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.

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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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?
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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 ...
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2 votes
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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 ...
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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 ...
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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 ...
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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, ...
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FMCW radar sensor for vital sign signal processing

In order to get started with radar signal processing in MATLAB, I want to capture the heart frequency and respiration of a person with a FMCW radar. I only want to do post signal processing in MATLAB, ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 : https://www.mathworks.com/help/phased/ug/doppler-shift-and-pulse-doppler-...
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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 ...
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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-...
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Friendly target identification in radar

Crossposted from Signal Processing stack exchange, How do radar systems identify friendly targets to avoid AA locks during combat scenarios? Do friendly planes broadcast a known signal or is something ...
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How to plug CAN Bus radar to Pixhawk Cube Orange flight controller?

I want to plug my radar (which is a CAN Bus) to my Pixhawk flight controller. (https://ardupilot.org/copter/docs/common-thecubeorange-overview.html)I bought the radar from China and the site i bought ...
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Is the impulse response of a real system is always a real function?

As stated in the title, is the impulse response of a real system is always a real function? Can it ever be complex/analytic, etc.? I'm more interested in terms of radar systems. Any info would be ...
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Estimating Safe Pulsed RF Power given Continuous Wave Power Rating

For a university project I am designing a RADAR transmit/receive module at 9.4 GHz. Right now I'm working on an input power limiter to protect an LNA, but my colleague designing the LNA quotes its ...
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Building a 77GHz Band FMCW Radar with 0.25 Degree Angular Resolution

First some context. My group recently acquired some hardware for a radar related project, specifically a Texas Instrument AWR1843Boost (https://www.ti.com/tool/AWR1843BOOST) and a Texas Instruments ...
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1 vote
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FMCW radar FFT(Fast Fourier Transform)

I am trying to design a simple FMCW radar for the ideal case. Below are steps I planned. Transmit signal, Tx = cos(T) receive signal, Rx = cos(R) Mix transmitted signal and received signal, Sx1 = cos(...
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What is beam coupling coefficient for linear beam klystron?

What does beam coupling coefficient exactly tell? For eg. a voltage gain coefficient tells how much times the input was amplified. So what does beam coupling coefficient tell, like does it tell how ...
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Typical power reflected off wall/window/wooden shelves etc

For interference purposes, I would like to quantify how much signal power I would receive back when my transmitted signal is reflected off an object (a wall, glass window, wooden shelf) at a distance ...
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2 votes
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Feasibility of rat-race as RF mixer without active devices

My understanding is that RF mixers generally use some sort of active device (sometimes diodes) to produce output rich in harmonics, and rat-race couplers can be used to get the sum or difference ...
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Finding a material transparent to 26GHz radio waves for radome protecting a radar rangefinder probe

I want to use a 26GHz radar probe to measure water levels for some outdoors applications. These are pretty common devices, one manufacturer among many others is for example: https://en.supmea.com/...
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HB100 Range extension with Dish Antenna

I have interfaced HB100 sensor with ATMega Microcontroller. It easily detects my hand movement upto 5-6 inches only. I want to extend range of the sensor so that it detect movement upto atleast ...
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Why does medical ultrasound use pulses instead of chirps?

My background is in radar where it's quite common to use chirped excitation signals (i.e. pulse compression). I have noticed that this method seems to not be used in medical ultrasound. Why not?
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How do we tell distance to target at the receiver from frequency modulation?

Was thinking about radar and how to tell distance using FM. If you send a wave with a consistent wavelength of 1 meter, and it hits a target 1000 meters away and then comes back, it will have gone ...
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How does stretch processing work for SFCW?

I've been reading about FMCW radar, and I understand that a chirped signal can be de-chirped by mixing it with a copy of itself, which yields a beat frequency which is much easier to process and is ...
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1 vote
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Best waveform for Radar

I was wondering what would be the best waveform to generate for a phased array short range imaging radar? Square, sine, etc. Also what frequency would be best to operate at for the carrier wave given ...
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IC / logo identification: 5.8 GHz radar MMIC marked "5810"

Can anyone identify the pictured IC or the manufacturer logo on it? It's a 5.8 GHz radar MMIC with 1 Tx, 1 Rx, PLL, power amplifier, mixer, and low noise amplifier, presumably from an Asian ...
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How to calculate Doppler Shift for multipaths from moving objects?

Let's say we have a radar where the transmitter and receiver are placed together, and form an angle theta with a target object moving with velocity ...
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Why use convolution for pulse compression in radar instead of correlation?

I have not understood the way to process pulse compression in radar signal processing. I think it's correct to use correlation for pulse compression, but I saw many materials about pulse compression. ...
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Resonant Radar -- How aspect independent is it? [closed]

Resonant Radar: transmitting at a bandwidth that encapsulates nearly the natural resonance frequency of a reflective object in hopes of illuminating it upon return (higher amplitude.) I have read ...
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1 vote
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Geometric spreading of an impulse antenna

I am new to radar and curious about the geometric spreading in free space. I set up an air-coupled antenna about a half meter above the ground, with a large PEC on the ground. Then I adjusted the ...
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What do you believe was meant by FEA?

( RCS = radar cross section ) FEA wasn't mentioned in the acronyms or keywords list.
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Sampling Frequency of a pulsed radar signal

I'm new to radar. please excuse my question if it doesn't make sense to you. In a pulsed radar signal, why is the required sampling frequency "2 times the inverse of pulse width" instead of "2 times ...
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