Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g. TV or radio) waves. -Wikipedia

learn more… | top users | synonyms

16
votes
3answers
2k 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
votes
0answers
32 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
votes
1answer
31 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
votes
1answer
55 views

Best way to fix bent antenna elements [closed]

I'm about to inherit a High Gain (Long VHF elements) VHF/UHF antenna that I understand satellite/cable installers have bent some of the elements of! The elements are believed to be hollow tubed ...
0
votes
0answers
46 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 ...
-1
votes
1answer
38 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
votes
3answers
58 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 ...
0
votes
1answer
38 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
votes
1answer
30 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
108 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
vote
1answer
40 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
vote
1answer
58 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 ...
1
vote
1answer
31 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
vote
1answer
71 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
134 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
votes
1answer
50 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
vote
0answers
33 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
23 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
votes
0answers
56 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
vote
1answer
45 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
vote
1answer
37 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
50 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
votes
0answers
43 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
69 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 ...
0
votes
2answers
31 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 ...
0
votes
0answers
24 views

Adding U.FL connector to XBee

I recently bought two XBee Series 2 Pros, and I want to increase the range on them. I found an appropriate 2.4GHz antenna with a U.FL connector. I already have one XBee with a U.FL connector and from ...
0
votes
1answer
62 views

Basic NFC Loop Design on PCB

I'm a college student learning the basics of NFC loop antenna design. As a starting point, I'm trying to design a PCB-based rectangular NFC loop operating at 13.56 MHz, matched to 50Ω. (NFC ...
0
votes
1answer
129 views

Unknown short-circuit between GND and ANTENNA pins of GSM module

I have a Quectel M72FA GSM module, brand new one. I have just soldered it onto my PCB and found that: there is a short-circuit between the GND and RF_ANT pins. This is the pinout: I have checked ...
-2
votes
2answers
95 views

configuring a DPDT switch to choose between two RF signals

I have 2 different signals coming in I wanted to be able to switch between them (choose what to transmit) using a simple DPDT switch. I have the following configuration, but I feel like I'm missing ...
0
votes
0answers
40 views

What does KFD stand for in a N type RF Connector

A RFID antenna supplier specified the antenna connector as N-50KFD Female. After a lot of googling I was unable to determine what does the KFD stand for. Is there a standard for these letters. I ...
0
votes
1answer
33 views

How do you account for receiver sensitivity in tranceiver half wave dipoles?

if you are to design 2 halfwave dipoles, both can transmit to each other using 3 watts and have receiver sensitivity of -80dbm (a picowatt). Suppose they are 800m and have same height from ground. How ...
0
votes
0answers
27 views

ANTENNA pin and GND pin low Ohmic resistance (looks like short-circuit) WISMO218 GPRS chip

I have for my school project a WISMO218 GPRS chip that I had to interface in order to send and receive SMSes, I had my board printed, soldered this chip (SMD) to the board and it seemed that the ...
2
votes
1answer
68 views

FM Antenna Question

I am a swim coach trying to play music for my swimmers while they swim. I am currently using this transmitter with this antenna . I have no issues with the transmitter as it is more than powerful ...
3
votes
3answers
353 views

What makes this active antenna “active?”

I'm using a external taoglas GPS/Glonass active antenna. It has a male SMA connector and I don't see where any voltage source hooks up to thing. So how is it active? Or does the power required for the ...
1
vote
1answer
50 views

Coplanar waveguide vs open space?

I'm routing a U.FL connector to a cellular module (Telit GE864). According to this calculator a 1mm track with 0.16mm gaps should provide a 52Ω impedance path to an U.FL antenna connector. A ...
1
vote
1answer
69 views

Interfacing a GPRS chip (WISMO218) with an RF antenna. Calculating line width for the right impedance

I want to interface the WISMO218 GPRS chip with an antenna. The antenna lines on the PCB board have to be very specific, otherwise the system won't work. I have uploaded the part of the datasheet that ...
0
votes
2answers
111 views

433mhz micro directional antenna design

I'm trying to build a Radio wave penetration device that register the RSSI on the RX module. There are two 433 transceivers one is the RX and the other TX - I want to place between them different ...
1
vote
2answers
173 views

Explanation for: A monopole antenna must contain a resistor (or equivalent) and therefore must have 2 terminals?

Could someone explain why this sentence makes sense: A monopole antenna transfers energy from electrical domain to the electromagnetic domain, hence must contain (equivalently) a resistor, hence ...
0
votes
1answer
59 views

SPICE how to assign a variable voltage generator for receiving antenna

I would like to do an AC analysis, noise analysis and signal to noise simulations using TINA TI - LT spice is OK How do I assign a variable voltage with parameters to an AC voltage source in SPICE? ...
1
vote
1answer
60 views

Bluetooth Modules in a plastic enclosure

I would like to implement a bluetooth functionality in my project, preferably using STMicroelectronics SPBT2632C1A.AT2, with a protective enclosure. But I read from multiple sources that bluetooth ...
0
votes
1answer
58 views

Vivaldi Antenna: size & max input power & software simulation

First, I've to say I'm a beginner in this field so please forgive me if my questions were not smart. I was reading about Vivaldi antenna and I decided to do an experiment; I'm going to use a flat ...
1
vote
2answers
51 views

Antenna mounting question

Here is the datasheet and drawing of the antenna on this link I need to stick out the antenna from a thick metal enclosure, how much of the antenna should stick out? Is it 19 mm (the black rubber ...
0
votes
0answers
57 views

modeling AC resistance proximity and skin effect using LTSPICE

I'm designing an air-core loop receiving antenna from <1Hz - 50kHz. Is there a way to approximately model the skin/proximity effect using lumped circuit parameters in SPICE software? I think you ...
0
votes
1answer
28 views

Current and voltage distribution on a beverage and on a rhombic antenna?

Afternoon. I've been learning about antennas a lot lately, and right now i'm reading about both of these, been trying to find a read about their voltage and current distribution but so far i haven't ...
2
votes
2answers
127 views

How can I best fake an (AM radio) antenna signal?

I have an old (~late 1920s) AM radio that I'm currently working on. As I don't want to modify any of the internals significantly, it would be nice to have a way to fake antenna input. It's not ...
0
votes
1answer
56 views

Are all antennas traveling wave antennas?

I've been reading a lot about traveling and standing waves, and I am right now reading about traveling wave antennas, to my understanding ALL antennas should be traveling wave antennas, but this is ...
0
votes
0answers
20 views

RF Propagation of a beacon placed in a narrow hallway

If the walls are sufficiently thick concrete which have very high attenuation, and if the red circle is a beacon/ibeacon with an omni antenna, what is the expected propagation pattern? I want to ...
1
vote
2answers
50 views

Will an impedance matching network also act as a filter?

Will a matching impedance network also act as a filter? I'm using a pi network and am wondering if I should also add a filter. I designed the pi network by using the program SimSmith and it consists ...
0
votes
0answers
48 views

Transmitting data over Long range ,using a Low Power Circuit

I Have Been Designing a BOT That Would Travel Along the Pipeline And Detect Leakage Using Ultrasound Efficiently,And Locate The Position of Leakage Using A GPS MODULE using the Arduino,I have make it ...
0
votes
1answer
90 views

wifi / WIMAX antenna

What the different between WiFi antenna and WIMAX 4G antenna?, I want to boost the signal for my router to 4 km, I found this antenna in local store, but it seems weird there is only 1 leg, not like ...