#RF Antenna

[eteily4]

The 5G 12dBi Magnetic Antenna is a high-performance antenna designed for optimal 5G signal reception and enhanced connectivity. With a 12dBi gain, it delivers superior signal strength and coverage for faster data speeds.

[rfantennaindia]

[rfantenna]

[eteilytech]

[noosphe-re]

Novel antenna design with four concentric spirals, each having 2.5 turns. Rf power is connected to the centre and ground is at the outer connectors

Gans, Timo & Crintea, Dragos & O'Connell, Deborah & Czarnetzki, Uwe. (2007). A planar inductively coupled radio-frequency magnetic neutral loop discharge. Journal of Physics D: Applied Physics. 40. 4508. 10.1088/0022-3727/40/15/021.

[pc-98s]

sickest band merch ever

[wordacrosstime]

Practical RF Design Manual

[Practical RF Design Manual by Doug DeMaw (Milton F "Doug" DeMaw). 1997. MFJ Publishing. 2nd Edition 1997 : 246 pages. ISBN 1-891237-00-4]

For many years I was an amateur radio - "ham radio" - operator, beginning when I was 13 years old and going up until I was about 40 years old.  For those who are interested, my call sign was WA6FEB and I held an Extra Class ham radio license (this is the highest classification).  My fascination with radio was fostered by my step-father, the late Sam Martin (WB6WZN, later N7TBV), who had learned his electronics and radio theory while serving in the US Navy.

Sam had many years’ worth of a magazine called QST, which was one of the premier journals available for ham radio enthusiasts.  Doug DeMaw, the author of the book under review here, was a prolific contributor to QST and to other ham radio publications.  I was (and remain) a huge fan of his writings, especially his transmitter and receiver projects for ham radio folks.

What I did not know then, but have come to learn, is that DeMaw was truly a world-class electrical and electronic engineer.  He was known to much of the world as a ham radio person first and foremost, but he was a professional engineer who had an extraordinarily broad grasp of all aspects of radio transmission and reception, covering all power levels from the very tiny (what we in the ham radio community called QRP, or low-power, operation, usually less than 1 watt) to the industrial (the 50,000-watt and 100,000-watt “clear channel” broadcasts from commercial radio stations, for example).  DeMaw was well-versed in design considerations spanning operating frequencies from the US AM broadcast band (560 KHz to 1600 KHz) all the way up to the UHF range (where television broadcast channel 14 begins in the US, or around 470 MHz and beyond).  His knowledge went beyond component-level design of devices to include the design and tuning of antennas and other auxiliary devices to aid in the radio experience.

All of this knowledge is subsumed under the aegis of RF - radio frequency.  RF in modern terms is usually linked to RF ID chips, which are becoming quite common in scenarios that require tracking (such as shipment packages), but this is a very restricted window into the RF world.  To really see just how vast an enterprise RF electronics is, one might consult this book.

This volume is truly a gem.  I dearly wish I had access to it back in the early 1970s when I was first getting into radio.  It would have illuminated a lot of practical design issues for me, especially on the design of receivers.  Receivers are generally more complicated and finicky than transmitters – it’s easier to generate radio energy and cast it out into the universe than it is to gather it in and make sense of it.  This book leads the reader through 7 broad-based topics and roughly 40 overall subsections within those topics, starting with transmitter and receiver fundamentals and leading the reader through considerations related to power regulation, signal quality, the use of different types of components for different frequencies of operation and different power levels, and so on.

Unlike much of DeMaw’s writing with which I had been previously acquainted, this book is definitely not a book for someone looking to do a home project.  There are no comprehensive instructions on assembling or testing transmitters, receivers, or other associated machinery.  This book is written for a true engineer who wants to become familiar with many (most) of the gotchas that accompany real in-the-trenches electronic engineering work.  And in this vein, this book is as useful to a professional radio engineer (such as someone who is the engineer-in-charge at a radio or television station, for instance) as it is to a radio hobbyist.  It is also not the sort of book from which to learn first principles of electronics; for this, there are many more suitable books that introduce electronics at the most elementary level (Ohm’s Law, Kirchhoff’s Law, how vacuum tubes and transistors work, what makes oscillators work, and so on).  This book assumes that the reader already has some engineering skin in the game, as the saying goes.

Whom would I recommend this book to?  Anyone who wishes to know something about electronics that precedes the modern all-digital era where whole systems are embedded on integrated circuit (IC) chips.  While those circuits may make for easier and more controlled design, they take away a lot of the learning, guesswork, and outright fun of figuring these things out for yourself.  DeMaw’s work hearkens back to what many of us current and former ham radio people think of as a sort of golden era of communications – a time before cell phones and before email.

A couple of comments about the text itself:

There are some typos both in the text and on the many diagrams.  For the most part these are easy to spot if you are already versed in basic electronics, but they would be profoundly confusing to someone who doesn’t know what they’re looking at.  Anyone who doesn’t know how to read a basic schematic diagram of a circuit will not find this volume very helpful.

Bearing in mind that some of the material in this book dates to the 1970s and 1980s, it is possible that some of the actual components cited in the text no longer exist or are not easily available.  Happily, the author describes them in sufficient detail that a modern engineer or hobbyist can find current components whose characteristics match what DeMaw had at his disposal when the book was written.  DeMaw was fairly fastidious about describing the important pieces of each circuit or circuit fragment in the book.  One needs but to pay attention to the text to make the connection.

I was delighted to read through this volume.  I am not currently an active hobbyist, but as I near retirement age, I am giving a return to ham radio serious thought.  With that in mind, this book will be an invaluable title in my collection when I once again wield a soldering iron and set out to make some more home-brew radio equipment as I did so many years ago.

[Photo credits with thanks to : Book Cover of 2nd edition 1 August 1997 © 1997 M F J Enterprises Inc / Portrait © Copyright Holder (apologies not known)]

Kevin Gillette

Words Across Time

10 January 2023

wordsacrosstime

[questioningespecialy]

Are EMF’s safe? (come, child, ruin your night)

y’all ready for this? I’m not anti-5G, btw turn your wifi off before bed and maybe stop keepin’ ya phone so close all the time

But like... why, though?

I've had my suspicions about cell towers being hazardous to health for a few years now and felt convinced enough to not bother researchin' it for confirmation. Now that I'm blah blah blah, I decided to actually bother. Since it got kinda heavy, I had to ask myself if I should put in hella more effort creatin' a damn research report of sorts for y'all asses present the info for others like it's a damn PSA. And my conscious won. T~T

But like... what, though?

A base station (aka: cell phone tower) is that shit you see everywhere but never notice. It's usually tall af and has panel antennas on it. It's "used for the transmission and reception of the radio signals between the mobile phones and the network." The problem with 'em is the electromagnetic field (EMF) their equipment can give off... for half a mile. 😐

In short, they've been found to cause health problems. Like cancer. 🤷🏿‍♂️

Fun fact, panel antennas can be installed on the roof/side of buildings that may be directly across the street from someone's workplace... with the antenna at their elevation. 🤷🏿‍♀️

Real Quick

For those who don’t trust EMF-Portal, it (sometimes) has links to the study/article. Full-text PDF can be requested directly from the authors on ResearchGate.net’s article for the study. Full-text PDF can (usually) be found online in English and German with the right search.

5 Studies

V/m = volts per meter 7191 cancer deaths were selected according to the above mentioned criterias out of a total of 22,493 cancer deaths. The most significant causes were lung cancer (19.6 %), stomach cancer (14.1 %), prostate cancer (12.6 %), and breast cancer (11.5 %). The mean electric field intensity of the measurements in 2008 was 7.32 V/m, varying from 0.4 to 12.4 V/m. At a distance of up to 100 m [328.08 ft], the absolute number of deaths was 3569, (49.6 % of all deaths), the mortality rate was 43.4 persons per 10,000 [0.43%] and the relative risk was 1.35 in relation to the mortality rate of 32.1 per 10,000 [0.32%] inhabitants of the entire Belo Horizonte municipality [in Minas Gerais, Brazil]. A mortality rate of 34.8 per 10,000 [0.35%] inhabitants was observed for the residents living within 500 m [1,640.42 ft] of the base stations; this rate decreased for residents living farther from the base stations.

—Mortality by neoplasia and cellular telephone base stations in the Belo Horizonte municipality, Minas Gerais state, Brazil; Science of The Total Environment (2011); EMF-Portal

ResearchGate.net’s article

The result of the study [of 967 permanent residents] shows that the proportion of newly developing cancer cases was significantly higher among those [320] patients who had lived during the past ten years at a distance of up to 400 metres [1,312.34 ft] from the cellular transmitter site, which has been in operation since 1993, compared to those patients living further away, and that the patients fell ill on average 8 years earlier. In the years 1999-2004, ie after five years' operation of the transmitting installation, the relative risk of getting cancer had trebled for the residents of the area in the proximity of the installation compared to the inhabitants of Naila[,Germany,] outside the area.

—The Influence of Being Physically Near to a Cell Phone Transmission Mast on the Incidence of Cancer (original title: ‘Einfluss der räumlichen Nähe von Mobilfunksendeanlagen auf die Krebsinzidenz’); Umwelt · Medizin · Gesellschaft (2004); ResearchGate.net

EMF-Portal

9 cancer cases were observed in the first period 2000 - 2004 and 14 cases in the period 2005 - June 2007 among [1,283] residents living within a radius of 400 m [1,312.34 ft] to a mobile phone base station [in Germany (Hennen, suburb of Iserlohn, Westfalia)]. The mean age of disease onset was 59.2 years in the first period and 59.3 years in the second period in comparison to the expected value of 66.4 years evaluated from the Saarland Cancer Registry. The authors concluded, that a statistically significant increase of cancer incidence was observed 5 years after the base station has been started operating.

—[Incidence of cancer adjacent to a mobile telephone basis station in Westfalia] (original title: Krebsinzidenz von Anwohnern im Umkreis einer Mobilfunksendeanlage in Westfalen - Interview-basierte Piloterhebung und Risikoschätzung); Umwelt · Medizin · Gesellschaft (2009); EMF-Portal

Area A: ≤ 350 m / 1148.3 ft from base station Area B: > 350 m / 1148.3 ft from base station Of the 622 people of area A, 8 cases of different kinds of cancer were diagnosed in a period of one year (from July 1997 - June 1998). The cancer incidence rate was 129 cases per 10,000 [1.29%] persons per year in area A compared to 16/10,000 [0.16%] in area B and 31/10,000 [0.31%] in the town of Netanya [in Israel]. Relative cancer rates for females were 10.5 for area A, 0.6 for area B and 1 for Netanya. The authors conclude that the study indicates an association between increased incidence of cancer and living in proximity to a mobile phone base station.

—Increased incidence of cancer near a cell-phone transmitter station; International Journal of Cancer Prevention (2004); EMF-Portal

ResearchGate.net

Took forever to get this damn infographic just right. >.>

A long-term study was conducted in Germany to investigate the influence of a mobile phone base station on neurotransmitters under true-to-life conditions. µW/m² = microWatts per square meter 24 out of 60 participants were exposed to a power density of < 60 µW/m², 20 participants to 60 - 100 µW/m², and 16 participants to more than 100 µW/m² . The values of the stress hormones adrenaline and noradrenaline grew significantly during the first 6 months after starting the GSM base station; the values of the precursor substance dopamine substantially decreased in this time period. The initial condition was not restored even after 1.5 years. Due to the not regulable chronic difficulties of the stress balance, the phenylethylamine levels dropped until the end of the investigation period. The effects show a dose-effect relationship and are situated far under the valid limit values.

—[Modification of clinically important neurotransmitters under the influence of modulated high-frequency fields - A long-term study under true-to-life conditions] (original title: Veränderung klinisch bedeutsamer Neurotransmitter unter dem Einfluss modulierter hochfrequenter Felder - Eine Langzeiterhebung unter lebensnahen Bedingungen); Umwelt · Medizin · Gesellschaft (2011); EMF-Portal

ResearchGate.net’s German article EMF:data page (German)

While I did find 17 different figures for it, I’mma save myself the bother of describin’ dat noise and not include ‘em thanks~.

But what does the FCC say?

FCC.gov’s conclusion seems to be that they’re generally safe for civilian life as long as you don’t get close and aren’t directly in front of the antenna’s trajectory (don’t climb a fuckin’ tower or enter those rooms/buildings). A very “it’s fine” set of conclusions tbh. Hella contrasted by other sources.

Nonetheless… below is the index...

FCC’s RF Safety FAQ Index:

What is "radiofrequency" and microwave radiation?

What is non-ionizing radiation?

How is radiofrequency energy used?

How is radiofrequency radiation measured?

What biological effects can be caused by RF energy?

Can people be exposed to levels of radiofrequency radiation and microwaves that could be harmful?

Can radiofrequency radiation cause cancer?

What research is being done on RF biological effects?

What levels are safe for exposure to RF energy?

Why has the FCC adopted guidelines for RF exposure?

How safe are mobile phones? Can they cause cancer?

How can I obtain the specific absorption rate (SAR) value for my mobile phone?

Do "hands-free" ear pieces for mobile phones reduce exposure to RF emissions?   What about mobile phone accessories that claim to shield the head from RF radiation?

Can mobile phones be used safely in hospitals and near medical telemetry equipment?

Are wireless and PCS towers and antennas safe?

Are cellular and other radio towers located near homes or schools safe for residents and students?

Are emissions from radio and television antennas safe?

How safe are radio antennas used for paging and "two-way" communications?   What about "push-to-talk" radios such as "walkie-talkies?"

How safe are microwave and satellite antennas?

Are RF emissions from amateur radio stations harmful?

What is the FCC's policy on radiofrequency warning signs?  For example, when should signs be posted, where should they be located and what should they say?

Can implanted electronic cardiac pacemakers be affected by nearby RF devices such as microwave ovens or cellular telephones?

Does the FCC regulate exposure to radiation from microwave ovens, television sets and computer monitors?

Does the FCC routinely monitor radiofrequency radiation from antennas?

Does the FCC maintain a database that includes information on the location and technical parameters of all the towers and antennas it regulates?

Which other federal agencies have responsibilities related to potential RF health effects?

Can local and state governmental bodies establish limits for RF exposure?

Where can I obtain more information on potential health effects of radiofrequency energy?

The Government Accountability Office (GAO) prepared a [2012] report of its investigation into safety concerns related to mobile phones.  The report concluded that further research is needed to confirm whether mobile phones are completely safe for the user, and the report recommended that the FDA take the lead in monitoring the latest research results.

Professional Opinion...

Safe Distance from Cell Towers…

It is also difficult to predict a safe distance from cell towers.  For example, cell towers are designed to transmit most of their radio frequency (RF) energy horizontally.  Some areas below the tower may have lower levels than locations farther away that are more in line with the vertical height of the antennas. The exposure from a cell tower will depend on the type of antennas, the number of antennas, how much the antennas are actually being used, the time of day, etc.  The distance needed to reduce exposures down to the General Public Precautionary Level of 100 microwatts per meter squared (μW/m²) is often around a quarter of a mile (1320 feet) or more.  Due to the uncertainty, on-site testing with a broadband RF test meter is strongly recommended. A German study reported that people living within 400 meters (1312 feet) of cell towers had over 3 times the normal rate for new cancers (City of Naila 2004).  In an Israeli study, the relative risk for cancer was about 4 times greater within 350 meters (1148 feet) of the cell tower (Wolf et al. 1997).  Based on findings like these, a minimum safety distance of 1/4 mile (1320 feet) might be considered prudent. (...) The suggestions for safety distances in this chart are generally based on Michael Neuert’s [engineer, licensed electrician, and health educator] professional on-site testing of the various EMF sources in the San Francisco Bay Area since 1992.

—What Distance is Safe? By Michael R Neuert, MA, BSME, ©2023

helpful table if you want all that info: What EMF Level is Safe? By Michael R Neuert, MA, BSME, ©2023

i know what i said

Based on the accumulated evidence, we recommend that IARC [the International Agency for Research on Cancer] re-evaluate its 2011 classification of the human carcinogenicity of RFR [radio-frequency radiation], and that WHO [the World Health Organization] complete a systematic review of multiple other health effects such as sperm damage. In the interim, current knowledge provides justification for governments, public health authorities, and physicians/allied health professionals to warn the population that having a cell phone next to the body is harmful, and to support measures to reduce all exposures to RFR.

—Risks to Health and Well-Being From Radio-Frequency Radiation Emitted by Cell Phones and Other Wireless Devices; Front Public Health (2019 Aug 13); NCBI

Lookup (or pull out) your cellphone’s manual and search for the sections on “radio frequency exposure” and “Specific Absorption Rate (SAR) information” to see how close the phone can safely be kept near your body… and that it should be kept away from “the bellies of pregnant women and for teenagers, away from the lower abdomen.” 😐

For an informative giggle, here’s the “Harmful Cell Phones” segment from season 7 of The Colbert Report.

[sigalrm]

Antennen by Pascal Volk

[futureelectronic1527]

Panasonic: New Product Introduction: PAN1770 Series Bluetooth Low Energy RF Module

https://www.futureelectronics.com/m/panasonic . Panasonic PAN1770 Series is based on the Nordic nRF52840 single-chip controller that allows you to attach an external antenna via uFL. With the Cortex®-M4F processor, 256 kB RAM, and the built-in 1 MB flash memory, the PAN1770 Series can easily be used in standalone mode, eliminating the need for an external processor saving complexity, space, and cost. https://youtu.be/8Ur-bFMieHw

[ersantenna]

How to Secure a Job as an Antenna Test Engineer

Are you interested in a career as an Antenna Test Engineer? Do you have a passion for ensuring that wireless communication devices perform at their best? If so, you're on the right track. In this article, we will guide you through the steps required to land a job as an Antenna Test Engineer. With the increasing demand for connectivity and wireless technology, this field offers promising career prospects. So, let's delve into the details and understand what it takes to become an Antenna Test Engineer.

Understanding the Role of an Antenna Test Engineer

Before we dive into the qualifications and requirements, it's essential to understand the responsibilities of an Antenna Test Engineer. Antenna Test Engineers play a crucial role in the development and testing of antennas used in various wireless communication devices such as smartphones, routers, and IoT devices. Their primary responsibilities include:

Antenna Design and Optimization: Antenna Test Engineers design, simulate, and optimize antenna systems to ensure efficient signal reception and transmission.

Testing and Measurement: They conduct extensive tests and measurements to assess antenna performance, including radiation patterns, gain, and impedance.

Quality Assurance: Engineers ensure that antennas meet industry standards and regulatory requirements.

Problem Solving: They troubleshoot and solve issues related to antenna performance and signal interference.

Educational Requirements

To kickstart your career as an Antenna Test Engineer, you'll need the right educational background:

Bachelor's Degree: A bachelor's degree in electrical engineering, telecommunications, or a related field is typically required. This provides a solid foundation in electronics and communication systems.

Master's Degree (Optional): Pursuing a master's degree can enhance your knowledge and make you a more competitive candidate in the job market.

Essential Skills and Knowledge

RF Fundamentals: A deep understanding of Radio Frequency (RF) principles is essential for working with antennas. This includes knowledge of RF circuit design and electromagnetic theory.

Software Proficiency: Familiarity with software tools such as MATLAB, CST Microwave Studio, and HFSS for antenna design and simulation is crucial.

Testing Equipment: Proficiency in using testing equipment like Vector Network Analyzers (VNAs) and Spectrum Analyzers is required for conducting antenna tests.

Communication Skills: Effective communication is vital when working in a team and conveying technical information to non-technical stakeholders.

Problem-Solving Abilities: Antenna Test Engineers often encounter complex challenges, so strong problem-solving skills are a must.

Gaining Practical Experience

Internships: Consider interning with companies that specialize in antenna design and testing. This hands-on experience can be invaluable when seeking a full-time position.

Certifications: Obtaining relevant certifications, such as Certified Wireless Network Administrator (CWNA) or Certified Wireless Technician (CWT), can enhance your credentials.

Building a Strong Resume and Portfolio

Resume: Craft a well-structured resume that highlights your education, skills, internships, and certifications. Tailor it to the specific job you're applying for.

Portfolio: Create a portfolio showcasing your antenna design projects and test results. This visual representation of your work can impress potential employers.

Job Search and Networking

Online Job Portals: Utilize online job portals and professional networking platforms like LinkedIn to search for job openings.

Networking: Attend industry events, conferences, and workshops to expand your professional network. Networking can open doors to job opportunities.

Acing the Interview

Interview Preparation: Prepare for interviews by reviewing common interview questions related to antenna engineering. Be ready to discuss your experiences and problem-solving abilities.

Conclusion

Becoming an Antenna Test Engineer requires a solid educational foundation, practical experience, and a passion for wireless communication technology. By following these steps and continuously improving your skills, you can increase your chances of securing a job in this exciting and evolving field. Remember, persistence and dedication are key to success in your journey towards becoming an Antenna Test Engineer. Good luck!

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[rfantenna]

[netboon]

NETBOON manufacturer of world class telecom parts like 5G Antennas, 4G GSM Magnetic Antennas, LPDA Antennas, Wifi Rubber Duck Antennas, GPS Navigation Antennas, Omni Antennas, Feeder Cables, LMR Coaxial cables, RF connectors, Lightning Arrestors, Modules, RF Attenuators, t type adapters, crimping tools etc.