Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g. TV or radio) waves. -Wikipedia

learn more… | top users | synonyms

0
votes
1answer
51 views

Will my car's AM/FM antenna boost the signal of a tablet/carputer GPS?

I'm installing an Android tablet as a carputer in my '97 Hunk-o'-Junk Crapwagon, and saw a reddit post detailing a carputer install where OP linked his Jaguar's antenna to a USB GPS adapter. OP also ...
1
vote
1answer
36 views

Simultaneously using 4 MIMO cellular transceivers on a single antenna - feasible?

I have a set of four commercial cellular tranceivers that support 3G and 4G(LTE). These phones have two antenna connectors (for MIMO/diversity) in an embeddable industrial form factor (eg. just ...
-1
votes
1answer
24 views

How to calculate the line impedance for WLAN antenna path and how to determine which kind of antenna is efficient for automotive product

I would like to know how to calculate RF antenna Line impedance, and makes the Pi filter values exactly in my Antenna path. I need a general guidelines and clear understanding of it. Please help me ...
3
votes
3answers
152 views

Does an antenna violate the principal of a circuit having a return path?

Seems weird that an antenna has no return path. Also, what about capacitive coupling. How are these circuits?
0
votes
0answers
28 views

External whip 868MHz Antenna via coaxial cable. Ground Issues

I have a RF module that works at 868MHz.It works as transmitter and as receiver. (lambda:0.345m lambda/4=8.64cm). The RF module ground plane (GND_PCB) is 10x10cm, so bigger than lambda/4. By default, ...
0
votes
0answers
24 views

How do I design an antenna in desired frequency with preset equivalent circuit model?

I am working on a project that an oscillator drives 1 mH inductor in 7.5 KHz. This oscillator also happens to be very efficient. However, I am constrained with inductor value. So, to make my design ...
0
votes
1answer
32 views

How did four-course LF radio navigation ranges have their beams other than at 90° / 180° angles?

The four-course Low Frequency Radio Range system used for aircraft navigation (in the US and elsewhere) in the 1930s and 1940s used a pair of directional antenna (with figure-of-8 shaped radiation ...
1
vote
1answer
149 views

Why are fractal antennas able to receive so many more frequencies than a conventional one? [closed]

Why is it that so much more different values of frequencies can be received by a fractal antenna than a conventional one? Is it because of the self-similarity, when you look at different scales of the ...
1
vote
0answers
13 views

How should I properly connect two MIMO antennas in WiFi bridge? [migrated]

Given: I am setting up a WiFi bridge using two identical Dual polarized directional MIMO panel antennas ...
0
votes
1answer
76 views

Range of Electromagnetic Waves/Radio waves? [closed]

What basically determines that how far the electromagnetic waves will travel away from the source ? In our world where there is air and other materials how electromagnetic waves would generally ...
3
votes
1answer
52 views

What is the antenna gain of a mobile phone?

I'm working on a GSM/3G Project and my team has a small doubt about antenna gain selection. All along we were using a 3dB PCB Antenna connected via U.FL/IPEX connector. The antenna does a good job ...
0
votes
1answer
33 views

Using Pulse W3006 Dualband Wifi Antenna with a CPW-G Trace and Single RF_Out on MC

Pulse W3006 Chip Antenna Being Used We are designing a custom PCB which uses a micro-controller with a single RF-out capable of doing 2.4G/5G/Bluetooth. This questions has 3 parts: Using the Chip ...
0
votes
2answers
28 views

quazi-isotropic broadband bowtie antenna design?

I am not an expert in radio-electronics, as you will see shortly (a biochemist by training), and I am reading on ways to focus electromagnetic waves (light, actually), across a spectrum of lambdas ...
33
votes
3answers
4k views

Can people act like antennas?

I was watching my oscilloscope as I was holding a very short wire attached to the probe. It was showing about 0 voltage (small spikes) until I touched the metal. When I touched the metal, the scope ...
0
votes
1answer
48 views

Yagi gain reduction when using off frequency (2.3Ghz WiMax system using 2.4Ghz WiFi Yagi)

I have a new WiMax 2.3Ghz broadband service that has marginal reception. As the frequency 2.3Ghz used is close to WiFi I am thinking I can use a cheap WiFi yagi instead of a much rarer (and expensive) ...
1
vote
1answer
47 views

What are the capacitor values and why there are holes in PCB? - Semtech's reference design - SX1272MB1DCS

Semtech is providing a reference design concerning the SX1272 chip: SX1272 modules: SX1272MB1DCS - 868 MHz - Combined RFI and RFO, switchless (Ref design only) I can't find the values of C12, C14, ...
2
votes
1answer
47 views

How to make an impedance matched circuit for fabbed antenna?

Okay I have developed an antenna for a system and need to create an impedance matching circuit. The theory of conjugate matching is simple, but actually implementing it is something I can't find ...
0
votes
1answer
85 views

Maximum range of 27 MHz ISM band NLOS radio broadcast

What is the maximum range of a 27 MHz ISM band when transmitting at full power? I am interested in general situation for US and EU but that will go back to the power limits allowed. My country (CZ in ...
3
votes
1answer
71 views

Design for planar antenna that radiates in the plane of the antenna

Im trying to find a reference planar antenna design. The goal would be to design an antenna that radiates omnidirectionally on the pcb plane. One solution would be to use an electrically small loop ...
-11
votes
1answer
73 views

Mobile signal jammer [closed]

I am trying to make a mobile signal jammer for GSM 900 and GSM 1800 using this circuit . Actually I am having doubts regarding antenna . What type of Antenna can be used . I tried using copper and ...
1
vote
1answer
37 views

Antenna and balun for MRF49XA

I am trying to do a project that involves proximity detection. I need a few devices omnidirectionally detecting each other at short distance (under 20 feet). It seemed to me that sub-1Ghz RF is the ...
-2
votes
1answer
57 views

1dB beamwidth of half wave dipole antenna

Could anyone kindly help me out with this assignment question? "Derive the mathematical formula for the 1-dB beam-width of a center-fed half-wave dipole antenna."
1
vote
0answers
35 views

how to identify pads of a chip antenna?

I am using a chip antenna called ACA-102-T. The linked document says that Pad No1 is the input pad, and Pad No2 is the ground short pad and an example circuit I am going to solder the ...
-1
votes
1answer
70 views

RF energy harvesting using UHF and HF from tv, radio and cell towers [duplicate]

I am busy with a project where I want to harvest energy from UHF and VHF such as tv broadcasts, radio and cell phone towers to charge a 100uf capacitor to be able to power a low power appliance such ...
0
votes
1answer
109 views

Why does an antenna sometimes has a bending on the end of the wire?

I sometimes see antennas as follows ( Paint ;) ): It sometimes is even in manufactured wires. This gives the clue that there is a scientific explanation for this bending. I have searched on the ...
3
votes
1answer
40 views

coupling in transmission line

I have a very basic and rather silly question which I have not found any suitable answer yet. Suppose I have 2 transmission lines. One carrying a high frequency sinusoidal signal. Is there coupling ...
0
votes
1answer
62 views

Understanding 75 ohm antenna connection on a hifi receiver

Dear electrical engineers! I am trying to understand what stands behind a 75 ohm (unbalanced) antenna connection on my hifi receiver? I understand the "unbalanced" part, however not the "75 ohm" one. ...
2
votes
1answer
43 views

Antenna gain and aperture

Consider two different antennas with equal gain. Let's say one of them is a vivaldi antenna and the other is a horn antenna I want to learn how much of the incident power these antenna will be ...
4
votes
3answers
321 views

How can I reproduce ambient EM fields inside a Faraday enclosure?

I am part of a research team looking at the possible effects of EM fields on psychological function. The experiment calls for participants to perform a series of tests while inside a Faraday tent that ...
0
votes
0answers
29 views

Compact alternative to discone for wideband VHF/UHF reception?

I have a discone antenna and it works great for wideband reception in a stationary configuration. The discone, however, is somewhat unwieldy and would not work well on a car. I am trying to find a ...
0
votes
2answers
50 views

antenna gain, calculating voltage scaling

I am working on a software defined radio project, but I am kind of new to antennas. There's so much info out there on antennas that I'm having trouble finding the answer to my specific question. ...
2
votes
2answers
69 views

How to avoid interferences (antenna effect) in long traces in PCB?

I am working on a PCB layout in which I have a 40cm long traces (bus of 4 traces). This traces will support between 50mA to 100mA and 5V. I want to minimize possible antenna effects that may occur due ...
1
vote
4answers
309 views

How can I tune an antenna for receiving (VHF)?

I have a number of books on antennas and without exception they all describe balancing antennas only for transmission. Since I do not even own any transmitters these guides are useless. I have only ...
1
vote
1answer
60 views

Link between RF433 emitter and antenna [closed]

I am looking for a way to link a RF433 emitter to a RF433 antenna Since there is an "ANT" pin on the emitter I assume I can connect an antenna to it. However, I do not know how to do this kind ...
-5
votes
2answers
59 views

how much voltage pass through antenna? [closed]

I want to know how much maximum voltage can be generated on a receiving antenna. Also, please help me to find an antenna design with maximum received signal voltage; I dont have proper knowledge of ...
0
votes
1answer
40 views

Loop antenna's electric field

Loop antenna's are often solved for magnetic field and we perfectly know how they behave towards magnetic coupling as shown in this image : However, I am looking for the electric field lines ...
1
vote
2answers
106 views

Antenna for broadcast AM reception on ARM Radio SDR

I'm trying to build the ARM Radio project detailed here. I routed and fabricated a PCB for the anti-alias filter and preamplifier shown on page 2 of the linked PDF, and reproduced here: ...
0
votes
0answers
42 views

Intel Edison External WIFI/BT Antenna Certification

I want to bring my device with Edison using external WIFI antenna for FCC certification. The test lab asked me how to set continuous Tx and Rx, but I can't find any instruction from Edison developer ...
5
votes
1answer
88 views

Why longer antenna coaxial cable has better efficiency?

I am not an RF engineer and I don't understand why for the same PCB antenna but with longer cable length can have better return loss and efficiency. I am comparing W3538B0150 with W3538B0200. I ...
0
votes
1answer
52 views

Does length of wire to NFC antenna affect ability to read tags?

Most questions regarding NFC antennas pose the question if it's possible in increase the reading area of an antenna. I'm curious: given a fixed size antenna, does increasing the length of wire ...
0
votes
1answer
79 views

Antenna Coverage Area using H-plane E-plane diagrams

On many antenna product sheets the H-plane and E-plane angles are given. On some data sheets you can find the diagrams for aformentioned planes. Are these values the same as where manufacturers ...
1
vote
2answers
183 views

What are the units in which a radio signal's strength is measured?

I'm kind of confused about which is the most correct unit when it comes to the measure of wireless signal's strength. It seems that the correct unit is V/m (usually expessed in dBuV/m), however it ...
0
votes
1answer
89 views

Amplitude of antenna-voltages induced by microwaves [closed]

Iā€™m rather new to electronics and I encourage you to prepare yourself both mentally and physically for some very stupid questions ā€“ and some assumptions of my own (possibly very wrong) ā€“ about ...
1
vote
1answer
55 views

Sharp corners in RFID antennas

I have heard anecdotally that a square HF RFID antenna performs worse than a circular one, but I am struggling to find any articles on why this is the case. I assume there is a charge concentration ...
2
votes
1answer
61 views

RF generator TX antenna with low impedance can damage generator?

I got an RF generator R&S HAMEG HM8135 that I use in a testsystem to generate FM and AM stimuli in order to check if FM antenna and AM antenna is correctly mounted on the testobject in a ...
4
votes
2answers
95 views

Does antenna feed line length affect impedance

I built my own antenna but when I measure the impedance (VNA) I see they are off. One is 30+25J, the other 15 + 10J. I built these by hand, the only difference I see is the feed line to one is about ...
0
votes
2answers
56 views

Minimum separation between antennas in receiving

It's known that there has to be a separation between antennas of same frequency to minimize interference. But this is really necessary when antennas are mostly in reception mode?
0
votes
2answers
71 views

What is load on an antenna? Is it safe to short the antenna port?

On the readme page of https://github.com/pwarren/rtl-entropy, it says: If you're serious about the cryptographic security of your entropy source, you should probably short, or put a 50 Ohm load ...
0
votes
1answer
46 views

matching network design for transceiver with differential outputs

I'm trying to learn about matching networks. I have a 2.4GHz radio chip with differntial TXP/TXN outputs, and RXP/RXN input. These both share the same single ended antenna. I've been reading and I ...
0
votes
1answer
83 views

WWVB Antenna Reciever 1st Amplifier stage, no signal

I made a high input impedance JFET CS amp as the 1st amplifier stage for a 60kHz Loopstick Antenna. I am using an RF JFET (J211) and ceramic capacitors. The only signal I see is a 60Hz sine wave ...