustment | |
| CN108459302A (en) | Modulation Continuous Wave Radar receiving and transmitting front end | |
| Melzer et al. | Real-time mitigation of short-range leakage in automotive FMCW radar transceivers | |
| CN111007469B (en) | Receiver of radar simulator | |
| CN111190144B (en) | Radar device and leakage correction method thereof | |
| US20200326416A1 (en) | Miniaturized digital radar system | |
| CN109361477B (en) | Instantaneous frequency measuring device and measuring method | |
| CN105553495A (en) | Method for receiving frequency band signal above 20GHz in spread spectrum manner through millimeter wave receiver | |
| CN112485768B (en) | High-precision continuous wave speed measuring radar echo simulation method based on frequency division and multiplication mode | |
| Chou et al. | An X-band frequency-modulated continuous-wave radar sensor system with a single-antenna interface for ranging applications | |
| RU2631422C1 (en) | Correlation-phase direction-finder | |
| KR20210074976A (en) | High sensitivity uwb impulse radar and radio receiver | |
| Boukari et al. | A heterodyne six-port FMCW radar sensor architecture based on beat signal phase slope techniques | |
| Baskar et al. | A software defined radar platform for waveform adaptive MIMO radar research | |
| EP3696563A1 (en) | Transmitter-receiver leakage suppression in integrated radar systems | |
| Mercuri et al. | Monostatic continuous-wave radar integrating a tunable wideband leakage canceler for indoor tagless localization | |
| CN104467904A (en) | Millimeter wave receiving and transmitting front end based on receiving and transmitting double-source local oscillators | |
| LU101013B1 (en) | A double frequency continuous wave doppler radar circuit structure for suppressing DC bias | |
| CN109407057B (en) | Signal source of S-band wave-measuring radar | |
| US3766482A (en) | Radiant energy receivers | |
| KR101766765B1 (en) | System for Linear Phase shift Type Reflectometer | |
| CN210075198U (en) | Ka frequency band broadband linear frequency sweep source |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FG | Patent granted |
Effective date: 20190628 |