Using laser-sourced light beams rather than wireless RF to link spacecraft with Earth offers the possibility of a significant increase in data rates. Still, there are significant technical challenges to the concept. The previous part of the article established the need for higher-speed data links to spacecraft and their missions and looked at some of […]
Wireless
Optical links for spacecraft, Part 1: The throughput limitation
Using laser-sourced light beams rather than wireless RF to link spacecraft with Earth offers the possibility of a significant increase in data rates. Still, there are significant technical challenges to the concept. Scientists, engineers, and researchers communicating with spacecraft have a problem: there’s so much data coming from these spacecraft – and to send to […]
Single-chip AFE integrates optical, ECG, and bio-impedance measurement systems
Simplify the design of wearable remote patient monitoring (RPM) devices by measuring four vital signs with one MAX86178 triple-system vital signs analog front end (AFE) from Analog Devices, Inc. This single-chip AFE integrates three measurement systems (optical, ECG, and bio-impedance) to obtain four common vital signs: electrocardiogram (ECG or EKG), heart rate (ECG or optical […]
A look at intrinsic broadband noise spectral density
You can think of noise as an unwanted signal. This signal creates an error by combining with the desired signal in your circuit. Exterior sources can couple into your circuits, such as your 50 or 60 Hz DC mains signal or your cell phone. The starting point in your circuit’s noise evaluation is to reach […]
3D printing for 5G systems
MIMO antennas, waveguides, traveling wave tubes, and RF substrates are fabricated using various 3D printing technologies. For example, 3D printing has been used to produce highly dense and integrated waveguide signal interconnects modules in a single monolithic unit. By printing the waveguide modules in one component, the part count was significantly reduced from tens or […]
VSWR and impedance, Part 6: Microstrip and stripline
Understanding the role and implications of impedance in RF transmission lines and antennas is vital to successful system performance. The traditional matching approaches are still in wide use, but new application requirements and advances in components, modeling and simulation, and manufacturing precision have also provided new ways to address the matching problem. Q: What is […]
VSWR and impedance, Part 5: Making a match
Understanding the role and implications of impedance in RF transmission lines and antennas is vital to successful system performance. The importance of impedance matching, minimizing reflections, and keeping a low VSWR means these topics have been studied extensively, ranging from analytical perspectives through many physical designs and implementations. This section looks at some matching techniques. […]
VSWR and impedance, Part 4: Measurements
Understanding the role and implications of impedance in RF transmission lines and antennas is vital to successful system performance. The previous section looked at the basics of VSWR. This section looks at two approaches to measuring impedance and VSWR. Q: What do engineers and users need to know? A: For some applications, such as connecting […]
VSWR and impedance, Part 3: Implications
Understanding the role and implications of impedance in RF transmission lines and antennas is vital to successful system performance. The previous sections looked at the basics of impedance and VSWR. This section looks at the implications of VSWR measurements. Q: Why should I care about reflected waves due to impedance mismatch and resultant non-unity VSWR? […]
VSWR and impedance, Part 2: Reflected power
Understanding the role and implications of impedance in RF transmission lines and antennas is vital to successful system performance. Part 1 of this article looked at the basics of impedance matching and power transfer. This part looks at the closely related topic of nominal impedance and VSWR. Q: Why all this worry? Aren’t RF systems […]
