Questions tagged [antenna-array]
The antenna-array tag has no summary.
71 questions
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How can you simulate an antenna array with a resistor in power splitter
I am simulating a 2 by 2 patch antenna array with Wilkson power splitter.
This power splitter require 100 ohm resistor. I use 0603 for this SMD resistor.
Here is my EM simulation s-paramter plot in ...
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RX only radar phased array with multiple targets
I saw some FMCW automotive radar modules with phased array antenna only on the RX portion. I'm wondering how such antenna differentiates multiple targets.
Let's say there are 2 targets illuminated by ...
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Simultaneous measurement of phased array elements
I’m studying on how to characterize each antenna working simultaneously in a phased array. I found a paper Link added.
Looking at Fig.1, as far as I understand, it does four measurements, each for ...
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Phasing of circular-polarized antennas array
If we take two orthogonal dipoles and feed them with 90° shift, we get a cirular polarized antenna. But if we want to make a phased array of such antennas, how do we control their phases for beam ...
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(Conceptual)Antenna Array as a Problem, Negative effect, What do engineers do when arrays are created unintentionally
I was in my first lecture of antenna array where I was studying the basic infinitesimal antennas at lambda/4 distance, one of the slide it had was
And it made me think, what if we have a broadcasting ...
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Patch Antenna lower Gain with bigger ground
I am designing a circular patch antenna. The design seems good, achieving <-25 dB S11 and 9dB gain. I am trying to reach even higher gain. For different reasons I need to extend the ground from ...
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Can radio waves be focused to a point using a phased array?
I've seen many examples of ultrasonic phased arrays being used with non-linear phase relationship between elements to concentrate all the power at a specific point, for example here:
...
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Does antenna arraying for deep space communications affect the CMB contribution?
My question pertains to the reduction in SNR achieved by arraying parabolic antennas in deep space communications. My engineering education is a bit out of date, so my thanks for your patience.
I ...
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How can I connect a CHW1010-ANT1-1.0-ND to an nrf5340 development board?
I would like to connect a CHW1010-ANT1-1.0-ND to an nrf5340 development board to implement direction finding.
This is in the datasheet of the CHW1010-ANT1-1.0
The nrf5340 has a Murata MM8130-2600RA2 (...
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How to find the phase values for the desired steering angle?
The picture attached is self-explanatory.
The antenna system system 24 antenna elements with inter antenna element spacing of wavelength/2.
There are two types of arrangements.
The first one is ...
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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 ...
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What is the behaviour of this antenna array?
I have a subarray-based antenna system as shown here:
The four subarrays are arranged vertically. In each subarray there are six antenna elements. Only the bottom three in each subarray have a common ...
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Gain of a signal passed through a N element phased array?
Assuming a isotropic phased array of N elements, the gain would be 10*log10(N) dB which is provided in theory.
However, when same signal is passed through all the N elements, the gain is 20 * log10(N) ...
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Phase Differences and Wave Equation in ULA Antennas with Far-Field Assumption
I am analyzing a signal received by two antennas, where the second antenna is positioned farther than the first in the direction of wave propagation. I am encountering some confusion when it comes to ...
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What is a good way to mute antenna while keeping the aperture unchanged?
I have an 2D array of 64 antenna element. Lets say each antenna is connected to one RF chain. with this array total 64 parallel data streams can be transmitted with some pre-processing. When the load ...
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Proper way to combine same-frequency PCB antennas
I want to combine 2 identical PCB antennas to increase gain. The antennas are designed to work on 2.4GHz and have 50ohm impedance, linear polarization with Omni-Directional radiation pattern, they are ...
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What is the maximum possible aperture efficiency of an antenna?
The aperture efficiency of an antenna is defined as the ratio of the effective aperture divided by the physical aperture. The typical values are between 0.35 to more then 0.70. Wikipedia
What is the ...
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Why does literature call the response of an antenna array the array "manifold" vector?
Van Trees' Optimum Array Processing and other works (e.g. Wikipedia) refer to an antenna array's response (shifts in phase and differences in gain due to the angle of reception) at each element as the ...
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How can polar plots of radiation fields/array factors be made by hand?
In one of my courses we are expected to plot array factors and other radiation fields by hand. I am comfortable deriving expressions for the array factor by hand but I am struggling when trying to ...
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How well synced do digital channels in a phased array need to be?
In order for a narrowband phased array to be coherent channel to channel, what is the maximum timing jitter that can be tolerated between channels? I assume there can be a constant timing error ...
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Antenna: three element array, Balanis problem 6.3
I am trying to solve the below Problem (only question (a)), where I am mainly stuck on figuring out how to read this z/y drawing of the magnitude and phases.
The problem has to do with 3 antennas ...
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Antenna mutual coupling and estimation of angle of arrival
If I have two RX (receive) antennas at a distance of lambda/2 from each other there is a formula which relates the phase difference to the angle of arrival.
The formula is however assuming no mutual ...
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What is the frequency measurement range of a NanoVNA?
I have tried to measure a fabricated patch antenna which has theoretically multiband ranging from 1 GHz to 8 GHz, but when I tried to measure it through NanoVNA it barely shows the result from 1 GHz ...
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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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Best antenna design with the following requirements?
I'm looking for the best antenna design with the following requirements
Small
Discrete
Wideband (LTE and WiFi)
Directional
High gain (20-25dBi with relatively high transmission power)
Could anyone ...
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215
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Is an antenna array with a tilted (rotated) antenna element always less optimal than a perfectly aligned antenna array?
Suppose I have a traditional linear antenna array. My element factor follows a cosine shape between 0-180 degrees. The relationship between my theoretical total antenna array pattern and the element ...
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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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Can phased-array (ULA) gain tapering effects be modelled using digital windows?
I am attempting to model the general behaviour of various tapering techniques. It seems applying gain tapering to a ULA has very similar effects to that of applying a digital window to a signal. In ...
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Why is the linear phased array pattern a sinc (visual interpretation)?
It has for sure a very obvious answer, but I must admit I find it very difficult to visualize how a linear phased array can focus the beam with a sinc pattern. I'm not talking about the mathematical ...
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Symmetric PCB stack-up for phased-array antennas
We all know that a symmetric PCB stack-up is always recommended since it makes manufacturing easier and more reliable. However when designing PCB for antennas application this became quite a difficult ...
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What does "degree of freedom" mean in Direction Of Arrival (DOA) estimation?
Recently, I was reading this paper, Nested Arrays: A Novel Approach to Array Processing With Enhanced Degrees of Freedom. In the abstract, it is mentioned:
This structure is obtained by ...
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Finding the side lobe level of an antenna array
I have a circular antenna array with N elements, for which the array factor can be defined as follows:
$$AF(\phi)=\sum_{n=1}^N I_n \cdot e^{j \cdot(kr \cdot \cos(\phi-phi_n)+\beta_n}$$
I search a lot, ...
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MU-MIMO - do all antennas stream in different frequencies?
I have few questions on how MU-MIMO in WiFi works.
Do all antennas stream in different frequencies or stream in same channel but different sub carriers(OFDMA?)
Do MIMO antennas always work in OFDM ...
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Derivation of Dolph-Taylor Synthesis
Today, I was trying to deduce by myself the Dolph-Taylor Synthesis. After arriving at the expression:
$$AF(\theta) = P_{N-1} \left( \cos \left( \frac{\psi}{2} \right) \right) = T_{N-1} \left(x_o \cos \...
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Which is the cause of "scan losses" in a linear phased antenna array?
in a linear phased array it is possible to move the peak angle ("beam steering") by applying proper phase shift between the excitation currents:
The second picture represents the array ...
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How reflection occuring in antenna fed by transmission line affects performance?
Transmission line considered is lossless.
Basically the configuration is simple.
For transmitter side : a non ideal source (can be voltage current or power) feeding a transmission line (TL1) with ...
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Why are transmitting antennas generally larger than receiving antennas?
The reasons I can think of are transmitting antenna has to be more directive also larger length will imply larger power and thus will help compensating for losses. But on contrary if receiving antenna ...
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Difference between IRS and phased array/reflectarray
just wondering out of curiosity the difference between intelligent reflecting surface (IRS) and more traditional antenna arrays such as phased array and reflectarray?
From the surface it looks a whole ...
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Combination of different antennas
I was wondering if there was a mathematical way to combine two different types of antenna elements. Let's say that I have an antenna of $$\lambda/2$$ and I want to combine it with an antenna of $$\...
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How can one compare resonant and non resonant antenna based on parameters like Directivity, Radiation resistance, Cross polarisation, Efficiency?
Basically I want to make a choice between two antennas when ample space is given objectively based on parameters
1.Directivity
2.Radiation Resistance
3.Cross Polarization ratio
4.Loss resistance
I'll ...
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What is difference between resonant and non resonant antennas?
I don't know if it's right place to ask it, but I searched google and books the answer I get seems to be like resonant antenna have small bandwidth and have standing wave instead non resonant antennas ...
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Design of 5+ channel microphone array
I'm interested in designing a microphone array which will have 5+ inputs which need to be synced, possibly more. I want to sample each input at 20-30khz at 8-10 bit resolution.
I would prefer not have ...
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Do beam-forming devices expect a particular antenna configuration?
Do beam-forming devices expect a particular antenna configuration? For instance, do they expect the antennas to be a certain distance from one another? Or parallel to one another? Etc.
Background Info:...
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Why do we need array antennas?
If we can increase the directivity of the single element antenna by increasing its electrical size then why do we need array antennas?
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How to connect a 4:1 balun to a a log periodic antenna?
I'm following a plan for a home made LTE/4G UHF antenna here: https://www.thingiverse.com/thing:3221812
...because it looks to be of a very similar to design to a very expensive 4G anntenna I know ...
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Dipole array antenna radiation pattern
I have the radiation pattern for a dipole antenna with working frequency of 11 GHz, it looks like figure 1. I wanted to create an array antenna consisting of 2 elements with that same individual ...
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Rayleigh distance of array antenna
Far field zone of a single antenna can be determined by using the equation below.
$$R>\dfrac{2D^2}{\lambda}$$
Where D is the biggest dimension of the antenna.
This equaiton is suitable for single ...
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Can you create a circularly polarized signal with dipoles that are perpendicular but not crossed?
All of the circularly polarized phased arrays that I can find use elements that are themselves circularly polarized, that is, two perpendicular dipoles that are crossed at their midpoints (the picture ...
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Antenna Array - Hundreds of elements forming thousands of beams - How?
How would an antenna array of 100 elements be able to form 5000+ simultaneous beams?
Or do I have it wrong, there would only be a maximum 100 beams from the 100 elements at any one time and those ...
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What is counterpoise?
I was reading about the radio telescope - Murchison Widefield Array (MWA) situated in western Australia. Antennas of this telescope are quite unique and different from usual dish radio telescope. In ...
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