TV-SAT, CCTV, WLAN Dipol Weekly Review

A quantum antenna with rubidium atoms.

A team of researchers from the Department of Physics and the Centre for Quantum Optical Technologies has built an innovative all-optical radio receiver that exploits phenomena characteristic of so-called 'Rydberg atoms' - those in which at least one electron is at a very high energy level. The device is distinguished by its exceptional sensitivity and built-in self-calibration mechanism, and its operation is based solely on laser light power. The results of the research were presented in the renowned journal Nature Communications.

In today's world, huge amounts of digital data are transmitted around us every second. Much of it is transmitted by radio, i.e. via electromagnetic waves. For many years, amplitude modulation has been used to transmit information - varying the intensity of the waves, sending them stronger at one time and weaker at another. Modern communication systems also use phase modulation, which involves a controlled shift of the wave oscillations relative to a fixed rhythm. Both transmitters and receivers are equipped with extremely precise synchronising circuits that determine this rhythm - a process known in technical terminology as superheterodyne detection.

In actual radio communication systems, signals are received by means of metal antennas that collect the energy of electromagnetic waves and transmit them on to a receiver. The captured energy allows both the amplitude and phase of these waves to be measured electronically. Currently, this is realised through so-called frequency mixing. The electrical signal from the antenna, which oscillates billions of times per second (i.e. in the gigahertz range), enters special circuits called mixers. Their job is to convert this very fast signal into oscillations at a much lower frequency - in the megahertz range - so that the amplitude and phase information it contains can be read out. At this stage, unwanted signals that we do not want to receive can also be easily separated out. Modern electronics are capable of taking millions of voltage measurements per second, allowing the waveform to be digitally reconstructed and the data to be further analysed using advanced signal processing algorithms, its amplitude and phase.

A small amount of rubidium is placed in a vacuum glass cell. Under the right conditions, individual atoms are released from this metal and float inside the bubble. Each rubidium atom has an electron with a fairly loose bond to the nucleus, and the scientists have imposed a complex, precisely controlled 'dance' around a core of the remaining 36 electrons. The role of the orchestra in this performance is played by three lasers whose frequencies have been extremely precisely tuned to the natural vibrational frequencies of the electrons in the ruby - according to the principles of quantum mechanics. The researchers chose the parameters of the lasers so that some of the electrons spend parts of the cycle in very distant orbits - the so-called Rydberg states. In these states, electrons are extremely susceptible to microwaves that curve their trajectory. They are particularly responsive to these radio waves, whose rhythm corresponds to the 'melody' generated by lasers. Electrons excited to Rydberg states cannot remain there indefinitely - after a certain time, they 'fall' to lower energy levels, like a satellite descending from orbit. When microwave oscillations affect their motion, the electrons fall along a different path and, in the process, emit infrared radiation that is different from that of lasers. This makes them easy to detect. Most importantly, however, the phase of the microwaves is exactly mapped to the phase of the emitted infrared light. This means that if the microwaves 'hit' earlier in the cycle, the electrons also fall faster and send out their quantum pulses of light earlier.

The centrepiece of the experiments carried out is a cell containing rubidium pairs - devoid of any metal parts that could conduct electricity and interfere with the radio field. All that is needed to convert radio waves into infrared radiation are rubidium atoms, a sealed glass housing and precisely tuned lasers. In the long term, the scientists envisage miniaturising the entire system. Ultimately, the detector could take the form of a small thickening on an optical fibre, through which all the necessary laser beams would be delivered and the emitted infrared radiation received. Such a design would allow measurements and analyses to be carried out even tens of metres away from the area where the radio waves are present. This would make extremely subtle and completely non-invasive monitoring of electromagnetic fields possible.

Buffer power supply for mobile systems.

In vehicles, additional systems such as a mobile DVR, network devices, LTE routers, communication modules or other systems requiring a constant power supply are sometimes installed. In order to ensure their continuous operation irrespective of the ignition status, ATTE has developed the LVUPS-140-UN1-OF M18725 universal buffer module for use with 12 V or 24 V vehicle installations. Its main task is to ensure the continuity of power supply to network devices - both while driving and when the vehicle is stationary. This ensures that the monitoring system remains active even when the engine is switched off, without the risk of discharging the main car battery.

The system automatically detects the vehicle's operating state (ignition or rest) based on the supply voltage. When the vehicle is moving, the module charges the buffer battery, while when the vehicle is stopped, the power supply to the equipment is seamlessly switched to this additional battery. This automation eliminates the need for external control signals and simplifies installation in the vehicle. The module can be built into any housing and integrated into the existing vehicle electrical system. The unit adapts to the voltage of the battery used (12 V or 24 V), ensuring the same voltage at the inverter output.

Ballast masts for mounting on flat surfaces.

Ballast masts are structures designed for the installation of antennas, lighting, signalling or other equipment on roofs and other flat surfaces, without the need to interfere with the structure of the ground. Their stability is ensured by appropriately selected ballast (usually concrete weight plates), which prevents the mast from toppling under the influence of wind or vibrations. Ballast masts are widely used in temporary and permanent installations, particularly where permanent anchoring of the mast is not possible or where the integrity of the roofing is required. A variety of mast heights are available as required and the ballast weight is selected to meet the safety requirements of the wind zone. The size of the ballast frames / ballast has been selected so that they can be lifted onto the roof even through a small roof hatch.

DIPOL's range of ballast masts has been extended by 3 new models:

Name	ZB-1000/38 +RAM2/415*265	ZB-1500/38 +RAM4/415*265	ZB-1100/50 +RAM6/415*265
Code	E8746	E8745	E8748
Mast length [m]	1	1.5	1.1
Mast diameter [mm]	38	38	50
Number of frames	2	4	6

Features and benefits of ballast masts:

Building monitoring using ColorVu 3.0 cameras with Smart Hybrid Light technology.

The diagram below shows a monitoring system for a block of flats based on a Hikvision IP DVR and hybrid cameras ColorVu 3.0 belonging to the Easy IP 4.0+ series. Smart Hybrid Light cameras from ColorVu combine the advantages of traditional cameras and ColorVu series cameras. Traditional cameras have an IR illuminator, which illuminates the scene and enables night-time image recording at the expense of colour detail loss. ColorVu cameras can record colour images around the clock, but the use of white light illumination is not always expected. Smart hybrid cameras with ColorVu technology are equipped with three scene illumination modes: classic infrared, white LED light and smart mode. In intelligent mode, the camera triggers white light when a human silhouette or vehicle is detected, thereby providing a colour image. Once the object leaves the detection zone, the camera switches back to IR mode. In addition to illuminating the scene to provide a colour image, the LED light has the additional function of deterring an intruder. The user decides which mode the camera will operate in. The described facility from the outside has been protected with 8 cameras in compact housing DS-2CD2047G3-LIY K03206 with a resolution of 4 MPix, equipped with a fixed focal length lens of 2.8 mm and viewing angle of 111°. Inside the facility, there are 4 dome cameras DS-2CD2147G3-LIS2UY K00921 with a resolution of 4 MPix, equipped with a fixed focal length lens of 2.8 mm and viewing angle of 111°. The cameras have a white light and IR illuminator with a range of up to 30 m.

The proposed positioning of the cameras allows accurate identification of people. A 16-port PoE switch N29986 was used to power the cameras and connect them to the DVR. The cameras support the codecs: H265+, H.265, H.264+, H.264. Using 2 disks of 4 TB each, e.g. M89305, H.265 compression and setting continuous recording at 25 fps for all cameras, the recordings on the hard disks will be stored for 14 days.

A state-of-the-art DS-7616NXI-K2 K22146 DVR was used as the video recording device, which supports VCA analytics (virtual line, intrusion area, etc.), motion detection 2.0 and face analysis functionality. Monitoring access from the external network is provided by a Mercusys AC12G N2933 router.

Repair of damaged DAC.

DAC fibre optic cables (Direct Access Cable) thanks to their hard outer sheath can be laid directly in the ground - without the need for additional protective pipes. Such a cable, although resistant to crushing, can be damaged. The most common cause of cable breakage is the use of an excavator or spade.

The repair consists of either removing a small section of the cable and reconnecting the two ends, or, if it is not possible to remove the section, making an "insertion", i.e. inserting a short section of the same cable between the two ends of the broken cable.

The splice location(s) (in the case of an "insert") should be secured with the L56040 or L56060 repair coupler. The former is suitable if the cable has a maximum of 4 fibres, the latter will allow up to 12 splices to be secured.

What type of UPS to choose? Choosing the right UPS (Uninterruptible Power Supply) depends on the type of equipment you want to protect and how important continuity of power is to you. There are three basic types available on the market: Offline (standby) UPS, Line-interactive UPS and Online (double conversion) UPS. Each works in a slightly different way and will perform well in different applications...>>>more