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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32 views

Antenna matching circuit - weird behaviour

I have a 2.4GHz device with room for a Pi matching circuit. I cut J5 (to disconnect the MCU - brown line in layout picture), soldered the ground of the coaxial cable in the white region and the ...
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44 views

Why does changing CRT to HDTV lose antenna channels? [closed]

We have an internal antenna that is connected to a tiny CRT TV through a digital converter box. I recently replaced this CRT TV with an HDTV, and I removed the digital converter box since the HDTV ...
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59 views

How to understand this dipole antenna's feed structure

Trying to understand this feed structure, and have questions in mind. It clearly seems that two 180 degree couplers and one 90 degree coupler utilized to get the antenna circularly polarized. Since ...
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1answer
29 views

Which type of balun to use for unbalanced line (Coax) to a dipole antenna?

How can I choose a balun for the transformation? What to look carefully? Generally I see on commercial baluns that one input for unbalanced coax and two output. Does that two output mean one for the ...
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28 views

PCB 2.4 GHz Inverted-F Antenna

I am looking for theory of PCB 2.4 GHz Inverted-F Antenna (equations) to calculate the resonant frequency and primitive .... etc for finding t differents values (inputs) for present in HFSS
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1answer
39 views

How to transmit and receive a ping over long distance? [closed]

I need to transmit a ping over a long distance (>1km) I'm struggling to get the right google queries together to work out how to do this. I'm imagining a simple transmitter that pings continuously, ...
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1answer
34 views

FCC Complaince & Removable Bluetooth Antennas

We are developing a product that will hopefully soon be sold internationally and will therefore be put through FCC & CE Certification testing. Part of that design is an audio mixer with an ...
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2answers
46 views

Plot Z vs Freq for RL-C circuit

I am trying to simulate the resonance frequency of an Antenna, that can be modeled by a resistor in series with an inductor , both in parallel with a capacitor: By attaching the antenna to a AC ...
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1answer
77 views

What is >> (double chevron) in far field communication

I keep seeing this notation with no justification or explanation as to what it is – it appears to be being used as greater than but I don't know why > isn't sufficient. Didn't want to ask it as a ...
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1answer
40 views

Power Transmitting and Receiving from antenna of same frequency? [closed]

I want to ask something about power transmitting and accepting. If we have a source antenna of 2.45GHz and a receiver antenna of 900MHz. Could the receiver accept the power transmitting by the source? ...
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2answers
70 views

On which layers of 4 should the trace antenna be (433MHz)?

I have designed a simple PCB with the follow layers Top Layer, high speed traces (rest ground copper) Inner 1, Ground Copper area everywhere apart on the very left side where the trace antenna will ...
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0answers
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Can I directly connect a wifi-antenna to an NRF24L01 chip without SMA-connector?

I have an NRF24L01 wireless communication chip with an onboard, copper trace antenna. I saw a guide on soldering a wire to the end of the copper trace in order to extend the signal/reception. I happen ...
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43 views

Impedance Matching between Two Antennas

In order to maximize power transfer, and minimize signal reflection, one would impedance match between a output load and an antenna and between an input load and an antenna. However, is there any ...
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54 views

DCF77 antenna preamplifier from available components

I plan to build a DCF77 receiver, which includes an active antenna. When I was looking for inspiration to design an antenna preamplifier, I came across a scheme that I liked. Here is the link. When I ...
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2answers
133 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 ...
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2answers
38 views

What's the effect of S21 in two port antenna system?

When designing two port antenna, S11 is quite well with other antenna performance like gain, efficiency, etc. However, S21 is around between -6 / -10 dB. If we consider that a commercial coupler will ...
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34 views

Active Antenna with Off The Shelf GPS Module

I'm trying to use an active antenna with the GY-GPSV3-NEO-M8N GPS module. In the hardware manual for NEO-M8N it is said that I need a DC bias circuit like shown in the picture below. As shown I need ...
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2answers
54 views

which antennas is better for 433 Mhz 30dbi LoRa module [closed]

I am searching a antenna for LoRa module. my first priority is distance. which is more long range, it is better for me. There are 3, 433Mhz 3dBi antennas. Can you help me which is best and why? if you ...
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2answers
40 views

Impedance Matching using Transmission line

Hi! I was looking at this research paper for Energy Harvesting through Rectanna and I stuck with this thing. The author, first, calculated the Rzin of the rectifier circuit. He had a source resistance ...
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1answer
42 views

Some sort of reflector behind a spiral antenna

I was in an antenna laboratory, and I saw a spiral antenna with a sort ground plane, about 0.5 cm behind the antenna (probably a reflector as the antenna was not connected to it.) Is that a known ...
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1answer
64 views

Left and right circularly polarized antennas - which one to choose for reception-emission?

I've read that the spiral antenna is circularly polarized, either right or left circularly polarized, depending upon the construction. I want one antenna be the emitter, and the second one be the ...
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37 views

Is it safe to leave the GND from an antenna jack unconnected from an active antenna amplifier?

I need help with trying to use properly this circuit, the original idea came from the late Tony Van Roon who designed it. According to the article it seems that the logic behind it is that the dim ...
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25 views

Listening for Avalanche Beacon Signals

I'm working to build an avalanche beacon proof-of-concept for a school project. I'm fine taking care of the display, buttons, battery, case, etc. but I'm far from understanding the RF side of things. ...
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1answer
44 views

Does the signal to the NFC antenna require shielding?

My design requires a NFC antenna to be located on a different board and due to space limitations, a uFL connector can't be placed for a mini coax connection. A flex cable solves many of the design ...
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1answer
38 views

How to correct dB from antenna factors

I am using a TBMA1 biconical antenna from TekBox to make emissions measurements on my hardware (datasheet.) I want to confirm that I understand how the antenna factor plays into dB correction. At 190 ...
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1answer
61 views

How to separate PCB antenna and SMA connector?

I am designing a prototype PCB for a Lora node. It will have an SMA connector (J2) and a PCB antenna. Switching RF connectors are not available in my area, so as an amateur enthusiast what is a good ...
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1answer
103 views

What type of antenna is this? (glide slope aircraft antenna)

This is a glide slope antenna from an aircraft. They are installed in or near the nose cone of an aircraft for the reception of the glide slope signal beams. The antenna is tuned for 329 to 336 MHz ...
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1answer
28 views

Connecting Ashtech antenna to mobile device [closed]

Just recently I got my hands on some old GNSS survey equipment from Ashtech, which was originally brought to the market around 2010. It consists of two ASH111660 antennas with corresponding two ...
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1answer
83 views

PCB antenna connector and copper signal names

I am trying to build a PCB antenna similar to what is shown in this video. At the 6:24 mark it shows the circuit layout below: I am using Eagle to layout the PCB on a two layer board. ...
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4answers
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How does a GPS antenna have only two connections yet have all this circuitry inside?

This GPS module I have broke (just gets hot and won't work) so I took it apart and am amazed to see all of this circuitry under the ceramic antenna but only two connections (gnd and signal). When ...
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1answer
67 views

Why does a soldered IPEX MHF4 (WIFI card) connection result in signal attenuation?

In my laptop, the WIFI card was connected to the 2 antennas by IPEX MHF4 connections, which look like tiny coax connectors. Unfortunately the antenna connectors got broken, so I have removed them and ...
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1answer
78 views

Is a dedicated bandpass filter chip really neccessary for the BLE antenna of STM32WB?

I am designing a custom STM32WB board. Checking the reference boards of STM32WB (Nucleo and Feather board) I noticed a dedicated multilayer ceramic bandpass filter in the matching/tuning network path. ...
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1answer
33 views

Connect antenna to FM circuit

I designed a Colpitts oscillator with a single transistor amplifier stage. I now have to connect the antenna to the circuit through a coaxial cable. Do I have to redesign the output impedance of the ...
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3answers
387 views

How does the length of the antenna affect wavelength of the wave?

I want to do some calculation of how varying lengths of the antenna will change the wavelength of the wave.
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38 views

433 MHz Antenna Layout

I'm trying to build a remote control unit and want to 'remote' the antenna from the 433 MHz Tx unit. I'd appreciate some feedback before I order as my antenna/RF theory is sketchy and I want to know ...
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1answer
44 views

What's the maximum possible power output of this RF CATV amp?

please tell me what is the maximum possible output wattage that this RF CATV distribution amp (see below for specifications) would likely output with maximum possible input before damage? ~13 mW is ...
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1answer
72 views

Will the antenna be detuned by the presence of the MHF3 plug in parallel?

This is a design question. Below is the layout of a project that involves some features, including an ESP32 circuit and its antenna: The part of the schematic related to both images is: THE PROBLEM: ...
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2answers
35 views

Distance an inverted F antenna should be from the bottom and side edges of a PCB?

Distance from the bottom is usually either in the center of the PCB or close to the bottom edge with the length arm always pointing toward the farthest edge from the antenna position. CENTER? OR EDGE?...
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1answer
80 views

Circumvent 433MHz antenna printed on PCB

I'm tinkering on a cheap chinaware alarm center which receives signals from its detectors on 433MHz. It is located inside a metal box which forms a faraday cage and apparently reduces the range too ...
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1answer
37 views

Understanding Total Response

QUICK INFO: I am currently studying about closed and open-loops systems. BACKGROUND STORY: Imagine a big antenna is placed on a hill and there is a lot of wind. You want to turn the potentiometer so ...
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31 views

Electric Field of Patch Antenna

I am working on developing Patch antenna for 5G Applications. As the first step, I am trying to understand the working and properties of Microstrip patch antenna. All the resources I have read state ...
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1answer
36 views

LW/MW and FM antenna suggestion for old car radio (25 years old)

First of all, i want to listen in my house, you can forget a car. It has been in the warehouse for a long time. Yesterday i tried it. Although I haven't connected an antenna yet, it still works. ...
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4G Cellular Antenna

I have a Huawei E3372H-153 USB 4G dongle. It has two external antenna ports. What I want to know is that how can I make the full use of those two antenna ports to get the best 4G reception possible? ...
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1answer
59 views

Long range RFID for tracking stationary object

I am totally new to the field of RFID, I want to make a device that can track RFID passive antenna in at least 10m radius and if possible 20m radius (just by latency know how far away from the antenna ...
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7answers
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Is it possible to generate light with an antenna?

An antenna (e.g. a dipole) is able to radiate at a certain frequency thanks to the EM field generated by a current provided by a signal generator at such a frequency. So, for instance: Voltage source ...
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1answer
25 views

Log periodic antenna intuitions for its region properties

a log periodic antenna shown In the diagram shown bellow. As you can see there are reflective region and non radiative region. there are phase shift of 180 degrees between neighbor "wings". ...
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1answer
33 views

how to understand grating lobe problem in broadside array

In a broad side array we have a radiation pattern for which the Array factor development is shown bellow. I can understand what is the problem that is called "grating lobe". Below we have ...
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microstrip patch antenna representation as an array of two slots

from the article bellow we can see the microstrip antenna as an array of two radiating slots which are separated by half a wavelength As shown in the photo bellow.these Electric fields cause magnetic ...
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1answer
91 views

how to prove that TE modes cannot exist in microstrip structures

I kow that the modes in microstrip are TM modes. I know that we have boundary conditions to see if the mode exists. What boundary condtions i need to use for TE and TM? Where do i put them in the ...
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4answers
77 views

Is the antenna gain time dependent?

Premise The antenna gain of a transmitting antenna relates its radiation intensity U(θ,ϕ) to its input power as shown in the following formula: $$G(θ,ϕ)=\frac{U(θ,ϕ)}{P_{IN}/4\pi}$$ Where the ...

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