Questions tagged [antenna]
Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g. TV or radio) waves. -Wikipedia
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Monopole antenna with coil design
(Note: I'm a beginner in antenna theory)
When browsing for low cost antennas online, there seems to be class of monopole antennas that have a built in coil or two into the monopole, and are advertised ...
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AM-Receiver circuit, problems with saturation?
I have a question about this specific circuit. I marked the potential-point I have "problems" with. I think there will be saturation in this point at some time. This point doesn't look to be ...
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How to design magnetic driveway alarm system?
I want to design "driveway alarm" which detects when a car passes by. I want to do the detection "magnetically" so it's easy to detect is a car and nto person or some animal. I was ...
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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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How to improve the electromagnetic field in this HFSS design for microstrip patch antenna?
[electromagnetic field for my patch antenna design]
The thing is I am trying to design a patch that resonates at four different frequencies with the dimensions of 13mm x 13mm x 0.25mm. I am actually ...
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how to start and end S-parameters at 0 dB [closed]
i have designed some antennas which are having good return loss and bandwidth....but my concern is that I want s-parameters should start and end at 0dB and to resonate at any frequency in the ...
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Does the law of reciprocity hold true for the phase response of an antenna?
I know that an antennas spectral transfer function should be the same in both transmit and receive due to the law of reciprocity, however does this law hold true for the phase response (AKA phase ...
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Impedanace matching on VNA does not match calculation (with detail steps included)
I have a PCB with pi-matching network, and I want to calculate the components values for the matching network.
I use LiteVNA and this antenna for this project:
https://www.we-online.com/components/...
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Adalm Pluto SDR - Second RX channel signal issues
I have a Pluto SDR rev c, on which I just enable the second TX and RX channel. I am sending a simple sinusoidal signal at a specific frequency (fc), but different phase and amplitude, using the two TX ...
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Balanced vs differential signals
I would like to verify my understanding of the following scenario with regards to why coax is 'unbalanced' and how a choke interacts with this unbalance:
Consider a half-wave resonant dipole, if one ...
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What is the actual physics and reasoning for the “Ground plane” underneath a GPS patch antenna
From my very limited knowledge of EM, I believed that anything tied to earth can absorb radio waves, so if an antenna was to be placed above a ground plane, why does the ground plane not just absorb ...
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Calculating the SLL of an antenna array of 8 elements
I'm given an array of 8 half-wave dipoles separated 0.15m each and I'm told to calculate the SLL in dB (the ratio between main and secondary lobes). The thing is that The only formula that comes ...
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Yagi antenna with 16 dBi gain, is it bottle necked by the power input?
I want to expand my PC's WiFi range, but the NIC delivers only 5 W. When I connect the antenna, not much more range is achieved. Is the antenna not the right one, or is the output of 5 W not enough? ...
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Does an aggregation of two lambda/2 dipole antennas z-axis oriented radiate towards the mentioned axis?
I'm asked whether by grouping two dipole antennas pointing towards the z-axis, they'll radiate in that direction. I'm aware each dipole alone doesn't do that thus refraction lobes in the z-axis ...
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High power, wideband balun transformer
I wish to design a 'somewhat'(ill-defined; i take what i can get) compact balun connected from a coax cable to a custom design dipole antenna. The design of the antenna is wideband in the sub 1 GHz ...
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RFID antenna and LoRa module/flex antenna on the same PCB
I need to place LoRa module on the PCB I designed. There is already an RFID antenna on this PCB that I designed before, and it is not possible to change its location.
Is the distance between LoRa ...
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Understanding Parameters of Antennas
I would appreciate it if you could check my assumptions regarding the application of antennas in my design, which usually involve cellular and Wi-Fi technologies. Sometimes, I come across parameters ...
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Antenna tuning of 2.4GHz WiFi board
I am new to the RF electronics and tuning of antennas. I am working on a 2.4GHz Wi-Fi board design using an ESP32-S2 chip. The board consists of a 50 ohm single ended impedance trace for the antenna ...
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Visualize antenna radiation pattern [closed]
I am looking for a free tool or codebase to visualize 2d and 3d antenna radiation patterns, as in the picture below:
Bonus points if open source. My goal is to visualise common antenna patterns in 2d ...
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Antenna polarization confusing
How do we mount an antenna which is a meandered line shape, to be in vertical or horizontal polarization? Vertical pol means that the antenna mounted to vertically to the earth. I’m confused just ...
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Can the Antenna Factor of a passive antenna be improved by adding a pre-amplifier?
If so what are the main considerations with respect to the noise of the amplifier?
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Does the directivity of a λ/2 dipole antenna depend on its length?
They tell me to choose the correct answer (one and only one) regarding a half-wave antenna from the following options:
a) Its directivity depends on its length.
b) They all have the same radiation ...
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Antennas Far field radiation pattern
I want to understand this Far field graph of an antenna generated in CST, from the picture:
Is this a good radiation pattern?
If yes, then how?
How to explain the graph?
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What's the impact of super high VSWR? Need help from experts
Is it realistic to make an antenna system with VSWR as high as 20 to transmit 50MHz signal? I am thinking of increasing bandwidth of a small antenna by sacrificing its mismatch efficiency. Assuming ...
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What parts of the trace count for the feedline impedance in antenna design?
I'm trying to incorporate a ceramic chip antenna in a wearable device due to its low footprint and affordability. After reading the datasheet countless times and YouTube tutorials I'm still not 100% ...
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FPC and PCB trace antennas difference
I see lots of PCB trace antennas in green color layer, as I know the dielectrics. On the other hand, there are FPC antennas (flexible printed circuit board antennas) are mostly in somehow black color, ...
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Does this antenna break Chu's limit?
I ran into this antenna datasheet and found it interesting.
https://www.johansontechnology.com/datasheets/0433AT62A0020/0433AT62A0020.pdf
From my understanding, the return loss graph on page3 shows ...
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Designing a voltage-current converter circuit to drive a coil as a mutual inductance antenna
I'm trying to design a voltage to current converter circuit to drive a coil antenna to transmit an analog signal through mutual inductance (very short range, around 3 inches). My frequency range is ...
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Calculating maximum gain of an antenna depending on a parameter
Consider an antenna that radiates in a direction for which the normalized gain is:
$$G(\theta, \phi) = \cos^n(\theta),\ 0 < \theta < \frac{\pi}{2}$$
Calculate the maximum directivity as a ...
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Broadband Impedance Matching Simulation of Helical Antenna: Convergence to High-Low Zo Transitions
Hello esteemed colleagues,
I've embarked on a comprehensive study involving the simulation of broadband propagation of helical antenna impedances through a segmented transmission line (TL) impedance ...
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If any "antenna" can be impedance matched to the source, can any piece of metal be tuned to perform the same as a physically tuned antenna? [closed]
I have heard online its better to get an antenna physically tuned than a matching network, but I don't understand exactly why. If the matching network would stop reflections and increase power ...
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Two port antenna isolation effect
I wonder and imagine if one antenna systems having two ports for two different working frequencies (so two different antenna elements included inside of it), what is the port isolation importance in ...
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How to calculate frequency band of a dipole antennae
I'm a bit puzzled on why dipole antennas can be used in FM receivers. Given that dipole antennae is just tuned to one particular frequency which can be derived from it's length using \$\frac{c}{2L}\$ ...
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Connecting SMA connector for GNSS & 4G LTE to Modem
A friend and I are developing a device which needs a connection via a Simcom7080G modem to 4G LTE and GNSS. Now, We are embedded software engineers and have some understanding of electronics but we ...
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RF antenna with satisfied impedance matching. Does it work really?
Before I start, how I did an impedance matching for the antenna of my RF source, let me show couple pictures, so I can manage what I am talking about. Below there are:
The impedance matching ...
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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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Phenomena of antenna out-of-band mismatch effect on LNA
I m very confused about something and I wanna ask it by giving example. Let’s assume that an antenna has a frequency band of 1000 MHz to 1010 MHz with VSWR level 1.5 and impedance of 50 Ω, and uses a ...
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GPS signal combiner
I want to use WP4N+ as a GPS signal combiner with NEO 6M receiver. Here is my schematic.
On power on, resistor 22 Ω is getting VERY VERY HOT and I do not receive any signal from the satellites. ...
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How to determine beamforming pattern?
I have a beamforming vector, which includes amplitude and phase information. How can I determine the corresponding beamforming pattern for the antenna and plot it in Matlab? For example, I have a ...
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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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Where and how I can calculate and simulate PCB antenna?
For example, if have inverted "F" PCB antenna and I need use it in my PCB project to 2.4 GHz (for ESP32). Of course, I can use calculated cases, but I want learn how it’s calculated and ...
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What is the name of those ports circled in red please?
I know those ports are u.fl but I am not what they are they and where can I find cables that plugs into them and have SMA connector on the other end.
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Why am I getting incomplete geolocation data for long periods of time using SIM7070g?
I'm facing a problem while working on a tracking application using the SIM7070G module for GNSS data. The application alternates between sending data and retrieving GNSS coordinates due to SIM7070G ...
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The effect of the wavelegth on the receiving power in Friis equation
In the Friis transmission equation,
$$\frac{P_r}{P_t} = G_t G_r \left( \frac{\lambda}{4 \pi d} \right)^2,$$
it seems that if the frequency is halved while the other parameter values are fixed, the ...
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ESP32-C3 RF pin design question
I have a question regarding the ESP32-C3.
I would like to have a transmission and receiver antenna in my system. The transmission antenna needs to be close to isotropic and the receiver must be very ...
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Can I improve the GPS accuracy by choosing a different antenna?
I am currently looking for an antenna to determine GPS location.
The question is a general one, but I have listed the equipment that I am using to help ensure that answers are more likely to be ...
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AM Radio Transmitter
I have been trying to make an AM transmitter and I found this schematic from a persons college project. I understand what is circled in red but the rest I am struggling with. The part circled in red ...
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Where does the RF power go that is sent to a reactive portion of an antenna?
The impedance of an antenna can be lumped-represented as Rr (radiation resistance), Ro (ohmic resistance), XL (inductive reactance), and XC (capacitive reactance). The incident power from a generator ...
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Antenna impedance (one port network), represented as ABCD (transfer) matrix?
I guess that ABCD matrices are not intended for one port, but, in this case, for the purpose of cascading two networks, 2 port (impedance transformer) and 1 port (antenna), by ABCD matrix ...
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Information sources to design a spiral PCB antenna
I am starting a huge experimental project and I want/need to explore the frequency independent antennas. I settled on two very interesting antenna topologies that are possible to design as a PCB (...
