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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61 views

How do I make a antenna more sensitive to radio waves [closed]

What components do I need to make a antenna more sensitive to radio waves I'm working with 2.4GHz but I don't want to extend my antenna. I'm trying to make it more sensitive to radio waves. Do I ...
1
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0answers
44 views

How to choosing the right transistors for active antennas

I'm trying to build a Mini Whip active antenna that receives 10KHz to 20MHz. But I'm having trouble finding the right components especially the transistors. It calls for a J310 and a 2N5109, which ...
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2answers
27 views

How to solve Power Density Function?

How to solve this problem: A radio receiver needs $$ 1 \textrm{ nW/}\textrm{m}^2 $$ of power density function, how far away from a 1-watt point source will it continue to work?
0
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0answers
35 views

How do I learn to design a Bluetooth Low Energy board using TI CC2650? [closed]

I wanted to make a 15mm square pcb using the free version of Eagle (2 layers). I have read quite a bit, but I am not confident I can make a board that radiates to 1.5 meters (at least). I have so many ...
3
votes
2answers
62 views

How can current flow in dipole antennas when there is no potential across them?

I have been trying to understand antennas and I've been trying to analyze how the transmitter's energy is transferred. It is clear that for current to flow there must exist a potential difference ...
1
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1answer
89 views

Why do we not use both E and B fields for a receiving antenna?

An antenna is an electrical device which converts electric power into radio waves and vice versa we all know this. In transmission, a radio transmitter supplies an electric current oscillating at ...
1
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3answers
79 views

Shortening the coax on UHF CB antenna caused SWR to get worse, why?

I shortened the coax cable on my car's 477MHz CB antenna because the braid was frayed at the transciever connector end, and a metre or so of spare coax was coiled up behind the dash. I thought if I ...
-2
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0answers
35 views

Frequency presence to light up LED

Can anyone provide a simple circuit schematic that uses an antenna to detect the presence of a specific frequency and in response lights up an LED. I have been doing some reading on resonant (LC) ...
0
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1answer
122 views

Can you help me identify the antenna? Looking to add External Antenna

I'm looking to add an external antenna and I want to find out I add the antenna using a Mini PCI U.FL to RP-SMA Antenna WiFi Cable Signal Connector Network Adapter I got off of ebay to a Trendnet ...
1
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0answers
31 views

Cell phone bluetooth range

I've got this phone I'm doing some range testing with...Namely, a Samsung S5 with the latest firmware and I'm testing the WLAN/Bluetooth radio. This phone has unbelievable range...but, when I replace ...
0
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1answer
61 views

“Drawing” signals with antenna

Can you produce max waves, adding them, creating massive spikes like it showed in this video with water, but with multi antennas. Can you do this with electromagnetic wave in air with some complex ...
1
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1answer
56 views

Difference between antenna resistance and impedance

From what I understand about antennas, they have a certain impedance. At the antenna's resonant frequency, the capacitive and inductive reactances cancel and the reactive part of the antenna ...
1
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0answers
19 views

Advice on Coplanar Waveguide and Ground layout of Antenna

I've this antenna model AH316M245001-T. Datasheet: http://www.mouser.com/ds/2/396/chipantenna01_e-587795.pdf RF signal will be routed using CPW with ground vias. RF freq. is 2.4Ghz, 50ohm line. I ...
1
vote
2answers
82 views

Definition of antenna efficiency

I have two definitions for antenna efficiency: \$ \varepsilon = \dfrac{P_{rad}}{P_{in}}\$ and \$ \varepsilon = \dfrac{R_{rad}}{R_{rad} + R_{ohm}}\$ Coming from physics, I was wondering if there is ...
0
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0answers
30 views

RFID antennae at distances of 2 cm

I want to arrange RFID antennae spaced equally at distances of 2 cm. And I'll be connecting those using a MUX. The other end of the MUX is connected to a reader. How should I go about designing that? ...
1
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1answer
96 views

Wi-Fi transmitter/receiver in close proximity: Override interference?

I'd like to control a camera via Wi-Fi (zoom, trigger shutter, etc.), and possibly also capture a live video stream. This will be at an event with a huge number of Wi-Fi devices, and connectivity is ...
0
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0answers
73 views

Using a flagpole for a Wifi antenna

I would love to use an existing flagpole as a makeshift Wifi antenna, but am not allowed to attach anything to it. I.e. no J-pole, mounted antenna or coax running down it. Will this be at all remotely ...
2
votes
0answers
26 views

PCB antenna: ground plane layers and dimensions?

I'm using an Inverted-F antenna on a Bluetooth Low Energy peripheral/device I'm designing and I'm not sure how I should design the ground plane. The ground plane should not be "too big" nor "too ...
1
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0answers
26 views

antenna matching with lumped elements

Is there any resources online that describe how to match antenna elements to a TX line with a lumped element matching network? I've got a 50 ohm load and a TX line that i'm trying to match to a ...
1
vote
1answer
57 views

Using 1/4 dipole antenna on RF module

Good day to you all. Am new to RF designs. Presently, am working on a device using RF module for transmitting my signal from TX to RX. Am using the common 315-433MHZ RF module bought from ebay. My ...
0
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0answers
30 views

Wifi Antenna Selection

For a project I like to use a Wifi Antenna that has directional properties. Imagine the little box as my product that sits on the ground and I want most of the energy to be transmitted upwards. ...
1
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1answer
56 views

PCB microstrip antenna

I have a query regarding PCB microstrip antennas. Most of my antennas have been straightforward with the U.fl being placed close to the RF feed point. Maybe a PI filter is added. But I have seen many ...
1
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1answer
78 views

What is the name of the tiny PCB radio connectors? (e.g. Apple WiFi/Bluetooth antenna ports)

What is the name of the nearly-flush flat antenna connector often found in laptops/tablets for its external antennas? They are very small and the antenna lead usually has a 90º male plug that snaps ...
2
votes
1answer
288 views

2.4GHz antenna feed routed through pcb via?

I'm working on designing a BLE device, and have settled on using a chip antenna. It seems, however, that my BLE SoC is going to have to be on the underside of the board, which might be significantly ...
0
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1answer
60 views

what is meaning of wavelength in very short conductor length

I know the wavelength is distance between 2 point of maximum sine wave. when the conductor length is very shorter than wavelength, what is meaning of wavelength? ??(how long distance propagate in ...
3
votes
1answer
156 views

What is this type of radio fm antenna connector called?

I'm looking for an antenna replacement for my dad's busted radio (iHome IH8) and I'm having some trouble finding the name of this type of plug. The only things I find when searching online are coaxial ...
21
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4answers
3k views

True GPS Location - At the Antenna or Receiver Chip?

Suppose I have a GPS unit attached to an antenna through a 50 meter coax cable. How would the location as calculated by the GPS unit be affected by the cable length? As a bonus question, how would ...
0
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0answers
34 views

Why does this smart card use antenna with different space between turns along different sides?

I've extracted and zoomed to 400 percent parts of image from this post. The original image features the inner parts of Visa PayWave enabled smart card. Here're card corners zoomed to 400 percent so ...
0
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1answer
47 views

ANT-MMCX and Microstripe line and UHF RFID module circuit designing

Below, you see the only schematic of a 6 pages-datasheet of an UHF RFID module (working frequency = 840...930 MHz): There are three questions: What is that ANT-MMCX? I search it in Google and I ...
0
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0answers
49 views

Occasionally blinky reception; Damaged cable (pic incl.) contributing?

Please see: & Higher resolution versions are at (respectively) http://i.imgur.com/93Fk7HN & http://i.imgur.com/K7vTK52 Every few minutes our TV has pieces of the picture appear ...
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1answer
47 views

Wireless amplifier antenna

There is something like an antenna that works like an amplifier, repeating every signal in the device frequency operation range but wireless. I mean that this "dumb" active antenna receive every ...
0
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3answers
85 views

Can a magnetic wire be used to extend/strengthen the signal coverage of a cellphone? [closed]

When i'm inside of our apartment, getting a cellphone signal is very hard, often times I wouldn't get any bar in my iPhone. My unit is in the ground floor and is surrounded by tall walls. My apartment ...
1
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1answer
50 views

Send action signal via radio using energy generated by piezo

I have an idea going on in my mind but I am not sure if it is even feasible, so please be patient! Here is my problem. I have a set of chairs, say several dozens. I would like to be able to monitor ...
0
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1answer
53 views

Two 2.4GHz radio modules (XBee+Bluetooth) on same PCB. How to minimize interference?

I'm designing a PCB with XBee radio module and a bluetooth module (RFDuino SMD with XBee 2mW Radio). Since both of these modules are using 2.4GHz, are there any special consideration about how to ...
0
votes
1answer
119 views

how electron flow in circuite, when wavelenght is very long such as 5 kilometer?

1-My first question is: when signal with low frequency such as 100khz the wavelength of that is 5 kikometer that means between high and low voltage must be 5 kilometer .so when signal propagate by ...
1
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1answer
64 views

Can I create paths to two external GPS antennae but use only one

I am making a PCB for a SIM968 GSM/GPS device. Printing PCBs in my country is expensive. I am making this PCB for two different purposes. One is to work in an open environment where there is enough ...
1
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1answer
90 views

one antenna working as receiver and transmitter

I want to know, if an antenna which transmits and receives the reflected signal can be modeled as an impedance. For example, the antenna is coupled to a Collpits oscillator and sends out an ...
2
votes
1answer
43 views

Solder wire antenna on XBee Pro u.fl

I'd like to buy one XBee Pro with Wire Antenna, and another with an u.fl connector. The problem is that, on the only website I can buy them, the U.Fl one costs 20 € less than the one with a Wire ...
1
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1answer
76 views

Objections to use an RCA connector for antenna in broadcast FM receiver

Due to budget & space restrictions, I am thinking about replacing a PCB BNC connector used to attach an external FM antenna. It seems to me an RCA connector could be an option, given its good ...
4
votes
3answers
163 views

Possibility of an extremely directional antenna

I'm fairly new to RF technology, but a direction-finding application has come up where a highly directional antenna can offer a convenient solution, so I started searching for such antennas. Most, ...
0
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1answer
66 views

Antenna Gain explanation

I'm looking for an explanation about what type of relation have antenna gain with it's efficiency. For example I want to use a ceramic antenna that is a dipole antenna. It has: Average Gain of -0.5 ...
1
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0answers
48 views

HF RFID Impedance Matching

I come from a software background and I am learning about hardware. I built a simple arduino based bread board circuit that interfaces with a Skyetek M1-mini HF RFID module. I have had success using ...
0
votes
0answers
30 views

How antenna array factor is related to FFT of antenna weights

I have an uniform antenna array of N elements with unknown element spacing. Each element is fed with phase weights p1,p2,... ,pN. All elements are fed with uniform amplitude. I will take the M point ...
0
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0answers
58 views

Antenna elements within antenna arrays, confusion!

My questions here are regarding antenna array, RF chains, antenna elements, antenna gain. I will provide an example to illustrate question. Assuming we have 4 RF chains (transceivers) and a uniform ...
1
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1answer
90 views

Help to understand/ explore small sized 3G and GPS Antenna Design

I recently came across an exciting device called Automile, from Sweden and what caught my eye is this - I am really impressed by the packaging and overall quality of hardware integration they have ...
1
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1answer
45 views

Ceramic antenna for wifi applications

I want to ask how to choose correct ceramic antenna for wifi applications. I've very tight space constrictions and I need to use a small smd antenna. Which is the best antenna(characteristics) for ...
0
votes
1answer
52 views

How much power does a phone consume each time it ping its SIM's ID to the nearest cell tower? [closed]

I am trying to build a device than can be tracked through the cellular network. Like a phone, for every few second the device will ping its identity to near by cell tower, which will inform the Mobile ...
0
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0answers
44 views

What's the purpose of these peninsula-like areas in this smart card circuit?

Here's a scan of a stripped MIFARE Ultralight smart card. Note the underlined peninsula-like areas. They are simply connected from one end to the antenna track. They don't look like a patch antenna ...
5
votes
2answers
70 views

Why is outer turn of this smart card antenna wider than the other turns?

Here's a scan of a stripped MIFARE Ultralight smart card. Most of the wiring is the antenna which effectively consists of a single spiral track. The outer spiral turn clearly is a bit wider than the ...
1
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3answers
60 views

Dipole antenna VS. coil for RF transmission or recieving

Correct me if I am wrong, but all RF light waves are created via a changing electric and magnetic field. But when looking at all kinds of radios and RF circuits, this light wave is always made with a ...