RF category

Drones- A Blessing or a Curse?

The increasing popularity of unmanned aerial vehicles (drones) has created a lot of security issues and possible privacy threats. Drone manufacturers have made them easy to fly so that any person without any experience can buy one and fly it without reading the instruction manual first. This has made them attractive for consumers, but also for criminals. Most of them have a camera to allow the user to go to distances beyond their sight. As a result, drones are now being used by many companies to make deliveries such as Amazon, by people to take selfies, by explorers, by authorities etc. This increased amount of usage may pose security threats to privacy and commercial space.

For example, there is already reported cases of drones almost crashing into military aircrafts, or invading the helicopters flying area when trying to put out a forest fire, hacked drones, or drones being used to smuggle drugs. Additionally, there are a lot of reports involving drones constantly flying over private properties while recording. Drones are difficult to detect because of their size, so the company Aaronia produced a new drone detection system that tracks the high-frequency signal between these devices and it´s remote control.

The device consists of a IsoLOG 3D antenna, a Spectran V5 spectrum analyzer and a plug in for the RTSA software. It offers the user a long detection range, functionality in poor visibility, high resolution of signal detection, portability, drone identification etc.

This system provides detailed information of signal distribution, and can be combined with different devices to provide a bigger range of detection. It can be programmed to set off an alarm when some selected parameters are exceeded. The IsoLOG 3D has 16 sectors that provide full 360 RF spectrum overview including an image of the monitored area. It has W signal sensitivity and continuous data streaming with up to 4 TB per day.

Militaries could use this device to protect large areas, and even in the future to stop the drones from entering areas where they could interfere with life threatening situations or confidentiality sensitive scenarios. For now, only detection is possible, but it is a huge step toward fixing the security concern posed by drones. Some parts in the United States have already implemented laws to register all drones and to prohibit the users from flying them above certain heights and close to airports. These governmental measures can help the Aaronia device to easily identify the drones, and the device could help the authorities to stop people from breaking the law.


NFC Key Protects Your Data by Disconnecting Chips From Antenna

Cameron Coward @ blog.hackster.io writes:

Like most connected technology these days, near-field communication (NFC) is susceptible to hacking. By its very nature, NFC is normally accessible by anyone nearby. NFC, as it was originally intended, is designed to provide data wirelessly to any nearby readers without requiring a power source of its own.

Fortunately, N-O-D-E, one of our favorite open source hardware developers, has come up with a solution called the NFC Key. This handy little keychain-friendly device protects your NFC chips in the simplest way possible: by physically disconnecting them from the antenna. Without the antenna connected, the chips just cannot be powered or transmit data.

NFC Key Protects Your Data by Disconnecting Chips From Antenna – [Link]

WattUp – RF based Wireless Charging at a Distance

WattUp Far Field Transmitter

Recently, many big companies such as Samsung have developed wireless chargers which work by induction. These chargers usually consist of a station which needs to be in contact with the device in order to charge. The station defeats the purpose of being able to move and walk while still charging the device. Energeous, a global leader in RF- based wireless charging, created the award-winning device WattUp in order to give mobile power to everyone.

The WattUp transmitter converts electricity into radio frequencies, then beams the energy to nearby devices that have the right receiving equipment. This system has proved to be more practical than induction since it can work from up to 3 feet away. Energeous wants to make a wire free charging ecosystem by taking into advantage the fact that the transmitter can charge multiple devices at a time, and as WIFI it would be able to charge your phone even if you are Samsung and the transmitter is Apple. All kind of devices can be charged using WattUp including (but not limited to) cameras, smartphones, tablets, wearables, and toys.

The receiver uses multiples antennas to collect the micro energy beams created by the transmitter (which makes it safe because power is received in small amounts). There is also an application available in which you can control the devices that are receiving power, how much power for each one, and even what times you want it charging. For example, you can prioritize cellphone charging in peak hours of use and leave other electronics to charge at night just with the click of a button.

The WattUp has already been FCC (federal communications commission) approved, and Energeous offers a variety of prices depending on the range of the transmitter, but it is still not available in the market. The company will be in CES 2018 showing their product, this event will take place on January 9th– 12th in Las Vegas.

Wireless charging not only benefits consumers, but also offers real benefits in terms of efficiency, productivity, and safety in industrial applications. Moreover, cables require maintenance and are easily damaged which makes them unreliable and expensive to maintain. In hospitals there is a constant need for big equipment that uses battery packs or cables, but to maintain a sterile environment WattUp could be a good alternative. Furthermore, in the future this technology could be used to power electric cars avoiding the need for charging every 10 to 40 miles.


Changing Hospital Waiting Rooms with RFID Technology

Engineers at Cornell university have created a new system for measuring vitals, which could revolutionize hospital experience for everybody. Usually, getting sick means having to go to the hospital which because of today´s procedures takes almost all your day (if not more), and most of the time is spent in waiting rooms. What if you could be “attended” while still in the waiting room? Because of RFID technology this is now possible with a device that can measure your vitals while you wait.

RFID (short for radio frequency identification) uses electromagnetic fields to track and identify tags attached to objects. Passive tags collect energy from a nearby RFID reader (they don’t require a battery) and can operate several meters away. The signal from the reader induces a small electric current enough to operate the CMOS of the tag.

This new system uses cheap sensor that don’t require their own power supplies, while the reader powers them and gathers data wirelessly. These tags are applied to the skin, and using radio waves they can measure blood pressure, breath rate, heart rate etc. The reader can gather data from hundreds of these tags at the same time, and they are cheap to produce. Nowadays, the price of the tags depends on memory, type of packaging and the volume of tags requested, but passive tags cost around 7 to 15 U.S cents.

As a result, not only waiting times could be shortened, but the work of many doctors and nurses could be lightened. Currently, monitoring vitals takes a lot of equipment which is expensive and big. With this new technology, big and not practical equipment will be no longer needed, and the work done by many devices will be done by a small sticker with the size of a finger or smaller.

In the beginning RFID had security issues because anyone could access the information on the tags, but nowadays security protocols have been implemented to encrypt and protect users data. This makes this device not only practical and affordable, but also safe and private.


ESP8266 WiFi Analyzer

This instrucatables show how to make an ESP8266 version WiFi Analyzer clone.

WiFi Analyzer is a handy app in Android, it help to visualize the WiFi signal information around you. It is very useful for helping select a right channel for setting a new AP. If you selected a channel that as same as another AP near you, you may encounter interference and degrade the network performance.

ESP8266 WiFi Analyzer – [Link]

Tiny UHF Tracker Transmitter

@ instructables.com writes:

This is a little circuit that could be used to track an object up to 400m.

It is essentially an SAW stabilized OOK modulated RF transmitter. The modulation is done with two low frequency ultra low power oscillators that activate the transmitter every two seconds for a short period.

With the setup shown here I got up to 400m range. Current consumption is about 180uA average so it’ll work for a couple of days with the little button cell. Frequency 915MHz.

Tiny UHF Tracker Transmitter – [Link]

xaVNA – A low cost two port Vector Network Analyzer

xaVNA is a simple and cheap vector network analyzer that allows you to easily tune up antennas, filters, and amplifiers by plugin it to USB. It is able to display smith charts/graphs on the including PC software.

The main board connects to a PC through usb and communicates via a virtual serial port device; the PC software sets the frequency and other parameters by sending two-byte register write commands, and the device sends averaged vector values representing magnitude and phase of measured wave.

The project is open source and available on github and a kickstarter campaign is live with 31 days to go.


  • Frequency range: guaranteed 137MHz – 2500MHz, typical 135MHz – 3500MHz
  • Measurement signal level (controlled using on-board switches, iteration 1 board only): -5dBm to 10dBm, with 2dB increments
  • Measurement signal level (controlled using spi interface): -20dBm to 10dBm, with 1dB increments
  • 3 receivers: forward coupled, reverse coupled, through; can measure S11 and S21 of a two port device. To measure S22 and S12 the DUT needs to be manually reversed.

Homemade 6 GHz FMCW radar

Henrik Forstén has a nice build log on his newest version of this homemade 6 GHz FMCW radar:

Frequency Modulated Continuous Wave (FMCW) radar works by transmitting a chirp which frequency changes linearly with time. This chirp is then radiated with the antenna, reflected from the target and is received by the receiving antenna. On the reception side the received signal that was delayed and undelayed copy of the transmitted chirp are mixed (multiplied) together.

Homemade 6 GHz FMCW radar – [Link]

Teardown and experiments with a Doppler microwave transceiver

Kerry Wong did a teardown of Microsemi’s C900502 X-band planar transceiver:

I got a couple of Microsemi’s C900502 10.525 GHz X-band Doppler radar motion sensors a while ago. This batch was made in UK and had “UK patents 2243495 and/or 2253108 apply” printed on the case. I have seen a teardown of an HB100 Doppler radar module before and was wondering if I this one is any different inside.

Teardown and experiments with a Doppler microwave transceiver – [Link]

SeaTalkie keeps you SAFE during water sports

John Mak @ kickstarter.com tipped us with his latest project and he asks for our support.

SeaTalkie is an innovative waterproof walkie talkie designed for water sports. Especially for CHILDREN playing at crowded beaches.

SeaTalkie connecting in UHF radio band. Thus SeaTalkie can connect to other walkie talkies. Furthermore, Different walkie has different features. Some have further transmit range, some have larger batteries, some are louder in speaker. And SeaTalkie is featured strongly in waterproof, simply operating and mounting accessories for sports. Therefore, for better performance, A team may integrate different featured walkies all together to optimise the performance of communication. Of course including SeaTalkie.

SeaTalkie keeps you SAFE during water sports – [Link]