Antennas, antennas, and more antennas are one of the keys to successfully developing 5G new radio (NR) devices employing millimeter wave (mmWave) bandwidths. 5G NR handsets are highly complex devices. They have to handle the new 5G mmWave bands, including 4×4 multiple input and multiple output (MIMO) antennas, 3GPP specified Evolved Universal Terrestrial Radio Access […]
FAQ
What is the 5G RF/mmWave signal chain?
The 5G RF/mmWave signal chain is expected to be the same as, and different from, the RF signal chain for today’s LTE Advanced devices. 5G consists of two separate frequency bands, FR1 is mostly repurposed LTE bands and FR2 bands are in the mmWave region. As a result, 5G in the FR1 frequencies can use […]
Transistor circuit configurations and Spice
In a recent post, we reviewed the basics of Spice circuit simulators. Most circuit simulations involve transistors, either as discrete components or within an integrated circuit. So it is useful to understand a few basics about how Spice models transistors. Transistors may have multiple states, typically saturation, cutoff, active and reverse. And transistors have an […]
Basics of mmWave and its applications
The millimeter band spans from 30 to 300 gigahertz (GHz) and lies between the super high frequency band, and the far infrared band, the lower part of which is the terahertz band. Radio waves in this band have wavelengths from ten to one millimeter; thus, radiation in this band is called millimeter waves, sometimes abbreviated […]
Understanding stop/start automobile-engine design, Part 6: Responses and work-arounds
Stop/start operation is both complicated and controversial. Despite the sophisticated algorithms it employs, no algorithm is perfect under all conditions. In addition, there are some “human factors” issues with respect to driver expectations and even nearby pedestrians, which stop/start brings. Q: What are some “issues” with stop/start? A: First, there’s the issue of added vehicle […]
Understanding stop/start automobile-engine design, Part 5: Additional considerations
Thus far, we have looked at mostly non-electronic and mechanical implications of stop/start, such as requirements on the battery technology, the crankshaft, and the starter motor itself. There is also an impact on the vehicle’s power electronics and battery management system (BMS). Q: How does stop/start begin to affect the “electronics”? A: It begins with […]
When you can use Spice and it’s variants, when you can’t
It has been a long time since it was practical to breadboard even moderately complex IC designs to evaluate them prior to manufacture. This is particularly true because of subtle parasitic and characteristic impedance effects that rear their ugly head in the frequency ranges of many modern circuit designs. That is the rationale for Spice […]
Understanding stop/start automobile-engine design, Part 4: Mechanical wear issues
It seems “obvious” that starting and stopping a car’s engine repeatedly adds to stresses on the mechanical components and therefore shortens the life of the power train. But does it? The answer is “yes and no.” This part explores some of the underlying issues. Q: How many stop/start cycles are we looking at? A: Numbers […]
What are RF inductors?
Radio frequency (RF) inductors have several uses and are available in various construction types to suit the performance needs of specific applications. Matching, resonators, and chokes are common uses for inductors in RF circuits. Matching involves eliminating impedance mismatches and minimizing reflection and losses in the lines between circuit blocks such as the antenna and […]
Understanding stop/start automobile-engine design, Part 3: The battery situation
The stop/start approach has significant implications for the car’s battery and battery management system (BMS). Q: How does the battery charge/discharge cycle function in a non-stop/start vehicle? A: In a car without a stop/start system, starting the engine is a one-time event for the duration of the trip. While the engine is running, it also […]