IEEE Spectrum September 24, 2020 Researchers at UC Santa Barbara have been developing a device that could be critical to efficiently pushing 6G’s terahertz-frequency signals out of the antennas of future smartphones and other connected devices. They show that N-polar GaN deep recess HEMTs grown on sapphire match the power performance of a device on SiC up to 14 V with 5.1 W/mm of output power density. At 16 V the device on sapphire starts to suffer from thermal effects but still demonstrated 5.5 W/mm with an associated 20.6% power-added efficiency. This work also examines the impact of encapsulating the […]
Category Archives: Communications technology
Inflatable Antennas for High Data Rate Satellite and 5G Communications
Next Big Future September 22, 2020 The inflatable antenna system enables big data from cubesats and small low-cost spacecraft. The 3-dimensional phased array antenna technology can provide high data rate communication at virtually any frequency at a fraction of the size and cost of any existing solution. They have a 5G communication antenna which is superior for communication in a city. The 5G antenna can replace 3-4 traditional antennas. The antenna has a fully electronic beam steering, 360-degree coverage eliminates moving parts to dramatically reduce cost and complexity. It is small, lightweight, reliable, provides low-cost access to large volumes of […]
Space communication: developing a one photon-per-bit receiver using near-noiseless phase-sensitive amplification
Phys.org September 17, 2020 Phase-sensitive optical amplifiers (PSAs) with their uniquely low noise figure of 0 dB promise to provide the best possible sensitivity for Gb/s-rate long-haul free-space links. An international team of researchers (Sweden, USA – MIT, UC San Diego, industry, Japan) demonstrate a novel approach using a PSA-based receiver in a free-space transmission experiment with an unprecedented bit-error-free, black-box sensitivity of 1 photon-per-information-bit (PPB) at an information rate of 10.5 Gb/s. The system adopts a simple modulation format (quadrature-phase-shift keying, QPSK), standard digital signal processing for signal recovery and forward-error correction and is straightforwardly scalable to higher data rates…read more. […]
Terahertz receiver for 6G wireless communications
Phys.org September 8, 2020 Future 6G wireless networks will consist of a multitude of small radio cells that need to be connected by broadband communication links. An international team of researchers (Germany, USA – industry) has developed a novel concept for low-cost terahertz receivers that consist of a Schottky barrier diode that offers large bandwidth and that is used as an envelope detector to recover the amplitude of the terahertz signal. To overcome the problem of losing the time-dependent phase of the terahertz wave that is usually lost during rectification, they use digital signal processing techniques in combination with a […]
Revolutionary quantum breakthrough paves way for safer online communication
Phys.org September 2, 2020 An international team of researchers (UK, Austria, Croatia) used multiplexing which splits the light particles, emitted by a single system, so they can be received by multiple users efficiently. They designed a network for eight users using just eight receiver boxes As the user numbers grow, the logistics become increasingly unviable—for instance 100 users would take 9,900 receiver boxes. To demonstrate its functionality across distance the receiver boxes were connected to optical fibres via different locations across Bristol. The ability to transmit messages via quantum communication was tested using the city’s existing optical fibre network. The […]
Beating noise via superposition of order
Phys.org August 25, 2020 Classically no information can be transmitted through a completely noisy channel. But with quantum mechanics, adding a second channel actually provides a way to successfully get the information through. Researchers in Australia have shown that by combining the noisy channels such that you don’t know which noisy channel was applied first, it becomes possible to transmit some information. They considered two limiting cases – when both channels are fully depolarising, the ideal limit is communication of 0.049 bits;, when one channel is fully depolarising the ideal limit is communication of 1 bit. Their results offer intriguing […]
Greater connectedness in remote areas: A Ka-band transceiver for satellite communications
EurekAlert August 4, 2020 The transceiver developed by researchers in Japan using standard CMOS technology uses 27-31 GHz frequency range for uplink and 17-21 GHz range for downlink. A high-quality transformer is used to achieve efficient power use and high linearity in transmission, resulting in lower distortion during transmission. Two RX channels allows for receiving signals from two satellites simultaneously in parallel using either two independent polarization modes or two different frequencies. It can perform adjacent-channel interference cancellation increasing the dynamic range of the system, thus allowing it to operate correctly even in less-than-ideal scenarios with stronger noise and interference. […]
Researchers Use Lasers to Bring the Internet Under the Sea
IEEE Spectrum June 22, 2020 Researchers in Saudi Arabia have developed underwater WiFi which they call Aqua-Fi. The system is fully compliant with IEEE 802.11 wireless standards. A Wi-Fi signal was used to connect the device to a Raspberry Pi functioning as a modem. The modem converted the wireless signal to an optical signal (in this case, a laser) that was beamed to the receiver attached to a surface buoy. From there, established communications techniques were used to send the signal to an orbiting satellite. For the underwater device to receive data, the process is simply reversed. The system is […]
Long-range Communications without Large, Power-Hungry Antennas
DARPA News June 9, 2020 To break the dependence on big antennas and amplifiers for establishing long-range tactical communications for U.S. troops in remote locations, DARPA recently announced the Resilient Networked Distributed Mosaic Communications (RN DMC) program which aims to provide long-range communications through “mosaic” antennas composed of spatially distributed low SWaP-C transceiver elements or “tiles.” This approach replaces high-powered amplifiers and large directional antennas with mosaics of dispersed tile transceivers. Transmit power is distributed among the tiles, and gain is achieved through signal processing rather than by a physical antenna aperture to concentrate energy. The antenna mosaic concept could […]
Formula may help 5G wireless networks efficiently share communications frequencies
Science Daily May 26, 2020 Researchers at NIST have developed a formula using Q-learning technique which enables transmitters to rapidly select the best subchannels for successful and simultaneous operation of Wi-Fi and License Assisted Access (LAA) networks in unlicensed bands. The transmitters each learn to maximize the total network data rate without communicating with each other. The scheme rapidly achieves overall performance that is close to the result based on exhaustive trial-and-error channel searches. The formula takes into account multiple network layers, the physical equipment and the channel access rules between base stations and receivers. The study addressed indoor scenarios, […]