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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36 views

How to detect several agents within a radius, what is the best and easiest way to do it?

I have a room with 30 objects which may or not be present, and I want to be able to detect which objects are in the room. My first idea was to attach a RFID tag to each one of these objects and have ...
2
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1answer
30 views

Analyzing reflection and transmission without a VNA

The wikipedia page for network analyzers mentions "reflection and transmission of electrical networks are easy to measure at high frequencies" but doesn't give any hint on how this is done or what it ...
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1answer
28 views

Trying to understand directivity of an ultrasonic sensor

I am trying to understand this plot of directivity from the following link: http://www.nicera.co.jp/pro/ut/pdf/T4010B4(ENG).pdf How do I read this plot? I can say that at 0 degree , the energy ...
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0answers
11 views

How to De-embed 3-port Network on ADS

ADS 2013 no longer has odd-port de-embedding. I want to eliminate the effect of a 3-port balun board on the measurement of the antenna. How can I do that in ADS? I tried using a 4-port de-embedding ...
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2answers
32 views

Shared antenna on multiple 2.4Ghz receivers

I want to use several 2.4 Ghz transcievers (not sure which IC yet, either Atmel AT86RF*** or TI CC) in order to build a simultaneous multi-channel sniffer. The transciever output is differential. I am ...
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4answers
71 views

Will having two antennae at the receiver give better reception?

I have a 300mbps router with two antennae (tp-link td-wd8968). I'm building a PC and looking for a wireless network card. I have seen seen cards with a single antenna (150mbps) and cards with two ...
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1answer
22 views

Using RF for relative direction finding for short ranges (sub 10m)

I'm considering building a short-distance direction finder to determine the relative position of two objects. I want to be able to determine direction through other objects, which eliminates IR or ...
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3answers
76 views

How to interpret these antenna radiation patterns?

The datasheet for this chip antenna shows a couple of radiation plots, but I don't know how they correspond to the physical orientation of the antenna. I want to orient the antenna so that the ...
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1answer
34 views

What's the correlation between spectral graphs produced using near field probes and ones produced using an antenna?

I've been looking at getting some equipment for EMC-precompliance on a budget (about £5k). I understand that I can get a spectrum analyser with some EMI options and some near-field probes (about £2k) ...
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2answers
58 views

Antenna phase shift

My question is regarding RF measurement systems which use antennas signal arrival time as principle of operation e.g. GPS. It is known that impedance of well-matched antenna immersed in lossy ...
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1answer
33 views

Dual GPS Antenna Connection to Possitioning Module

I am using a Positioning module that has a SMA port to hot plug an SMA antenna. It also has pins available through its foot print to connect a GPS Antenna. The module name is SIM908. I was not able ...
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0answers
51 views

Can I put a bluetooth dongle inside a cantenna?

I've got a remote temperature doohickey for my BBQ that bluetooths to my phone. Works great; love it; nice UI. It's small, 4 cm diam x 2 cm thick, but the range is good, 50-60 feet. But. I want a ...
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0answers
50 views

How do radio engineers control which modes gets to propagate through a wave guide?

Suppose we designed a rectangular wave guide and computed the possible cutoff frequencies for each modes (i.e. TE01, TE10, TM11/TE11) and determined a list of modes can be used to propagate a signal. ...
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3answers
245 views

High Altitude Balloon Communication

Our team is planning to make a HAB (High Altitude Ballon) project for our university. We are planning to use XBee pro 868 RF modules (we are in Europe so we can not use 900 MHz band). We have to ...
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2answers
64 views

Waveguides: How can you propagate at only one frequency?

In a rectangular waveguide, we know we can find cut off frequency as a function of mode and geometry. Is there a way to design the waveguide so to ensure that we can limit the frequency of ...
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1answer
63 views

Impedance Matching of Antenna and Amplifier

I've been doing a lot of research on impedance matching and I am just having a hard time understanding some of the specifics and I was wondering if someone here could help me out. I have a 50 Ohm ...
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0answers
30 views

EDGE/GPRS connectivity vs SMS connectivity through 2G GSM

I use a GSM module in my design which will be working in low signal areas such as inside forests. My application is designed to transmit information to a server via an SMS but I would like to use ...
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0answers
41 views

Antenna to reject 5.8Ghz Interference

I live a couple miles past where "normal" high-speed internet is available, and for years I have used a radio WAN link on a 70' radio tower to connect to my ISP in town, 4.65 miles away. I have a ...
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1answer
40 views

Building a NFC extension Antenna

I'm trying to find out how to build a circuit to extend the NFC range. NOT the range from the chip itself, but like following example: I have NFC enabled Tablet that has an built-in NFC chip. I ...
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1answer
58 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 ...
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1answer
48 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 ...
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1answer
41 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
38 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 ...
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3answers
615 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 ...
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1answer
126 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
84 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 ...
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2answers
61 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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39 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 ...
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1answer
29 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 ...
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4answers
400 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
53 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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42 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 ...
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0answers
34 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 ...
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1answer
149 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). ...
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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
38 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
48 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
72 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
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2answers
62 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: ...
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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
89 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
votes
1answer
349 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
73 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
51 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
36 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, ...
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1answer
37 views

Working of resonance phenomenon

How does actually the resonance phenomenon help to receive AM signals in a receiver?
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2answers
140 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 ...
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3answers
167 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
69 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
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1answer
72 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 ...