GB875315A - Improvements in or relating to radar apparatus - Google Patents
Improvements in or relating to radar apparatusInfo
- Publication number
- GB875315A GB875315A GB20421/59A GB2042159A GB875315A GB 875315 A GB875315 A GB 875315A GB 20421/59 A GB20421/59 A GB 20421/59A GB 2042159 A GB2042159 A GB 2042159A GB 875315 A GB875315 A GB 875315A
- Authority
- GB
- United Kingdom
- Prior art keywords
- frequency
- signal
- sawtooth
- mixer
- modulated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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
- 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
- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
- G01S13/26—Systems for measuring distance only using transmission of interrupted, pulse modulated waves wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
-
- 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
- G01S13/342—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 sinusoidal modulation
-
- 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
- G01S13/343—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 sawtooth modulation
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
875,315. Frequency-modulated radar. PHILIPS ELECTRICAL INDUSTRIES Ltd. June 15, 1959 [June 18, 1958], No. 20421/59. Class 40(7) Relates to a sawtooth frequency-modulated radar in which the beat frequency obtained by heterodyning the received signal with a local oscillation frequency-modulated in the same manner as the transmitted signal is analysied by applying it in parallel to a plurality of differentlytuned wide band-pass filters BF1, BF2 . . . Fig. 1. According to the present invention the signal noise ratio of such a system is improved by additionally modulating the frequency of the transmitted signal to a comparatively small modulation depth by an auxiliary sinusoidal oscillation of stable frequency q greater than the sawtooth frequency, the output from each beat frequency filter BF being applied to an indicator A via a frequency demodulator FD and a filter FH tuned to the frequency q and having a very narrow pass band, e.g. 1 c/s. As shown in Fig. 2 oscillation of frequency p and W m are frequently modulated in modulation FM1 and FM2 by sawtooth and sinusoidal oscillators ZG and GH respectively, the resultant signals, Figs. 2a and 2b, being heterodyned in a mixer Ml to give a resultant sum signal Fig. 2c which is heterodyned in a mixer M2 with a fixed frequency W_ from an oscillator DG. The sum output from the mixer M2 is applied to the transmitting aerial ZA through a gate P which is opened during the first half of each sawtooth period by a multivibrator MV controlled by the sawtooth oscillator ZG, the frequency variation of the intermittent transmitted signal being indicated by waveform D, Fig. 2d. The signal El, Fig. 2d received after reflection at a target is heterodyned in a mixer M3 with the constant frequency W c from the oscillator DG and the resultant difference signal E1, Fig. 2e, is heterodyned in a mixer M4 with the sawtooth frequency-modulated output Z, Fig. 2e, from the modulator FM1 giving an intermittent difference signal F1, Fig. 2f, which is applied in parallel to the band-pass filters BF1, BF2 . . . , the mean frequency #1 of the signal F1 being inversely proportional to range. The purpose of the gate p is to minimize overlap between the transmitted signal D, Fig. 2d, and weak signals from distant targets; with such an arrangement a common aerial may be employed for transmitting and receiving.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL875315X | 1958-06-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB875315A true GB875315A (en) | 1961-08-16 |
Family
ID=19851365
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB20421/59A Expired GB875315A (en) | 1958-06-18 | 1959-06-15 | Improvements in or relating to radar apparatus |
Country Status (3)
| Country | Link |
|---|---|
| DE (1) | DE1084327B (en) |
| FR (1) | FR1227158A (en) |
| GB (1) | GB875315A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015059260A1 (en) * | 2013-10-25 | 2015-04-30 | Rosemount Tank Radar Ab | Frequency modulated radar level gauging |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2981312B2 (en) * | 1991-08-08 | 1999-11-22 | 富士通株式会社 | FM-CW radar device |
| FR2688900B1 (en) * | 1992-03-20 | 1994-05-13 | Thomson Csf | METHOD AND DEVICE FOR DETERMINING THE PASSAGE TO A PRESETTED DISTANCE FROM A REFLECTOR POINT USING THE PROPAGATION TIME OF A CONTINUOUS WAVE. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE855586C (en) * | 1944-01-18 | 1952-11-13 | Patelhold Patentverwertung | Wireless rangefinder |
-
1959
- 1959-06-13 DE DEN16846A patent/DE1084327B/en active Pending
- 1959-06-15 GB GB20421/59A patent/GB875315A/en not_active Expired
- 1959-06-16 FR FR797592A patent/FR1227158A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015059260A1 (en) * | 2013-10-25 | 2015-04-30 | Rosemount Tank Radar Ab | Frequency modulated radar level gauging |
| US9234784B2 (en) | 2013-10-25 | 2016-01-12 | Rosemount Tank Radar Ab | Frequency modulated radar level gauging |
Also Published As
| Publication number | Publication date |
|---|---|
| FR1227158A (en) | 1960-08-19 |
| DE1084327B (en) | 1960-06-30 |
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