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

3
votes
4answers
572 views

Trying to reverse engineer a simple circuit

My only experience with electronics is a bit of playing around with an Arduino starter's kit, but nevertheless I decided to buy a cheap little remote control car and figure out how it works and see if ...
2
votes
3answers
92 views

PCB design consideration for a SMA antenna

I am designing a PCB with the transceiver SX1231 (868MHz) with a SMA connector for the antenna. I don't know much about antennas. I would like to know if there is some parameters I need to be careful ...
3
votes
2answers
339 views

433MHz RF transmission only working when holding usb cable in the air

I'm really puzzled about this. I have a simple transmission between two ATTiny85's going on with a 433MHz receiver and transmitter. The transmitter is in the basement so the signal is rather weak but ...
1
vote
2answers
26 views

Altium clear region

I have a four layer board: Signal, GND (internal power plane), VCC (internal ground plane), signal. My design includes a chip antenna that requires a completely cleared region at the edge of the PCB. ...
0
votes
2answers
22 views

Can the range of a monostatic RFID antenna be increased using an amplifier?

How does an RFID reader monostatic antenna both transmit and receive at the same time, are they CW or pulsed? I would like to extend the read range of a reader by using an amplifier between the ...
0
votes
2answers
48 views

Reception voids with two omni antennas at 90 degrees

We are using two omni ferrite rod antennas to transmit a signal at 125 KHz. The two antennas are positioned at 90 degrees from each other on the PCB plain, and the device installation is with the PCB ...
0
votes
1answer
26 views

What is feed coefficient / weight of the array factor in an antenna array ?

In the image, ri means the location of the element in space(x,y,z). and k is alpha + pi*d*cos(thetha)/Lambda and the R(theta,phi) is the radiation pattern of individual element. In the array ...
1
vote
0answers
46 views

Antenna array weights and Power input

A big request for clearing this simple doubt. For an application, I am using antenna arrays(say dipoles and array length is 11 elements). Now, this antenna array will have the beamforming vectors ...
0
votes
0answers
51 views

Tuning a loop antenna to reject unwanted signals

I have a loop of wire which is used to receive a modulated signal from a small transmitter that I made. The transmitter is attached to an RC car and allows lap timing by detecting when the car passes ...
3
votes
2answers
120 views

How small can a radio transmitter be?

Lately, I've heard about a fascinating new technology called DNA Origami, where incredibly tiny machines are folded out of DNA. Using CAD software they are able to build all sorts of interesting ...
0
votes
1answer
38 views

DIY RFID reader antenna array

I want to build a DIY RFID reading system that can read a wide surface area. My idea is to connect one single PN532 chip with multiple RFID antenna using multiplexing. The antenna must be as thin as ...
2
votes
1answer
86 views

How does a cube sat communicate with ground station with a 1w antenna

I heard that cubesat signals can be received with a hand held radio. Its confusing me that how a 1 metre antenna radiating 1watt energy can simply be received using hand held radios. I am designing a ...
2
votes
1answer
49 views

433MHz sender/receiver modules share antenna

I am using a sender and a receiver for the 433MHz band, looking like these. Is it possible to share the send and receive antenna and attach one good instead of two wire antennas?
6
votes
0answers
119 views

Does putting a car remote on your chin make it more effective? [duplicate]

Recently asked on Physics.SE: Why does a remote car key work when held to your head/body? And also, similar claims abound. RF engineers know that putting a big conductive thing like a human head ...
1
vote
1answer
43 views

Routing traces for GPS antenna input

I'm trying to integrate a breakout board circuit from SparkFun into my own design. It uses an external coax antenna with a SMA connector. I've brought their circuit over in its entirety, and from a ...
0
votes
1answer
54 views

What's a good way to detect ambient EMF from a distance?

I am an artist working on a project that, distilled for simplicity, will change the color of LED lighting based on ambient EMF. I've got a prototype built (based on A MAKE magazine project video) ...
1
vote
1answer
82 views

To what extent can Gielis' so-called “Superformula” be used to improve the efficiency of WIFI antennas? [closed]

I am new to this Stack Exchange venue, so please don't shoot me if this question is not appropriate. This question was taken Math Stack Exchange. In 2003, the Belgian plant biotechnologist Johan ...
1
vote
1answer
65 views

Placing UFL connector in 3G dongle

I purchased a 3G dongle from an unknown manufacturer (ZD Incorporated), and I am trying to boost its signal with a 3G antenna. I'm on the assumption that the manufacturer did not put an antenna there, ...
2
votes
1answer
40 views

Transceivers - how to select an appropriate antenna?

I was considering purchasing these small transceiver modules but am unsure about sizing the antenna. I recall having read somewhere that the antenna must be in proportion (wavelength/4) to the ...
0
votes
0answers
42 views

No radio signals with antenna

I have an antenna I made with about 2 feet of insulated copper wire, stripped at one end. The antenna is connected to the positive side of a 1000uF capacitor, using this circuit. I am using a 741 ...
0
votes
0answers
31 views

Amplifying an antenna signal before rectifying it

I do not have any germanium diodes for a radio project I am working on. Due to this, I must amplify the antenna signal before I rectify the signal, as I will be using a silicon diode. How do you ...
0
votes
0answers
36 views

Grounding a monopole antenna in an amplifying circuit

I have an antenna that is a spool of wire with one end stripped. I have a configuration like this. When I test the light green and cyan wires on this diagram with a multimeter, I do get a positive ...
1
vote
2answers
63 views

Horn antenna Radiation pattern

Ok This might sound dumb but I am trying to get an equation for the radiation intensity of a pyramidal horn antenna in spherical coordinates. I got a whole bunch of books and they all have the same ...
1
vote
4answers
199 views

Are wireless links symmetrical in practice?

From the top of my knowledge in the theory of EM propagation, two antennas show the same gain if used to transmit from A to B or ...
3
votes
2answers
56 views

How can I deal with interference from a test RF signal (XM radio) in order to get a live RF signal of the same type?

I'm located at a manufacturing plant where they have a test XM radio signal. I have a software engineering department located at the same plant that needs to work with a live XM signal. The plant's ...
5
votes
1answer
78 views

How do I calculate the hysteresis losses of a straight line inductor?

In using a particular type of conductor for an antenna in AC frequencies between 3MHz and 30MHz (HF), it was suggested that magnetic hysteresis losses may be significant if the permeability of the ...
0
votes
0answers
48 views

Do I need an antenna analyzer to make a good aerial?

I assemble a low-power FM transmitter (100MHz carrier wave) with a whip antenna. Can I get a reasonable efficiency using only EZNEC-like soft or do I need an antenna analyzer? By reasonable ...
2
votes
1answer
106 views

Wirelessly power multiple LEDs with antenna?

I'm working on a project that requires me to build an antenna and I'm not very experienced with wireless transmission. Here is an overview of my project: Four parking spots for cars with pressure ...
0
votes
1answer
74 views

Why an antenna is used in this electronic electroscope circuit?

Why is an antenna is used in this electronic electroscope circuit? I would like to do this as my mini project.
0
votes
2answers
68 views

Directional Wifi Antenna

I am looking for small size(preferably pcb mount) wifi antenna that is directional, more specifically half sphere coverage area. The product I build stays on the ground and I like utilized antenna ...
0
votes
2answers
72 views

Reducing system voltage whilst getting the same output from a PCB antenna

I have built a small prototype transmitter, based on a schematic available online. It transmits on a 5Mhz carrier and uses BPSK modulation. It works well enough for my purposes. The schematic for ...
2
votes
2answers
398 views

What type of antenna does the Xbox One controller use and how can you disable it?

I recently cracked open an Xbox One controller, the impetus for doing so was two-fold: First and foremost the engineer in me likes to see how things work under the hood as I learn a great deal that ...
2
votes
2answers
63 views

Two chip antennas, same ground plane?

I would like to use a 430mhz RF antenna and a 1575mhz GPS antenna. Both antennas are chip and drive current in the ground plane to radiate. The RF antenna is only useful 1s every minute. The GPS has ...
1
vote
2answers
216 views

What is this inductor looking (RF) component?

This PCB antenna circuitry supposedly is able to transmit on both 406MHz and 121.5 MHz. I can clearly see a micro-strip printed antenna. ...
1
vote
1answer
84 views

GSM 3G VSWR and antenna testing question

I'm a recently converted SW engineer to EE (Graduated less than 3 years ago, BS in Comp Eng, focus on Digital hardware) and I've been made the hardware lead on a project here at work. The project is ...
2
votes
1answer
87 views

Can anyone identify this tiny 2.4/5.8GHz antenna connector?

I'm looking to add a pigtail and larger antenna to small wireless video receiver. It came with a removable antenna with a connector I don't recognize. Sorry for the blurry pictures. If they're not ...
3
votes
2answers
120 views

Why does coaxial cable cause this effect?

This is a follow-up question related to my non-contact voltage detection circuit (here). I wanted to be able to detect voltage in a wire a few feet away from the Arduino, so I added a length of RG174 ...
2
votes
1answer
96 views

GPS accuracy problems outside vs inside with repeater

I have an interesting problem testing GPS receivers: While working inside our lab, we get reasonable results. We have a GPS repeater, as shown in the picture. Inside the lab, I get good accuracy ...
1
vote
1answer
99 views

Prototyping an antenna array receiver

Disclaimer: I am decent with math/theory, but I have zero hardware knowledge (apart from some basic microcontrollers). I'm looking to build a (possibly crude, but functional) hardware prototype of a ...
2
votes
2answers
240 views

Updated. Extending Range of a microstrip antenna with a SMA 2.4GHz Omni Direction 20db wifi antenna

Dear all I have the bellow A2DP bluetooth module which has a zigzag microstrip antenna. I want to extend the gain in the antenna with my 20db wifi antenna. I know as far as that I need to scrape the ...
1
vote
2answers
87 views

What is the difference between a tuner and an antenna?

I was just told by my TV's customer service that my TV had a tuner but no Antenna as a response to my question - Can I use my TV's inbuilt Antenna to pick up over the air channels? I was wondering if ...
2
votes
1answer
112 views

RFID Based Listening Device

I was just trying to make a passive cavity resonator based listening device just the same way as Leon Theremin did (the great seal bug). I know that I am to use metallized mylar film as the diaphargm, ...
1
vote
1answer
77 views

How to modify a router's antenna? [closed]

I have tried to extend the antenna of my router in order to increase its range. I added a wire few cm long. There was no modification however in the range. The power (-db/m) was the same. Why is that? ...
4
votes
1answer
164 views

Properties of a WWVB Receiver

In this article the author dissects a radio-controlled clock that syncs with the NIST transmitter, WWVB, in Colorado. The radio receiver seems to be a single integrated unit: Of special note is ...
1
vote
1answer
102 views

50 Hz antena for monitoring mains frequency fluctuations

I would like to follow fluctuations of the mains frequency (50 Hz, yes, I know they are very low) in the lab without connection to the wall socket. I suppose it should be kind of antenna (capacitive ...
4
votes
2answers
218 views

13.56MHz RFID Antenna design

I am currently in the process of building an RFID access system for my house + car. I've worked out the software side (I am using an arduino) but am having difficulty with the hardware side. I bought ...
2
votes
0answers
44 views

Antennas size vs wavelength [closed]

I have heard that the antenna (transmit of receive) has to be \$\frac{1}{2}\$ wave length. Could someone please explain why that is and also why can't we do with an antennas smaller or larger than ...
0
votes
1answer
82 views

Differenece between TV Indoor antenna and Satellite Dish [closed]

Satellite Dish for TVs enables you to gain access to paid tv shows through subscription. I'd like to know if the Indoor antenna specs below can also get paid signals on the air and if it could be an ...
4
votes
1answer
318 views

433MHz Module Antenna Ground

I have these common ebay 433 module pairs pictured below And trying to hook up external antenna. On the TX there is a little hole marked ANT which works for that. On the RX pictured (XD-RF-5V) there ...
1
vote
3answers
69 views

Multiplexing RF Sources to a Single Output

I have two wide-band VCOs, one 800-1600 MHz and the other 1600-2700 MHz which I would like to multiplex so that they can share the same output (SMA jack). (They are both configured to produce ~5 dBm ...