A helical antenna is an antenna consisting of one or more conducting wires wound in the form of a helix. A helical antenna made of one helical wire, the most common type, is called monofilar, while antennas with two or four wires in a helix are called bifilar, or quadrifilar, respectively. In most cases, directional helical antennas are mounted over a ground plane, while omnidirectional designs may not be. The feed line is connected between the bottom of the helix and the ground plane. Helical antennas can operate in one of two principal modes: normal or axial. In the normal mode or broadside helical antenna, the diameter and the pitch of the aerial are small compared with the wavelength. The antenna acts similarly to an electrically short dipole or monopole, equivalent to a 1/4 wave vertical and the radiation pattern, similar to these antennas is omnidirectional, with maximum radiation at right angles to the helix axis. For monofilar designs the radiation is linearly polarized parallel to the helix axis. These are used for compact antennas for portable hand held as well as mobile vehicle mount two-way radios, and in larger scale for UHF television broadcasting antennas. In bifilar or quadrifilar implementations, broadside circularly polarized radiation can be realized. In the axial mode or end-fire helical antenna, the diameter and pitch of the helix are comparable to a wavelength. The antenna functions as a directional antenna radiating a beam off the ends of the helix, along the antenna's axis. It radiates circularly polarized radio waves. These are used for satellite communication. Axial mode operation was discovered by physicist John D. Kraus (Wikipedia).
How does an Antenna work? | ICT #4
Antennas are widely used in the field of telecommunications and we have already seen many applications for them in this video series. Antennas receive an electromagnetic wave and convert it to an electric signal, or receive an electric signal and radiate it as an electromagnetic wave. In t
From playlist Internet & Telecommunication Technology
Electric Dipole Propagation Pattern [Dipole Antenna] 📡
Here, 3D propagation pattern of an electric dipole (antenna) is being shown. In addition to the radiation pattern, we also project the transversal and vertical planes of the propagation pattern and actually show how the waves would be propagating in different planes. Basically, along the
From playlist Engineering Animations
Tracking Satellites in Orbit - Part 1
We've built a couple radio telescope on this channel over the years. The first took a picture of the sky in microwave frequencies and the second took a picture of wifi signals in a building. This time we're scaling up both the size of the telescope and the quality and utility of the build.
From playlist Radio and Radio Astronomy
Physics 50 E&M Radiation (5 of 33) Parabolic Antenna and E&M Radiation and Temperature
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain electromagnetic radiation by studying the parabolic antenna. Next video in series: http://youtu.be/VtzyIr6CLpg
From playlist PHYSICS 50 ELECTROMAGNETIC RADIATION
Physics 50 E&M Radiation (6 of 33) Dipole Antenna and E&M Radiation
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain electromagnetic radiation and the dipole antenna (AM radio). Next video in series: http://youtu.be/dJEQBAYAjPQ
From playlist PHYSICS 50 ELECTROMAGNETIC RADIATION
#292 Wi-Fi Antennas with Gain and ESP32 Long-Range Mode (part2)
Everybody talks about LoRa to bridge long distances. Today we will have a look into how we can extend the range of a normal ESP32 using the Arduino IDE. You will also learn how to do that and stay legal. And maybe we even can reduce the power consumption of the chip if we do not need the e
From playlist ESP32
World's Most Powerful Visible Diode Laser
"The NUBM44 Laser Diode" The World's Most Powerful
From playlist Lasers
GRCon21 - Passive bistatic RADAR using spaceborne Sentinel1 non-cooperative source...
Passive bistatic RADAR using spaceborne Sentinel1 non-cooperative source, a B210 and a Raspberry Pi4 presented by Jean-Michel Friedt and Weike Feng at GNU Radio Conference 2021 We have previously demonstrated passive bi-static RADAR using a static emitter and static (passive bistatic RADA
From playlist GRCon 2021
This video introduces the concept of phased arrays. An array refers to multiple sensors, arranged in some configuration, that act together to produce a desired sensor pattern. With a phased array, we can electronically steer that pattern without having to physically move the array simply b
From playlist Understanding Phased Array Systems and Beamforming
Horn Antenna Simulation using Finite Difference Time Domain (FDTD) Method 📡
Here we show the radiation from various horn antenna types using the finite difference time domain algorithm. First we starts with a basic horn antenna and compare it with free space propagation. Then, horn antenna is compared to a waveguide without any horns. Finally the impact of horn an
From playlist Electromagnetic Animations
What's That Infrastructure? (Ep. 5 - Wireless Telecommunications)
The airwaves are awash with invisible communications keeping us connected and facilitating our information society. All that telecommunication requires a lot of infrastructure! Today's episode of WTI shows some wireless telecommunications. Have a cool infrastructure photo? Send it in the
From playlist Civil Engineering
Physics 50 E&M Radiation (7 of 33) Dipole Antenna and E&M Radiation
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain the dipole antenna to better understand electromagnetic radiation. Next video in series: http://youtu.be/8Eae3lqdtBY
From playlist PHYSICS 50 ELECTROMAGNETIC RADIATION
EEVblog #1207 - ARM Dev Boards Falling From The Sky!
Hackable STM32 based ARM RF dev boards are literally falling from the sky! A teardown of two weather balloon Vaisala radiosondes, the RS41 and RS92. Repurposing tre RS41: http://www.om3bc.com/docs/rs41/rs41_en.html Github: https://github.com/bazjo Conference Talk: https://www.youtube.com
From playlist Teardown Tuesday
How to Pull Images from Satellites in Orbit (NOAA 15,18,19 and METEOR M2)
Over the past 2 months, me and my friend Artem have been building antennas to receive signals from weather satellites as they pass overhead. This video chronicles our progress through this project and goes through some of the science involved in working with radio and receiving transmissio
From playlist Highlights
EEVblog #721 - Globalstar Satellite Phone Teardown
What's inside a 2000 vintage Globalstar GSP1600 Tri-Band Satellite Phone? Behold the Erectile Antenna, a helical designed extending antenna. Thanks to: Electronics Responsible Recyclers: http://er2.com/ Forum: http://www.eevblog.com/forum/blog/eevblog-721-globalstar-satellite-phone-teardo
From playlist Teardown Tuesday
DEFCON 19: DCFluX in: License to Transmit
Speaker: Matt Krick "DCFluX" Chief Engineer, New West Broadcasting Systems, Inc. When cell phones, land lines and the internet break down in a disaster, Amateur radio is there. Considered to be one of the earliest forms of Hacking, this talk will take a look at some of the things that can
From playlist DEFCON 19
Under-Cabinet Television: Equipment Autopsy #64
http://www.thegeekgroup.org - In this teardown video, Chris takes apart an old under cabinet TV to see what's inside. Learn how ferrite beads work, how audio speakers are specified and the basic rf circuit board layout of a TV. Chris explains how ferrite is used to tune parts of the circ
From playlist Equipment Autopsies
Mailbag Monday Forum: http://www.eevblog.com/forum/blog/eevblog-860-mailbag/ SPOILERS: Supermicro AMD Opteron Server Motherboard http://www.supermicro.com/Aplus/motherboard/Opteron6000/SR56x0/H8QG6-F.cfm http://support.amd.com/TechDocs/44549.pdf http://support.amd.com/TechDocs/43869.pdf
From playlist Mailbag
Physics 50 E&M Radiation (8 of 33) Dipole Antenna Radiation Pattern
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain the dipole antenna radiation pattern. Next video in series: http://youtu.be/SF_6qiEeuII
From playlist PHYSICS 50 ELECTROMAGNETIC RADIATION
#291 External antennas and ESP32 Long-Range mode
Everybody talks about LoRa to bridge long distances. Today we will have a look into how we can extend the range of a normal ESP32 with the Arduino IDE. You will also learn how to do that and stay legal. And maybe we even can reduce the power consumption of the chip if we do not need the ex
From playlist ESP32