Vacuum-channel transistors are a promising technology capable of being operated at frequencies above microwaves and below infrared—a region of the spectrum known as the terahertz gap because of how difficult most semiconductor devices have to operate at those frequencies. Some key applications for terahertz equipment are directional high-speed communications and hazardous-materials sensing.
A back-gated vacuum channel transistor on a Silicon-on-insulator (SOI) substrate
Field enhancement by reduction in a gap spacing. This image represents two terminal electrodes with different gap spacing to figure out the minimum gap spacing to satisfy the target turn-on voltage. The gap spacing below 50 nm showed a turn-on field at 2V.
For more details see my EDN blog entitled Vacuum tube technology resurrected
Reference: Nanoscale Vacuum Channel Transistor, Jin-Woo Han and M. Meyyappan, Center for Nanotechnology, NASA Ames Research Center, Proceedings of the 14th IEEE International Conference on Nanotechnology.
On-going improvements in Gallium Nitride (GaN) power semiconductor technology and modular design architectures have made it possible to achieve high power continuous wave (CW) and pulsed amplifiers at microwave frequencies. GaN power semiconductor technology has thus contributed to improved performance levels in RF/microwave power amplification to the L-band.
A conventional DPA is shown in schematic 1a and the DPA with a Wideband output GaN combiner is shown in 1b. (Image courtesy of Reference 1)
For more details see my EDN blog entitled GaN RF Power transistors: Not just power, but speed to L-Band and beyond
One key application of high speed Helmholtz coils is to generate uniform and time-varying high frequency magnetic fields for applications like magnetic field susceptibility, calibration, and scientific experiments. A Helmholtz coil driver will be necessary to generate the needed magnetic field. The driver challenges include high current, which is needed to generate a high magnetic field and the coils exhibiting a high impedance.
Accel Instruments developed the T250 Waveform Amplifier, an AC-coupled or DC-coupled input, a selectable input impedance, a selectable gain stage, a high current amplifier, and a DC output offset.
The T250 waveform amplifier functional equivalent diagram.
For more details see the EDN article entitled High Frequency Helmholtz Coils Generate Magnetic Fields
Strategic agreement between e2v and Peregrine. Peregrine has the expertise in high reliability RF and e2v has the aerospace and defense qualified semiconductor products for space including signal chain solutions from RF to back-end with data converters and high performance data processing.
Potential areas of engagement include beam-forming as 5G relates to Space solutions. The same technologies in an iPhone can exist in Space with the addition of high-reliability, and rad hard techniques and expertise in wide temperature ranges.
For more details see the EDN article entitled e2v and Peregrine Semiconductor strengthen Space and High reliability signal chain solutions
Modern RADAR advances for object detection include high speed receiver architectures like Direct Conversion and Super Heterodyne to achieve RF-to-bits signal chains. On the transmit side Phase shifters are a key component.
A typical next generation X-Band (7.0 to 11.2 GHz) Transceiver RADAR example block diagram using two levels of mixers or Modulation/Demodulation to mix the X-band signal down to the levels that and A to D converter works best.
For more details see my EDN blog entitled A technical view into modern MIL AERO RADAR systems
The Lockheed-Martin F-35 design includes some super state-of-the-art high speed circuitry in its Communications, Navigation and Identification (CNI) System and Avionics including Software Defined Radio (SDR). Also the Grumman Active Electronically Scanned Array (AESA) RADAR system design has superb high speed system design.
A typical block diagram of an AESA radar system (Image courtesy of NXP)
For more details see my EDN blog entitled F-35 Lightning II: Advanced electronics for stealth, sensors and communications
Video is traditionally transported through a broadcast studio using 75 ohm coaxial cables. The equipment’s physical location within the studio may demand cable runs that exceed 30 to 50 meters, thus requiring additional signal conditioning electronics at the receive end. Cable equalizers can extend the usable working length between two video equipment systems.
For more details see the EDN article entitled 12 Gbps SDI cable performance estimation
In today’s electronics industry, the USB Type-C is in the of every system designer. This interface consolidates data, power and video into a single connector interface.
USB Type-C cable pin configuration
For more details see the EDN article entitled USB 3.1 Implementation of USB Type C
Designers need to know how to navigate data sheets, especially with high speed specifications and performance. A fan-out buffer is used in timing applications that require multiple copies of a clock signal to be distributed. In order to select the correct fan-out buffer for your timing applications, it is helpful to understand additive phase jitter specifications when comparing different product data sheets specifications.
For more details see the EDN article entitled Comparing clock buffer data sheet specs for additive jitter
Quantenna Communications developed the industry’s first 10G Wave 3 Wi-Fi product family. The products are built on Quantenna’s True 8×8™ QSR10G Wi-Fi platform with multi-user MIMO (MU-MIMO) technology for home wireless access points and residential gateways.
Quantenna’s design has up-to-12-streams 10G Wave 3 in their product family which enables higher Wi-Fi performance, reliability and capacity for high-density environments, and is able to address both the service provider and retail market segments.
Dual 4×4 radios need filters because each 5GHz radio operates on a separate channel. The addition of filters prevents Adjacent Channel Interference (ACI). Radio 1 is restricted by low pass hardware filters and Radio 2 is restricted by high pass hardware
For more details see the EDN article entitled Quantenna develops first 802.11ac 10G Wave 3 Wi-Fi product line and Freescale takes advantage