Tagged Questions

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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1answer
44 views

Cheap 2.4GHz Antenna Tuning

I am planning on making a board which will have some 2.4GHz RF capabilities, and would like to know if there is a cheap way to tune an IFA cheaply. If I had access to the right equipment I could ...
1
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1answer
33 views

Wireless transmission power for multiple receivers

I have just started learning about wireless systems and for some reason I'm hung up on what I feel is a fundamental idea. Consider some transmitter-receiver pair with isotropic antennas. The receiver ...
0
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1answer
30 views

Helical wire antenna normal mode or axis mode?

I have bought theses two RF-transceiver CC1101 module from e-bay(image below), and I want to know if it is a helical antenna in normal mode or in an axis mode. The specification doesn't say anything ...
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0answers
31 views

IFA PCB Design Concern

The question that came to my mind once I did the tracing is , should I place a ground plane in the bottom layer of the PCB only and make the IFA trace in the top layer and then place a via in the head ...
5
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3answers
516 views

What will it take to build a DIY 2km (city conditions) RF transmitter (433Mhz)?

This is my first question on this site. I am not an electronics/electrical engineer so pardon my depth of knowledge. I am trying to build an RF transmitter/receiver. These are my end goals : a text ...
0
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1answer
89 views

Why does the GND of the Arduino oscillating as well?

I have an Arduino Uno and what it does is simply output an oscillating signal of 1 MHz on PIN11. I measured the signal using a oscilloscope and a probe with a ground clip. First, I connected the probe ...
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3answers
70 views

Antenna + LNA Design

I am trying to design and build an antenna + LNA board. Antenna: http://www.yageo.com/documents/recent/An_FR4_1690_2405_0.pdf LNA: http://www.avagotech.com/docs/AV02-1237EN The antenna is specced ...
0
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2answers
60 views

DIY antenna voltage output

If I make a basic 2.4 GHz antenna like from this link (http://www.wikihow.com/Design-a-Simple-Antenna) and connect signal pin and ground pin to oscilloscope what would I see ? I mean will there any AC ...
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0answers
34 views

How to debug and resolve an antenna interference problem?

We have had a board made that features an interacting processor, chip antenna and GPRS/3G module. We have proved the functionality of the board - it works - but the board is not stable. We have ...
0
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1answer
24 views

antenna feeds for SMT GPS patch antenna

I am designing a GPS board with an SMT patch antenna (SGP.25cfrom Taoglas). I understand that the rf feed is 50Ohms impedance controlled track. But the datasheet shows 2 feeds - inner feed and outer ...
9
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4answers
375 views

How is it possible to have a 5W transmitter driving 50 ohms with a 12V supply?

So let's say you have a circuit, which generates a carrier wave at some frequency (let's say 27MHz) and it's connected to a 50 ohm dummy load (which I gather is equivalent to an antenna for circuit ...
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1answer
37 views

Can A HP8756A Network Analyzer Measure The Resonant Frequency Of A GPS Chip Antenna?

I'm wondering if a HP8756A network analyzer by itself is enough to measure the resonant frequency of a GPS chip antenna? The reason I am concerned that it cannot is because I cannot see a "RF Out" ...
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0answers
34 views

Isolation between GSM and GPS antenna

We are doing a prototype for a gps based tracker. We got a problem in placing the GSM and GPS antenna. Both the GSM and GPS antenna are omni-directional antennas. In forums and application notes, the ...
0
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0answers
32 views

Is this an antenna or an inductor or both? And does the wire length/core diameter matter?

I have a small transmitter, and attached to it is this device: However, one of the wires attaching the circuit board to to circular red device is broken. I figured that since I have it all taken ...
1
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1answer
81 views

Connecting external 2.4GHz antenna to Intel Edison

I would like to connect an external 2.4GHz antenna to an Intel Edison. According to Mouser, there are different Edison part numbers for different antenna configurations (internal or external). ...
0
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2answers
75 views

Is possible to use wave guide to decrease beam width?

If I use a normal 1/4 monopole antenna "30 MHz for example" and cover it with metallic wave guide has a narrow beam width, should the gain increasing according to this formula below? $$G = 10 \; log ...
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0answers
34 views

Is possible to get very narrow beamwidth antenna?

Is possible to make 60 dBi sector or patch antenna by make its beam width 0.17°/0.17° only ? how to calculate ideal dimensions against frequency at this range of beam width ?
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1answer
37 views

How can I render my 2.4GHz antenna directional?

With barely no knowledge in this field, I would like to render my antenna used with Bluetooth BLE devices more directional. I tried to shield the antenna with different kind of metals with no luck. ...
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3answers
67 views

Calculating gain of multiple antenna system

Some radars have thousands of antennas, there are also some routers that have multiple antenna systems. But I want to know how to calculate total gain of multiple antennas in a system? Is it simply ...
2
votes
2answers
55 views

Inductor burning out in a GPS bias tee circuit

I've got a tracking device that uses a Telit GE864-GPS combined GSM/GPS module. The GPS antenna is connected to the Telit module via a bias tee circuit, as shown below: ...
0
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1answer
64 views

Data transmission in ocean

What is the greatest depth where we can communicate with the submarine over the sonar system in ocean? Also, how can we calculate how much data can be transmitted using this method?
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2answers
83 views

Does an antenna work inside a plastic box

I need to put two antennas for GSM and GPS communication on my PCB. My final product will be embedded in a user-friendly plastic box with buttons, leds and switches. I have not choosed yet which type ...
2
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1answer
310 views

What is an antenna amplifier ? How does it add gain?

I don't know what exactly does antenna amplifier mean. Is it possible to increase the gain of a Tx antenna ? Where do I connect the antenna amplifier to it ? If, for example, the Tx has a power of 20 ...
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0answers
61 views

Can a PC sound card (realtek) be used to transmit radio signals

If I were to use software such as PureData to generate a 20 KHz sine wave and perform AM on the wave, played it out the line-out on the right channel, with the ground and the left channel sent to a ...
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0answers
48 views

Easy-to-use Antennas for beginners

I am designing an embedded system with a GPS and a GSM modules both from the u-blox company. I need external antennas for my GSM and GPS modules. From what I see when I looked for antenna integration ...
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0answers
33 views

Arduino Broadband Peak Frequency Detector

I'm hoping to build a peak frequency detector, but am wondering whether I'm going to need more than just a couple of antennas. I'd like to be able to detect between 5Hz and 5GHz. So one question is, ...
0
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1answer
35 views

Working of resonance phenomenon

How does actually the resonance phenomenon help to receive AM signals in a receiver?
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2answers
139 views

Where does radiated power come from?

I've had electromagnetism classes back in uni, but I'm having a hard time linking them with that matter: Take a car antenna -which I assume is simply a wire, coiled or not-, and apply a voltage ...
2
votes
3answers
163 views

How should I test a coaxial cable?

I'm a ham radio operator, but haven't been very active on HF bands for a while. I have an inverted-V antenna and a long run (approximately 25m) of coax that runs from my upstairs "shack" down the ...
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0answers
58 views

How to increase the read range of an active NFC tag?

I want to read a NFC tag at a distance of 1m from my NFC enabled smartphone. Is it possible to do so by enhancing the antenna of the NFC tag (not the one on the phone). Size of the NFC tag is not an ...
1
vote
1answer
66 views

Two different length antennas can cause problems?

I am using two 443 MHz transceivers (FY-605 transceiver) with both having different antenna lengths. One antenna is around 12cm long and the other antenna is around 17cm long. Will this cause ...
1
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1answer
50 views

Relationship of antenna size to gain and directivity

This question is derived from certain answers I received for a previous question I posted. Case : Let's say I have two GSM antennas of the exact same shape, design and material. The only difference ...
1
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1answer
42 views

Gain vs. Directivity and effect of animal body to Antennas

My design works in a foresty area inside a collar of an elephant. These areas have at least -110dBm GSM strength (accurate ref. map linked) but, usually higher as I live in a small country where GSM ...
1
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1answer
86 views

How does a receiving antenna generate current/voltage?

I have see on many websites people explaining how antennas radiates energy. But I am failed to find an explanation on how a receiver (i.e. receiving antenna) generates current/voltage? Can anyone ...
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3answers
67 views

Waterproofing a GPS antena

I need to use this GPS antenna on a model boat. As a result of placement, it will be submerged periodically (though I don't expect it to work while submerged), and damp often. What can I encase it in ...
0
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0answers
235 views

433MHz quarter-wave length antenna: Longer is better?

I am trying to conduct an RF project using some cheap modules: link here My problem is that even though most blogs and Google searches for these modules use a quarter-wave length antenna (roughly ...
1
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1answer
51 views

How does the impedance that voltage “sees” while traveling down a tranmission line affect how the current move down the line?

It is well known that the voltage sees different impedances while traveling down a tramission line, and this impedance is a function of the intrinsic impedance of the line Zo and tangent of wave ...
0
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1answer
148 views

Length of a 40MHz antenna

A few days ago I had the brilliant idea of replacing the ugly antenna of a 40MHz car remote control with an extendable one. Now the range decreased from 50 meters to 3-4m. I don't know exactly what I ...
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2answers
68 views

What is actually transformed in quarter wave transformer?

I'm reviewing some stuff on quarter wave transformer for a transmission line but since I have not had any experienced in handling these type of stuff, I am struggling to understand this concept ...
5
votes
1answer
261 views

Antenna Design for specific directions

I am designing an antenna for a device and was hoping to gain some insight in the correct design direction for the antenna. The Idea: A receiver & antenna that fits in a 6" diameter by 3" deep ...
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0answers
57 views

Material that Degrade GPS Signal Reception

Between clear tempered glass (see through,thick & very strong) Vs. coloured plastic material, which would result in more degradation of GPS signals if used to make a box? The box contains a ...
0
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1answer
52 views

Important Parameters to Check while Chosing a GSM/GPRS Antenna [duplicate]

what technical parameters decide the performance of a GSM/GPRS antenna? (excluding power consumption and size) I have found out several antennas that have 3dBi gain. And I want to chose between them. ...
0
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0answers
59 views

Mobile Phone GSM Antennae Used | What are the Latest Types?

What is the best antenna type mobile phones are incorporating nowadays for GSM/GPRS connectivity? Is it PCB etched antennas or anther? I want to know this because mobile phones have the same ...
2
votes
0answers
53 views

Is 3dBi PCB etched GSM/GPRS Antenna Possible?

Is it possible to design a GSM/GPRS antenna that has a gain of 3dBi? if not, what is the maximum gain possible with a PCB GSM/GPRS etched antenna? I'm thinking of a PCB sized 11cm long and 5cm width. ...
0
votes
1answer
45 views

Impedance line matching and component value matching

I have the following circuit for the SIM900's antenna connection, using the A10393 antenna from digikey: In closer look: First of all my knowledge on RF design is not great. My questions now are ...
1
vote
1answer
68 views

Connecting dipole antenna for transmission

I have a small FM transmitter on a breakout, the antenna is a single connection. It came with a thin blue wire for this purpose; below it spirals up and out the top of the photo. This works fine ...
4
votes
1answer
76 views

How to reduce objects/hands impact on PCB antenna efficiency

I am trying to learn about planar inverted F antennas creation and have designed two different designs for two different frequencies with success. One seems pretty much unaffected by the proximity of ...
0
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1answer
119 views

Is it possible to extend the reach of a pn532 NFC/RFID shield?

I am working off an Arduino UNO with an AdaFruit pn532 NFC/RFID shield. The goal is to have a shoe box, with a false bottom. Under that false bottom would be my prototype, which hopes to be able to ...
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0answers
58 views

RFID reading / sniffing demonstration at a live-event

In the context of a live-event, we want to demonstrate how easy it is for someone with the right equipment to sniff RFID devices, including clear-text information. Our idea is to hide a RFID reader ...
0
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1answer
66 views

What components do I need to connect a phone to my device via Bluetooth?

I have a phone I want to connect to a docking station I am making, via Bluetooth for as cheap as possible. As I understand the situation, all I need is something that can pick up a bluetooth signal ...