This selection of power amplifier classes is used to strengthen AC signals. The letter symbols differentiate between amplifier types and indicate the expected performance and characteristics. Basic amplifier classes such as A, B, AB, and C relate to the time that the amplifier is operating, or conducting, expressed as a fraction of the period of […]
What causes noise in analog designs and how can it be controlled?
Controlling noise in analog and mixed-signal circuits is important but not simple. Data integrity is dependent on controlling noise in the signal chain. If left uncontrolled, noise can impair or disrupt system operation. This FAQ starts by looking at the various sources and types of noise, looks at how noise can enter the signal chain […]
Five considerations for mixed-signal PCB layouts
Printed circuit board (PCB) layout is an important activity when developing mixed-signal applications. A lot can go wrong, and everything needs to be correct for a successful design. Impedance control is an obvious consideration, but it needs to include trace resistance as well as parasitic inductances and capacitances. Maintaining signal integrity can be challenging. This […]
When is a high CMRR needed in an op amp?
Common mode rejection ratio (CMRR), also called common mode rejection (CMR), quantifies the ability of an operational amplifier (op amp) to reject common-mode signals. Common-mode signals are signals that appear simultaneously and in phase on both inputs. This FAQ begins by defining what CMRR is and how it’s quantified, reviews some design considerations related to […]
What is PSRR and why is it important in op amps and LDOs?
The power supply rejection ratio (PSRR) describes the ability of a circuit to suppress any power supply variations from passing to its output signal and is typically measured in dB. It’s most often used with operational amplifiers (op amps), dc/dc converters, linear regulators, and low drop out regulators (LDOs). For op amps, the PSRR describes […]
What are some common EMI/EMC tests?
An EMC test is known as Electromagnetic compatibility, a certification for electronic devices to maintain their limitation of electromagnetic waves. As discussed in the previous article, there are two types of EMC tests: emission (EMI) and immunity (EMS). EMI (Electromagnetic Interference) tests measure the magnetic waves emitted by the device, and EMS (Electromagnetic Susceptibility) tests […]
The basics: what is EMC?
EMC stands for Electromagnetic compatibility, which means that a device is compatible with (i.e., no interference is caused by) its electromagnetic (EM) environment. It does not emit levels of EM energy that generate electromagnetic interference (EMI) in other devices in the vicinity. Electromagnetic interference (EMI) is the interference caused by one electrical or electronic device […]
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 […]
What are the applications of 3D and 4D printed electronics?
3D printing is the fabrication of a three-dimensional object under computer control, with one or more materials being added layer by layer. 3D printing, or additive manufacturing, is used across various electronics applications, including circuit boards, energy storage devices, actuators, and sensors. It can be implemented using a variety of technologies, including selective laser sintering […]
What is passive intermodulation?
Passive intermodulation (PIM) is a pernicious and destructive phenomenon for cellular network operators. PIM shows up as a set of unwanted signals created by mixing two or more strong RF signals. Mixing generally produces the sum and difference frequencies of the two transmit signals F1 and F2. These signals are F1 + F2 and F1 […]









