Skip to main content

Questions tagged [radar]

Anything related to RADAR (RAdio Detection And Ranging) systems, their operations and circuits. RADAR systems are used to detect and locate a target by sweeping a beam of microwaves across a region of space and detecting echo signals reflected by the target.

Filter by
Sorted by
Tagged with
3 votes
2 answers
70 views

Numbers in Generating Phase Coherent Electronic Systems

I am reading the following paper 'Störmer’s numbers in generating phase coherent electronic systems' written in 1969. More or less I understand that in microwave applications there is clearly a use ...
Mikhail Gaichenkov's user avatar
-1 votes
1 answer
71 views

Active RF signal repeater

I have two stations, A and B. Station A broadcasts a pure 10MHz sinusoidal signal on air. A ...
epsi1on's user avatar
  • 101
0 votes
1 answer
70 views

Phase array for long waves

Can I make phase array for waves that are much longer than the array? For instance, I am looking at 1m array for waves of up to 100m. is it possible?
TQQQ's user avatar
  • 1,347
0 votes
0 answers
67 views

SAR and ISAR sampling time

I'm seeking insight into the typical values of sampling times or refresh rates in radar systems. Specifically, I want to understand the time interval a radar operator must wait to receive new output ...
matteogost's user avatar
0 votes
1 answer
99 views

Radar's radiation inside air traffic control tower [closed]

As a person working in a tower cab on which a ground movement radar is installed, I am curious what the typical power flux density would be inside the cab due its proximity. The frequency of the radar ...
logicWP's user avatar
4 votes
2 answers
550 views

How to determine the Doppler radar frequency required to measure an object moving at a given speed

I'm trying to build a DIY tool to measure the speed of something moving very fast in a straight line, e.g. a bullet exiting the barrel of a rifle, based on the Doppler effect. I've looked for several ...
GuiTeK's user avatar
  • 195
0 votes
1 answer
39 views

Do solid state phased arrays need isolated power supplies?

Non-isolated DC/DC supplies could have higher power density but it seems that high power solid state phased arrays utilize mostly isolated DC/DC converters to power each of their amplifiers. Why are ...
MaxwellEE's user avatar
  • 346
0 votes
1 answer
77 views

What kind of antennas does a modern AESA (e.g. AN/APG-81) use?

The AN/APG-81 has been used on F-35 airplanes. The Wikipedia page give some details about it, including its predecessor and successor. From the image on Wikipedia page, and that for the predecessor AN/...
paki eng's user avatar
  • 703
1 vote
3 answers
154 views

Skills to build an airborne radar [closed]

I am currently working on a project to develop an airborne ground penetrating radar - a payload to be put on a drone - we are aiming to develop a synthetic aperture ground penetrating radar of this ...
Drill_zoo's user avatar
  • 111
0 votes
1 answer
213 views

Keysight vs Tektronix: AWG+RT SigAn or VSG+RT Oscilloscope?

I'm evaluating some new RF hardware for one of my university's research labs, for antenna testing. We are between a Keysight vector signal generator and a real-time oscope versus a Tektronix AWG and a ...
kconway6's user avatar
6 votes
1 answer
343 views

Radar received RF signal phase-shifted by 90 to obtain I/Q signals

I am trying to get idea how marine radar works before start any repairing process. And this part confused me, most articles that i saw explain that in mixing stage we obtain I/Q signals using LO ...
Tremax's user avatar
  • 65
0 votes
1 answer
68 views

Advice on measuring relative speed and position of an active transmitting and reveiving object

Using multiple transmitter/receiver stations on ground and the doppler shift to measure relative velocity and position of an airborne active receiver/transmitter in low altitude (0-2 km). I want to ...
leikqon's user avatar
0 votes
0 answers
437 views

How is Doppler beam sharpening and synthetic aperture forming the same thing?

There's a quote here from Carl Wiley, the inventor of synthetic aperture radar: "I had the luck to conceive of the basic idea, which I called Doppler Beam Sharpening (DBS), rather than Synthetic ...
Robbie Mallett's user avatar
1 vote
0 answers
55 views

Chirp pulse compression as described in Stimson's book

I reference the below diagram, from Stimson's Airborne Radar, 2nd Ed. In the text he discusses how the frequency increases linearly throughout the duration of tau. The sketch of the frequency x time ...
fpd011's user avatar
  • 23
3 votes
2 answers
197 views

LED limit to short pulse and high power

I’m studying the viability of a small footprint distance detector that relies on a LED, a photodetector and some lenses. It’s meant for a distance above 150m, where the light beam travel time is ...
PDuarte's user avatar
  • 1,399
0 votes
0 answers
110 views

SAR: Why can images have complex pixels?

I come from an astronomical long-baseline interferometry background, where images are synthesized from sampled complex visibilities (Fourier components). LBI and polarization can be combined when ...
Nick Elias's user avatar
0 votes
0 answers
119 views

FMCW or FSK radar signal processing using an Arduino Nano

I have been trying to build a car detection system with range measurement using an Arduino Nano, an AgilSense AP88 (this provides I/Q output, butI am using only the I output,) and an MPU4725 DAC (...
Magum23's user avatar
1 vote
1 answer
106 views

Recommendation for 5 V, >2.5 A supply brick with 2.1 mm barrel jack (center positive) power supply

I purchased an AWR1843BOOST automotive radar sensor evaluation module. The power supply must be purchased separately. The specifications say I need a 5 V, >2.5 A supply brick with a 2.1 mm barrel ...
Pankaj Sejwal's user avatar
2 votes
1 answer
566 views

Why doesn't CDM324 (CW doppler radar) work as an FMCW radar when a fluctuating voltage is applied

Yes, I know CDM324 is a doppler radar module, however, Signal Path posted a nice video taking a deep dive into this module and observed that when the VCC applied is varied between 4 and 5 volts there ...
Alek's user avatar
  • 21
0 votes
0 answers
70 views

Is it possible to couple Tx signal to RTL-SDR Rx signal for a FMCW radar?

Above one can see a typical (AFE) diagram for a FMCW. Other block diagrams I found include the processing blocks and and so on as well, but my question rests on the following: can I mix the TX and RX ...
Nick S.'s user avatar
  • 35
0 votes
0 answers
101 views

What is the bandwidth of a radar operating at 5 GHz?

This is the question I have been working on recently. I am trying to figure out how the time-bandwidth product is calculated. If anyone can send me any useful links that I can learn from I'd be very ...
Maxim Kasnedelchev's user avatar
0 votes
3 answers
423 views

What methods can be used for sampling an analog signal using a microcontroller?

I'm in the early stages of design a project I'm working on for fun - a radar speed detector using a simple Doppler radar module and an Arduino (or possibly another similar microcontroller). I've ...
Mac's user avatar
  • 115
1 vote
1 answer
140 views

Basic question about radar

I am learning about automotive radars and have a very basic question about them. If two or more cars on a road have the same radar, using the same radar tech (e.g. CWFM radar) how will one car's radar ...
Radar's user avatar
  • 19
1 vote
1 answer
195 views

What kind of low-cost equipment do I need to learn and experiment with RADAR at home?

I am interested in RADARs. However, I don't have enough time to go to school for studying RADARs. Therefore, I am thinking about self-study. What kind of low-cost equipment do I need to learn and ...
user366312's user avatar
2 votes
0 answers
77 views

A question on radar cross section of rain by using radar reflectivity factor

The question is one of the past exam papers of the RADAR 1 course given in TUDelft, unfortunately, solutions are not provided to the past paper yet. The question: What will be the radar cross-section ...
cn_97's user avatar
  • 29
0 votes
2 answers
78 views

How could you determine the point in time a Radar antenna is directly facing a stationary RF receiver station?

I am currently doing experiments involving Software Defined Radio and Radar systems. Since I am new in this field and currently try to refresh my physics/math skills, I encountered some problems along ...
thehnm's user avatar
  • 3
-3 votes
2 answers
3k views

Is it possible to build radar system for drones detection at home? [closed]

Can I build DIY radar system using ESP32 or Raspberry Pi modules + a bit of soldering that will be able to detect drones in a radius 1-2km? Is it possible? What do I need for this and how much will it ...
Robotex's user avatar
  • 153
1 vote
0 answers
151 views

Range Profile in Radar System

I am slightly confused on the range profile I am obtaining from my SCFW radar dataset. I am understanding of how fftshift works in shifting positive and negative frequency components to be centered ...
Victor Ramirez's user avatar
1 vote
1 answer
186 views

Frequency response of antennas

Electromagnetics and antennas are not my main area of expertise. However, I have a specific question about antennas that I want to get right in order to make sure my signal processing is right. What ...
Jerry's user avatar
  • 11
0 votes
3 answers
157 views

Active Radar Homing with single antenna

From what I remember there are a few A2A and S2A missiles which have their own onboard radar system but I don't think they have multiple radar antennas for phased Array use. I'm curious how radar ...
FourierFlux's user avatar
0 votes
0 answers
51 views

Using LIDAR in a 360-degree configuration

(I do not know an appropriate place for this on Stack Exchange. There does not appear to be any groups dedicated to LIDAR or ranging, so this will do for now. Please let me know if there is a better ...
HFOrangefish's user avatar
4 votes
0 answers
264 views

Creating a Range Profile

I am relatively new to the radar/signal processing community. However, my team has been struggling in developing a range profile in our programming. Here are the details for a NI LabVIEW forum I ...
Victor Ramirez's user avatar
0 votes
2 answers
114 views

Why does an isotropic antenna becomes anisotropic inside a phased array (mutual coupling neglected)?

in this paper the following statement is written: An area A is allotted to each element in the infinite array. This is the maximum area available to each element, and is usually greater than the ...
Kinka-Byo's user avatar
  • 3,550
-2 votes
2 answers
193 views

Radial velocity of two moving targets [closed]

The radial velocity is the velocity which is in the direction of the connecting line. I would like to find the Doppler frequency of two moving targets, but as you know, this frequency only shows me ...
Spider Man 93's user avatar
0 votes
3 answers
175 views

Problem in the book "Radio Antennas and Propagation"

I came across a problem in an electronics textbook by William Gosling, Radio Antennas and Propagation. I am an undergraduate and I sent this to my lecturer to help solve but unfortunately, her answer ...
Finance_sav's user avatar
3 votes
1 answer
776 views

Why are many radar antenna arrays not rectangular but rather octagonal÷icosagonal?

I've seen that, despite some phased array antennas are rectangular, many of them are not. They are octagonal, decagonal and even more. Why are they built in this way?
Kinka-Byo's user avatar
  • 3,550
0 votes
3 answers
101 views

How does the author get to his equation for the ellipse and the antenna's beam?

I am trying to understand how the author of this textbook (Basic Radar Analysis by Mervin C. Budge) realizes the equation for the ellipse shown in the image attached labeled Figure 2.3 (found in ...
VHDLover's user avatar
2 votes
1 answer
130 views

Confusion on what the RF input to a PLL does

I am designing an FMCW radar, for which I need to generate an RF signal ramped in frequency. To accomplish this, I want to use a direct digital synthesizer (DDS) to generate the ramp at baseband then ...
brunerm99's user avatar
2 votes
1 answer
73 views

Can traffic counting be done with just doppler radar?

I'm planning on using radar to count car traffic on a slow speed road. What I'm wondering is if I should expect doppler radar to be good enough to get an accurate count? Alternatively I could also use ...
user avatar
0 votes
2 answers
66 views

Need help with the choice of a motion sensor for use in arctic temperatures

We are a group of students, who are currently investigating how to build a robot that is meant to work at arctic temperatures (peaks at roughly -30 degrees Celsius). We would like to equip our robot ...
Theo85's user avatar
  • 13
0 votes
1 answer
176 views

Why is my clipping circuit involving 1N5819 Schottky diodes in my radar receiver not working?

I have built the circuit shown below and been testing it on a breadboard. Everything works except the positive half clipping circuitry. I need it to clip after 3.3V. It currently just clips below 0V, ...
Ian Edwards's user avatar
0 votes
0 answers
160 views

Low Voltage Oscillation in OpAmp Circuit

I have a small signal from a radar sensor (in the range of 300 µV) which I want to amplify to something I can reliably measure. Fortunately the application notes of the sensor provide a recommended ...
Jocobes's user avatar
  • 33
1 vote
0 answers
155 views

Uniform circular array (UCA) beamforming using FFT

As far as I know, conventional beamforming using FFT can return a range-angle map. However, this only works with a uniform linear array (ULA). I'm wondering if the same approach works for UCA. I guess ...
dondon's user avatar
  • 11
0 votes
1 answer
3k views

How do I compute the angular resolution of a radar system?

I hope this is the right place to ask a radar related question, otherwise I would be grateful for a pointer to the correct forum. I want to compute the angular resolution of a radar system but so far ...
sehan2's user avatar
  • 103
2 votes
3 answers
493 views

What is the difference (and the link) between the RADAR cross section (RCS) and the equivalent area of the target?

Here it is written that: The radar cross section (RCS) σ of a target is the equivalent area seen by a radar. It is the fictitious area intercepting that amount of power which, when scattered equally ...
Kinka-Byo's user avatar
  • 3,550
0 votes
4 answers
2k views

What is the purpose of range gating in a tracking mode of a Radar?

I am trying to understand what happened in the famous incident where the Patriot failed to intercept a Scud missle because of a software bug. The reprot can be found here. Why does the radar need to ...
Artium's user avatar
  • 287
4 votes
2 answers
5k views

Which is the cause of "scan losses" in a linear phased antenna array?

in a linear phased array it is possible to move the peak angle ("beam steering") by applying proper phase shift between the excitation currents: The second picture represents the array ...
Kinka-Byo's user avatar
  • 3,550
2 votes
0 answers
409 views

Pulse Doppler radar system simulation using MATLAB

How to code this project in MATLAB I'd tried coding this project (prob. 3-2, third paragraph) in MATLAB through this tutorial: Doppler Shift and Pulse-Doppler Processing I'd changed PRF to 100 and ...
Ali Ent's user avatar
  • 121
0 votes
1 answer
663 views

STM32 DMA for IQ modulation

I’m trying to develop an application where I use an STM32F405RGT6 microcontroller IC to drive a radar that operates in multiple ISM bands (433.92 MHz, 915 MHz, 2.4 GHz, and 5.8 GHz). The overall idea ...
jerrybenny18's user avatar
1 vote
1 answer
317 views

FMCW Radar Signal Processing based on MIT Open Course

I am working on a self-made FMCW radar - for the signal processing, I am using the MIT open course (https://ocw.mit.edu/resources/res-ll-003-build-a-small-radar-system-capable-of-sensing-range-doppler-...
user267451's user avatar