Part 2 looked at two types of RF/microwave filters, but there are many more, including ceramic coaxial filters and helical filters. They are discussed in this part. Microstrip filters Microstrip filters are built as a carefully defined pattern on a PC board. There is almost no limit to the filter designs which can be built […]

The well-known and extensively analyzed lumped-element bandpass filter is generally not suitable for the RF/microwave region, but there are many distributed-element, energy-based alternatives. Part 1 of this article established the context for these RF/microwave filters, which operate in the spectrum from several hundred MHz and higher, and increasingly cannot use discrete lumped-circuit elements (RLCs). Instead, […]

The well-known and extensively analyzed lumped-element bandpass filter is generally not suitable for the RF/microwave region, but there are many distributed-element, energy-based alternatives. Just say the word “filters,” and for many engineers, the mention of this topic stirs a mix of feelings ranging from fear to relief. Why fear? Because filters as a topic in […]

The terahertz part of the electromagnetic spectrum between millimeter waves and optical range remains a largely untapped, difficult-to-use resource; researchers are investigating different techniques for efficiently generating terahertz waves to promote the use of this part of the spectrum.   Approach #3: Laughing Gas A team at MIT in close collaboration with one at nearby […]

The terahertz part of the electromagnetic spectrum between millimeter waves and optical range remains a largely untapped, difficult-to-use resource; researchers are investigating different techniques for efficiently generating terahertz waves to promote use of this part of the spectrum. Approach #2: Infrared Lasers and Plasma A research group based at TU Wein (Vienna University of Technology), […]

The terahertz part of the electromagnetic spectrum between millimeter waves and optical range remains a largely untapped, difficult-to-use resource; researchers are investigating different techniques for efficiently generating terahertz waves to promote the use of this part of the spectrum. Approach #1: Lasers and Acoustic Modulation A recent project and paper by a collaborative team from […]

The terahertz part of the electromagnetic spectrum between millimeter waves and optical range remains a largely untapped, difficult-to-use resource; researchers are investigating different techniques for efficiently generating terahertz waves to promote the use of this part of the spectrum. Electromagnetic energy in the terahertz (THz) region of the spectrum, nominally 300 GHz/0.3 THz to 10 […]