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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16 views

How to install an embedded GPS patch antenna

How should I install an embedded GPS antenna? Here is the antenna in question: http://www.robotshop.com/ca/en/seeedstudio-embedded-gps-antenna-for-gps-bee.html It has a 9 cm cable. My project ...
-1
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0answers
38 views

Antenna Diversity: two Yagi antennas to the Rx and Rx/Tx u.fl-male points on the wifi-NIC?

I looked at the BCM4312 file - available as as doc or a pdf - and it says: BCM4312 has 2 radio chains, one is a dedicated Rx chain, the other is shared by TX and > RX chain using an RF switch ...
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2answers
43 views

RF Energy Harvesting Project

I am presently working on an energy harvesting system using RF signals. I have read some of the other posts made on this topic and have learnt quite a few things. However, I have some questions that I ...
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0answers
58 views

What kind of antenna is this?

The product page for this antenna supplies meager information. Do any of you RF gurus have a guess what kind of antenna this is as well as any other insight or reference radiation patterns?
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1answer
19 views

Multi-antenna extension for NFC

Like many, I am new to this. I am working on a project that would require a short read range over a covered space, like a person's body or table top. Could I make an extended antenna from my smart ...
3
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2answers
205 views

AM and FM reception with the same antenna

I'm designing a radio with the Si4735 chip to use in a car, and I want to use the existing FM antenna for both FM and AM reception. I'm not sure how to go about this, exactly. How would I go about ...
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1answer
48 views

Improving reception of 318MHZ remote control

We have a gate opener with keyfob-type RF remote transmitters that operate at 318MHZ. The range from inside the car is about 75 feet -- less than we'd like due to the time taken by the gate ...
-1
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1answer
49 views

Separate antenna for radio transmitter and receiver

I am building a HAM radio. Do I need a separate antenna for transmitter and receiver? I will be using 20m band and voice communication (No Morse code). My primary requirement is that I should be able ...
-1
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2answers
58 views

What are evanescent fields?

I am not able to understand what is the origin of the evanescent field, how do they interact and what is the physics behind it.
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1answer
57 views

SNR vs Signal Strength for digital throughput

I'm trying to compare two antennas, A and B for WiFi. A is showing: Signal Strength of -77dBm, but SNR of 9dB. B is showing: ...
0
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1answer
100 views

What is the difference between peak-power, average power and true RMS power in RF measurement?

What difference between peak-power, average power and true RMS power in RF measurement? I have read a peak-power measurement can calculate average power measurement also. Does any of these needs ...
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2answers
84 views

What power is measured by a spectrum analyzer?

Is the signal level that is shown in a spectrum analyzer power of the signal being measured. If yes then what power is it: average power, true power or peak power? Also when using a power meter for ...
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0answers
41 views

Determine current so that you have circular polarization

I have a problem in resolving the first point of exercise on antennas. Note: if it wasn't clear \$\phi_1\$ and \$\phi_2\$ are phase of alternate currents \$I_1\$ and \$I_2\$ I know that to have a ...
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1answer
69 views

How does square metal plate antenna work?

I have a GPS receiver(works at 1575.42 MHz) with chip-antenna: As I understand, this metal square plate is an antenna which is connected to PCB with short 5-6mm metal rod. This metal rod is hidden ...
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votes
1answer
76 views

What signal will come in?

I have a simple setup as shown, I would like to know what kind of RF signal will come in? Since the filter is configured around 2.4GHz, will all ISM (WiFi, Bluetooth, Zigbee, etc.) come in? The ...
2
votes
1answer
56 views

Patch Antenna Inset Feed Past Exam Question

I'm trying to work out what 3.d) is meant to be. I'm not entirely sure which part of the antenna it is referring to; I assume it's referring to width of the gap between the feed and the patch. If ...
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0answers
49 views

How to calculate Input backoff per carrier of a satellite

I was trying to calculate the sizing of SSPA in my satcom network where input backoff per carrier is required to calculate Power flux density. My current network configuration in C band is Total ...
6
votes
1answer
128 views

A poor man's alternative to a network analizer for antenna matching

I'm doing a small board with a 915 MHz transceiver. A small helical antenna is used, which is located on board with a very short path (10 mm) from the IC, including balun and a matching network. There ...
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0answers
41 views

ADC and Pre-Amp Suggestion for RBpi

I want to receive VLF signals (between 15kHz to 30kHz) with my RBPI. So I can found only this antenna: Miniature Very Low Frequency Antenna ANTM1. This miniature 6 inch long antenna can be ...
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0answers
47 views

The BLE antenna make my CC2541 chip broken?

I design a BLE board for transfer data, In the beginning, I can burn the program into the CC2541, and work well. But, when I transfer the data about few minutes the CC2541 was broken, and the ...
3
votes
1answer
109 views

Antenna matching network. What? Why? How?

I'm designing a small board featuring a transmitter in the 900 MHz band. Since RF is definitely not my strongest subject, I'm basically trying to follow all the datasheet recomendations regarding ...
3
votes
1answer
96 views

How does this antenna match work?

I had a matching technique described to me by a professional broadcast engineer. Here's the problem: you have a vertical antenna with a low resonant impedance1, let's say \$38\Omega\$, but you need a ...
6
votes
2answers
196 views

How does this quartz antenna work?

I picked up something called a quartz antenna at a surplus store for $2.75 so I could tear it apart. This is what I found: There were two small cardboard boxes filled with loose quartz crystals ...
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1answer
58 views

Good book/reference for electromagnetism and distributed elements model

I am looking for a good explanation of what is in "between" of Maxwell's equations and the lumped model. I am talking specifically of RF electronics and the distributed elements model. I am ...
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1answer
94 views

Connect VLF antenna to raspberryPi

I want to connect two VLF antenna (given below) to a RaspberryPi using it's GPIO ports with a MPC3008 ADC. Desired frequency range is between 3kHz to 30kHz, and MPC3008 supports 200,000 samples/sec ...
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2answers
272 views

Does the orientation of a Bluetooth antenna affect the transmission distance?

I'm doing a project with a Bluetooth device for the first time, specifically with a JY-MCU Bluetooth module: As you can see, the antenna is on the green PCB, which is in turn soldered to a breakout ...
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0answers
33 views

MIPI RFFE software implementation

I'm currently trying to implement the MIPI RFFE (As master) protocol on a simple AVR microcontroller, the specs says that the clock frequency can go down to 32 kHz, so I guess this it should be ...
2
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4answers
110 views

“If an antenna can transmit, it can usually receive as just as well”

Scenarios So, I set up an induction loop, just a simple single wire loop around a house with a little pickup coil for picking up the loop audio. Lets say I want to run this in REVERSE I have heard ...
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2answers
55 views

Antenna gain of cell tower

I am doing the link budget for a device several hundred meters away from the typical cell tower. I have already found out how much antenna gain for that device. I am wondering how much antenna gain ...
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1answer
110 views

RF: what are some sources that are transmitting few hundred of watts signal power?

I am looking for some source (TV broadcasting station, or cellular tower,etc) that transmit a few hundred watts of power. (Just typically please). Please give me some idea to get me started so I can ...
1
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1answer
46 views

Anttenna: RF, need help

I am trying to find a path loss model for "wireless sensor network". More specifically, I am looking for model for Cellular tower 100~1000MHz) and (60~600W) as transmitter and a small wireless sensor ...
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3answers
82 views

Bluetooth general question about antenna

I want to ask you about Bluetooth antennas. I saw that some modules like HC-07 have a zig zag antenna on them: And others like BTM-331 do not have such an antenna: Is this antenna mandatory? How ...
1
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1answer
76 views

Tradeoff between embedded chip and external GPS antennas

I'm currently redesigning a board that implements GPS positioning. Until now I've been using a Fastrax IT520 module, which is very nice but has been discontinued. This forces me to rethink my board ...
4
votes
1answer
309 views

DIY NFC boosting antenna for a mobile device

I am very new to this. I'm a dentist trying to improve client flow in a busy office. I would like to develop a cheap proof of concept for an NFC enabled client tracking system using a hacked mobile ...
3
votes
4answers
638 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
249 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
443 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 ...
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3answers
80 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. ...
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2answers
81 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 ...
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2answers
64 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 ...
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1answer
45 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 ...
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0answers
70 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
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0answers
113 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
159 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 ...
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1answer
616 views

Boost 433MHz receiver module receiving signal (XY-MK-5V)

I am using some "no-name" (In Fact "XY-MK-5V" stands on the board) 433MHz receiver (and transmitter) on an Arduino project. I can receive the signals sent from my other Arduino very good (it sends ...
0
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1answer
121 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
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1answer
154 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
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1answer
130 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?
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0answers
120 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 ...
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1answer
59 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 ...