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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42 views

How big a ground plane does a gps antenna need?

How big a ground plane does a gps antenna need? I am using a GPS puck antenna that has a magnetic base to hold it on to, typically, the roof of a car. I would like to use it from my room at home, on ...
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1answer
38 views

Does a regular signal booster with antenna work for cell phone?

I am not that much familiar with communication and antennas. I want to build a gsm repeater (gsm signal booster), but I am not sure if it works if I do it like the way we do for a radio. What I am ...
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3answers
80 views

What is the voltage source and ground on an antenna?

I've seen a few diagrams relating to AM demodulation, and I can't for the life of me figure out where the voltage source and ground come from in an antenna. From what I understand, an antenna can ...
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2answers
59 views

Antenna VS Coil

So I sorta understand that antennas are just wires connected to a signal out with no reference to ground. (That's for a different question) How does a coil/inductor with one side attached to v+, one ...
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1answer
54 views

RF - separate transmitter and receiver antennas for half duplex

i was wondering why is it for just half duplex systems, don't we have a dedicated transceiver and a dedicated transmitter antenna. ok, just hear me out... assuming we are using grounded monopoles, ...
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3answers
98 views

Antenna Gain definition and uses [closed]

What it is Antenna gain? If the gain of the antenna is high, does that mean it has a big coverage area?
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0answers
24 views

What are the first 3 natural resonant frequencies of a bi-filar antenna? Any length.

I have a different type of question - in regards to 3D extruded antennas. What are the first 3 natural resonant frequencies of a bi-filar antenna? Any length.
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1answer
58 views

How to Calculate maximum distance between transmitter and receiver in wireless communication

how to calculate maximum distance between transmitter and receiver in free space radio communication by having transmitted power, antenna gain and noise-to-signal ratio ?
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0answers
39 views

ESP8266 serial-wifi: antenna options

The cheap ESP8266 boards are offered on ebay with two built-in antenna options: with a PCB trace antenna with a ceramic(?) antenna (PCB photographs see below.) Has somebody bought both and ...
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0answers
27 views

Voltage Across Patch Antenna and Power Output

I'm modeling a patch antenna using two copper plates (ground plane and patch), ceramic in between the copper plates, and a lead connecting the patch and ground plane that runs through the ceramic in ...
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2answers
40 views

Antenna efficiency and PCB impact

I'm trying to improve the range on my 433 MHz radios and came across http://www.att.com/edo/en_US/pdf/AntennaFundamentals.pdf. (Geez, there's so much RF information in many bits and pieces, if only ...
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3answers
248 views

Design of an electronic device to disable remote access ability of contactless payment cards without visible alterations and damage to the card

Question: How could I build an electronic device which disabled the remote interaction functionality of contactless payment cards while not affecting the functions which are accessed via the on-card ...
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0answers
54 views

motorcycles and vehicle ground loop detectors

I have been asked if it is feasible to make a motorcycle accessory that will trigger the traffic ground loop antenna sensors that typically fail to register the motorcycles presence. Reading up on ...
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0answers
37 views

Shared feed/GND pad on Pulse W3011 antenna

This is my first post; sorry if I've unwittingly broken any rules or accepted conventions around here... I'm using a Pulse Engineering W3011 ceramic GPS antenna. As is common with these small ceramic ...
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1answer
39 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
34 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
35 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
38 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
79 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
27 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 ...
2
votes
3answers
77 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
38 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
60 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
45 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
54 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
51 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
271 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
69 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
73 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
46 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
46 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
63 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
70 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
51 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
44 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
43 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
819 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
129 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
91 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
63 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
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 ...
0
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1answer
31 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
427 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
66 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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56 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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37 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
302 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
77 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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41 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 ?