Any unwanted signal that’s combined with the desired signal is called noise. In any circuit, noise can come from anywhere; from external systems as well as from within a circuit itself. External sources include a number of sources such as power lines, RF transmitters, nearby conductors, ignition systems, or motors that turn on and off […]
FAQ
mmWave antennas and antenna management for 5G
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 […]
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 […]
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 […]
Designing a DAC-controlled, high-side constant current source
by KlausST, supermoderator on EDABoard.com Here I’d like to show how to design a DAC controlled high -side constant current source. Since it is often used as 0..20mA (or 4..20mA) current loop interface, we will focus on the interface requirements. * low speed ( maybe some 10Hz up to some kHz) * high precision * […]
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 […]
The basics of FR-4 Printed Circuit Boards
Part 1 of this FAQ provided context and background on the PC board, and discussed its first widespread appearance as a phenolic-based board. Part 2 looks at some board issues and the widely used FR-4 PC board substrate. Q: I see the term “solder mask” — what is that? A: Solder mask (also called a […]
Step-by-Step PCB Soldering tips for newbies
The traditional, older type of solder is a mixture of lead (Pb) and tin (Sn). This type of (60/40 – Pb/Sn) solder melts at 200°C and is typically made up of 60 percent tin and 40 percent lead. However, lead-free solder is desirable today, in terms of avoiding a toxic environment. Lead-free solder is a […]
Magnetic resonance imaging (MRI), Part 1: How it works
The modern MRI system is an amazing blend of diverse technologies, based on the realization that a small but critical aspect of the spin of hydrogen nuclei could be leveraged to provide a safe, non-invasive way to see inside a human body. Magnetic resonance imaging (MRI) is an extraordinarily valuable and vital tool for non-invasive […]
The microstrip antenna, Part 1: Basics
The microstrip antenna is a convenient, planar, easy-to-fabricate antenna with some attractive attributes and features, as well as some distinct limitations. The passive antenna is a critical part of any wireless communications link, for both transmit and receive sides. Depending on the application, the same antenna may be used for both roles, or radically different […]
