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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28 views

Using CP antenna for receiving and LP for transmitting

I've set up two antennas with Linear Polarization (LP) in both sides, in 2.4 GHz no more than 4 meters each other, but they are facing strongly obstruction object (like a big steel wall in they line ...
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1answer
28 views

Detect incidence angle with an antenna array

Having an antenna array, how can we determine incidence angle of an incoming signal. I know it is related to the phase of the signal in each antenna but I only found information about how to send a ...
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28 views

Which antenna combination is the best?

I understand that the polarizing affects of helical and clover/mushroom antennas can help to extend the range of a transmitter receiver pair. I'm not sure though, if I can mix the two so that I would ...
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0answers
56 views

How to improve FM radio reception [on hold]

I have a Pioneer HiFi amplifier+tuner but the FM radio reception is very poor, probably because I don't have the antenna cable anymore to plug here (see image below). (But I also remember that when I ...
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3answers
51 views

How to adjust receive-only antenna?

I don't understand most of the antenna balancing instructions I read; for one thing they virtually all seem to assume the antenna is being used to transmit. In my case I am only interested in ...
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1answer
34 views

2.4GHz Bluetooth PCB Trace Antenna Range

I have designed a PCB trace antenna for a BLE module. I used an existing reference design, which is offered to be used in your own design. I am able to connect to the radio, and on a spectrum analyzer ...
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3answers
50 views

Efficiency of Antennas vs operating frequency

I have refereed a document from TI which mentions that antenna efficiency decreases as frequency is further decreased. Although 136 - 240 MHz has highest range for equal power, the efficiency of ...
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0answers
18 views

HF RFID 13.56MHz Interference from WiFi/BLE 2.45GHz?

If a Wifi/BLE antenna were placed within a multicoil loop antenna for 13.56MHz HF RFID, would there be significant crosstalk/interference?
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3answers
323 views

Radio wave interference

While studying radio electronics I stumbled across a small article about wave interference on the same frequency. The article was very simple explaining that if there a stronger emitter on the ...
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1answer
36 views

multiband antenna for RF

I'd like to make a small chip using either the Texas Instruments CC1101 or the Nordic nrf9e5 that provides a range of different frequencies. This is mostly meant to be a tool for playing around at my ...
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6answers
281 views

Reradiating antena for GPS

I need to test and maintain a batch of devices which contain GPS modules. I can work on the rest of the device, but when it comes to test the GPS part I have no signal on my desk, no matter how near I ...
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1answer
60 views

Should I use a passive or an active filter?

simulate this circuit – Schematic created using CircuitLab I need to design an am receiver as a project. On the front end I have three modules; BPF1 the "roofing filter" or the ...
2
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1answer
51 views

Wires acting as input and Output

I always wondered how ear phone wires acted as antenna giving input to the connected device and also acted as the output driving speakers... Does the the frequency of these has to do something with ...
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2answers
108 views

What RF attentuator would be used for the HackRF?

Background info: The HackRF is an SDR Radio capable of receiving and transmitting frequencies from 10MHz to 6GHz. Michael Mossmann, the creator of the HackRF, states in his wiki that: The ...
2
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1answer
45 views

impedance matching single vs series capacitor

Im looking at a impedance matching circuit on a schematic that shows a .75pF capacitor pulled to ground. With my current board design I have a 1pF and a 3.3pF on the board already so I am thinking ...
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2answers
57 views

What technique can I use to focus a Bluetooth 4 transmission (or at least shield it)?

I'm actually trying to focus an iBeacon that uses Bluetooth 4.0 LE. These transmit in the ISM band from 2.4 to 2.485 GHz. Normally these things radiate in a spherical, or half spherical pattern, but ...
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0answers
50 views

how to connect an 50 ohm antenna to 600 ohm amplifier?

May i connect an 50 ohm antenna to an 600 ohm amplifier using a: sma connector ; double shielded coaxial cable; twin flex
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4answers
106 views

In a gps receiver, how is the delay of the signal in the antenna lead allowed for?

In a gps receiver there is an inevitable time delay in the signal travelling in the antenna lead to the circuitry of the receiver. In a typical 5 metre lead the delay is about 15 nanoseconds, which, ...
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1answer
90 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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2answers
58 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
84 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
66 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
88 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
106 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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25 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
97 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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1answer
76 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
36 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
41 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
283 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
65 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
51 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
43 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
36 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
33 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
69 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
44 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
92 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
32 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
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3answers
89 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
67 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
63 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
70 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
52 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
306 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
73 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
81 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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74 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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57 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 ...